聚天冬氨酸基纤维水凝胶的制备及其释药性能

Preparation of poly( aspartic acid) based fiber hydrogel and its drug release behavior

为开发具有pH值敏感性的药物缓释体系,以pH值敏感型材料聚天冬氨酸(PASP)的中间体聚琥珀酰亚胺(PSI)和热塑性聚氨酯(TPU)为纺丝原料,以5-氟尿嘧啶为药物模型,采用同轴静电纺丝法制备皮芯结构PSI/TPU纤维膜,通过后处理制得PASP/TPU纤维水凝胶载药体系。探究纺丝参数、后处理工艺对纤维膜形貌结构、化学结构、力学性能和溶胀性能的影响,并分析了药物体外释放行为。结果表明:PSI/TPU纤维膜经交联、水解反应可形成PASP/TPU纤维水凝胶,随着同轴纺丝过程中内层TPU流速的增加,PASP/TPU纤维水凝胶的芯层变厚,力学性能增加,溶胀性能变差;PASP/TPU纤维水凝胶具有pH值敏感性,溶胀倍率随pH值升高而增加;PASP/TPU纤维水凝胶的药物体外释放速率随缓释介质pH值的不同而发生变化。

To develop a sustained drug delivery system with pH sensitivity,polysuccinimide(PSI),as the intermediate of pH-sensitive polyaspartic acid(PASP),and thermoplastic polyurethane(TPU)were used to produce electro-spun membranes,with 5-fluorouracil being the model drug.The PSI/TPU fiber membrane with skin-core structure was prepared by coaxial electrospinning.Then PASP/TPU fiber hydrogel based drug-loading system was obtained by post-treatment of PSI/TPU fiber membrane.The effects of electro-spinning parameters and post-treatment on fiber membrane morphology,chemical structure,mechanical properties and swelling properties were analyzed.The drug release behavior of PASP/TPU fiber hydrogel in vitro was studied.The results show that PASP/TPU fiber hydrogel is gained by crosslinking and hydrolysis of PSI/TPU fiber membrane.With the increase of inner layer flow rate during coaxial electrospinning,the core thickness and mechanical properties of PASP/TPU fiber hydrogel increase,while the swelling ratio of PASP/TPU fiber hydrogel decreases.In addition,PASP/TPU fiber hydrogel with pH sensitivity exhibits swelling ratio increase when increasing the pH value.Drug release rate of PASP/TPU nanofiber hydrogel in vitro varies according to the pH value of release medium.