Polymeric micelles comprising stearic acid-grafted polyethyleneimine as nonviral gene carriers.
Non-viral vectors composed of biodegradable polymers or lipids have been considered as a safer alternative for gene carriers over viral vectors. Among some of the cationic polymers, polyethyleneimine (PEI) possess high pH-buffering capacity that can provide protection to nucleotides from acidic degradation and promotes endosomal and lysosomal release. However, it has been reported that cytotoxicity of PEI depends on the molecular weight of the polymer. Hence modifications of PEI structure for clinical application have been developed in order to reduce the cytotoxicity, or improve the insufficient transfection efficiency of lower molecular weight PEI. In this study, 10 k PEI was modified by grafting stearic acid (SA) and formulated to polymer micelles with positive surface charge and evaluated for pDNA delivery. The amine group on PEI was crosslinked with the carboxylic group of stearic acid by 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide (EDC) as linker. PEI-SA micelles were then prepared using oil in water (o/w) solvent evaporation method. The success of PEI-SA conjugation structure was confirmed with 1H NMR. The average diameter and zeta potential determined by photon correlation spectroscopy was 149.6 +/- 1.2 nm and 64.1 +/- 1.5 mV, respectively. These self-assemble positive charge micelles showed effective binding to pDNA for transfection. PEI-SA micelles exhibited lower cytotoxicity compared to that of PEI only, while flow cytometry analysis revealed PEI-SA/pEGFP complex provided 62% high EGFP expression. Luciferase activity also showed high transfection efficiency of PEI-SA micelles for weight ratio above 4.5 that was comparable to PEI only. These results demonstrated that stearic acid grafted PEI micelles can provide high transfection efficiency comparable to unmodified PEI, and exhibit low cytotoxicity. Stearic acid grafted PEI micelles can be promising polymer carriers in genetic therapy.
Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan.
Wei-ti
WT
Kuo
Hong-yi
HY
Huang
Yi-you
YY
Huang
D002460:Cell Line; D004337:Drug Carriers / Q000737:chemistry / Q000633:toxicity; D005822:Genetic Vectors / Q000737:chemistry / Q000633:toxicity; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D008156:Luciferases / Q000235:genetics; D008422:Materials Testing; D008823:Micelles; D008970:Molecular Weight; D036103:Nanotechnology; D010316:Particle Size; D011094:Polyethyleneimine / Q000737:chemistry / Q000633:toxicity; D013229:Stearic Acids / Q000737:chemistry / Q000633:toxicity; D013499:Surface Properties; D014162:Transfection
D004337:Drug Carriers; D008823:Micelles; D013229:Stearic Acids; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C031183:stearic acid; D011094:Polyethyleneimine; D008156:Luciferases