Chitosan-based hybrid nanocomplex for siRNA delivery and its application for cancer therapy ; Chitosan을 이용한 siRNA 전달용 융합 나노복합체와 항암치료로의 활용

학위논문 (박사)-- 서울대학교 대학원 : 제약학과, 2014. 8. 김대덕. ; Chitosan, a natural and biocompatible cationic polymer, is an attractive carrier for siRNA delivery. The purpose of this study is to develop a chitosan-based hybrid nanocomplex that exhibits enhanced stability in the blood stream compared to conventional chitosan nanoparticles. Hybrid nanocomplexes composed of chitosan, protamine, lecithin, and thiamine pyrophosphate (TPP) were prepared for the systemic delivery of survivin (SVN) siRNA and evaluated for their in vitro and in vivo therapeutic efficacies. Physicochemical properties of the nanoparticles were investigated, which included particle size measurements in distilled water, cell culture media, and 50% fetal bovine serum conditions. Cellular uptake and target gene silencing efficiencies of the siRNAnanocomplexes in prostate cancer cells (PC-3 cells) were measured. In vivo tumor targetability and anti-tumor efficacy were assessed in PC-3 tumor xenografted mouse model by near-infrared fluorescence (NIRF) imaging and tumor growth monitoring, respectively. The SVN siRNA-loaded hybrid nanocomplex (GP-L-CT) showed of < 200 nm mean diameter with positive zeta potential value in water and maintained the diameter without aggregation even in serum. Mean SVN expression rate in PC-3 cells was reduced to 21.8% after treating with GP-L-CT. The fluorescence intensity in the tumor region and the tumor growth inhibitory effect of the new nanocomplex were indicative of the cancer theranostic efficacy in the prostate cancer mouse model. In conclusion, a chitosan-based hybrid nanocomplex was successfully developed for the systemic delivery of SVN siRNA, which could serve as an alternative to the cationic polymeric nanoparticles that are unstable in serum. ; ABSTRACT i List of Tables iii List of Figures iv 1. Introduction 1 2.Materials and methods 5 2.1. Materials 5 2.2. Gel retardation assays 6 2.3. In vitro transfection efficiency according to the chitosan type 7 2.4. Preparation of hybrid nanocomplex 8 2.5. Particle size and ...