Pan Yang, Wang Xiahui, Yin Zongning
Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Asian J Pharm Sci. 2019 Mar;14(2):144-153. doi: 10.1016/j.ajps.2018.03.004. Epub 2018 May 16.
To achieve targeted thrombolysis, a targeted delivery system of lumbrokinase (LK) was constructed using RGDfk-conjugated hybrid micelles. Based on the specific affinity of RGDfk to glycoprotein complex of GPⅡb/Ⅲa expressed on the surface of membrane of activated platelet, LK loaded targeted micelles (LKTM) can be delivered to thrombus. The hybrid micelles were composed of polycaprolactone-block-poly (2-(dimethylamino) ethyl methacrylate) (PCL-PDMAEMA), methoxy polyethylene glycol-block- polycaprolactone (mPEG-PCL) and RGDfk conjugated polycaprolactone-block- polyethylene glycol (PCL-PEG-RGDfk). PCL-PDMAEMA was synthesized via ring open polymerization (ROP) and atom transfer radical polymerization (ATRP). PCL-PEG-RGDfk was synthesized via ROP and carbodiimide chemistry. The prepared LKTM was characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). Colloidal stability assay showed the prepared LKTM was stable. Biocompatibility assay was performed to determine the safe concentration range of polymer. The assay of fluorescent distribution demonstrated that LKTM can be efficiently delivered to thrombi . Thrombolysis indicated the thrombolytic potency of LKTM was optimal in all groups. Notably, the laboratory mice treated with LKTM exhibited a significantly shorter tail bleeding time compared to those treated with LK or LK-loaded micelles without RGDfk, which suggested that the targeted delivery of LK using RGDfk-conjugated hybrid micelles effectively reduced the bleeding risk.
为实现靶向溶栓，构建了一种使用RGDfk偶联的混合胶束的蚓激酶（LK）靶向递送系统。基于RGDfk对活化血小板膜表面表达的糖蛋白复合物GPⅡb/Ⅲa的特异性亲和力，负载LK的靶向胶束（LKTM）可被递送至血栓部位。混合胶束由聚己内酯-嵌段-聚（甲基丙烯酸2-（二甲氨基）乙酯）（PCL-PDMAEMA）、甲氧基聚乙二醇-嵌段-聚己内酯（mPEG-PCL）和RGDfk偶联的聚己内酯-嵌段-聚乙二醇（PCL-PEG-RGDfk）组成。PCL-PDMAEMA通过开环聚合（ROP）和原子转移自由基聚合（ATRP）合成。PCL-PEG-RGDfk通过ROP和碳二亚胺化学合成。制备的LKTM通过动态光散射（DLS）和透射电子显微镜（TEM）进行表征。胶体稳定性测定表明所制备的LKTM是稳定的。进行生物相容性测定以确定聚合物的安全浓度范围。荧光分布测定表明LKTM可有效递送至血栓部位。溶栓实验表明LKTM在所有组中的溶栓效力最佳。值得注意的是，与用LK或不含RGDfk的负载LK的胶束治疗的实验室小鼠相比，用LKTM治疗的小鼠尾巴出血时间明显缩短，这表明使用RGDfk偶联的混合胶束靶向递送LK可有效降低出血风险。
