Neutral-Condition Synthesis of Gelatin-Enhanced Starch Hydrogels: Balancing Mechanical Integrity and Biocompatibility

Abstract

This study explores the graft copolymerization of starch gels prepared under neutral conditions using the thermal initiator 4,4′-azobis (4-cyanovaleric acid) (ACVA), with particular emphasis on the role of gelatin incorporation. Neutral conditions were chosen to maintain the physical and chemical integrity of the starch gels, providing a biocompatible and environmentally sustainable alternative to traditional alkaline processes. Hydrogels with and without gelatin were synthesized and comprehensively characterized in terms of their mechanical and biological properties. Fourier-transform infrared spectroscopy (FT-IR) identified distinct chemical modifications, particularly the formation of an amide-II bond due to gelatin incorporation. Rheological tests demonstrated that gelatin enhanced structural stability, rigidity, and elasticity, while puncture tests confirmed improvements in mechanical strength. However, cell viability tests revealed a decline in biocompatibility at higher gelatin concentrations, likely due to aggregation and matrix inhomogeneity. These findings underscore the importance of balancing mechanical strength and biocompatibility when designing hydrogels for biomedical applications. This work contributes to the development of advanced starch-based hydrogels by providing a framework for optimizing both structural integrity and biological compatibility.