Development of Vitreal Drug Delivery System with Biodegradable Polymeric Scleral Plug

我们已经开发了一种新的药物输送系统，在玻璃体中使用的生物可降解聚合物。评价植入睫状体平坦部的由生物可降解聚合物制成的巩膜塞，以确定其控制药物玻璃体内释放的能力。用聚乳酸-羟基乙酸制备含有更昔洛韦、5-氟尿嘧啶和氟康唑等多种药物的巩膜塞。使用兔和猴在体外以及体内研究了从塞的药物释放。还在兔和猴中评价了巩膜塞的生物相容性。体外研究表明，这些塞子可以释放药物数周到数月。体内研究表明，在植入栓塞后的一段时间内，药物浓度保持在有效范围内。临床及组织学检查均未见明显不良反应，提示生物可降解聚合物巩膜塞是一种很有前途的玻璃体内药物控释系统。

We have developed a novel drug delivery system in the vitreous body with the use of biodegradable polymers. Scleral plugs made of biodegradable polymers implanted at the pars plana were evaluated to determine its ability to control the intravitreal release of drugs. Scleral plugs containing various drugs, such as ganciclovir, 5-fluorouracil, and fluconazol, were prepared with poly(lactic-glycolic acid). Drug release from the plugs was studied in vitro as well as in vivo using rabbits and monkeys. Biocompatibility of the scleral plugs was also evaluated in rabbits and monkeys. The in vitro studies showed the plugs released the drugs for several weeks to several months. The in vivo studies showed the drug concentrations were maintained at effective ranges for certain period of time after the implantation of the plugs. No significant adverse reactions were observed in the ocular tissues both clinically and histologically.These results suggested that scleral plugs of biodegradable polymers are promising for a controlled drug delivery system in the vitreous.