%0 Journal Article %J PLoS ONE %D 2018 %T Systemic and vascular inflammation in an in-vitro model of central obesity %A A. Ahluwalia %A A. Misto %A G. Vozzi %A C. Magliaro %A G. Mattei %A Marescotti MC %A AVOGARO, A %A Iori, E. %K Bioengineering %X

Metabolic disorders due to over-nutrition are a major global health problem, often associated with obesity and related morbidities. Obesity is peculiar to humans, as it is associated with lifestyle and diet, and so difficult to reproduce in animal models. Here we describe a model of human central adiposity based on a 3-tissue system consisting of a series of interconnected fluidic modules. Given the causal link between obesity and systemic inflammation, we focused primarily on pro-inflammatory markers, examining the similarities and differences between the 3-tissue model and evidence from human studies in the literature. When challenged with high levels of adiposity, the in-vitro system manifests cardiovascular stress through expression of E-selectin and von Willebrand factor as well as systemic inflammation (expressing IL-6 and MCP-1) as observed in humans. Interestingly, most of the responses are dependent on the synergic interaction between adiposity and the presence of multiple tissue types. The set-up has the potential to reduce animal experiments in obesity research and may help unravel specific cellular mechanisms which underlie tissue response to nutritional overload.

%B PLoS ONE %8 02/2018 %G eng %U http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0192824 %R https://doi.org/10.1371/journal.pone.0192824.s001 %0 Journal Article %J Plos One %D 2017 %T On the adhesion-cohesion balance and oxygen consumption characteristics of liver organoids %A G. Mattei %A C. Magliaro %A S. Giusti %A S. D. Ramachandran %A S. Heinz %A J. Braspenning %A A. Ahluwalia %K Bioengineering %X

Liver organoids (LOs) are of interest in tissue replacement, hepatotoxicity and pathophysiological studies. However, it is still unclear what triggers LO self-assembly and what the optimal environment is for their culture. Hypothesizing that LO formation occurs as a result of a fine balance between cell-substrate adhesion and cell-cell cohesion, we used 3 cell types (hepatocytes, liver sinusoidal endothelial cells and mesenchymal stem cells) to investigate LO self-assembly on different substrates keeping the culture parameters (e.g. culture media, cell types/number) and substrate stiffness constant. As cellular spheroids may suffer from oxygen depletion in the core, we also sought to identify the optimal culture conditions for LOs in order to guarantee an adequate supply of oxygen during proliferation and differentiation. The oxygen consumption characteristics of LOs were measured using an O2 sensor and used to model the O2 concentration gradient in the organoids. We show that no LO formation occurs on highly adhesive hepatic extra-cellular matrix-based substrates, suggesting that cellular aggregation requires an optimal trade-off between the adhesiveness of a substrate and the cohesive forces between cells and that this balance is modulated by substrate mechanics. Thus, in addition to substrate stiffness, physicochemical properties, which are also critical for cell adhesion, play a role in LO self-assembly.

%B Plos One %8 03/2017 %G eng %U http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173206 %R http://dx.doi.org/10.1371/journal.pone.0173206 %0 Journal Article %J Scientific Reports %D 2017 %T Allometric scaling in-vitro %A A. Ahluwalia %K Bioengineering %X

About two decades ago, West and coworkers established a model which predicts that metabolic rate follows a three quarter power relationship with the mass of an organism, based on the premise that tissues are supplied nutrients through a fractal distribution network. Quarter power scaling is widely considered a universal law of biology and it is generally accepted that were in-vitro cultures to obey allometric metabolic scaling, they would have more predictive potential and could, for instance, provide a viable substitute for animals in research. This paper outlines a theoretical and computational framework for establishing quarter power scaling in three-dimensional spherical constructs in-vitro, starting where fractal distribution ends. Allometric scaling in non-vascular spherical tissue constructs was assessed using models of Michaelis Menten oxygen consumption and diffusion. The models demonstrate that physiological scaling is maintained when about 5 to 60% of the construct is exposed to oxygen concentrations less than the Michaelis Menten constant, with a significant concentration gradient in the sphere. The results have important implications for the design of downscaled in-vitro systems with physiological relevance.

%B Scientific Reports %V 7 %8 02/2017 %G eng %U http://www.nature.com/articles/srep42113 %R 10.1038/srep42113 %0 Journal Article %J Artificial Organs %D 2017 %T Decellularized Human Liver Is Too Heterogeneous for Designing a Generic Extracellular Matrix Mimic Hepatic Scaffold. %A G. Mattei %A C. Magliaro %A Pirone, A. %A A. Ahluwalia %K Bioengineering %X

Decellularized human livers are considered the perfect extracellular matrix (ECM) surrogate because both three-dimensional architecture and biological features of the hepatic microenvironment are thought to be preserved. However, donor human livers are in chronically short supply, both for transplantation or as decellularized scaffolds, and will become even scarcer as life expectancy increases. It is hence of interest to determine the structural and biochemical properties of human hepatic ECM to derive design criteria for engineering biomimetic scaffolds. The intention of this work was to obtain quantitative design specifications for fabricating scaffolds for hepatic tissue engineering using human livers as a template. To this end, hepatic samples from five patients scheduled for hepatic resection were decellularized using a protocol shown to reproducibly conserve matrix composition and microstructure in porcine livers. The decellularization outcome was evaluated through histological and quantitative image analyses to evaluate cell removal, protein, and glycosaminoglycan content per unit area. Applying the same decellularization protocol to human liver samples obtained from five different patients yielded five different outcomes. Only one liver out of five was completely decellularized, while the other four showed different levels of remaining cells and matrix. Moreover, protein and glycosaminoglycan content per unit area after decellularization were also found to be patient- (or donor-) dependent. This donor-to-donor variability of human livers thus precludes their use as templates for engineering a generic "one-size fits all" ECM-mimic hepatic scaffold.

%B Artificial Organs %8 05/2017 %G eng %U https://www.ncbi.nlm.nih.gov/pubmed/28543403 %R 10.1111/aor.12925. %0 Journal Article %J Bioinspiration & Biomimetics %D 2016 %T A bioreactor with an electro-responsive elastomeric membrane for mimicking intestinal peristalsis %A D. Cei %A J. Costa %A G. Gori %A G. Frediani %A C. Domenici %A F. Carpi %A A. Ahluwalia %X

This study describes an actuated bioreactor which mimics the pulsatile contractile motion of the intestinal barrier using electro-responsive elastomers as smart materials that undergo deformation upon electrical stimulation. The device consists of an annular dielectric elastomer actuator working as a radial artificial muscle able to rhythmically contract and relax a central cell culture well. The bioreactor maintained up to 4 h of actuation at a frequency of 0.15 Hz and a strain of 8%–10%, to those of the cyclic contraction and relaxation of the small intestine. In vitro tests demonstrated that the device was biocompatible and cell-adhesive for Caco-2 cells, which formed a confluent monolayer following 21 days of culture in the central well. In addition, cellular adhesion and cohesion were maintained after 4 h of continuous cyclic strain. These preliminary results encourage further investigations on the use of dielectric elastomer actuation as a versatile technology that might overcome the limitations of commercially available pneumatic driving systems to obtain bioreactors that can cyclically deform cell cultures in a biomimetic fashion.

%B Bioinspiration & Biomimetics %V 12 %G eng %U http://iopscience.iop.org/article/10.1088/1748-3190/12/1/016001/pdf %N 1 %0 Journal Article %J Frontiers in Neuroscience %D 2016 %T Clarifying CLARITY: Quantitative Optimization of the Diffusion Based Delipidation Protocol for Genetically Labeled Tissue %A C. Magliaro %A A. L. Callara %A G. Mattei %A M. Morcinelli %A C. Viaggi %A Vaglini, F %A A. Ahluwalia %K Bioengineering %X

Tissue clarification has been recently proposed to allow deep tissue imaging without light scattering. The clarification parameters are somewhat arbitrary and dependent on tissue type, source and dimension: every laboratory has its own protocol, but a quantitative approach to determine the optimum clearing time is still lacking. Since the use of transgenic mouse lines that express fluorescent proteins to visualize specific cell populations is widespread, a quantitative approach to determine the optimum clearing time for genetically labeled neurons from thick murine brain slices using CLARITY2 is described. In particular, as the main objective of the delipidation treatment is to clarify tissues, while limiting loss of fluorescent signal, the “goodness” of clarification was evaluated by considering the bulk tissue clarification index (BTCi) and the fraction of the fluorescent marker retained in the slice as easily quantifiable macroscale parameters. Here we describe the approach, illustrating an example of how it can be used to determine the optimum clearing time for 1 mm-thick cerebellar slice from transgenic L7GFP mice, in which Purkinje neurons express the GFP (green fluorescent protein) tag. To validate the method, we evaluated confocal stacks of our samples using standard image processing indices (i.e., the mean pixel intensity of neurons and the contrast-to-noise ratio) as figures of merit for image quality. The results show that detergent-based delipidation for more than 5 days does not increase tissue clarity but the fraction of GFP in the tissue continues to diminish. The optimum clearing time for 1 mm-thick slices was thus identified as 5 days, which is the best compromise between the increase in light penetration depth due to removal of lipids and a decrease in fluorescent signal as a consequence of protein loss: further clearing does not improve tissue transparency, but only leads to more protein removal or degradation. The rigorous quantitative approach described can be generalized to any clarification method to identify the moment when the clearing process should be terminated to avoid useless protein loss.

%B Frontiers in Neuroscience %G eng %U http://journal.frontiersin.org/article/10.3389/fnins.2016.00179/full %R http://dx.doi.org/10.3389/fnins.2016.00179 %0 Journal Article %J IEEE Transactions on NanoBioscience %D 2016 %T Polymeric microporous nanofilms as smart platforms for in vitro assessment of nanoparticle translocation and Caco-2 cell culture %A L. Ricotti %A G. Gori %A D. Cei %A J. Costa %A G. Signore %A A. Ahluwalia %K Bioengineering %B IEEE Transactions on NanoBioscience %G eng %U http://ieeexplore.ieee.org/document/7552480/ %R 10.1109/TNB.2016.2603191 %0 Journal Article %J Acta Biomaterialia %D 2016 %T Sample, testing and analysis variables affecting liver mechanical properties: A review %A A. Ahluwalia %A G. Mattei %K Bioengineering %X

Given the critical role of liver mechanics in regulating cell response and directing the development of tissue fibrosis, accurately characterising its mechanical behaviour is of relevance for both diagnostic purposes as well as for tissue engineering and for the development of in-vitro models. Determining and quantifying the mechanical behaviour of soft biological tissues is, however, highly challenging due to their intrinsic labile nature. Indeed, a unique set of values of liver mechanical properties is still lacking to date; testing conditions can significantly affect sample status and hence the measured behaviour and reported results are strongly dependent on the adopted testing method and configuration as well as sample type and status. This review aims at summarising the bulk mechanical properties of liver described in the literature, discussing the possible sources of variation and their implications on the reported results. We distinguish between the intrinsic mechanical behaviour of hepatic tissue, which depends on sample variables, and the measured mechanical properties which also depend on the testing and analysis methods. Finally, the review provides guidelines on tissue preparation and testing conditions for generating reproducible data which can be meaningfully compared across laboratories.

