title: A phase diagram for microfabrication of geometrically controlled hydrogel scaffolds.
abstract: 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.
authors.affiliation: Interdepartmental Research Center E Piaggio, Faculty of Engineering, University of Pisa, Via Diotisalvi 2, 56124 Pisa, Italy. a.tirella@ing.unipi.it
authors.forename: A
authors.initials: A
authors.lastname: Tirella
authors.forename: A
authors.initials: A
authors.lastname: Orsini
authors.forename: G
authors.initials: G
authors.lastname: Vozzi
authors.forename: A
authors.initials: A
authors.lastname: Ahluwalia
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001709:Biotechnology; D004058:Diffusion; D055119:Elastic Modulus; D020342:Finite Element Analysis; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D055616:Microtechnology / Q000295:instrumentation / Q000379:methods*; D013314:Stress, Mechanical; D054457:Tissue Scaffolds / Q000737:chemistry*; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D014867:Water; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid