- 學位論文
表面修飾犬尿酸之幾丁聚醣奈米微粒作為基因載體之研究
Study of Chitosan Nanoparticles with High Proportional Conjugation of Urocanic Acid as Gene Delivery Vector
摘要
並列摘要
Chitosan, one of cationic polymers, is a linear polysaccharide composed of β1 -->4 linked glucosamine partly containing N-acetyl-glucosamine. Chitosan can enhance the transport of polar drugs across epithelial surfaces, and is biocompatible and biodegradable. Chitosans are available for other biomedical applications such as bandages and gene carriers. Additionally, because chitosan is hypoallergenic, cationic, and has natural anti-bacterial properties, further supporting its use in biomedical application; we use chiosan as the material for gene delivery vector. First, chitosan has to be surface-modified with urocanic acid (UA) to enhance its proton sponge mechanism.By proton sponge mechanism, the transfection rate should be improved during the gene delivery process. In this research, chitosan-UA complex was synthesized by using 1-(3-Dimethyl-aminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-Hydroxysuccinimide (NHS) to conjugate chitosan with UA. Fourier transform infrared spectroscopy (FTIR), was used to demonstrate this conjugation process. The biological study showed that chitosan particle with UA conjugation was non-cytotoxicity and significantly enhance the tranfection rate in vitro test. From SEM and TEM image, we discover that the size of chitosan-UA/DNA particle is about 50~500nm. From zeta-potential test, we know that chitosan-UA carriers has high positive charge even after combination with DNA. In cell viability assay, we found that chitosan-UA show no LDH release and good biocompatibility. Finally image of gene expression for in-vitro transfection was examined by fluorescence microscopy.