Study On The Influence Factors Of DNA Tansfection Mediated By Hydroxyapatite Nanoparticles

Objectives The purpose of this study is to investigate the optimal parameters for DNA transfection by hydroxyapatite nanoparticles.Methods Observe the hydroxyapatite nanoparticles modified by Polyethylenimine(PEI)(PEI－nHA) at the room temperature and find their suspension stability . Four optimizing experiments including PEI－nHA content. DNA content,cell number and co-transfection time have been carried out in Hela cells by using the PEI-nHA and expression vector pTracer-CMV/Bsd-CX26 (GFP). Meanwhile using nHA,PEI-nHA and PEI as vectors taking pTracer- CMV/Bsd- CX26 (GFP) transfect Hela cells.Results The suspension stability of PEI－nHA is well in a wide range of concentrations after 24 hours. While,the ones lower than 500μg /ml have poor suspension stability in two month late. The result of tansfection : 1)The optimal concentration of PEI-nHA is 250μg/ml.2) The optimal DNA content is 2μg.3)The optimal cellular number is 4×105/culture well.4) The optimal co-transfection time is 6 hours. The transfection efficiency of nHA,PEI-nHA and PEI turn out to be 10%,28%,and 55%。Conclusion 1.The suspension stability of PEI－nHA is well in a wide range of concentrations. high concentration PEI-nHA has better suspension stability than low one.This remind us preserving PEI-nHA in high concentration.2.nHA modified by PEI has better transfection efficiency. 3.PEI has higher transfection efficiency than PEI-nHA.4.The ransfection in vitro of PEI-nHA is 28%.