A pH and redox dual-responsive composite hydrogel was developed, which was formed from triblock copolymer PEG-SS-PCL-SS-PEG and Ag/AgO/carboxymethyl chitosan (CMCS) hydrogel inclusion complexes. Dithiodipropionic acid and poly(ethylene glycol) (PEG) were esterified to synthesize a hydrophilic segment PEG-SS-COOH polymer containing a disulfide bond, and ε-caprolactone is ring-opened in Ar atmosphere to obtain a hydrophobic segment HO-PCL-OH homopolymer. The PEG-SS-PCL-SS-PEG triblock polymers were prepared by reacting the two in a certain ratio, and spontaneously assembled into micelles in an aqueous solution. Ag/AgO/CMCS composite hydrogels with a pH and redox dual-responsive were prepared by dispersing aspirin-loaded micelles into an Ag/AgO/CMCS hydrogel network loaded with another hydrophilic drug ciprofloxacin hydrochloride (CIP). The results showed that the micelles had redox sensitivity due to the insertion of disulfide bonds, and had certain stability within 24 h without reducing substances. In vitro simulated drug release test of composite hydrogel showed that the hydrogel network swelled or degraded, the micelles were lysed, and the release of the drug was triggered when the composite hydrogels were exposed to the micro-environment with high pH or high DTT concentration. Therefore, this composite hydrogel could potentially be one of the candidate materials for the dual drug delivery system.

开发了一种 pH 和氧化还原双响应复合水凝胶，它由三嵌段共聚物 PEG-SS-PCL-SS-PEG 和 Ag/AgO/羧甲基壳聚糖 (CMCS) 水凝胶包合物形成。二硫代二丙酸与聚乙二醇(PEG)经酯化合成含有二硫键的亲水链段PEG-SS-COOH聚合物，ε-己内酯在Ar气氛下开环得到疏水链段HO-PCL-OH均聚物。PEG-SS-PCL-SS-PEG三嵌段聚合物由两者按一定比例反应制备，并在水溶液中自发组装成胶束。通过将载有阿司匹林的胶束分散到载有另一种亲水性药物盐酸环丙沙​​星 (CIP) 的 Ag/AgO/CMCS 水凝胶网络中，制备了具有 pH 值和氧化还原双重响应的 Ag/AgO/CMCS 复合水凝胶。复合水凝胶体外模拟释药试验表明，当复合水凝胶暴露于高pH值或高DTT浓度的微环境中时，水凝胶网络膨胀或降解，胶束溶解，触发药物释放。因此，这种复合水凝胶有可能成为双重给药系统的候选材料之一。