Dual Cross-linked Biodegradable Polyelectrolyte Hydrogel Actuator for Bi-Directional pH-Responsive Drug Release

Abstract

Here, we present dual cross-linked hydrogel with bi-directional pH sensitivity for controlled drug release. The hydrogel was strategically developed with oppositely charged polyelectrolytes namely; gelatin and carboxymethyl cellulose (CMC). This hydrogel was stabilized by adding a cross-linking agent; 1,4-butanediol diglycidyl ether (BDDE). The prepared hydrogel senses lower as well as the higher environmental pH and swells to deliver the drug at the intended application site. The novelty of the proposed hydrogel resides in its reversible sensitivity to pH for on-demand drug delivery both in acidic environment (e.g. tumor site) and basic environment (e.g. chronic wounds). Neomycin sulphate; a common drug effective against chronic wounds and cancer, could be entrapped within the hydrogel with excellent entrapment efficiency (~84%). Entrapped neomycin sulphate is released on-demand in acidic (pH~6) as well as basic (pH~9) medium. This polyelectrolytesbased hydrogel gets bio-degraded within 21 days and exhibits remarkable biocompatibility. Therefore, thus prepared hydrogel may be a promising pH-responsive biomaterials for drug delivery applications.