title: Substrate stiffness influences high resolution printing of living cells with an ink-jet system.
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.
authors.affiliation: Faculty of Engineering, University of Pisa, Pisa, Italy. tirella@gmail.com
authors.forename: Annalisa
authors.initials: A
authors.lastname: Tirella
authors.forename: Federico
authors.initials: F
authors.lastname: Vozzi
authors.forename: Carmelo
authors.initials: C
authors.lastname: De Maria
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vozzi
authors.forename: Tazio
authors.initials: T
authors.lastname: Sandri
authors.forename: Duccio
authors.initials: D
authors.lastname: Sassano
authors.forename: Livio
authors.initials: L
authors.lastname: Cognolato
authors.forename: Arti
authors.initials: A
authors.lastname: Ahluwalia
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival; D002478:Cells, Cultured; D055615:Electrical Equipment and Supplies; D007281:Ink; D051379:Mice; D010209:Paper; D011327:Printing / Q000379:methods*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials