Preparation and in vitro evaluation of pH and glutathione dual-responsive drug delivery system based on sodium carboxymethyl cellulose.

Stimuli-responsive drug delivery systems based on sodium carboxymethyl cellulose (NaCMC) for drug release encounter inherent challenges. In this research, a novel pH and glutathione (GSH) dual-responsive system, CPT-S-S-NaCMC@ZIF-8/SP-PEG, was constructed. Firstly, the prodrug CPT-S-S-OH was synthesized and combined with NaCMC to form GSH-responsive micelles CPT-S-S-NaCMC, significantly enhancing the drug loading and grafting rates to 63.79 % and 91.99 %, respectively. Subsequently, zinc ions and dimethylimidazole can be assembled into porous materials (ZIF-8) on the surface of the micelles. This system exhibits dual pH-GSH responsiveness and effectively reduces the drug release from 84.76 % to 28.71 % at pH = 7.4. Moreover, incorporating pH-responsive spiropyran (SP)-modified polyethylene glycol (PEG) can reduce drug leakage to 16.09 % at pH = 7.4 and exhibit good fluorescence intensity at 722 nm.