Abstract
Smart and responsive drug delivery systems are key to next-generation biomedical therapies, offering precision and targeted action. This study reports the development of a novel biodegradable, pH-sensitive, and highly swellable hydrogel composed of locust bean gum, polyvinylpyrrolidone, chitosan, and (3-aminopropyl)triethoxysilane (APTES) as a crosslinker, incorporating Mallotus philippensis (MP) extract to enhance bioactivity. Structural, thermal, and morphological properties were characterized by FT-IR, TGA, and SEM. Swelling behaviour confirmed pH responsiveness, while gel content and biodegradation assays verified stability and degradability. Contact angle and porosity analyses showed favourable surface wettability and porous architecture. Antimicrobial activity demonstrated inhibition of bacterial strains, with cytocompatibility supported by brine shrimp lethality assay. Levofloxacin (LVX) was loaded into hydrogels with and without MP extract, achieving drug encapsulation efficiencies of 89% and 85%, respectively, with a slight decrease attributed to phytoconstituents interactions affecting network density. Drug release profiling at pH 5.5, 6.5, and 7.4 showed sustained release exceeding 80% within 3 h per USP standards. LPC-3AT and LPC-3AT-MP 400 released 87.04% and 94.5% LVX over 180 min in PBS, following a non-Fickian (anomalous) transport mechanism (diffusion exponent n = 0.62). These findings highlight the hydrogel's promise as an injectable platform for controlled drug delivery and advanced biomedical applications.