Nano-hydroxyapatite Mediated P53 Gene On Cancer Research

Hydroxyapatite (HAp) nanoparticles, a kind of calcium-and phosphate-containingcompound, is fundamental inorganic component with composition simulates the mammalianbone and tooth and has been used as biomaterials due to its high absorbability and enhancedbiocompatibility. Besides, hydroxyapatite nanoparticles sometime can inhibit cancer cellproliferation, while it is safe to normal cells. Nanoparticles can be transported into cells througha process called endocytosis and HAp nanoparticles can be decomposed in solution of weak acid,while microenviroment of cancer cells is of weak acid. So, hydroxyapatite nanoparticles areperspective to be used as new gene carriers.In this study, HAp nanoparticles were for the first time used for efficient delivery of p53gene to transfect human cancer cells. Herein three different sized HAp nanoparticles (L-HAp3.8μm, M-HAp141nm, S-HAp39nm) of similar shaped and surface charge but with differentparticle diameter were specially designed. Then the HAp nanoparticles absorbed pEGFP-C1-p53(expressing GFP-P53fusion protein). The effects of different HAp-DNA complexs on cellularuptake and behavior were studied on the human cancer cell lines A549, HUH7and HeLa andthe normal human cell lines QSG-7701and Beas-2B.The results indicated that these three different HAp nanoparticles could transfect p53geneinto cancer cells for protein expression. Flow cytometer (FCM) was used to evaluate the genetransfection efficiency, which were stably transduced with a green fluorescent protein gene. HApnanoparticles delivering pEGFP-C1-p53transfected about5%-10%of the tumor cells in cultureand about0.5%of the normal cells. However, apoptosis efficiency was up to80%. The M-HAphad higher transfection efficiency compared to L-HAp and S-HAp. Meanwhile, the results ofMTT assay and crystal violet staining showed that the HAp nanoparticles have low cytotoxicity.Therefore, our findings provide useful information that the new delivery system of gene forcancer gene therapy and strategies for the design of efficient gene carriers.