pH响应性纤维素纳米纤丝/海藻酸钠基水凝胶的制备及其释药性研究

将纤维素纳米纤丝（CNF）和海藻酸钠（SA）共混，然后在CaCl2的交联作用下，制得具有pH响应性的CNF/SA水凝胶，并通过物理包裹的方式将阿司匹林（ASP）、CNF和SA三者混合均匀后，在CaCl2的交联作用下制得ASP/CNF/SA载药水凝胶，研究ASP在不同pH值环境中的缓释行为。结果表明，ASP/CNF/SA载药水凝胶的载药量为194 mg/g，包封率达49.9%，且药物分子和水凝胶都保持了很好的热稳定性。ASP/CNF/SA载药水凝胶的药物释放具有pH响应性，药物分子的释放速率随着环境pH值的升高而加快。在p H值为1.5～11.0的缓释条件下，药物的释放行为均为溶蚀作用。

Study on Preparation and Drug Release of pH-responsive Cellulose Nanofibril/ Sodium Alginate-based Hydrogel

A pH-responsive cellulose nanofibril(CNF)/sodium alginate(SA)hydrogel was prepared by blending CNF with SA using CaCl₂as cross-linking agent.The aspirin(ASP)/CNF/SA drug-loaded hydrogel was further prepared through physical encapsulation by uniformly mixing ASP,CNF,and SA with subsequent cross-linking action of CaCl₂.The controlled-release behavior of ASP was studied in different pH value environment.The results showed that the drug loading and encapsulation efficiency of ASP/CNF/SA drug-loaded hydrogel was 194 mg/g and 49.9%,respectively,and both drug molecules and hydrogels exhibited good thermal stability.It was further demonstrated that the drug release of ASP/CNF/SA drug-loaded hydrogel was pH-responsive,showing accelerated releasing rate with increase in environmental pH value.The drug release behavior presented as dissolution at pH value of 1.5~11.0.