基于壳聚糖的可控缓释型微针制备与性能评价

在临床应用上，一种能够持续递送药物的微针(microneedle,MN)系统对于一些疫苗、激素类药物的递送具有重要价值。本文研究设计了一种基于壳聚糖的可控缓释型微针阵列(PVA/CS-MN)，将微针贴片与药物相结合用于药物的可控长效缓释。重点研究了PVA/CS-MN的制备优化工艺，并对MN阵列外观形貌、力学性能、溶解与溶胀性能以及体外刺入性能进行了表征。实验结果表明，使用最优工艺制备的PVA/CS-MN具有良好的形貌以及力学性能，可以顺利在皮肤上打开微通道，并实现可控的溶解与溶胀功能。同时，体外透皮扩散实验表明，以抗坏血酸(l-ascorbic acid)为模型药物制备的Vc-PVA/CS-MN在1 h内即释放了约57%的药物，随后12 h内缓慢释放了约66.7%的药物，7 d后最终释放了92%的药物。PVA/CS-MN具备可控的缓释特性以及优良的药物递送效率，为药物的持续透皮递送提供了一个新选择。

Preparation and performance evaluation of controlled-release chitosan-based microneedles

In clinical application, a microneedle system that continuously delivers drugs is of great value for the delivery of some vaccines and hormone drugs. In this study, a controlled-release chitosan-based microneedle array (PVA/CS-MN) was designed, combining microneedle patches with drugs for controlled-release of drugs. Here we report the optimization of the preparation process of PVA/CS-MN. The appearance, morphology, mechanical properties, dissolution and swelling properties, and in vitro penetration properties of the MN arrays were characterized. The PVA/CS-MN prepared by the optimal process showed good morphology and mechanical properties. PVA/CS-MN can smoothly open microchannels on the skin and achieve controllable dissolution and swelling functions. Ascorbic acid (l-ascorbic acid) was used as a model drug to prepare a Vc-PVA/CS-MN. In vitro transdermal diffusion experiments showed that the Vc-PVA/CS-MN released about 57% of the drug within 1 h. About 66.7% of the drug was slowly released within 12 h, and a total of 92% of the drug was released after 7 days. The controllable sustained-release properties and excellent drug delivery efficiency of PVA/CS-MN provide a new option for sustained transdermal drug delivery.