Microfluidic Fabrication of Gelatin Acrylamide Microgels through Visible Light Photopolymerization for Cell Encapsulation

Gelatin-based microgels are intriguing for various biomedical applications, which are conventionally prepared through photopolymerization of gelatin methacrylamide (GelMA). Here, we report on the modification of gelatin through acrylamidation to form gelatin acrylamide (GelA) with different substitution degrees, which was found to exhibit fast photopolymerization kinetics, better gelation, steady viscosity at elevated temperatures, and satisfying biocompatibility when compared to GelMA. By the online photopolymerization strategy with a home-made microfluidic setting, microgels of uniform sizes from GelA by blue light were obtained and their swollen properties were investigated. Compared to the microgels from GelMA, they showed an enhanced cross-linking degree and have better shape stability when swollen in water. Cell toxicities of the hydrogels from GelA and cell encapsulation from the corresponding microgels were investigated, which were found to exhibit superior properties than those from GelMA. We therefore believe that GelA has potential for constructing scaffolds for bioapplications and can be an excellent substitute for GelMA.