Design Of A Multifunctional Gene Delivery System Based On Gold Nanorods And Its Anticancer Application Research

Cancer has been one of the biggest threat for human health. At present, clinical treatment methods mainly have surgical operation, radiotherapy, chemotherapy and biotherapy. Biotherapy, especially gene therapy, is a novel anticancer method. It focuses on the source of disease and hopes to completely cure the cancer. For gene therapy, the effective gene carrier is the precondition for completion gene therapy and the key factor of influence gene therapy effect. Seeking for low cytotoxic, high efficient and stable gene carriers has been a hot research field.As we know, gold nanoparticles are low cytotoxic, good biocompatibility, bio-inert, easy to be prepared and modified. Moreover, different shapes of gold nanoparticles have different optical properties. For the application of gold nanoparticles as gene carrier, people has done plenty of researches. Although they have obtain many achievements, it still need further researches on the sides of the transfection efficience, the cytotoxicity and the versatility of gene carriers.Therefore, in order to improve transfection efficience of gene carriers which based on gold nanoparticles, reduce their cytotoxicity and utilize the unique optical properties of gold nanopaticles to develop gene carriers’ versatility, we designed a non-viral gene delivery system based on gold nanorods. We used low-molecular-weight polyethyleneimine as surface modifier. And the delivery system have multifunction of gene therapy, photothermal therapy and photoacoustic imaging. Through UV-Vis absorption spectroscopy, transmission electron microscopy, thermogravimetry, elemental analysis, Zeta surface electric potential and ICP-MS, we characterized the physical and chemical properties of materials. The results indicated that our materials have nano-size, strong near-infrared absorption and high surface charge. Moreover, through MTT assay, cellular transfection experiment, gel electrophoresis experiment, laser confocal scanning microscopy experiment, photothermal therapy experiment and photoacoustic imaging experiment, we researched the anticancer effect and multifunctionality of this delivery system on the level of cell and animal. According to study results, the delivery system have low cytotoxicity, high transfection efficiency and good stability. It not only could complete gene therapy, but also has good photothermal therapy effect. And it could be used for noninvasion biodistribution detection. The above all results would be expected to provide some references for research and application of gold nanoparticles in the field of gene therapy, and make a contribution to the development of anticancer therapy.