Li Tao, Zhang Ming, Han Yong, Zhang Hong, Xu Lingjuan, Xiang Yan
Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
J Huazhong Univ Sci Technolog Med Sci. 2010 Dec;30(6):798-803. doi: 10.1007/s11596-010-0661-8. Epub 2010 Dec 22.
Pigment epithelium derived factor (PEDF) has been proven to be an effective drug for the treatment of choroidal neovascularization (CNV). However, the lack of ideal administration route is the biggest bottleneck preventing PEDF from wider clinical use. In this study, we developed a novel PEDF-carrying system which employed immuno-nano-liposomes (INLs) under ultrasound exposure. PEDF-loaded INLs were prepared by conjugating nanoliposomes to the peptide ATWLPPR specifically targeting the receptor-2 for vascular endothelial growth factor (VEGFR-2) and reversely encapsuling PEDF. RF/6A cells were incubated with PEDF-loaded INLs. CNV models of BN rats were injected with PEDF-loaded INLs. MTT assay was used to evaluate the cytotoxicity of the INLs on RF/6A cells. Flow cytometry was conducted to detect the apoptotic rate of cells. Laser scanning confocal microscopy was employed to observe the binding and transmitting process of PEDF-loaded INLs and to calculate the area of CNV in the rat model. The results showed that the PEDF-loaded INLs could exclusively bind to CNV but not to the normal choroidal vessels. The CNV area was significantly decreased in PEDF treatment groups in comparison with control group (P<0.05). Moreover, PEDF-loaded INLs exposed under ultrasound were more efficient in reducing the CNV area (P<0.05). It was concluded that INLs in combination with ultrasonic exposure can transmit PEDF into cytoplasma with high specificity and efficiency, which strengthens the inhibitory effects of PEDF on CNV and reduces its side effects. PEDF-loaded INLs possibly represent a new treatment paradigm for patients with ocular neovascularization.
色素上皮衍生因子（PEDF）已被证明是治疗脉络膜新生血管（CNV）的有效药物。然而，缺乏理想的给药途径是阻碍PEDF更广泛临床应用的最大瓶颈。在本研究中，我们开发了一种新型的PEDF携带系统，该系统在超声照射下采用免疫纳米脂质体（INLs）。通过将纳米脂质体与特异性靶向血管内皮生长因子受体-2（VEGFR-2）的肽ATWLPPR偶联并反向包裹PEDF来制备负载PEDF的INLs。用负载PEDF的INLs孵育RF/6A细胞。给BN大鼠的CNV模型注射负载PEDF的INLs。采用MTT法评估INLs对RF/6A细胞的细胞毒性。进行流式细胞术检测细胞凋亡率。利用激光扫描共聚焦显微镜观察负载PEDF的INLs的结合和传递过程，并计算大鼠模型中CNV的面积。结果表明，负载PEDF的INLs可特异性地与CNV结合，而不与正常脉络膜血管结合。与对照组相比，PEDF治疗组的CNV面积显著减小（P<0.05）。此外，超声照射下的负载PEDF的INLs在减小CNV面积方面更有效（P<0.05）。得出的结论是，INLs与超声照射相结合可将PEDF高效、特异性地传递到细胞质中，增强了PEDF对CNV的抑制作用并降低了其副作用。负载PEDF的INLs可能为眼部新生血管疾病患者提供一种新的治疗模式。
