APRPG-modified nanoliposome loaded with miR-146a-5p inhibitor suppressed choroidal neovascularization by targeting endothelial cells.

INTRODUCTION: To explore the effect and mechanism of APRPG-modified nanoliposomes loaded with miR-146a-5p inhibitor (ANL-miR-146a-5p inhibitor) on endothelial cell proliferation, migration, tube formation, and choroidal neovascularization (CNV) in mice. METHODS: ANL-miR-146a-5p inhibitors were generated by thin film hydration; in vitro, endothelial cell uptake experiment was used to detect the targeting effect of ANL-miR-146a-5p inhibitor; endothelial cells proliferation, migration, and tube formation were detected, respectively, by CCK8 assay, scratch assay, and Matrigel tube formation assay. In vivo, the mice CNV models were established by 810 nm laser photocoagulation. Mice choroidal flatmounts were performed to detect the volume of CNV after intravitreal injection of L-miR-146a-5p inhibitor, ANL-miR-146a-5p inhibitor, or normal saline; the vascular endothelial growth factor (VEGF) expression of mice choroidal tissue was detected by ELISA; HE section and electrophysiology (ERG) were performed to check the toxicity of ANL-miR-146a-5p inhibitor on mice retina. RESULTS: ANL are targeted to endothelial cells and are more targeted in inflammatory environment. At the same concentration, ANL-miR-146a-5p inhibitor's ability to inhibit endothelial cell proliferation, migration, tube formation, CNV formation, and VEGF expression is better than L-miR-146a-5p inhibitor (p < 0.05); ANL-miR-146a-5p inhibitor had no toxicity on the structure of mouse retina; ANL-miR-146a-5p inhibitor had no toxicity on the a-wave and b-wave amplitudes and b-wave implicit times (p > 0.05). CONCLUSIONS: ANL-miR-146a-5p inhibitor can more effectively down-regulate the expression level of VEGF through its targeting to endothelial cells, thereby more effectively inhibiting endothelial cell proliferation, migration, tube formation, and mice CNV formation.

Triptolide-nanoliposome-APRPG, a novel sustained-release drug delivery system targeting vascular endothelial cells, enhances the inhibitory effects of triptolide on laser-induced choroidal neovascularization.

PURPOSE: To investigate whether triptolide-nanoliposome-APRPG (TP-nanolip-APRPG), a novel sustained-release nano-drug delivery system that targets vascular endothelial cells, could enhance the inhibition of triptolide (TP) on laser-induced choroidal neovascularization (CNV). METHODS: TP was encapsulated with or without APRPG (Ala-Pro-Arg-Pro-Gly) peptide-modified nanoliposomes. CNV was induced by laser photocoagulation in C57BL/6J mice. One microliter of 10 µg free TP monomer, TP-nanolip containing 10 µg TP, TP-nanolip-APRPG containing 10 µg TP, or an identical volume of PBS was intravitreally injected in mice immediately after laser photocoagulation. Seven days after laser photocoagulation, CNV volumes were calculated in each group. Infiltration of M2 macrophages as well as protein levels of vascular endothelial growth factor (VEGF) and inflammatory factors including ICAM-1 and MCP-1 in the RPE-choroid complex were determined. In vitro assays for cell proliferation, migration, and tube formation were also performed. RESULTS: TP-nanolip-APRPG was successfully synthesized and exhibited good TP delivery and enhanced the cellular uptake of TP in vitro. In vitro studies showed that TP-nanolip-APRPG was a better inhibitor of cell proliferation (31.34 ±â€¯3.89 % vs 41.25 ±â€¯4.67 % vs 53.55 ±â€¯5.76 %), migration (62.60 ±â€¯8.88 vs 104.60 ±â€¯13.32 vs 147.00 ±â€¯13.15), and tube formation (681.26 ±â€¯108.15 vs 926.75 ±â€¯54.01 vs 1189.84 ±â€¯157.14) than TP-nanolip or free TP (all P < 0.05). Intravitreal injections of free TP (77588.10±7719.28 µm3), TP-nanolip (64628.23 ±â€¯5857.96 µm3), and TP-nanolip-APRPG (50880.34 ±â€¯6606.56 µm3) inhibited the development of CNV compared with the PBS control group (120338.07 ±â€¯17428.90 µm3) (P < 0.01, n=6). TP-nanolip-APRPG and TP-nanolip significantly down-regulated the protein levels of VEGF (152.76±19.55 vs 182.24±19.98 vs 208.55±21.93 pg/mg total protein) and inflammatory factors including ICAM-1 (61.69±3.49 vs 72.04±3.49 vs 81.92±4.09 ng/mg total protein) and MCP-1 (40.14±3.50 vs 50.75±4.18 vs 60.27±5.23 pg/mg total protein) compared with the free TP monomer group (all P < 0.05, n=8), which paralleled the decreased infiltration of M2 macrophages in the CNV lesions. Moreover, no influence on retinal morphology and function was observed before or after treatment in each group (P > 0.05, n=6). CONCLUSIONS: TP-nanolip-APRPG, a novel sustained-release drug delivery system targeting endothelial cells of CNV lesions, could enhance TP inhibition of the development of CNV without toxicity in the retina, suggesting therapeutic potential for CNV-related diseases in future clinical practice.