A Preliminary Study On The MPEG-Chitosan Nanoparticles As Gene Delivery Vehicles And Protein Carriers

Objective:Methoxypolyethyleneglycol(mPEG) was grafted to the chitosan to modify the physical properties of chitosan in order to let it more suitable for gene delivery vehicles and protein carriers.Methods:The mPEGS000 was conjugated to the chitosan and the mPEG-CS was obtained.In this study,plasmid DNA(pDNA) and BSA were encapsulated in chitosan to prepare mPEG-chitosan-DNA and mPEG-chitosan-BSA nanoparticles using a complex coacervation process and ionic crosslinking method respectively.FT-IR,Gel retardation,AFM,Malvem particle size analyzer,Zeta potential measurements and DNase I protection experiment were used to investigate the characterization and the stability of mPEG-chitosan-DNA and mPEG-chitosan-BSA nanoparticles in vitro.Moreover,the cytotoxicity of mPEG-chitosan and mPEG-chitosan-DNA complexes on HeLa cells were detected by MTT assays.In addition,this system was also applied in the preparation of mPEG-chitosan nanoparticles encapsulated with insulin(INS).The characterization and the stability of mPEG-chitosan-INS nanoparticles were assayed.Results:The mPEG-chitosan-DNA/mPEG-chitosan-BSA nanoparticles size were within the range of 100-300 nm.The nanoparticles had high encapsulation efficiency and good stability in vitro.Results of DNase I protection assay showed that mPEG-chitosan-DNA nanoparticles could protect the encapsulated plasmid DNA from nuclease degradation.The nanoparticles could delay the DNA or protein release from the complexes and it has little cytotoxicity on HeLa cells. Moreover,the insulin was encapsulated in chitosan nanoparticles and the diameter was within the range of 100-200 nm.These nanoparticles could delay insulin release from the complexesConclusions:The chitosan conjugated by mPEG,is a potential vector for gene and protein delivery.