뇌졸중 유전자치료를 위한 덱사메타손이 봉입된 RV 펩타이드 마이셀의 개발

Abstract

R3V6 peptides which are composed of 3 arginines and 6 valines, formed self assembled micelles in aqueous phase with hydrophobic cores of valines and cationic surface of arginines. Dye quenching assays showed that hydrophobic fluorescent dye 5-dodecanoylaminofluorescein(DAF) interacted with and was loaded into the hydrophobic core of the micelles. In this study, dexamethasone was loaded as hydrophobic anti-inflammatory drug into the core of the peptide micelles. Dexamethasone loaded R3V6 peptides (R3V6-Dexamethasone) were also evaluated as a gene carrier as well as a drug carrier. In vitro transfection assay showed that R3V6-Dexamethasone had higher gene delivery efficiency than R3V6 peptides. It may be that hydrophobic dexamethasone stabilizes the micelle structure of R3V6 peptide by forming strong hydrophobic cores. Furthermore, R3V6-Dexamethasone reduced inflammatory cytokine level more efficiently than dexamethasone in lipopolysaccharides (LPS)-induced Raw264.7 cells.R3V6-Dexamethasone did not show any cytotoxicity in human embryonic kidney 293 (HEK 293) cells. Focal brain ischemia model was produced by middle cerebral artery occlusion (MCAO). A heme oxygenase-1 (HO-1) expression plasmid, pEpo-SV-HO-1, was complexed with R3V6-Dexamethasone. pEpo-SV-HO-1/R3V6-Dexamethasone complex was injected into the brain 1 hr prior to MCAO. Twenty four hours after ischemia-reperfusion, brain infarct size was measured by TTC staining. The results showed that the infarct size was reduced by the delivery of pEpo-SV-HO-1/R3V6-Dexamethasone complex. The results suggest that R3V6-Dexamethasone is useful in HO-1 gene delivery and stroke gene therapy with high transfection efficiency, low toxicity and anti-inflammatory effect.