Preparation and characterization of non-viral gene delivery systems with pEGFP-C1 Plasmid DNA

ABSTRACT In recent years, non-viral delivery systems for plasmid DNA have become particularly important. They can overcome the disadvantages of viral systems such as insertional mutagenesis and unpredicted immunogenicity. Some additional advantages of non-viral gene delivery systems are; good stability, low cost, targetability, delivery of a high amount of genetic materials. The aim of the study was to develop novel non-viral nanosystems suitable for gene delivery. Two formulations were developed for this purpose: water-in-oil microemulsion (ME) and solid lipid nanoparticles (SLN). The microemulsion was composed of Peceol, Tween 80, Plurol oleique, ethanol and water. The SLN was consisting of Precirol, Esterquat-1 (EQ1), Tween 80, Lecithin, ethanol and water. Characterization studies were carried out by measuring particle size, zeta potential, viscosity and pH. TEM imaging was performed on SLN formulations. Protection against DNase I degradation was examined. Cytotoxicity and transfection efficacy of selected formulations were tested on L929 mouse fibroblast cells. Particle sizes of complexes were below 100 nm and with high positive zeta potential. TEM images revealed that SLNs are spherical. The SLN:DNA complexes have low toxicity and good transfection ability. All results showed that the developed SLN formulations can be considered as suitable non-viral gene delivery systems.

Biological functions of SPA-PEI conjugate as one key component for construction of a novel antibody-targeted DNA delivery system / 重庆医学

Objective To investigate the biological function of SPA-PEI conjugate(staphylococcal protein A-polyethyleneimine cross-linker),which is one key component for construction of a novel antibody-targeted DNA delivery system.Methods The binding capacity of SPA-PEI conjugate with multiple sources of IgG was determined by enzyme-linked immunosorbent assay and neutralization inhibition assay.The binding capacity of SPA-PEI conjugate with DNA fragment was determined by DNA gel retardation assay,and its DNA condensing ability was measured by Ethidium bromide exclusion assay.Results SPA-PEI conjugate could bind well to many species-derived IgGs.SPA-PEI conjugate had no significant effect on the binding properties of SPA.SPAPEI conjugate could neutralize negative charges of the plasmid DNA or DzTi.Its DNA condensing ability was nearly same to that of free PEI,which suggested a excellent DNA condensing ability of the SPA-PEI conjugate.Conclusion SPA-PEI cross-linkers prepared by this project group maintained the biological activity of SPA and PEI.SPA-PEI cross-linkers could be used for the construction of a novel antibody-targeted non-virus DNA delivery system.