%B Acta Biomaterialia %G eng %U http://www.sciencedirect.com/science/article/pii/S1742706116304603 %R http://dx.doi.org/10.1016/j.actbio.2016.08.055 %0 Journal Article %J Scientific Reports %D 2015 %T Decoupling the role of stiffness from other hydroxyapatite signalling cues in periosteal derived stem cell differentiation %A G. Mattei %A Ferretti, C. %A Tirella, A %A A. Ahluwalia %A Mattioli-Belmonte, M. %K Bioengineering %B Scientific Reports %V 5 %P 10778 %G eng %U http://www.nature.com/doifinder/10.1038/srep10778 %R 10.1038/srep10778 %0 Journal Article %J Journal of Microscopy %D 2015 %T HisTOOLogy: an open-source tool for quantitative analysis of histological sections %A C. Magliaro %A Tirella, A %A G. Mattei %A Pirone, A. %A A. Ahluwalia %K Bioengineering %B Journal of Microscopy %8 08/2015 %G eng %R 10.1111/jmi.12292. %0 Journal Article %J International Journal On Advances in Life Sciences %D 2015 %T Improving African Healthcare through Open Source Biomedical Engineering %A C. De Maria %A D. Mazzei %A A. Ahluwalia %K Bioengineering %B International Journal On Advances in Life Sciences %8 01/2015 %G eng %0 Journal Article %J Journal of the Mechanical Behavior of Biomedical Materials %D 2015 %T The nano-epsilon dot method for strain rate viscoelastic characterisation of soft biomaterials by spherical nano-indentation %A G. Mattei %A G. Gruca %A Rijnveld, N. %A A. Ahluwalia %K Bioengineering %B Journal of the Mechanical Behavior of Biomedical Materials %V 50 %P 150–159 %G eng %U http://linkinghub.elsevier.com/retrieve/pii/S1751616115002088 %R 10.1016/j.jmbbm.2015.06.015 %0 Journal Article %J Journal of Biomedical Nanotechnology %D 2015 %T Nano-in-Micro Self-Reporting Hydrogel Constructs %A Tirella, A %A La Marca, M %A Brace, L.A. %A G. Mattei %A Aylott, J. %A A. Ahluwalia %K Bioengineering %B Journal of Biomedical Nanotechnology %V 11 %P 1451–1460 %G eng %U http://openurl.ingenta.com/content/xref?genre=article&issn=1550-7033&volume=11&issue=8&spage=1451 %R 10.1166/jbn.2015.2085 %0 Conference Paper %B The 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBS) %D 2015 %T Open Biomedical Engineering Education in Africa %A A. Ahluwalia %A D. Atwine %A C. De Maria %A C. Ibingira %A E. Kipkorir %A F. Kiros %A J. Madete %A D. Mazzei %A E. Molyneux %A K. Moonga %A M. Moshi %A M. Nzomo %A V. Oduol %A J. Okuonzi %K Bioengineering %B The 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBS) %I IEEE %C Milan, Italy, 25-29 August 2015 %0 Journal Article %J Journal of chemical neuroanatomy %D 2015 %T Parvalbumin expression in the claustrum of human dog. An immunohistochemical and topographical study with comparative notes of the structure of the nucleus %A Pirone, A. %A C. Magliaro %A Giannessi, E. %A A. Ahluwalia %K Bioengineering %B Journal of chemical neuroanatomy %V 64-65 %P 33-42 %8 03/2015 %G eng %U http://www.sciencedirect.com/science/article/pii/S0891061815000149 %R 10.1016/j.jchemneu.2015.02.004 %0 Journal Article %J PeerJ %D 2015 %T Profile analysis of hepatic porcine and murine brain tissue slices obtained with a vibratome %A G. Mattei %A I. Cristiani %A C. Magliaro %A A. Ahluwalia %K Bioengineering %B PeerJ %V 3:e932 %8 04/2015 %G eng %U https://peerj.com/articles/932/ %R 10.7717/peerj.932 %0 Journal Article %J Journal of Biomedical Materials Research - Part B Applied Biomaterials %D 2015 %T Realisation and characterization of conductive hollow fibers for neuronal tissue engineering %A Gattazzo, F. %A C. De Maria %A Whulanza, Y. %A Taverni, G. %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Journal of Biomedical Materials Research - Part B Applied Biomaterials %V 103 %P 1107-1119 %G eng %0 Conference Paper %B ALTEX Proceedings %D 2014 %T Autonomous bioreactor modules for disease models and detection of systemic toxicity %A A. Ahluwalia %A S. Giusti %A Sbrana, T. %A M. Wilkinson %A A. Misto %A Lehr, C.-M. %A M. Liley %E S. Horst %E D. Jírová %K Bioengineering %X

Advanced systems based on bioreactors and scaffolds are an essential step towards the development of more predictive and ethical alternatives to animal experiments. Size, modularity, automation, monitoring and essential design are crucial because these elements will ease the transition from old technology and accelerate their acceptance into mainstream research. Based on these requirements, the interconnected transparent sensorised “lego” bioreactors designed in our labs have been used to generate physiologically relevant disease and toxicity models which recapitulate systemic responses impossible to observe in standard cell cultures. The disease model is an interconnected bioreactor circuit with i) adipose tissue in 3D in 3 different concentrations representing normo-weight, over weight and obese body mass indices, ii) human hepatocytes on porous collagen scaffolds and iii) monolayers of human endothelial cells. High adiposity and elevated glucose levels induce systemic and endothelial inflammation in the circuit, as observed in overweight and diabetic humans (Iori et al., 2012). Using similar technology a three-tissue circuit for monitoring the absorption, distribution, metabolism and toxicity of nanoparticles was developed in the context of the EU project InLiveTox (Ucciferri et al., 2014). The results were strikingly similar to those observed in animal experiments demonstrating that the dynamic 3D in-vitro models are ethical, meaningful and economically viable replacements.

%B ALTEX Proceedings %C Prague, Czech Republic %P 43 %0 Journal Article %J Processes %D 2014 %T Design Criteria for Generating Physiologically Relevant In Vitro Models in Bioreactors %A G. Mattei %A S. Giusti %A A. Ahluwalia %K Bioengineering %X

In this paper, we discuss the basic design requirements for the development of physiologically meaningful in vitro systems comprising cells, scaffolds and bioreactors, through a bottom up approach. Very simple micro- and milli-fluidic geometries are first used to illustrate the concepts, followed by a real device case-study. At each step, the fluidic and mass transport parameters in biological tissue design are considered, starting from basic questions such as the minimum number of cells and cell density required to represent a physiological system and the conditions necessary to ensure an adequate nutrient supply to tissues. At the next level, we consider the use of three-dimensional scaffolds, which are employed both for regenerative medicine applications and for the study of cells in environments which better recapitulate the physiological milieu. Here, the driving need is the rate of oxygen supply which must be maintained at an appropriate level to ensure cell viability throughout the thickness of a scaffold. Scaffold and bioreactor design are both critical in defining the oxygen profile in a cell construct and are considered together. We also discuss the oxygen-shear stress trade-off by considering the levels of mechanical stress required for hepatocytes, which are the limiting cell type in a multi-organ model. Similar considerations are also made for glucose consumption in cell constructs. Finally, the allometric approach for generating multi-tissue systemic models using bioreactors is described.

%B Processes %V 2 %P 548–569 %G eng %U http://www.mdpi.com/2227-9717/2/3/548/ %R 10.3390/pr2030548 %0 Journal Article %J Rapid Prototyping Journal %D 2014 %T Development of a novel Micro-Ablation System to realise micrometric and well-defined hydrogel structures for Tissue Engineering applications %A C. De Maria %A Grassi, L. %A Vozzi, F. %A A. Ahluwalia %A G. Vozzi %A Campbell, R. I. %K Bioengineering %B Rapid Prototyping Journal %V 20 %G eng %0 Conference Paper %B Gruppo Nazionale Bioingegneria IV Congresso %D 2014 %T Fluid dynamics in porous scaffolds stimulated with cyclic squeeze pressure in the S2PR bioreactor %A M. Ferroni %A S. Giusti %A G. Spatafora %A F. Boschetti %A A. Ahluwalia %K Bioengineering %X

In cardiac tissue engineering, the use of bioreactors is fundamental for applying controlled mechanical stimuli on the cells and recreate a physiological environment for cardiomyocytes cultures. This work is focused on an innovative Sensorized Squeeze PRessure (S2PR) bioreactor, able to apply a periodic contactless hydrodynamic pressures on 3D porous constructs. The fluid-dynamic environment inside the bioreactor was fully characterized using computational models, focusing on the pressures and fluid velocity profiles generated in the porous scaffold during the cyclic stimulation.

%B Gruppo Nazionale Bioingegneria IV Congresso %C Pavia, 25-27 June %0 Conference Paper %B Proceedings of ICMMB2014 %D 2014 %T Fluid dynamics in porous scaffolds stimulated with cyclic squeeze pressure in the S2PR bioreactor %A M. Ferroni %A S. Giusti %A G. Spatafora %A F. Boschetti %A A. Ahluwalia %K Bioengineering %B Proceedings of ICMMB2014 %P 363–68 %U http://amsacta.unibo.it/4085/1/ProceedingsİCMMB2014.pdf %R 10.6092/unibo/amsacta/4085. In: Proceedings ICMMB A cura di: Zannoli, Romani ; Corazza, Ivan ; Stagni, Rita. %0 Conference Paper %B ESTIV 2014 %D 2014 %T Multi-organ-on-plate system for in-vitro studies of intestinal drug absorption and hepatotoxicity %A S. Giusti %A Sbrana, T. %A D. Giacopelli %A V. Di Patria %A A. Ahluwalia %K Bioengineering %X

More meaningful in-vitro models which simulate the physiological conditions of native tissue are becoming essential in the pharmaceutical field, for early and rapid screening of drug candidates. Here, we describe a multi-organ-on-plate system based on single and double flow mini bioreactor modules for dynamic in-vitro studies of intestinal drug absorption, drug metabolism and more relevant toxicity studies. The double flow module for membrane culture was firstly characterized using computational fluid dynamic models and measurements of pressure gradients, in order to indentify the optimal flow rates for maximizing the passage of solutes through the membrane. Then, cell culture experiments were performed with fully differentiated Caco-2 cells seeded on the semi-permeable membrane as a dynamic model of the intestinal epithelium, connected to a single flow chamber with metabolically competent human upcyte® hepatocytes (Medicyte GmbH, Germany) seeded on a 3D collagen cryogel. First we assessed the role of flow in modulating the passage of compounds across the epithelial barrier. Then toxicity tests were performed by administering different concentrations of hepatotoxic compounds (i.e. Diclofenac, Nimesulide, industrial nanoparticles) in the apical compartment of the MB, compared the data with cell cultures in transwells. Our results show: i) the presence of flow significantly increases translocation of all molecules tested across the membrane, ii) flow conditioned Caco-2 cells are more permeable to small hydrophilic compounds, despite having high TEER values iii) although they display higher levels of phenotypic markers (tight junctions, albumin expression etc), cells in the system are more susceptible to drug induced toxicity. In conclusion, the multi-organ-on-plate system predicts drug adsorption and toxicity better than traditional cell cultures and could be used to reduce, refine and eventually replace animal tests.

