Research Of The Lipid-Hydroxyapatite-DNA Composite In Gene Delivery

There were methods to increase the level of gene expression in gene delivery: higher DNA concentration at the cell surface; more concentration DNA entre into the cell and the carrier is low toxicity to the cell.We established a novel non-viral gene delivery system, named the lipid-hydroxyapatite-DNA (LHD) composition, and made experiments to demonstrate the efficiency of the system used as DNA carriers for gene delivery in vitro.First, we prepared and did their surface modification. The dissertation could be divided into three parts:1. Hydroxyapatite (HAP) nanoparticles with 1.67 Ca/P value showed good dispersant and average granularity.2. Hydroxyapatite nanoparticles surface modified had positive Zata potential and could stabilize in the buffer solvent for a long period, using organic micro-molecule as dispersant.3. HAP showed dependences of reaction temperature and PH value, whereas the concentration had little effection to the results.Second, we investigated the preparation of lipid-hydroxyapatite-DNA. Conclusions were:1. Used HAP with positive zeta potential to composite with different proportion of DNA. Confirmed the effective proporation of the HAP nanoparticals and DNA based on different samples.2. Using the rotary evaporation method to capsued the DNA-HAP into proliposomes, which make the LHD composition. The LHD composition showed sphericity, certain capsulation rate and perfect nuclease protection ability.3. Temperature and illumination effect the oxygenation rate of natural soyabean lecithin and capsulation of LHD are demonstrated.Third, we made experiments of gene transfection to identify LHD composition used as carriers. Estimation of transfection efficiency of LHD composites was performed by galactosidase assay with Hela cells. The results showed a higher transfection efficiency than liposomes. LHD may be a good non-viral vector for applications in gene delivery.