PREPARATION OF CALCIUM PHOSPHATE NANOPARTICLES AS NON-VIRAL VECTORS FOR GENE DELIVERY SYSTEM

摘要

A major aim of gene therapy is the efficient and specific delivery of therapeutic gene into the desired target tissues. Development of reliable vectors is a major challenge in gene therapy. The aim of this study is to develop calcium phosphate nanoparticles as novel non-viral vectors for the gene delivery system. Calcium phosphate nanoparticles were prepared by water-in-oil microemulsion method with a water to surfactant molar ratio, Wo = 2-10. This paper studies the design and synthesis of ultra-low size, highly monodispersed DNA doped calcium phosphate nanoparticles of size around 100nm in diameter. The structure of DNA-calcium phosphate nanocomplex observed by TEM was displayed as a shell-like structure. This study used pEGFP as a reporter gene. The encapsulating efficiency to encapsulate DNA inside the nanoparticles was greater than 80%. In the MTT test, both calcium phosphate nanoparticles and DNA-calcium phosphate nanocomplex have no negative effect for 293T cells. By gel electrophoresis of free and entrapped pEGFP DNA, the DNA encapsulated inside the nanoparticles was protected from the external DNaseI environment. In vitro transfection studies in 293T cell-line, the DNA-calcium phosphate nanocomplex could be used safely to transfer the encapsulated DNA into the 293T cells and expression green fluorescent protein. The characteristic of DNA-calcium phosphate nanocomplex to deliver DNA belongs to slow release. The property of DNA-calcium phosphate nanocomplex was fit in the requirement of non-viral vectors for the gene delivery system.