Silane-crosslinked graphene oxide reinforced chitosan/sodium alginate hydrogel for controlled release of insulin

Abstract

Diabetic patients require regular insulin administration to maintain standard glucose. However, conventional injection procedures frequently lead to low patient compliance and an elevated risk of hypoglycemia. To overcome these challenges, a hydrogel-based system has been developed, with preliminary findings suggesting its potential for sustained insulin release while exhibiting pH-responsiveness and biocompatibility. A hydrogel composed of chitosan, sodium alginate, and graphene oxide (GO) crosslinked with tetra ethoxy silane (TEOS) was synthesized via the solvent casting method. The hydrogel's structural and physicochemical properties were determined by various analytical techniques. Swelling behavior, gel fraction, antimicrobial studies, insulin encapsulation efficacy, and in vitro release were analyzed at different pH. The hydrogel demonstrated higher encapsulation efficacy of 94% and pH-responsive swelling behavior with maximum swelling of 100% at pH 7. This hydrogel exhibited complete crosslinking, ensuring robust structural integrity and prolonged drug release as indicated by gel fraction analysis (almost 96–100%). Initially, in vitro studies were carried out to evaluate the insulin release profile. This study indicated that insulin release is pH-dependent, and it is a maximum of almost 98% at pH 6.8. SEM revealed the well-developed porous and spherical morphology. However, TGA and DSC confirmed its excellent thermal stability. Additionally, CSGI hydrogel exhibited a strong antimicrobial effect.