@conference {2275, title = {Sensorized Squeeze Pressure Bioreactor For mechanical modulation of cardiomyocyte phenotype}, booktitle = {Journal of tissue engineering and regenerative medicine}, volume = {8 Suppl 1}, year = {2014}, pages = {67{\textendash}8}, keywords = {Bioengineering}, doi = {10.1002/term.1943}, url = {http://www.ncbi.nlm.nih.gov/pubmed/24912686}, author = {S. Giusti and Vozzi, F. and F. Pagliari and Tirella, A and D. Mazzei and Cabiati, M and S. del Ry and A. Ahluwalia} } @article {2290, title = {Sphyga: a multiparameter open source tool for fabricating smart and tunable hydrogel microbeads}, journal = {Biofabrication}, volume = {6}, year = {2014}, keywords = {Bioengineering}, doi = {10.1088/1758-5082/6/2/025009}, author = {Tirella, A and C. Magliaro and M. Penta and M. Troncone and Pimentel, R and A. Ahluwalia} } @conference {1793, title = {{SpHyGa: fabrication of hepatic lobule replicas using tissue derived material composites}}, booktitle = {ESB 2013}, year = {2013}, pages = {ID 520}, address = {Madrid}, keywords = {Bioengineering}, author = {M. La Marca and Tirella, A and G. Mattei and A. Ahluwalia} } @article {2281, title = {SQPR 3.0: A Sensorized Bioreactor for Modulating Cardiac Phenotype}, journal = {Procedia Engineering}, volume = {59}, year = {2013}, pages = {219{\textendash}225}, abstract = {

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.

}, keywords = {Bioengineering}, issn = {18777058}, doi = {10.1016/j.proeng.2013.05.114}, url = {http://linkinghub.elsevier.com/retrieve/pii/S187770581301028X}, author = {S. Giusti and F. Pagliari and Vozzi, F. and Tirella, A and D. Mazzei and Cabiati, M and S. del Ry and A. Ahluwalia} } @article {1790, title = {{Strain rate viscoelastic analysis of soft and highly hydrated biomaterials.}}, journal = {Journal of biomedical materials research. Part A}, year = {2013}, abstract = {

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{\textquoteright}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.

}, keywords = {Bioengineering}, issn = {1552-4965}, doi = {10.1002/jbm.a.34914}, url = {http://www.ncbi.nlm.nih.gov/pubmed/23946054}, author = {Tirella, A and G. Mattei and A. Ahluwalia} } @article {1488, title = {Substrate stiffness influences high resolution printing of living cells with an ink-jet system}, journal = {Journal of bioscience and bioengineering}, volume = {112}, year = {2011}, pages = {79{\textendash}85}, abstract = {

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.

}, keywords = {Bioengineering}, issn = {1347-4421}, doi = {10.1016/j.jbiosc.2011.03.019}, url = {http://www.ncbi.nlm.nih.gov/pubmed/21497548}, author = {Tirella, A and Vozzi, F. and C. De Maria and G. Vozzi and Sandri, T and Sassano, D and Cognolato, L and A. Ahluwalia} } @conference {1526, title = {Site Specific Nano-Tuning of Scaffolds Using Inkjet Printing}, booktitle = {NIP Conference}, year = {2010}, address = {Austin, Texas }, keywords = {Bioengineering}, author = {Tirella, A and F. Montemurro and Vinci, B. and Vozzi, F. and G. Vozzi and Sassano, D and Sandri, T and Cognolato, L and A. Ahluwalia} }