%B ESTIV 2014 %C Egmond aan Zee, The Netherlands %P 107 %0 Conference Paper %B ALTEX Proceedings %D 2014 %T The need of innovative technologies for new 3D relevant in-vitro models and the answer of Ivtech %A Sbrana, T. %A G. Mattei %A S. Giusti %A A. Ahluwalia %E J. Dagmar %E S. Horst %K Bioengineering %X

New relevant in-vitro models are priorities in pharmaco-toxicology, cosmetic and food research to reduce the animal tests. Therefore, invivo models show ethical issues, are not time and cost effective and are progressively showing scientific limitations: for instance they fail in detection of pathogens that are species specific (Mazzoleni et al., 2009). The search of more relevant pre-clinical models forced the researcher to move from 2D to 3D in-vitro models in order to maintain the phenotype of cells (Lovit et al., 2013; Mattei et al., 2014). Even if the significant progress in material science, the metabolic requirement of 3D tissues is higher than a 2D culture and the scaffold is a limitation in nutrients transport. Dynamic cell culture chambers are then required to assure the gas/nutrient supply, waste elimination, mechanical stimulation of cells, study of cross talk between different tissues and real time monitoring of cells. Nowadays the only systems that meet all these specifications are the Ivtech technologies. Ivtech is an innovative Italian start-up that grows up to solve the needs of in-vitro experts, offering and customizing several type of transparent, dynamic and modular cell culture systems, organizing workshops and training. The goal is to expand the 3D approach and permits a significant evolution towards highly relevant in-vitro models.

%B ALTEX Proceedings %C Prague, Czech Republic %P 45–6 %0 Journal Article %J Biotechnology journal %D 2014 %T A novel dual-flow bioreactor simulates increased fluorescein permeability in epithelial tissue barriers %A S. Giusti %A Sbrana, T. %A La Marca, M %A V. Di Patria %A V. Martinucci %A Tirella, A %A C. Domenici %A A. Ahluwalia %K Bioengineering %X

Permeability studies across epithelial barriers are of primary importance in drug delivery as well as in toxicology. However, traditional in vitro models do not adequately mimic the dynamic environment of physiological barriers. Here, we describe a novel two-chamber modular bioreactor for dynamic in vitro studies of epithelial cells. The fluid dynamic environment of the bioreactor was characterized using computational fluid dynamic models and measurements of pressure gradients for different combinations of flow rates in the apical and basal chambers. Cell culture experiments were then performed with fully differentiated Caco-2 cells as a model of the intestinal epithelium, comparing the effect of media flow applied in the bioreactor with traditional static transwells. The flow increases barrier integrity and tight junction expression of Caco-2 cells with respect to the static controls. Fluorescein permeability increased threefold in the dynamic system, indicating that the stimulus induced by flow increases transport across the barrier, closely mimicking the in vivo situation. The results are of interest for studying the influence of mechanical stimuli on cells, and underline the importance of developing more physiologically relevant in vitro tissue models. The bioreactor can be used to study drug delivery, chemical, or nanomaterial toxicity and to engineer barrier tissues.

%B Biotechnology journal %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/24756869 %R 10.1002/biot.201400004 %0 Conference Paper %B ICDS 2014, The Eighth International Conference on Digital Society %D 2014 %T Open Source Biomedical Engineering for Sustainability in African Healthcare: Combining Academic Excellence with Innovation %A C. De Maria %A D. Mazzei %A A. Ahluwalia %K Bioengineering %B ICDS 2014, The Eighth International Conference on Digital Society %P 48–53 %0 Journal Article %J Journal of Biomedical Materials Research Part B: Applied Biomaterials %D 2014 %T Realisation and characterization of conductive hollow fibers for neuronal tissue engineering %A Gattazzo, F. %A C. De Maria %A Whulanza, Y. %A Taverni, G. %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Journal of Biomedical Materials Research Part B: Applied Biomaterials %G eng %0 Conference Paper %B Journal of tissue engineering and regenerative medicine %D 2014 %T Sensorized Squeeze Pressure Bioreactor For mechanical modulation of cardiomyocyte phenotype %A S. Giusti %A Vozzi, F. %A F. Pagliari %A Tirella, A %A D. Mazzei %A Cabiati, M %A S. del Ry %A A. Ahluwalia %K Bioengineering %B Journal of tissue engineering and regenerative medicine %V 8 Suppl 1 %P 67–8 %U http://www.ncbi.nlm.nih.gov/pubmed/24912686 %R 10.1002/term.1943 %0 Journal Article %J Smart Membranes and Sensors: Synthesis, Characterization, and Applications %D 2014 %T Smart Sensing Scaffolds %A C. De Maria %A Whulanza, Y. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B Smart Membranes and Sensors: Synthesis, Characterization, and Applications %P 337 %G eng %0 Journal Article %J Biofabrication %D 2014 %T Sphyga: a multiparameter open source tool for fabricating smart and tunable hydrogel microbeads %A Tirella, A %A C. Magliaro %A M. Penta %A M. Troncone %A Pimentel, R %A A. Ahluwalia %K Bioengineering %B Biofabrication %V 6 %G eng %N 025009 %R 10.1088/1758-5082/6/2/025009 %0 Book Section %B Approccio Integrato per la medicina rigenerativa - book of XXXII School of Bioengineering %D 2013 %T Da scaffold a tessuti: progettazione, realizzazione e caratterizzazione di architetture 3D per la medicina rigenerativa %A Tirella, A %A C. De Maria %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B Approccio Integrato per la medicina rigenerativa - book of XXXII School of Bioengineering %G eng %0 Journal Article %J Journal of nanoscience and nanotechnology %D 2013 %T Electrical and Mechanical Characterisation of single wall carbon nanotubes based composites for tissue engineering applications %A Whulanza, Y %A L. Vannozzi %A Vomero, M. %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Journal of nanoscience and nanotechnology %P 188 - 197 %8 01/2013 %G eng %0 Conference Paper %B Advanced Cell Culture %D 2013 %T Gelatin-Hydroxyapatite hydrogels to investigate periosteal derived progenitor cells (PDPCs) response for tissue engineering applications %A G. Mattei %A Tirella, A %A Mattioli-Belmonte, M. %A Ferretti, C %A A. Ahluwalia %K Bioengineering %B Advanced Cell Culture %C Liverpool, UK %0 Journal Article %J Nanotoxicology %D 2013 %T In vitro toxicological screening of nanoparticles on primary human endothelial cells and the role of flow in modulating cell response %A Ucciferri, N %A Collnot, E. M. %A Gaiser, B. %A Tirella, A %A Stone, V. %A C. Domenici %A Lehr, C.-M. %A A. Ahluwalia %K Bioengineering %X

Abstract After passage through biological barriers, nanomaterials inevitably end up in contact with the vascular endothelium and physiological flow, and can induce cardiovascular damage. In this study the toxicity and sublethal effects of 6 nanoparticles, including 4 of industrial and biomedical importance, on human endothelial cells was investigated using different in vitro assays. The results show that all the particles investigated induce some level of damage to the cells and that silver particles were most toxic, followed by titanium dioxide. Furthermore endothelial cells were shown to be more susceptible when exposed to silver nanoparticles under flow conditions in a bioreactor. The study underlines that although simple in vitro tests are useful to screen compounds and to identify the type of effect induced on cells, they may not be sufficient to define safe exposure limits. Therefore, once initial toxicity screening has been conducted on nanomaterials, it is necessary to develop more physiologically relevant in vitro models to better understand how nanomaterials can impact on human health.

%B Nanotoxicology %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/23909703 %R 10.3109/17435390.2013.831500 %0 Journal Article %J Front. Neuroinform. %D 2013 %T NEuronMOrphological analysis tool: open-source software for quantitative morphometrics %A Billeci, L. %A C. Magliaro %A G. Pioggia %A A. Ahluwalia %K Bioengineering %B Front. Neuroinform. %V 7 %G eng %N 2 %R 10.3389/fninf.2013.00002.c %0 Conference Paper %B ESB 2013 %D 2013 %T {SpHyGa: fabrication of hepatic lobule replicas using tissue derived material composites} %A M. La Marca %A Tirella, A %A G. Mattei %A A. Ahluwalia %K Bioengineering %B ESB 2013 %C Madrid %P ID 520 %0 Journal Article %J Procedia Engineering %D 2013 %T SQPR 3.0: A Sensorized Bioreactor for Modulating Cardiac Phenotype %A S. Giusti %A F. Pagliari %A Vozzi, F. %A Tirella, A %A D. Mazzei %A Cabiati, M %A S. del Ry %A A. Ahluwalia %K Bioengineering %X

In cardiac tissue engineering, the use of bioreactors is fundamental for applying controlled mechanical stimuli on cells and recreate a physiological environment for cardiomyocyte cultures. This work is focused on the design of a sensorized Squeeze Pressure bioreactor (SQPR 3.0) able to apply a periodic contactless hydrodynamic pressure on tissue constructs. This system was then tested with H2c9, a murine cardiomyoblast cell line, to investigate the effect of different stimulation times (2h, 24h, 30h) on cell shape and cardiotypic marker expression.

%B Procedia Engineering %V 59 %P 219–225 %G eng %U http://linkinghub.elsevier.com/retrieve/pii/S187770581301028X %R 10.1016/j.proeng.2013.05.114 %0 Journal Article %J Journal of biomedical materials research. Part A %D 2013 %T {Strain rate viscoelastic analysis of soft and highly hydrated biomaterials.} %A Tirella, A %A G. Mattei %A A. Ahluwalia %K Bioengineering %X

Measuring the viscoelastic behaviour of highly hydrated biological materials is challenging because of their intrinsic softness and labile nature. In these materials it is difficult to avoid pre-stress and therefore to establish precise initial stress and strain conditions for lumped parameter estimation using creep or stress-relaxation tests. We describe a method ($ε$M or epsilon dot method) for deriving the viscoelastic parameters of soft hydrated biomaterials which avoids pre-stress and can be used to rapidly test degradable samples. Standard mechanical tests are first performed compressing samples using different strain rates. The dataset obtained is then analysed to mathematically derive the material's viscoelastic parameters. In this work a stable elastomer, PDMS, and a labile hydrogel, gelatin, were first tested using the $ε$M, in parallel stress-relaxation was used to compare lumped parameter estimation. After demonstrating that the elastic parameters are equivalent and that the estimation of short time constants is more precise using the proposed method, the viscoelastic behaviour of porcine liver was investigated using this approach. The results show that the constitutive parameters of hepatic tissue can be quickly quantified without the application of any pre-stress and before the onset of time dependent degradation phenomena.

