中文摘要：

利用溶剂蒸发法制备载有5-氟尿嘧啶（5-FU）可生物降解的聚乙丙交酯（PLGA）植入膜片,着重讨论了在降解过程中,聚合物的重均分子量（Mw）、数均分子量（Mn）和膜片的内部形态变化规律.通过在PLGA膜片表面分别涂层w=23%的凝胶溶液和PLGA（丙交酯∶乙交酯=50∶50,摩尔比）溶液对膜片进行改性,考察改性后的膜片对5-FU释放速率的影响规律.用零级释放和一级释放方程对5-FU释放曲线的各个阶段进行描述,通过非线性拟合得到了相关的释放系数,并且提出5-FU的释放机理.结果表明：与未改性的膜片相比,涂有明胶的PLGA膜片5-FU首次释放率从50%降低到20%,释放曲线分为两个阶段,前阶段的药物释放由凝胶降解控制,后阶段为零级释放;膜片涂有PLGA后阻止了突然释放率,且两个阶段5-FU的释放曲线均符合零级释放.

英文摘要：

Biodegradable PLGA laminar films loaded with 5-FU were prepared by a solvent-casting method. Mw, Mn and the morphology of the films were determined during the polymer degradation. In vitro drug release, zero-order equation and Peppas＇ equation were respectively used to describe the different phases in 5-FU release from the polymer-films and release parameters were estimated by nonlinear regression analysis. The possible mechanism of 5-FU release from the unmodified and modified polymer-films was proposed. The 5-FU release rate from PLGA implants was regulated by dispersing the films in 23% w/v gelatin solution and PLGA （50 ： 50） solution. The results show the gelatin coated on the films reduces the burst release from 50% to 20% compared with the unmodified films two parts, the former is controlled by gelatin degradation, the latte the films coated by PLGA （50 ： 50） successfully prevent the burst follow the zero-order kinetics within initial 14days. , and the release profile is divided into r follows the zero-release. Moreover, release and the 5-FU release profiles