RESUMO
PURPOSE: To explore the possibility of the PEGylated liposome-protamine-hyaluronic acid nanoparticles (PEG-LPH-NP) loaded with siRNA (PEG-LPH-NP-S) in ARPE19 cells and a laser-induced rat model for the treatment of choroidal neovascularization (CNV). METHODS: PEG-LPH-NP-S was characterized by dynamic light scattering and transmission electron microscopy (TEM). The encapsulation efficiency of siRNA in PEG-LPH-NP was analyzed by ultracentrifugation, whereas the protection of siRNA by PEG-LPH-NP was evaluated by electrophoresis. Human RPE cells (ARPE19) were used as the cell model for the studies of cellular uptake and the inhibition of VEGFR1 expression, visualized by a laser scanning confocal microscope. The area of CNV in the laser-induced rat model after intravitreous injection was measured. The distribution of the lipid nanoparticles in the retina after intravitreous administration was investigated by fluorescence microscopy. Finally, the TUNEL test and morphologic observation of the retina were conducted. RESULTS: It was indicated that PEG-LPH-NP-S was approximately 132 nm in particle size with a positive charge of approximately 20 mV, whereas the encapsulation efficiency of siRNA in PEG-LPH-NP was >95%. PEG-LPH-NP could protect the siRNA load and could facilitate the intracellular delivery of fluorescein-labeled siRNA to ARPE19 cells. VEGFR1 expression in ARPE19 cells could be inhibited, and the CNV area in the murine model could be reduced more effectively by PEG-LPH-NP-S compared with naked siRNA and by PEG-LPH-NP with negative siRNA. It seems that the toxicity of PEG-LPH-NP-S on the rat retina is low, based on the results of TUNEL testing and morphologic observation. CONCLUSIONS: PEG-LPH-NP may be a promising lipid nanoparticle system for the siRNA treatment of CNV.
Assuntos
Neovascularização de Coroide/terapia , Nanopartículas , RNA Interferente Pequeno/administração & dosagem , Epitélio Pigmentado da Retina/efeitos dos fármacos , Animais , Apoptose , Células Cultivadas , Neovascularização de Coroide/metabolismo , Neovascularização de Coroide/patologia , Modelos Animais de Doenças , Humanos , Marcação In Situ das Extremidades Cortadas , Injeções Intravítreas , Lipossomos , Masculino , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , RNA Interferente Pequeno/farmacocinética , Ratos , Ratos Endogâmicos BN , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/ultraestrutura , Resultado do Tratamento , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Adulto JovemRESUMO
AIM: To explore the effect of Simvastatin on the regeneration of sciatic nerve with crush injury in rats. METHODS: Animals were randomized into the following experimental groups: Simvastatin-treated, vehicle and sham-operated groups. Sciatic nerves with crush injury were performed. After surgery, the functional evaluation of nerve recovery, electrophysiologic assessment, histological assessment, serum IL-6 and lipid were performed. RESULTS: The toe spread index of Simvastatin-treated rats after operation was higher significantly than vehicle rats at 5 d and 8 d (P<0.05). CMAP was higher and NCV was faster (P < 0.05). The serum IL-6 at 5 d of post-operation was significant lower (P < 0.05). Total serum cholesterol of Simvastatin-treated animals was higher than that of other animals (P < 0.05) at 2 weeks of post-operation. The histological analysis showed that the numbers of myelinated axons and the thickness of myelin sheath of Simvastatin-treated crush injury animals at 4 weeks of post-operation were more than that of vehicle animals. CONCLUSION: The present study showed that Simvastatin could promote the regeneration of the sciatic nerve after crush injury in rats, partly through inhibiting immune and inflammatory responses and making the balance of serum cholesterol during these processes.