%B Journal of biomedical materials research. Part A %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/23946054 %R 10.1002/jbm.a.34914 %0 Conference Paper %B Advanced Cell Culture %D 2013 %T Towards a controlled and monitorable hepatic micro-environment %A Tirella, A %A La Marca, M %A Carroll, L. A. %A Aylott, J %A A. Ahluwalia %K Bioengineering %B Advanced Cell Culture %C Liverpool, UK %0 Conference Paper %B TERMIS 3rd World Congress %D 2012 %T Continuous functionally graded materials (cFGMs) for TE %A G. Mattei %A A. Ahluwalia %A Ferretti, C %A Mattioli-Belmonte, M. %A Tirella, A %K Bioengineering %X

Biological structures are not uniform but possess spatially distributed functions and properties, or functional gradients. To ensure functional, mechanical and structural integration, a tissue engineered (TE) scaffold has to reproduce these functional gradients. However the fabrication of functionally graded materials is challenging and usually an experimental trial-and-error approach is used. In this work we present a controlled method for the fabrication of cFGMs using the gravitational sedimentation of discrete solid particles within a primary fluid phase. To have an overall control over particle distribution, a time-varying dynamic viscosity solution (i.e. thermo-sensitive) was used as fluid phase. Computational fluid dynamic models were developed to have a fine control over particle distribution. Biomimetic osteochondral cFGMs scaffolds were fabricated using hydroxyapatite (HA) and gelatin. Glutaraldehyde was used to covalently bind gelatin-HA graded scaffolds. Mechanical properties were measured and correlated as a function of HA volume fraction. SEM-EDX analysis was used to further characterise HA content and its distribution within gelatin-HA cFGMs. Finally gelatin-HA cFGMs scaffold were seeded using periosteum derived progenitor cells, to investigate how the HA gradient modulates cell response. This approach represents an innovative yet simple tool for the fabrication of tailored cFGMs with biologically and physiologically relevant gradients for TE applications.

%B TERMIS 3rd World Congress %C Vienna, Austria %0 Journal Article %J International Journal for Computational Methods in Engineering Science & Mechanics (CMES) %D 2012 %T Functionally Graded Materials (FGMs) with predictable and controlled gradient profiles: computational modelling and realisation %A G. Mattei %A Tirella, A %A A. Ahluwalia %K Bioengineering %B International Journal for Computational Methods in Engineering Science & Mechanics (CMES) %P accepted %G eng %0 Journal Article %J Biotechnology progress %D 2012 %T The impact of fabrication parameters and substrate stiffness in direct writing of living constructs %A Tirella, A %A A. Ahluwalia %K Bioengineering %X

Biomolecules and living cells can be printed in high-resolution patterns to fabricate living constructs for tissue engineering. To evaluate the impact of processing cells with rapid prototyping (RP) methods, we modeled the printing phase of two RP systems that use biomaterial inks containing living cells: a high-resolution inkjet system (BioJet) and a lower-resolution nozzle-based contact printing system (PAM(2) ). In the first fabrication method, we reasoned that cell damage occurs principally during drop collision on the printing surface, in the second we hypothesize that shear stresses act on cells during extrusion (within the printing nozzle). The two cases were modeled changing the printing conditions: biomaterial substrate stiffness and volumetric flow rate, respectively, in BioJet and PAM(2) . Results show that during inkjet printing impact energies of about 10(-8) J are transmitted to cells, whereas extrusion energies of the order of 10(-11) J are exerted in direct printing. Viability tests of printed cells can be related to those numerical simulations, suggesting a threshold energy of 10(-9) J to avoid permanent cell damage. To obtain well-defined living constructs, a combination of these methods is proposed for the fabrication of scaffolds with controlled 3D architecture and spatial distribution of biomolecules and cells. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012.

%B Biotechnology progress %V 28 %P 1315–1320 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/22736619 %R 10.1002/btpr.1586 %0 Conference Paper %B National Conference of Bioengineering %D 2012 %T Monitoring cell culture 3D microenvironments: oxygen and pH nano-sensors within hydrogels %A Tirella, A %A Carroll, L. A. %A Aylott, J %A A. Ahluwalia %K Bioengineering %X

Ratiometric pH and O2 nanosensors were fabricated independently using a fluorophore that produces a signal proportional to the concentration of the analyte of interest, and a second fluorophore that produces a reference signal, insensitive to the analyte of interest. These fluorophores emit at different wavelengths and were either entrapped or covalently bound, within an inert optically transparent polymeric matrix. In this work uniform sized 3D micro-scaled alginate hydrogel constructs of approximately 100-300 $μ$m were fabricated. Through dual incorporation of HepG2 cells and nanosensors within these alginate constructs we aim to have a real-time, non-invasive method to measure microenvironmental pH and O2 content. Ratiometric fluorescent output from the microenvironment is used to monitor O2 concentrations and pH during cell culture. Measurements show that 3D micro-scaled constructs are suitable for cell growth and proliferation. Moreover O2 and pH values within the hydrogel cellularised microspheres are shown to have physiological values that enable the maintenance of the hepatic phenotype

%B National Conference of Bioengineering %C Rome, Italy %0 Conference Paper %B TERMIS 3rd World Congress %D 2012 %T {Monitoring microconstructs: cell and nanosensor encapsulation in alginate micro-beads} %A Tirella, A %A A. Ahluwalia %A Aylott, J %A Carroll, L. A. %K Bioengineering %K Nanotools %X

Monitoring and controlling the microenvironment of cell cultures is an ongoing challenge for many researchers. Much research has been conducted characterising individual aspects such as 3D architecture, mechanical properties, biochemicals, etc. The biggest deficits in existing models for monitoring analytes within the cellular environment is the lack of appropriate means for non invasive, real-time and integrated monitoring of the cellular responses. Nanosensors can overcome these issues: they are porous polymeric nanoparticles that are sensitive to a range of analytes including pH and O2. Microfabrication techniques are innovative tools to obtain controlled microstructures with a defined 3D architecture. In this work uniform sized 3D micro-scaled hydrogel constructs of approximately 300-400 um diameter were fabricated. Through dual incorporation of cells and nanosensors within these constructs we aim to have a real-time, non invasive method to measure microenvironmental pH value and O2 content. Ratiometric fluorescent output from the microenvironment is used to monitor O2 and pH during cell culture. Measurements show that 3D micro-scaled constructs are suitable for cell growth and proliferation. Moreover O2 content and pH within hydrogel cellularised microspheres are shown to have physiological values which enable the maintenance of the hepatic phenotype.

%B TERMIS 3rd World Congress %C Vienna, Austria %0 Conference Paper %B TERMIS 3rd World Congress %D 2012 %T A multi-stimuli environment for cardiac tissue engineering %A Tirella, A %A A. Ahluwalia %A P. Di Nardo %A Gaudiello, E %A S. Giusti %A F. Pagliari %K Bioengineering %K Bioreactors %K Dynamic 3D Cultures %X

The identification of the ideal cell source to generate cardiac tissue able to integrate into the host myocardium and with the contractile system is crucial for cardiac engineering. Amongst different cell sources so far proposed, human adult Cardiac Progenitor Cells (hCPCs) show the ability to proliferate and differentiate toward cardiac lineages when grown in appropriate microenvironmental conditions. It is widely accepted that conventional 2D cultures may provide a physiological environment for growing cells. For this reason the need to have an engineered microenvironment, matching physiological requirements, is crucial. A 3D context with spatial and time varying distribution of regulatory factors using mechanically matched scaffolds and bioreactors could represent an in vitro cell culture model being able to more closely reflects the in vivo conditions. In the present study, the possibility of using biocompatible and biodegradable scaffolds of collagen based or derivatives hydrogels in combination with Linneg/Sca-1pos hCPCs gathered from human heart biopsies was investigated. Bio-constructs were placed in the low shear, high flow MCmB (MultiCompartment modular Bioreactor) and the combined effects of dynamic culture conditions and 3D scaffolds on cell morphology and differentiation were studied in order to investigate the possibility of fabricating stem cell-derived cardiac patches to replace infarcted tissue.

%B TERMIS 3rd World Congress %C Vienna, Austria %0 Conference Paper %B National Conference of Bioengineering %D 2012 %T New method for the viscoelastic analysis of soft and highly hydrated biomaterials %A Tirella, A %A G. Mattei %A A. Ahluwalia %K Bioengineering %X

The role of materials mechanical properties is a new frontier for the evaluation of cell/material interaction, as well as for the determination of healthy/pathological state of a tissue. In these sense there is the need to have a unique method to measure materials viscoelastic properties. However, concerning with soft and highly hydrated constructs, the experimental set-up to precisely measure these properties is challenging because of the difficulty in defining zero stress or strain. To overcome these problems, we propose a novel and unique testing and data analysis technique (ERM) to derive materials viscoelastic properties. Results derived with this method can be compared to the ones obtained with standard testing techniques for viscoelastic materials. Pre-conditioning problems of testing soft and floppy materials are thus overcome, giving rise to have an accurate measure of viscous and elastic moduli of both hydrated materials and soft biological tissues. Small variations of measured properties can be also monitored with high precision, allowing a deeper investigation on the role of the scaffolding material or of tissue’s extracellular matrix (respectively in cell culture systems or in biomechanics measurements for the characterisation of soft tissues).

%B National Conference of Bioengineering %C Rome, Italy %0 Journal Article %J MOLECULAR BIOTECHNOLOGY %D 2012 %T A Novel Method to Produce Immobilised Biomolecular Concentration Gradients to Study Cell Activities: Design and Modelling %A G. Vozzi %A Lenzi, T %A F. Montemurro %A Pardini, C %A Vaglini, F %A A. Ahluwalia %K Bioengineering %B MOLECULAR BIOTECHNOLOGY %V 50 %P 99-107 %G eng %R 10.1007/s12033-011-9411-9 %0 Journal Article %J Rapid Prototyping Journal %D 2012 %T The PAM2 system: a multilevel approach for fabrication of complex three-dimensional microstructures %A Tirella, A %A C. De Maria %A G. Criscenti %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B Rapid Prototyping Journal %V 18 %P 299–307 %G eng %R 10.1108/13552541211231725 %0 Journal Article %J Methods in Molecular Biology %D 2012 %T Rapid Prototyping Composite and Complex Scaffolds with PAM2 %A G. Vozzi %A Tirella, A %A A. Ahluwalia %K Bioengineering %B Methods in Molecular Biology %V 868 %P 57–69 %G eng %0 Conference Paper %B Journal of tissue engineering and regenerative medicine %D 2012 %T Real Time and In-Situ control of environmental parameters in a modular bioreactor %A S. Giusti %A D. Mazzei %A A. Ahluwalia %K Bioengineering %X

Many researchers now recognize the importance of the external environment in which cells are cultured for cell function and differentiation. Most of the systems able to apply physiological-like stimuli also need a classical incubator or a specifically designed system to control the environmental parameters at some distance from the cells. Here, a standalone platform for cell, tissue and organ culture is described. The SUITE (Supervising Unit for In-vitro Testing) system can control local environmental variables like pH, temperature and hydrostatic pressure over long periods, to provide the optimal environment for cells outside the classical incubator and also to apply mechanical and chemical stimuli to simulate the physiological milieu. The SUITE platform is used with Multi-Compartmental modular Bioreactors (MCmB) to perform dynamic cultures of hepatocytes as in-vitro liver model. Preliminary tests demonstrated the capability of the system to maintain the target parameters for more than 72 h generating different hydrostatic pressures (20–30–40–50 mmHg). Then, two bioreactors were connected in series and cultured for 24 h in the SUITE platform with hydrostatic pressures of 20–30–40 mmHg. Static and dynamic controls were placed in the classical humidified incubator at 37°C, 5% CO2. The results show that cell function is enhanced in SUITE at up to 30 mmHg of hydrostatic pressure, as confirmed by viability, metabolic function and morphological analysis.

