Elastomeric Cell-Laden Nanocomposite Microfibers for Engineering Complex Tissues

Biomaterials-based three dimensional scaffolds with tunable elasticity hold promise in replacing failed organs resulting from injuries, aging, and diseases by providing a suitable cellular microenvironment to facilitate regeneration of damaged tissues. However, controlled presentation of biological signals with tunable tissue mechanics and architecture remain a bottleneck that needs to be addressed to engineer functional artificial tissues. Nanocomposite hydrogels that promote cells adhesion and demonstrate tunable viscoelastic properties could mimic key properties and structures of native tissue. We have developed elastomeric fiber shaped cellular constructs from poly(ethylene glycol) diacrylate, silicate nanoparticles, and gelatin methacrylate via ionic and covalent crosslinking. By controlling the interactions between nanoparticles and polymers, nanocomposite hydrogels with tunable mechanical and degradation properties are fabricated. By encapsulating multiple cell types in these cellular constructs, we demonstrate materials-based control of cell spreading, survival, and proliferation. As a proof-of-concept, we assembled the hydrogel microfibers to obtain multicellular elastomeric tissue constructs. These elastic microfibers may serve as model systems to explore the effect of mechanical stress on cell-matrix interactions. Moreover, such elastomeric hydrogel fibers can be used to engineer scaffold structures, fabric sheets, bundles, or as building blocks for 3D tissue construction.