Microribbon-Like Elastomers for Fabricating Macroporous and Highly Flexible Scaffolds that Support Cell Proliferation in 3D



Hydrogel-based scaffolds are widely used for culturing cells in three dimensions due to their tissue-like water content and tunable biochemical and physical properties. Most conventional hydrogels lack the macroporosity desirable for efficient cell proliferation and migration and have limited flexibility when subject to mechanical load. Here microribbon-like elastomers that, when photocrosslinked, can form macroporous and highly flexible scaffolds that support cell proliferation in 3D are developed. These microribbons are produced by wet-spinning gelatin solution into microfibers, followed by drying in acetone, which causes asymmetrical collapse of microfibers to form microribbon-like structures. Gelatin microribbons are then modified using methacrylate anhydride to allow further photocrosslinking into 3D scaffolds. The macroporosity and mechanical properties of the microribbon-based scaffold may be tuned by varying wet-spinning rate, drying temperature, choice of drying agent, level of glutaraldehyde crosslinking, and microribbon density. When encapsulated in the microribbon-based scaffold, human adipose-derived stromal cells proliferated up to 30-fold within 3 weeks. Furthermore, microribbons-based scaffold demonstrate great flexibility and can sustain up to 90% strain and 3 MPa stress without failing. The unique mechanical properties of microribbon-based scaffolds make them promising tools for engineering shock-absorbing tissues such as cartilage and intervertebral discs.