%B Journal of tissue engineering and regenerative medicine %C Vien, Austria %V 6 Suppl 1 %P 331 %U http://www.ncbi.nlm.nih.gov/pubmed/22941753 %R 10.1002/term.1586 %0 Journal Article %J Biomatter %D 2012 %T Realization of a poro-elastic ultrasound replica of pulmonary tissue %A Spinelli, A %A Vinci, B. %A Tirella, A %A Matteucci, M %A Gargani, L %A A. Ahluwalia %A C. Domenici %A Picano, E %A Chiarelli, P %K Bioengineering %B Biomatter %V 2 %P 27–26 %G eng %U http://www.landesbioscience.com/journals/biomatter/article/19835/ %0 Conference Paper %B Journal of tissue engineering and regenerative medicine %D 2012 %T Replicating the 3D cardiomyocyte environment in the squeeze pressure bioreactor %A S. Giusti %A Tirella, A %A Galli, E %A Vozzi, F. %A Cabiati, M %A A. Ahluwalia %K Bioengineering %B Journal of tissue engineering and regenerative medicine %V 6 Suppl 1 %P 341 %U http://www.ncbi.nlm.nih.gov/pubmed/22941753 %R 10.1002/term.1586 %0 Conference Paper %B TERMIS 3rd World Congress %D 2012 %T Replicating the cardiac environment in the Squeeze Pressure Bioreactor %A S. Giusti %A Tirella, A %A Galli, E %A Vozzi, F. %A Cabiati, M %A A. Ahluwalia %K Bioengineering %B TERMIS 3rd World Congress %0 Journal Article %J Materials Letters %D 2012 %T Riboflavin and collagen: New crosslinking methods to tailor the stiffness of hydrogels %A Tirella, A %A Liberto, T %A A. Ahluwalia %K Bioengineering %X

Fabricating materials with tailored mechanical properties is a challenge and crucial for their successful application in a variety of fields such as tissue engineering. Here collagen and riboflavin were used to create hydrogels with controlled mechanical properties mimicking those of soft tissues (e.g. liver). Collagen-based hydrogels were obtained using a two-step gelation method. Firstly a physical gelation step (i.e. modulation of temperature and pH) was used to fix a specific shape; then photo-initiated cross-links were formed to increase the stiffness. Specifically the chemical cross-linking step was initiated with UV (ultra-violet) radiation to obtain riboflavin derivatised radical polymerization of collagen chains. Cylindrical shaped samples with controlled dimensions were fabricated, and then tested using compressive loading. We show that the compressive elastic modulus of collagen-based hydrogels can be tuned between 0.9 and 3.6 kPa by changing collagen concentration, irradiation with UV in the presence of riboflavin and freeze-drying.

%B Materials Letters %V 74 %P 58–61 %G eng %U http://dx.doi.org/10.1016/j.matlet.2012.01.036 %R 10.1016/j.matlet.2012.01.036 %0 Journal Article %J ADVANCED MATERIALS %D 2011 %T Cooperation of Biological and Mechanical Signals in Cardiac Progenitor Cell Differentiation %A S. Pagliari %A A.C. Vilela-Silva %A G. Forte %A F. Pagliari %A C. Mandoli %A G. Vozzi %A S. Pietronave %A M. Prat %A S. Licoccia %A A. Ahluwalia %A E. Traversa %A M. Minieri %A P. Di Nardo %K Bioengineering %B ADVANCED MATERIALS %G eng %0 Conference Paper %B Proc. Annual Int Engineering in Medicine and Biology Society,EMBC Conf. of the IEEE %D 2011 %T Development and evaluation of a social robot platform for therapy in autism %A D. Mazzei %A Lazzeri, N. %A Billeci, L. %A Igliozzi, R. %A A Mancini %A A. Ahluwalia %A Muratori, F. %A D. De Rossi %K Bioengineering %B Proc. Annual Int Engineering in Medicine and Biology Society,EMBC Conf. of the IEEE %P 4515–4518 %G eng %R 10.1109/IEMBS.2011.6091119 %0 Journal Article %J Biotechnol Bioeng %D 2011 %T A flexible bioreactor system for constructing in vitro tissue and organ models. %A Vozzi, F. %A D. Mazzei %A Vinci, B. %A G. Vozzi %A Sbrana, T. %A Ricotti, L. %A Forgione, N. %A A. Ahluwalia %K Bioengineering %X

To develop in vitro models of cells, tissues and organs we have designed and realized a series of cell culture chambers. Each chamber is purpose designed to simulate a particular feature of the in vivo environment. The bioreactor system is user friendly, and the chambers are easy to produce, sterilize and assemble. In addition they can be connected together to simulate inter-organ or tissue cross-talk. Here we discuss the design philosophy of the bioreactor system and then describe its construction. Preliminary results of validation tests obtained with hepatocytes and endothelial cells are also reported. The results show that endothelial cells are extremely sensitive to small levels of shear stress and that the presence of heterotypic signals from endothelial cells enhances the endogenous metabolic function of hepatocytes.

%B Biotechnol Bioeng %V 108 %P 2129–2140 %8 Sep %G eng %R http://dx.doi.org/10.1002/bit.23164 %0 Patent %D 2011 %T High throughput sensorized bioreactor for applying hydrodynamic pressure and shear stress stiumli on cell cutlures %A A. Ahluwalia %A C. De Maria %A D. Mazzei %A G. Vozzi %K Bioengineering %8 10/2011 %G eng %0 Conference Paper %B Euromat-FEMS %D 2011 %T How dimension a substrate for the realisation of controlled micro- and bio-inspired environment %A Tirella, A %A A. Ahluwalia %A C. De Maria %A Vozzi, F. %A G. Vozzi %A Sandri, T %A Sassano, D %A Cognolato, L %K Bioengineering %X

European Congress and Exhibition on Advanced Materials and Processes - Oral

%B Euromat-FEMS %C Montpellier, France %0 Book Section %B Myocardial Tissue Engineering %D 2011 %T {Inherently Bio-Active Scaffolds: Intelligent Constructs to Model the Stem Cell Niche} %A P. Di Nardo %A M. Minieri %A Tirella, A %A G. Forte %A A. Ahluwalia %E Boccaccini, A. R. %E Harding, S. E. %K Bioengineering %X

The oft-abused phrase “genes load the gun, environment pulls the trigger” can be applied to stem cells and stem cell niches as well as to cell–material interfaces. Much is known about cell–material interaction in general, perhaps a little less about how these interactions condition cell phenotype. With the increasing interest in stem cells and, in particular, their applications in tissue regeneration, the regulation of the stem cell microenvironment through modulation of intuitive or smart materials and structures, or what we term IBAS (Inherently Bio-Active Scaffolds) is poised to become a major field of research. Here, we discuss how cardiac regeneration strategies have undergone a gradual shift from the emphasis on biochemical signals and basic biology to one in which the material or scaffold plays a major role in establishing an equilibrium state. From being a constant battle or tug-of-war between the cells and synthetic environments, we conceive IBAS as intuitively responding to the cell’s requirements to instate a sort of equilibrium in the system.

%B Myocardial Tissue Engineering %S Studies in Mechanobiology, Tissue Engineering and Biomaterials %I Springer Berlin Heidelberg %C Berlin, Heidelberg %V 6 %P 29–47 %@ 978-3-642-18055-2 %G eng %U http://www.springerlink.com/content/j3k541l113233424/ %R 10.1007/978-3-642-18056-9 %0 Conference Paper %B Euromat-FEMS %D 2011 %T Modelling and realisation of smart graded hydrogel scaffolds %A Tirella, A %A G. Mattei %A F. Montemurro %A G. Vozzi %A A. Ahluwalia %K Bioengineering %X

European Congress and Exhibition on Advanced Materials and Processes - Poster F12-P-2-08

%B Euromat-FEMS %C Montpellier, France %0 Book Section %B Bioreactors: Design, Properties and Applications %D 2011 %T Multi-Compartmental Modular Bioreactor as Innovative System for Dynamic Cell Cultures and Co-Cultures %A D. Mazzei %A S. Giusti %A Sbrana, T. %A A. Ahluwalia %E Antolli, P. G. %E Zhiming Liu %K Bioengineering %X

In this chapter, the design, fabrication process and preliminary tests of a Multi- Compartmental Modular Bioreactor used as a system for dynamic cell cultures and co-cultures is described. Although the microwell (MW) plate has become a standard in cell culture, the complexity of the physiological environment is not replicated in petri dishes or microplates. All cells are exquisitely sensitive to their micro-environment which is rich with cues from other cells and from mechanical stimuli due to flow, perfusion and movement. Microwells do not offer any form of dynamic chemical or physical stimulus to cells, such as concentration gradients, flow, pressure or mechanical stress. This is a major limitation in experiments investigating cellular responses in-vitro since the complex interplay of mechanical and biochemical factors is absent. Most researchers and industry have started to accept that classical in vitro experiments offer poor predictive value or mechanistic understanding and are shifting their interests to new technologies such as bioreactors. For this reason, a large number of bioreactor systems for cell culture have been recently designed and described. With the purpose of developing cell culture models to establish a physiological-like interaction between different cell types, a novel Multi-Compartmental Modular Bioreactor (MCmB)was realized. The modular chamber was designed with shape and dimensions similar to the 24-MultiWell allowing an easy transfer of microwell protocols. The MCmB consists of a cell culture chamber made of bio-compatible silicon polymer, with excellent self-sealing proprieties, transparency and flexibility. The modular chambers can be also connected together in series or in parallel as desired, in order to allow cell-cell cross-talk or replicate in vitro models of metabolism or diseases using allometric design principles. In this chapter we describe the bioreactor design process starting from a finite-element method (FEM) model, developed in order to study the shear stress and the oxygen concentration at the cell surface. A further version of the MCmB is also described, in which a semipermeable membrane is placed into the bioreactor allowing to create a double-chamber system (MCmB-dc) for biological barriers simulation like for example lung or intestine. Allometric methods for designing in-vitro organ models using combinations of different cell types or tissues cultured in different chambers are also presented. Allometric laws mathematically correlate non linear quantities such as organ mass, blood flow, blood retention time and metabolic rate. Using these laws the modules can be assembled in various configurations enabling organ and system physiology to be recapitulated in vitro. Preliminary experiments using the modules are also described.

%B Bioreactors: Design, Properties and Applications %I Nova Science Publishers, Inc %P 159 - 178 %G eng %& Multi-Compartimental Modular Bioreactor as Innovative System for Dynamic Cell Cultures and Co-Cultures %0 Journal Article %J Tissue Eng Part C Methods %D 2011 %T PAM2 (Piston Assisted Microsyringe): A New Rapid Prototyping Technique for Biofabrication of Cell Incorporated Scaffolds %A Tirella, A %A Vozzi, F. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B Tissue Eng Part C Methods %V 17 %G eng %R 10.1089/ten.tec.2010.0195 %0 Journal Article %J BIOSENSORS & BIOELECTRONICS %D 2011 %T Sensing scaffolds to monitor cellular activity using impedance measurements %A Whulanza, Y %A Ucciferri, N %A C. Domenici %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B BIOSENSORS & BIOELECTRONICS %G eng %0 Journal Article %J Tissue engineering. Part C, Methods %D 2011 %T Squeeze pressure bioreactor: a hydrodynamic bioreactor for noncontact stimulation of cartilage constructs %A C. De Maria %A S. Giusti %A D. Mazzei %A A. Crawford %A A. Ahluwalia %K Bioengineering %X

A novel squeeze pressure bioreactor for noncontact hydrodynamic stimulation of cartilage is described. The bioreactor is based on a small piston that moves up and down, perpendicular to a tissue construct, in a fluid-filled chamber. Fluid displaced by the piston generates a pressure wave and shear stress as it moves across the sample, simulating the dynamic environment of a mobile joint. The fluid dynamics inside the squeeze pressure bioreactor was modeled using analytical and computational methods to simulate the mechanical stimuli imposed on a construct. In particular, the pressure, velocity field, and wall shear stress generated on the surface of the construct were analyzed using the theory of hydrodynamic lubrication, which describes the flow of an incompressible fluid between two surfaces in relative motion. Both the models and in-situ pressure measurements in the bioreactor demonstrate that controlled cyclic stresses of up to 10 kPa can be applied to tissue constructs. Initial tests on three-dimensional scaffolds seeded with chondrocytes show that glycosaminoglycan production is increased with regard to controls after 24 and 48 h of cyclic noncontact stimulation in the bioreactor.

%B Tissue engineering. Part C, Methods %V 17 %P 757–64 %G eng %U http://online.liebertpub.com/doi/abs/10.1089/ten.tec.2011.0002 http://www.ncbi.nlm.nih.gov/pubmed/21410315 %R 10.1089/ten.TEC.2011.0002 %0 Book Section %B Bioreactors: Design, Properties and Applications %D 2011 %T The Squeeze Pressure Bioreactor: Design and Modelling of a Non-Contact Device for Mechanical Stimulation of Tissue Engineered Constructs %A S. Giusti %A A. Ahluwalia %A C. De Maria %E Antolli, P. G. %E Z. Liu %K Bioengineering %X

Diseases of hyaline cartilage represent one of the major health problems, especially in industrialized countries with high life expectancy. The erosion of the articulating surfaces of joints, known as osteoarthritis, currently affects more than 200 million citizens worldwide, and more than 50% of the patients need or will need a surgical treatment. Articular cartilage is a three dimensional avascular tissue, which covers the ends of all synovial joints. During normal daily function, articular cartilage can be repeatedly subjected to forces up to several time body weight, but it is able to provide articulating joints with a nearly frictionless motion. Despite its tremendously important function, articular cartilage has limited capacity for auto regeneration after degenerative and rheumatic diseases, like arthritis, as well as traumatic injuries. Cartilage problems are a huge and still unsolved medical issue, which therefore represents one of the most important tissue engineering targets requiring high quality products as fast as possible. For this reason, the possibility to recreate in vitro cartilage substitutes as a real alternative to total joint replacement represents an increasing and hopeful market, in which many research groups are still working. At the moment, one of the main findings in invitro cartilage studies is the importance of the role of mechanical stimuli and dynamic loads for the chondrocytes growth and differentiation. Several studies using cartilage explants or chondrocytes seeded in 3D scaffolds have shown that mechanical compressive loads affect the cells metabolic activity and their matrix production. In order to simulate the in vivo environment, the use of bioreactors is becoming fundamental: bioreactors can provide the chemical and mechanical signals that optimize tissue development. Furthermore, bioreactors could be an important instrument to reduce the cost of clinical studies, used as in vitro predictors of in vivo performance. In this way,the use of bioreactors can reduce animal studies, helping the scientists to focus their attention in the right direction before starting pre-clinical studies, which are usually more expensive than preliminary research. In the past few years, several systems for the application of different mechanical stimuli to chondrocytes have been developed. Most of these can generate biomechanical-like forces such as the direct compression, tensile and shear forces, or hydrostatic pressure, in order to stimulate the articular chondrocyctes to increase their matrix production. Generally, the most important requirements that a culture system has to satisfy are high reliability and usability, perfect sterility, easy control of all the important culture parameters and low cost. In this work, a new system, inspired by the synovial environment of mobile joints and able to apply an innovative type of stimulation on articular chondrocytes is described and modeled. The SQPR (SQueeze PRessure) bioreactor chamber is designed to impose a cyclic hydrodynamic pressure on cell cultures, constructs or tissues slices. The basic principle of this new system is the generation of a localized contact less overpressure on articular chondrocytes, using a simple vertical piston movement. This kind of stimulation is particularly useful for neo-tissue or fresh-constructs, in which cells require a dynamic environment to maintain their differentiate state, but at the same time do not tolerate direct compression or high shear stress. When the piston moves down, a controlled hydrodynamic overpressure and a shear stress is generated over the cell surface, stimulating the chondrocytes to improve their matrix production. The fluid dynamics inside the SQPR bioreactor is illustrated from an analytical and numerical point of view. We show how these models can predict the pressure, velocity field and wall shear stress generated on the cell surface of the construct. The bioreactor design is presented in detail and validation tests on chondrocytes are described.

%B Bioreactors: Design, Properties and Applications %I Nova Science Publishers, Inc. %C Hauppauge NY %P 199–214 %G eng %U https://www.novapublishers.com/catalog/product\_info.php?products\_id=22653 %0 Journal Article %J Journal of bioscience and bioengineering %D 2011 %T Substrate stiffness influences high resolution printing of living cells with an ink-jet system %A Tirella, A %A Vozzi, F. %A C. De Maria %A G. Vozzi %A Sandri, T %A Sassano, D %A Cognolato, L %A A. Ahluwalia %K Bioengineering %X

The adaptation of inkjet printing technology for the realisation of controlled micro- and nano-scaled biological structures is of great potential in tissue and biomaterial engineering. In this paper we present the Olivetti BioJet system and its applications in tissue engineering and cell printing. BioJet, which employs a thermal inkjet cartridge, was used to print biomolecules and living cells. It is well known that high stresses and forces are developed during the inkjet printing process. When printing living particles (i.e., cell suspensions) the mechanical loading profile can dramatically damage the processed cells. Therefore computational models were developed to predict the velocity profile and the mechanical load acting on a droplet during the printing process. The model was used to investigate the role of the stiffness of the deposition substrate during droplet impact and compared with experimental investigations on cell viability after printing on different materials. The computational model and the experimental results confirm that impact forces are highly dependent on the deposition substrate and that soft and viscous surfaces can reduce the forces acting on the droplet, preventing cell damage. These results have high relevance for cell bioprinting; substrates should be designed to have a good compromise between substrate stiffness to conserve spatial patterning without droplet coalescence but soft enough to absorb the kinetic energy of droplets in order to maintain cell viability.

%B Journal of bioscience and bioengineering %V 112 %P 79–85 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/21497548 %R 10.1016/j.jbiosc.2011.03.019 %0 Patent %D 2011 %T Supporto per camere di coltura cellulare %A A. Ahluwalia %A Sbrana, T. %A D. Mazzei %K Bioengineering %8 11/2011 %G eng %0 Journal Article %J MATERIALS SCIENCE AND ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS %D 2011 %T Tuning polycaprolactone-carbon nanotube composites for bone tissue engineering scaffolds %A Mattioli-Belmonte, M. %A G. Vozzi %A Whulanza, Y %A Seggiani, M %A Fantauzzi, V %A Orsini, G %A A. Ahluwalia %K Bioengineering %B MATERIALS SCIENCE AND ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS %G eng %0 Conference Paper %B Congresso Nazionale di Bioingegneria 2010 %D 2010 %T Enzymatic cross-linked hydrogel: role of Lysyl oxidase as an initiator of fibroblast inflammatory response %A Tirella, A %A G. Vozzi %A N. Tirelli %A A. Ahluwalia %K Bioengineering %B Congresso Nazionale di Bioingegneria 2010 %G eng %0 Conference Paper %B Proc. IEEE RO-MAN %D 2010 %T The FACE of autism %A D. Mazzei %A Billeci, L. %A Armato, A. %A Lazzeri, N. %A Cisternino, A. %A G. Pioggia %A Igliozzi, R. %A Muratori, F. %A A. Ahluwalia %A D. De Rossi %K Bioengineering %B Proc. IEEE RO-MAN %P 791–796 %G eng %R 10.1109/ROMAN.2010.5598683 %0 Journal Article %J Toxicology in vitro %D 2010 %T Finite element modelling and design of a concentration gradient generating bioreactor: Application to biological pattern formation and toxicology %A G. Vozzi %A D. Mazzei %A Tirella, A %A Vozzi, F. %A A. Ahluwalia %K Bioengineering %X

This paper describes the use of a microfluidic gradient maker for the toxicological analysis of some conventional biomolecules such as hydrogen peroxide and a local anaesthetic, lidocaine on different cell cultures, human endothelial cells and myoblasts, respectively. The microfluidic device was designed and simulated using COMSOL Multiphysics(R) and the concentration gradient in the microfluidic network was analysed through a fluid-dynamic and mass-transport study. Subsequently the device was fabricated with soft lithography, casting PDMS in a master to obtain channels about 250mum deep. Hydrogen peroxide was tested on human endothelial cells, while lidocaine was tested on C2C12 myoblasts and an analysis was performed using propidium iodide staining followed by an imaging processing routine to obtain quantitative dose-response profiles in the gradient maker. The results show that the Gradient Maker (GM) bioreactor is a more sensitive method for detection of cell toxicity, and compared with testing of drug toxicity using microwells with individual cell cultures, allows one shot testing with a single cell culture exposed to a large number of concentrations. Moreover, the Gradient Maker was also modelled in order to realise biological pattern formation using two morphogenes acting as activator and inhibitor with varying diffusion rates.

