Dual-responsive chitosan/pluronic F-127 composite hydrogels for smart controlled drug delivery

In this study, a dual-responsive composite hydrogels were successfully developed using pH-sensitive chitosan (Cs) and the thermosensitive polymer Pluronic F-127 (PF-127) to explore its potential for drug delivery. The NaOH treatment was employed to modify the hydrogen-bonding interactions within Cs, enabling designed molecular organization prior to its incorporation into PF-127. This strategy effectively tuned the sol gel transition behaviour and viscosity of the system, resulting in an LCST (lower critical solution temperature) of approximately 37 °C ideal for biological applications. In cytotoxicity assays, the PF-127-Cs hydrogel exhibited potent cytotoxic effects at physiological pH (7.4), reducing cell viability, the DOX-loaded PF-127/Cs hydrogel showed significantly enhanced anticancer activity, reducing neuroblastoma cell viability to approximately 10% and 6% at 200 µg mL^-1 after 48 and 72 h, respectively. In contrast, under acidic conditions (pH 5.5), cytotoxicity was markedly reduced, with cell viability remaining around 50% and 46%. This pH-dependent behavior demonstrates that the composite hydrogel not only integrates thermal and pH responsiveness but also provides stable performance and controlled drug-release characteristics. These findings suggest that the hydrogel is a promising material for an injectable, localized drug-delivery platform in cancer therapy, offering a smart and adaptive treatment modality.