RESUMO
Objective To investigate the role of hydroxyapatite nanoparticle (nHAP) in the gene transfection of human colorectal cancer cell line SW480/M5 and the possible mechanisms.Methods The combination and protection of nHAP-Mg2+ to DNA were analyzed by gelose gelatin electrophoresis.Liposome and nHAP modified by magnesium chloride was combined,and the PEGFP-N1 plasmids were transfected into SW480/M5 cells.The gene transfection rate and the mean fluorescence intensity were observed by flow cytometry.The effect of nHAP-Mg2+ on the growth of the cells were studied by MTT.Results At appropriate proportion,nHAP-Mg2+ could combine the plasmids compeletly and protected the DNA.The gene could not be transferred by nHAP-Mg2+ alone.Combining the nanoparticles and liposome,the gene could be transferred very efficiently and the transfection rates were significantly higher than the liposome (P ＜ 0.05).The inhibition of cell growth was increased along with the concentration of nHAP-Mg2+ wether it was used alone or with the combination of liposome (P ＜ 0.05).Conclusions nHAP-Mg2+ has the ability to combining and protecting DNA and can be used to transfer gene as the adjunct carrier of liposome for the gene therapy of tumor cells to elevate the gene tansfection and expression rate and also enhance the anti-tumor effection.