%B Toxicology in vitro %V 24 %P 1828–1837 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/20580814 %R 10.1016/j.tiv.2010.05.010 %0 Conference Paper %B NIP Conference %D 2010 %T Hydrogel Bioactive Scaffold Fabricated with PAM2 System: Realization of Complex Shaped Scaffold with a Homogeneous Dispersion of HepG2 cells %A Tirella, A %A Vozzi, F. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B NIP Conference %G eng %0 Conference Paper %B Congresso Nazionale di Bioingegneria 2010 %D 2010 %T In silico model of hepatic metabolism of Diclofenac %A A. Moschetti %A F. Montemurro %A C. De Maria %A Vozzi, F. %A A. Ahluwalia %A G. Vozzi %B Congresso Nazionale di Bioingegneria 2010 %G eng %0 Journal Article %J Biotechnol J %D 2010 %T In vitro liver model using microfabricated scaffolds in a modular bioreactor. %A Vinci, B. %A Cavallone, D. %A G. Vozzi %A D. Mazzei %A C. Domenici %A Brunetto, M. %A A. Ahluwalia %K Bioengineering %X

Hepatocyte function on 3-D microfabricated polymer scaffolds realised with the pressure-activated microsyringe was tested under static and dynamic conditions. The dynamic cell culture was obtained using the multicompartment modular bioreactor system. Hepatocyte cell density, glucose consumption, and albumin secretion rate were measured daily over a week. Cells seeded on scaffolds showed an increase in cell density compared with monolayer controls. Moreover, in dynamic culture, cell metabolic function increased three times in comparison with static monolayer cultures. These results suggest that cell density and cell-cell interactions are mediated by the architecture of the substrate, while the endogenous biochemical functions are regulated by a sustainable supply of nutrients and interstitial-like flow. Thus, a combination of 3-D scaffolds and dynamic flow conditions are both important for the development of a hepatic tissue model for applications in drug testing and regenerative medicine.

%B Biotechnol J %V 5 %P 232–241 %8 Feb %G eng %R http://dx.doi.org/10.1002/biot.200900074 %0 Journal Article %J Biotechnol Bioeng %D 2010 %T A low shear stress modular bioreactor for connected cell culture under high flow rates. %A D. Mazzei %A M. A. Guzzardi %A S. Giusti %A A. Ahluwalia %K Bioengineering %K Bioreactors %X

A generic "system on a plate" modular multicompartmental bioreactor array which enables microwell protocols to be transferred directly to the bioreactor modules, without redesign of cell culture experiments or protocols is described. The modular bioreactors are simple to assemble and use and can be easily compared with standard controls since cell numbers and medium volumes are quite similar. Starting from fluid dynamic and mass transport considerations, a modular bioreactor chamber was first modeled and then fabricated using "milli-molding," a technique adapted from soft lithography. After confirming that the shear stress was extremely low in the system in the range of useful flow rates, the bioreactor chambers were tested using hepatocytes. The results show that the bioreactor chambers can increase or maintain cell viability and function when the flow rates are below 500 microL/min, corresponding to wall shear stresses of 10(-5) Pa or less at the cell culture surface.

%B Biotechnol Bioeng %V 106 %P 127–137 %8 May %G eng %R http://dx.doi.org/10.1002/bit.22671 %0 Conference Paper %B Congresso Nazionale di Bioingegneria 2010 %D 2010 %T Pam scaffold for heart tissue engineering %A M. Nardi %A C. De Maria %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Congresso Nazionale di Bioingegneria 2010 %G eng %0 Conference Paper %B Congresso Nazionale di Bioingegneria 2010 %D 2010 %T PAM2 microfabricated three-dimensional bioactive hydrogel systems: realisation of a hepatic-like structure %A Tirella, A %A Vozzi, F. %A Vinci, B. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B Congresso Nazionale di Bioingegneria 2010 %G eng %0 Conference Paper %B 2010 International Conference on Biofabrication, 4-6 October 2010, Philadelphia, USA %D 2010 %T PAM2 System: a Modular Approach for the Realisation of Complex Shaped Scaffold Able to Reproduce the Main Features of a Specific Micro-environment, %A A. Ahluwalia %A Tirella, A %A G. Vozzi %K Bioengineering %B 2010 International Conference on Biofabrication, 4-6 October 2010, Philadelphia, USA %G eng %0 Book Section %B Computer-Aided Tissue Engineering %D 2010 %T Rapid Prototyping Composite and Complex Scaffolds with PAM2 %A G. Vozzi %A Tirella, A %A A. Ahluwalia %K Bioengineering %B Computer-Aided Tissue Engineering %V 868 %P 57-69 %G eng %& Rapid Prototyping Composite and Complex Scaffolds with PAM2 %0 Conference Paper %B Congress of the European Society of Biomechanics, ESB 2010 %D 2010 %T Resident cardiac stem cells on PAM scaffold for Heart tissue engineering application %A M. Nardi %A C. De Maria %A G. Forte %A P. Di Nardo %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Congress of the European Society of Biomechanics, ESB 2010 %G eng %0 Conference Paper %B Congresso Nazionale di Bioingegneria 2010 %D 2010 %T Sensorised "Smart" Scaffold to Monitor Cell Processes Based on Impedance Characteristics %A Whulanza, Y %A Ucciferri, N %A G. Vozzi %A A. Ahluwalia %A C. Domenici %K Bioengineering %B Congresso Nazionale di Bioingegneria 2010 %G eng %0 Conference Paper %B NIP Conference %D 2010 %T Site Specific Nano-Tuning of Scaffolds Using Inkjet Printing %A Tirella, A %A F. Montemurro %A Vinci, B. %A Vozzi, F. %A G. Vozzi %A Sassano, D %A Sandri, T %A Cognolato, L %A A. Ahluwalia %K Bioengineering %B NIP Conference %C Austin, Texas %G eng %0 Conference Paper %B 2009 Ninth International Conference on Intelligent Systems Design and Applications %D 2009 %T ENMET: Endothelial Cell Metabolism Mathematical Model, %A G. Orsi %A C. De Maria %A Vozzi, F. %A M. A. Guzzardi %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B 2009 Ninth International Conference on Intelligent Systems Design and Applications %P 654 - 659 %G eng %0 Journal Article %J COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE %D 2009 %T A new library of HEMET model: Insulin effects on hepatic metabolism %A CUTRONE, A %A C. De Maria %A Vinci, B. %A Vozzi, F. %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE %V 94 %P 181–189 %G eng %N 2 %R 10.1016/j.cmpb.2008 %0 Journal Article %J Biofabrication %D 2009 %T A phase diagram for microfabrication of geometrically controlled hydrogel scaffolds %A Tirella, A %A Orsini, A %A G. Vozzi %A A. Ahluwalia %K Bioengineering %X

Hydrogels are considered as excellent candidates for tissue substitutes by virtue of their high water content and biphasic nature. However, the fact that they are soft, wet and floppy renders them difficult to process and use as custom-designed scaffolds. To address this problem alginate hydrogels were modeled and characterized by measuring stress-strain and creep behavior as well as viscosity as a function of sodium alginate concentration, cross-linking time and calcium ion concentration. The gels were then microfabricated into scaffolds using the pressure-assisted microsyringe. The mechanical and viscous characteristics were used to generate a processing window in the form of a phase diagram which describes the fidelity of the scaffolds as a function of the material and machine parameters. The approach can be applied to a variety of microfabrication methods and biomaterials in order to design well-controlled custom scaffolds.

%B Biofabrication %V 1 %P 045002 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/20811111 %R 10.1088/1758-5082/1/4/045002 %0 Conference Paper %B 3B International Conference in Bioprinting and Biofabrication %D 2009 %T Pneumatic module of PAM2 microfabrication system: realization of bio-inspired complex scaffolds %A C. De Maria %A Tirella, A %A A. Ahluwalia %A G. Vozzi %K Bioengineering %X

poster

%B 3B International Conference in Bioprinting and Biofabrication %C Bordeaux, France %0 Book Section %D 2008 %T Biomaterials fabrication and processing handbook %A G. Vozzi %A A. Ahluwalia %K Bioengineering %P – %G eng %& Rapid Prototyping Methods for Tissue Engineering Applications %0 Conference Paper %B International Conference on Digital Printing Technologies Conference Proceedings %D 2008 %T Biomimicry of PAM Microfabricated Hydrogel Scaffolds %A Tirella, A %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B International Conference on Digital Printing Technologies Conference Proceedings %P – %G eng %0 Journal Article %J JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART A %D 2008 %T Chitosan/gelatin blends for biomedical applications %A PULIERI, E %A V. Chiono %A G. Ciardelli %A G. Vozzi %A A. Ahluwalia %A C. Domenici %A Vozzi, F. %A P. Giusti %K Bioengineering %B JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART A %V 86 %P 311–322 %G eng %0 Journal Article %J INTERNAL MEDICINE %D 2008 %T Comparative study of porous and engineered biomaterials %A Mattioli-Belmonte, M. %A K KYRIAKIDOU %A LUCARINI, G %A ZIZZI, A %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B INTERNAL MEDICINE %V 15 %P 4–8 %G eng %0 Journal Article %J BIOMEDICAL MICRODEVICES %D 2008 %T Controlled in vitro growth of cell microtubes: towards the realisation of artificial microvessels %A Migliore, A. %A Vozzi, F. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B BIOMEDICAL MICRODEVICES %G eng %0 Journal Article %J STEM CELLS %D 2008 %T Criticality of the Biological and Physical Stimuli Array Inducing Resident Cardiac Stem Cell Determination %A G. Forte %A CAROTENUTO, F %A F. Pagliari %A S. Pagliari %A COSSA, P %A FIACCAVENTO, R %A A. Ahluwalia %A G. Vozzi %A Vinci, B. %A SERAFINO, A %A RINALDI, A %A E. Traversa %A CAROSELLA, L %A M. Minieri %A P. Di Nardo %K Bioengineering %B STEM CELLS %V 26 %P 2093–2103 %G eng %0 Journal Article %J MATERIALS SCIENCE AND ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS %D 2008 %T Electroactive Carbon Nanotube Actuators: Soft-Lithographic Fabrication and Electro-chemical Modelling %A A. Mazzoldi %A M. Tesconi %A A. Tognetti %A W. Rocchia %A G. Vozzi %A G. Pioggia %A A. Ahluwalia %A D. De Rossi %K Bioengineering %B MATERIALS SCIENCE AND ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS %P – %G eng %0 Journal Article %J JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE %D 2008 %T Genipin-crosslinked chitosan/gelatin blends for biomedical applications %A V. Chiono %A PULIERI, E %A G. Vozzi %A G. Ciardelli %A A. Ahluwalia %A P. Giusti %K Bioengineering %B JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE %G eng %0 Journal Article %J COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE %D 2008 %T HEMET: mathematical model of biochemical pathways for simulation and prediction of HEpatocyte METabolism %A C. De Maria %A GRASSINI, D %A Vozzi, F. %A Vinci, B. %A A. Landi %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE %V 92 %P 121–134 %G eng %0 Journal Article %J IEEE T Ind Electron %D 2008 %T A High-Throughput Bioreactor System for Simulating Physiological Environments %A D. Mazzei %A Vozzi, F. %A Cisternino, A. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B IEEE T Ind Electron %V 55 %P 3273–3280 %G eng %R 10.1109/TIE.2008.928122 %0 Patent %D 2008 %T IMPROVED BIOREACTOR CHAMBER %A A. Ahluwalia %A D. Mazzei %A Vozzi, F. %K Bioengineering %G eng %0 Journal Article %J INTERNAL MEDICINE %D 2008 %T In vitro engineering of the liver using multiple axis stimuli %A Vinci, B. %A G. Vozzi %A AVOGARO, A %A A. Ahluwalia %K Bioengineering %B INTERNAL MEDICINE %V 15 %P 13–15 %G eng %0 Conference Paper %B Congresso Nazionale Biomateriali 2008 %D 2008 %T Microfabbricazione di scaffold in alginato con proprietà  meccaniche modulabili %A Orsini, A %A Tirella, A %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Congresso Nazionale Biomateriali 2008 %P – %G eng %0 Conference Paper %B TERMIS-EU %D 2008 %T Microfluidic Gradient Maker for Pattern Generation %A Tirella, A %A D. Mazzei %A G. Vozzi %A A. Ahluwalia %K Bioengineering %X

