Development of bullfrog collagen- and gelatin-based hydrogels as novel cellular encapsulants

Methacrylated gelatin (GelMA) hydrogels as cell encapsulants have gained traction for their improved, tunable physical properties and retained cell-supporting capacity as compared to the commonly used native gelatin and collagen. However, limited studies evaluating the potential applicability of methacrylated collagen (ColMA) exist, likely due to a lack of collagen sources that permits high degrees of methacrylation. Here, American bullfrog (Rana catesbeiana) skin-derived collagen and gelatin were exploited to develop, characterize and optimize ColMA and GelMA hydrogels, and to explore their potential in the application of Janus rods. Additionally, their effects on cell response parameters upon encapsulation were investigated. ColMA and GelMA hydrogels were successfully fabricated, with ColMA hydrogels displaying significantly lower degrees of methacrylation (56.45 0.65% vs. 72.64 1.59%, p < 0.05) and storage moduli (5.16 1.7kPa vs. 47.92 16.65kPa, p < 0.05), oblong pores and rougher texture as compared to GelMA. These properties permitted cell spreading, while GelMA’s higher physical properties and smaller, rounder pores led to cell confinement and rounding in an overnight cell viability study. The higher methacrylation extent in GelMA also conferred greater binding abilities with subsequent layers in Janus rods. With further optimization of the processing and modification steps, bullfrog skin-derived ColMA and GelMA hydrogels collectively serve as promising materials for cell encapsulation.Bachelor of Science in Biological Science