Preparation, Charcterization And Anti-tumor Effect Of Gold Nanoshell Coated OA Liposomes

The purpose of this work was to prepare gold nanoshell coated oleanolic acid(OA) liposomes, and in-depth study of its anti-tumor effect. In the process of experiments, chitosan as the modified material was choosed, which was in order to make the gold nanoshell coated OA liposomes not only have the p H sensitivity of the chitosan and are advantage of targeting into the negatively charged tumor tissue, but also realize the controlled release of OA under the irradiation of near-infrared light.The chitosan-coated OA liposomes and gold nanoshell coated OA liposomes had marked positive charges, which were inclined to combine with the negative charges on the surface of tumor cells, and then targeted and inhibited the growth of cancer cells; The average sizes distributions of the two kinds of liposomes were within 150-200 nm, and the dimension was more easily trapped into the tumor tissue; The morphologies of chitosan-coated OA liposomes and gold nanoshell coated OA liposomes were measured. Both of the liposomes presented an almost spherical morphology, which can clearly be observed in close-coated gold nanoparticles; By EDS analysis, proved the existence of the gold on liposomes; Through UV-vis experiment, the gold nanoshell coated OA liposomes had the near infrared absorption, therefore, they can realize the controlled release of OA under the irradiation of near-infrared light; The Fourier transform infrared spectroscopy(FTIR) result indicated that chitosan already anchored the liposomes successfully. The characteristic peaks of –OH and –NH2 were also distincted in the gold nanoshell coated OA liposomes, indicating that the structure of chitosan was not damaged by the gold nanoshell. The formation of gold nanoshell may be due to gold nanoparticles interact with-OH and –NH2 of chitosan.The stability study showed that the stability of gold nanoshell coated OA liposomes were the best; The chitosan-coated OA liposomes and gold nanoshell coated OA liposomes exhibited a slow, controlled OA release at p H 7.4, and a rapid release at p H 5.5 in vitro, which was benefical for controlling tumor targeting drug release. The gold nanoshell coated OA liposomes can realize the controlled release of OA under the irradiation of near-infrared light; To normal cells, any a liposome formulations were no toxicity, but all can inhibit the tumor cells growth. Among them, gold nanoshell coated OA liposomes with the near-infrared light can achieve more ideal anti-tumor effects than others.Gold nanoshell coated OA liposomes can target to tumor cells by p H sensitivity, and can realize the controlled release of OA under the irradiation of near-infrared light. Hence, it was a most promising drug carrier.