以叶酸为靶向基团，将其连接到羧甲基壳聚糖（CMCS）上，制得偶联叶酸的羧甲基壳聚糖（FCMC），在FCMC溶液中碳酸钙自组装形成一种具有靶向性的FCMC/CaCO₃混合纳米球。同时对纳米球结构进行表征，并对比了修饰叶酸前后混合纳米粒理化性能。在此基础上，将亲水性药物二甲双胍作为模型药物，对2种载体的包封率、载药量及释放行为进行了对比研究。结果表明，FCMC/CaCO₃混合纳米球大小均一，分散性良好，碳酸钙的引入使得纳米球对亲水性药物包封率较高，该纳米球对药物的释放具有较好的pH敏感性和缓控释放能力，是潜在的智能药物给药系统基质材料。

Folate as a target group is attached onto carboxymethyl chitosan (CMCS) to obtain folate coupled carboxymethyl chitosan (FCMC).Then a kind of targeted FCMC/CaCO₃ hybrid nanospheres is formed by self-assembly of calcium carbonate in FCMC solution.The structure of as-prepared nanospheres is characterized and the physicochemical properties of the hybrid nanospheres before and after modification by folate are compared.Besides,the influences of folate modification on the drug loading amount,the encapsulation efficiency and the release behavior of the hybrid nanospheres are also analyzed with hydrophilic metformin as a model drug.The results show that FCMC/CaCO₃ hybrid nanospheres have uniform size and good dispersion performance and the addition of calcium carbonate can help to increase entrapment efficiency for hydrophilic drug.The prepared nanospheres have a good pH-sensitivity and high controlled release ability for the release of drug,which are potential substrate material for smart drug delivery system.

刘举慧(1993-),男,硕士研究生,研究方向为功能高分子材料,872721187@qq.com