新型生物纳米载药系统在糖尿病视网膜病变治疗中的研究

Diabetic retinopathy (DR) is the major blinding eye disease worldwide, mainly manifested by neovascularization, enhanced microvascular permeability and vitreous in hemorrhage, etc. Currently there is no treatment available in the clinic. Anti-angiogenesis therapy based on anti-VEGF is one of the most promising therapies. However, low systemic delivery efficiency, high cost and side effects caused by intravitreal injection limit the clinical adoption of anti-VEGF drugs. Previously our group demonstrated successfully that exosome, a biological nanoparticle secreted by most cells, can be used as a delivery vehicle for a functional repair protein to mediate the repair function of target cells effectively. And our previous work showed that a novel exosome anchor peptide CP05 was screened successfully, which can realize the easy and high-efficiency loading of exosome. Based on these results, in this proposal, we plan to investigate the feasibility and therapeutic potential of exosome with the anchor peptide CP05, as a novel biological nanoparticle drug delivery system of the anti-VEGF peptide KV11, for the treatment of DR in vitro and in vivo. Meanwhile, new injection methods will be explored to provide new strategies and methods for improving the targeted delivery of anti-VEGF drugs in retina. Moreover, further studies on underlying mechanisms will provide theoretical guidance for the application of this novel biological nanoparticle drug delivery system in ophthalmology and other related diseases.

糖尿病视网膜病变（DR）是世界范围内的主要致盲眼病，表现为眼底血管增生、渗透性增强和玻璃体出血等。临床现有治疗手段难以治愈。以抗VEGF为主的抗血管新生治疗是最具应用前景的治疗方法之一，但抗VEGF药物存在系统运输效率低、成本高、玻璃体腔内注射药物会产生副作用等局限性。本课题组前期工作中，成功利用细胞分泌的一种纳米级囊泡结构-exosome，运输膜修复功能蛋白，有效介导靶细胞损伤修复功能。并筛选到新型exosome锚定肽CP05，实现exosome简单高效修饰。因此，本项目针对抗VEGF药物运输效率低的问题，在DR模型上，系统测试负载抗VEGF短肽KV11的新型生物纳米载药系统在DR治疗中的可行性和应用潜力，同时探索新的注射途径，为提高抗VEGF治疗药物的视网膜靶向运输提供新的策略和方法，并通过对其作用机理的阐释，以期为该新型生物纳米载药系统在眼科其他相关疾病中的应用提供理论指导。

糖尿病视网膜病变（DR）是世界范围内的主要致盲眼病，表现为眼底血管增生、渗透性增强和玻璃体出血等。临床现有治疗手段难以治愈。以抗VEGF为主的抗血管新生治疗是最具应用前景的治疗方法之一，但抗VEGF药物存在系统运输效率低、成本高、玻璃体腔内注射药物会产生副作用等局限性。为实现药物在视网膜内的高效运输，本项目将抗血管生成肽KV11，利用前期工作中筛选到的新型exosome锚定肽CP05，连接到血管内皮细胞分泌的exosome上，得到新型生物纳米载药系统EXOKV11，可以高效负载抗血管生成肽KV11至exosome表面。本研究在血管内皮细胞以及小鼠中测试了药物运输效率，通过氧诱导视网膜病变（OIR）模型和VEGF注射模型测试了EXOKV11对新生血管形成、内皮细胞增殖和血管通透性的影响并对其安全性进行了评估。通过体外实验验证了EXOKV11的作用机制并分析了EXOKV11对内皮细胞增殖、迁移和发芽的影响。结果显示：利用exosome-CP05负载系统，抗血管生成肽KV11可以被有效地运送至视网膜血管。在OIR模型和VEGF注射模型中，EXOKV11均比单独使用KV11更显著抑制血管新生和血管渗漏，并且治疗效果与玻璃体腔注射VEGF-trap效果相当。安全性测试的结果显示EXOKV11未对视网膜组织和主要器官产生毒副作用。在机制上，EXOKV11比KV11表现出更强的抑制VEGF下游信号通路的作用，同时更为显著地抑制了内皮细胞的增殖、迁移和出芽。综上，本研究针对抗VEGF药物运输效率低的问题，利用exosome-CP05运载抗血管生成肽KV11，实现了视网膜内高效的药物运输，为提高抗VEGF治疗药物的视网膜靶向运输提供新的方法，也为糖尿病视网膜病变及其他相关疾病的治疗提供一种新的策略。