In vitro Degradation Analysis of 3D-architectured Gelatin-based Hydrogels

Abstract

Multifunctional biopolymer-based materials are promising candidates for next generation regenerative biomaterials. Understanding the degradation behavior of biomaterials is vital for ensuring biological safety, as well as for better control of degradation properties based on rational design of a material’s physical and chemical characteristics. In this study, we decipher the degradation of a hydrogel prepared from gelatin and lysine diisocyanate ethyl ester (LDI) using in vitro models, which simulate hydrolytic, oxidative and enzymatic degradation (collagenase). Gravimetrical, morphological, mechanical and chemical properties were evaluated. Notably, the hydrogels were relatively resistant to hydrolytic degradation, but degraded rapidly within 21 days (>95% mass loss) under oxidative and collagenase degradation. Oxidative and collagenase degradation rapidly decreased the storage and loss modulus of the hydrogels, and slightly increased their viscous component (tan δ). For each degradation condition, the results suggest different possible degradation pathways associated to the gelatin polypeptide backbone, urea linkages and ester groups. The primary degradation mechanisms for the investigated gelatin based hydrogels are oxidative and enzymatic in nature. The relative hydrolytic stability of the hydrogels should ensure minimal degradation during storage and handling prior to application in surgical theatres.