poster

%B TERMIS-EU %C Porto, Portugal %P 879 %0 Journal Article %J Toxicology in vitro %D 2008 %T A microfluidic gradient maker for toxicity testing of bupivacaine and lidocaine %A Tirella, A %A Marano, M %A Vozzi, F. %A A. Ahluwalia %K Bioengineering %X

A great deal of effort is being dedicated to the development of new devices able to conduct effective in vitro toxicology analyses. This paper describes the use of a microfluidic gradient maker for the toxicological analysis of two conventional local anesthetics, bupivacaine and lidocaine on cell cultures. The microfluidic device was designed and simulated using COMSOL Multiphysics and the concentration gradient in the microfluidic network was analysed through a fluidodynamic and diffusive study. Subsequently the device was fabricated with soft lithography, casting PDMS in a master to obtain channels about 250 microm deep. Both drugs were tested on C2C12 myoblasts and an analysis was performed using propidium iodide staining followed by an imaging processing routine to obtain quantitative dose-response profiles in the gradient maker. The system was critically compared with microwell-based toxicity testing. The results show that the GM is a more sensitive method for detection of cell toxicity, and compared with testing of drug toxicity using microwells with individual cell cultures, allows one shot testing with a single cell culture exposed to a large number of concentrations. However, the flow rates required to obtain a suitable concentration range across the device may damage shear sensitive cells.

%B Toxicology in vitro %V 22 %P 1957–64 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/18940244 %R 10.1016/j.tiv.2008.09.016 %0 Patent %D 2008 %T MULTI-CAVITY BIOREACTOR CHAMBER %A A. Ahluwalia %A D. Mazzei %A Vinci, B. %K Bioengineering %G eng %0 Journal Article %J TISSUE ENGINEERING, PART A %D 2008 %T Optimization of PAM Scaffolds for Neural Tissue Engineering: Preliminary Study on an SH-SY5Y Cell Line %A KULLENBERG, J %A ROSATINI, F %A G. Vozzi %A BIANCHI, F %A A. Ahluwalia %A C. Domenici %K Bioengineering %B TISSUE ENGINEERING, PART A %G eng %0 Conference Paper %B National Conference of Bioengineering %D 2008 %T PAM Composite Scaffold of PCL and Carbon NanoTubes for Bone Tissue Regeneration %A Mattioli-Belmonte, M. %A Fantauzzi, V %A K KYRIAKIDOU %A Tirella, A %A A. Ahluwalia %A G. Vozzi %K Bioengineering %X

poster

%B National Conference of Bioengineering %C Pisa, Italy %P 369 %0 Journal Article %J MACROMOLECULAR BIOSCIENCE %D 2008 %T PAM-microfabricated polyurethane scaffolds: in vivo and in vitro preliminary studies %A G. Vozzi %A Rechichi, A %A F. Dini %A C. Salvadori %A Vozzi, F. %A S. Burchielli %A F. Carlucci %A ARISPICI, M %A G. Ciardelli %A P. Giusti %A A. Ahluwalia %K Bioengineering %B MACROMOLECULAR BIOSCIENCE %G eng %0 Journal Article %J IEEE INDUSTRIAL ELECTRONICS MAGAZINE %D 2008 %T A patented drop-free trocar for ophthalmic applications: design and realization [from mind to market] %A Guerrini, P. %A G. Vozzi %A A. Ahluwalia %A Palla, M. %K Bioengineering %B IEEE INDUSTRIAL ELECTRONICS MAGAZINE %V 2 %P 4–8 %G eng %0 Journal Article %J IEEE INDUSTRIAL ELECTRONICS MAGAZINE %D 2008 %T A patented drop-free trocar for ophthalmic applications: design and realization [from mind to market] %A Guerrini, P. %A G. Vozzi %A A. Ahluwalia %A Palla, M. %A G. Vozzi %B IEEE INDUSTRIAL ELECTRONICS MAGAZINE %V 2 %P 4–8 %G eng %0 Journal Article %J JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART A %D 2008 %T Rapid-prototyped and salt-leached PLGA scaffolds condition cell morpho-functional behaviour %A Mattioli-Belmonte, M. %A G. Vozzi %A K KYRIAKIDOU %A PULIERI, E %A LUCARINI, G %A Vinci, B. %A PUGNALONI, A %A BIAGINI, G %A A. Ahluwalia %K Bioengineering %B JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART A %P – %G eng %0 Conference Paper %B Congresso Nazionale Biomateriali 2008 %D 2008 %T Realizzazione di strutture micro fabbricate tramite tecnica di micro Laser Sintering per applicazione alla Tissue Engineering %A G. Criscenti %A Tirella, A %A A. Ahluwalia %A P. Giusti %A G. Vozzi %K Bioengineering %B Congresso Nazionale Biomateriali 2008 %P – %G eng %0 Conference Paper %B Congresso Nazionale Biomateriali 2008 %D 2008 %T Sviluppo e caratterizzazione meccanica di scaffold a base di collagene per la rigenerazione della cartilagine %A G. Mattei %A F. Montemurro %A A. Ahluwalia %A G. Vozzi %K Bioengineering %B Congresso Nazionale Biomateriali 2008 %P – %G eng %0 Journal Article %J EUROPEAN JOURNAL OF NEUROSCIENCE %D 2007 %T Acute retinal ganglion cell injury caused by intraocular pressure spikes is mediated by endogenous extracellular ATP %A RESTA, V. %A NOVELLI, E. %A G. Vozzi %A SCARPA, C. %A CALEO, M. %A A. Ahluwalia %A SOLINI, A. %A SANTINI, E. %A PARISI, V. %A DI VIRGILIO, F. %A GALLI-RESTA, L. %K Bioengineering %B EUROPEAN JOURNAL OF NEUROSCIENCE %V 25 %P 2741–2754 %G eng %0 Conference Paper %B Termis Eu-Meeting London (UK) 4-7 September 2007 Tissue Engineering 2007, 13 (7): 1647 %D 2007 %T Cardiac and Mesenchymal Stem Cell Growth and Selective Differentiation on Three Dimensional Bioerodable Scaffolds %A G. Forte %A CAROTENUTO, F %A G. Vozzi %A COSSA, P %A FIACCAVENTO, R %A M. Minieri %A F. Pagliari %A S. Pagliari %A Romano, R. %A A. Ahluwalia %A E. Traversa %A P. Di Nardo %K Bioengineering %B Termis Eu-Meeting London (UK) 4-7 September 2007 Tissue Engineering 2007, 13 (7): 1647 %P – %G eng %0 Conference Paper %B Proc. IEEE Int. Symp. Industrial Electronics ISIE 2007 %D 2007 %T Design and realisation of drop-free trocar for ophthalmic applications %A Guerrini, P. %A G. Vozzi %A A. Ahluwalia %A D. Mazzei %A Palla, M. %A Rizzo, S. %K Bioengineering %B Proc. IEEE Int. Symp. Industrial Electronics ISIE 2007 %P 2810–2814 %G eng %R 10.1109/ISIE.2007.4375056 %0 Conference Paper %B Proc. IEEE Int. Symp. Industrial Electronics ISIE 2007 %D 2007 %T Development of a high-throughput bioreactor system for biomedical applications %A D. Mazzei %A G. Vozzi %A A. Ahluwalia %A Cisternino, A. %K Bioengineering %B Proc. IEEE Int. Symp. Industrial Electronics ISIE 2007 %P 2788–2792 %G eng %R 10.1109/ISIE.2007.4375051 %0 Journal Article %J JOURNAL OF MATERIALS CHEMISTRY %D 2007 %T Microfabrication for tissue engineering: rethinking the cells-on-a scaffold approach %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B JOURNAL OF MATERIALS CHEMISTRY %P – %G eng %0 Journal Article %J JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART B, APPLIED BIOMATERIALS %D 2007 %T Microfabrication of fractal polymeric structures for capillary morphogenesis: applications in therapeutic angiogenesis and in the engineering of vascularized tissue %A BIANCHI, F %A ROSI, M. %A G. Vozzi %A EMANUELI, C. %A MADEDDU, P. %A A. Ahluwalia %K Bioengineering %B JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART B, APPLIED BIOMATERIALS %V 81 %P 462–468 %G eng %0 Conference Paper %B Proceedings of: XIV Edizione del Congresso della Fisiologia Clinica-CNR %D 2005 %T Functional and Pharmacological testing of endothelial cells cultured in dynamic conditions %A Vozzi, F. %A Gentile, C. %A D. Mazzei %A G. Vozzi %A C. Domenici %A A. Ahluwalia %K Bioengineering %B Proceedings of: XIV Edizione del Congresso della Fisiologia Clinica-CNR %P 82-96 %G eng %0 Conference Paper %B Proceedings of: 4Th Annual Meeting of the European Tissue Engineering Society (ETES) %D 2005 %T Realisation of a concentration gradients cell chamber to study their effect of biomolecules on the cell activity %A D. Mazzei %A Vozzi, F. %A G. Vozzi %A A. Ahluwalia %K Bioengineering %B Proceedings of: 4Th Annual Meeting of the European Tissue Engineering Society (ETES) %G eng %0 Conference Paper %B First International Symposium on Measurement, Analysis and Modeling of Human Functions %D 2001 %T Piezoresistive fabrics for monitoring body kinematics and gesture %A A. Ahluwalia %A D. De Rossi %A F. Lorussi %A A. Mazzoldi %A P. Orsini %A E. P. Scilingo %K Biomechanics %K Smart Textiles %B First International Symposium on Measurement, Analysis and Modeling of Human Functions %C Sapporo, Japan %P 395-399 %8 September %G eng