Fabrication of pH-responsive hydrogel beads based on coumaric acid–grafted aminated gellan gum and alginate for colon-targeted delivery of resveratrol

Abstract

This study presents a novel polymeric delivery system for nutraceuticals, specifically resveratrol, using a pH-sensitive method for colon-specific release. The polymeric carrier system consists of aminated gellan gum (AGG) conjugated with coumaric acid (CA) and alginate (Alg), forming hydrogel beads that protect the encapsulated components from the acidic gastric environment while enabling targeted release in the small intestine. Experimental findings demonstrate a pronounced pH-responsive swelling behaviour and drug release of the hydrogel beads, effectively restraining the release of resveratrol at gastric pH and facilitating a controlled release at the intestinal pH of 7.4. The release exponents from the kinetic analysis using different models indicates a non-Fickian diffusion mechanism governing the release of resveratrol from the polymer matrix. Furthermore, the synthesised gel beads exhibit high biocompatibility, as demonstrated with the Caco-2 cell line. Notably, the phenol-grafted polymer system for the delivery of nutraceutical has not been reported previously and this study marks the first report. The developed hydrogel beads hold significant promise as an effective drug delivery vehicle for nutraceutical applications, potentially improving the therapeutic efficacy of encapsulated compounds.

Graphical abstract