具有pH和还原双重敏感性壳聚糖纳米微凝胶的制备及其控释性能

以含双硫键的N,N-二（3-羧基丙烯酰）胱胺(BCCy)为交联剂，在1-（3-二甲氨基丙基）-3-乙基碳二亚胺盐酸盐/N-羟基琥珀酰亚胺（EDC/NHS）的催化下将壳聚糖（CS）交联，在水溶液中制备了纳米微凝胶。通过红外、元素分析、纳米粒度仪和扫描电镜等对其结构和形貌进行了表征，考察了pH和还原性环境对粒径的影响。对抗癌药物喜树碱（CPT）进行了负载，考察了载药粒子在还原性环境中对药物的控释性能。结果表明：随交联剂用量的增加，纳米微凝胶的粒径减小。该纳米微凝胶具有较好的生物相容性、较显著的pH和还原敏感性。

Preparations and Drug Controlled Release of pH and Reduction Dual Sensitive Nano Gels Based on Chitosan

Chitosan(CS) nano gels were prepared using N,N-bis(3-carboxy-acryloyl) cystamine (BCCy) containing disulfide bonds as crosslinker and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-Hydroxysuccinimide (EDC/NHS) as catalyst in aqueous solution. The structures and morphologies of the nano gels were characterized by FT-IR, elemental analysis, nano particle size analyzer and SEM. The effect of pH and reduction environment on particle size was studied. As a model drug, camptothecin(CPT) was loaded on the nano gels for investigating the controlled release. Results showed that the particle size decreased as the amount of crosslinking agent increased. The nano gels had good biocompatibility and significant pH and reduction sensitivities.