新型陽離子型高分子Bis-(PLGA-Phe-PEG)-qDETA之奈米粒子在基因轉殖研究

Abstract

Gene therapy has gained significant attention over the past two decades as a potential method for treating genetic disorders. One of research directions was focused on designing effective carrier vectors that compact and protect oligonucleotides for gene therapy. In these gene vectors, viral vectors were associated with fundamental problems, including toxicity, immunogenicity, and limitations etc. Other most researches were to focus on designing non-viral vectors, such as cationic polymers that can form complexes with DNA to apply for gene delivery. Cationic lipids and polymers, the most important non-viral vectors, have many advantages over viral ones as non-immunogenic, easy to produce and not oncogenic. However, the efficiency and toxicity are still obstacles to the application of non-viral vectors to gene therapy, for instance, transfection efficiency of PEI has been studied over a wide range of molecular weights, but high molecular weight polymers also result in significantly higher cytotoxicity. The main objective of the present work was the development of new cationic nanopolymer carrier system for the delivery of plasmid DNA (pDNA). New amphiphilic muti-block cationic copolymer based on diethylenetriamine (DETA) monomer and quaternization of amine of DETA (qDETA) bring the positive charge to decrease toxicity. However, the Bis-(PLGA-Phe-PEG)-qDETA of new cationic copolymer was synthesized by quaternary ammonium moiety, PEG, phenylalanine and PLGA. Among them, PLGA has hydrophobicity, biodegradability and biocompatibility, PEG can be reduced immunity and prolonged the circulation time in vivo, and the phenylalanine which can be improved the hydrophobicity and regarded as UV detector. Finally, new cationic nanoparticles have been prepared by water miscibility of solvent. The molecular structure of the synthesis molecules were evaluated with 1H-NMR, mass spectrometry and UV/VIS spectroscopy. Properties of the pDNA/Cationic-nanoparticles were evaluated with particle size, zeta-potential, SEM/TEM and PEG antibiotic assay. Cytotoxicity and gene transfection efficiency of pDNA/Cationic-nanoparticles were tested in vitro using cell culture. The N/P ratio of pDNA/Cationic-nanoparticles was 2/1 showed an optimal zeta-potential and binding affinity than others, suggesting the lower toxicity of the pDNA/Cationic-nanoparticles. The cationic-nanoparticles of Bis-(PLGA-Phe-PEG)-qDETA copolymers showed higher gene transfection efficiency. These results indicate that new cationic copolymer is promising candidates for gene delivery vehicles or hydrophobic drug carrier.