银纳米粒子治疗鼠皮肤及虹膜黑色素瘤有效性及生物毒性的实验研究

发布时间：2018-07-10 01:10

本文选题：纳米银 + 光热治疗　；参考：《中国人民解放军医学院》2015年博士论文

【摘要】：目的：近几年,光热治疗(Photothermal therapy,PTT)被广泛应用于肿瘤的治疗,然而在眼科的应用几乎是空白。我们研制出一种新型的PTT介质——具有二氧化钛包壳的银纳米粒子(Ag@TiO2 nanoparticles, Ag@ TiO2 NPs),它比其他PTT介质具有更加强大的红外吸收峰以及更强的光热转换效率却又成本低廉。本课题通过体内体外实验证实此纳米材料可能成为一种新型PTT材料有效的用于皮肤及虹膜黑色素瘤的治疗。方法：通过两步法,在晶种的基础上合成银纳米粒子。在此基础上,利用溶胶凝胶法制得具有Ag@ TiO2核壳结构的纳米粒子。通过调节反应时间和溶胶凝胶前驱体引入量,可以使氧化物壳层的厚度从1-15纳米范围内精细可调。银纳米粒子的光热转换效率性质通过：用2W·cm-2功率密度的808rnm近红外光直接照射其在石英池中一毫升不同质量分数水溶液来测定。体外实验用不同浓度的银纳米粒子溶液和B16F10, OCM-1细胞共培养后,评估银纳米粒子的体外毒性；并通过808nm近红外激光照射不同浓度的银纳米粒子溶液共培养的细胞评估银纳米粒子的光热效果。体内实验构造皮下黑色素瘤和前房虹膜膜黑色素瘤动物模型,在局部组织注射一定浓度的银纳米粒子,立刻用近红外光激光照射。随后记录不同时间点实体瘤的体积并评估其体积变化。此外行组织学检查鼠尾静脉注射银纳米粒子老鼠1月后各脏器的变化。结果：我们开发出一种简便的溶胶凝胶法合成Ag@ TiO2纳米结构,并且实现去厚度可调。由于氧化物壳层的保护作用,这种纳米粒子在生物体内和体外实验中,均展现出良好的生物相容性和稳定性。这种纳米粒的局域化的表面等离子共振(plasmon resonance, LSPR)吸收谱带可调到近红外窗口(808纳米)。当波长为808纳米的入射光照射到这种纳米粒子表面,其周围环境的温度会明显随之升高,直接导致B16F10(p0.01)和OCM-1细胞(p0.01)死亡。经PTT治疗后黑色素瘤均变小,皮下肿瘤模型治疗16天后瘤体逐渐消失；虹膜黑色素瘤模型治疗后三天瘤体体积开始下降。生物毒性实验提示细胞对银纳米粒子表现出良好的耐受性，在200μg/ml细胞仍有较强的活性；同时动物在治疗后1个月仍然全部存活。结论：我们证实Ag@ TiO2是一种局部治疗实体肿瘤的有效PTT介质。
[Abstract]:Objective: in recent years, photothermic therapy (PTT) has been widely used in the treatment of tumor, but the application of PTT in ophthalmology is almost blank. We have developed a new PTT medium, Ag @ TiO2 NPs (Ag@ TiO2 NPs), which has a stronger infrared absorption peak and higher photothermal conversion efficiency than other PTT media. In vitro and in vivo experiments have proved that this nanometer material may be an effective PTT material for the treatment of skin and iris melanoma. Methods: silver nanoparticles were synthesized on the basis of seed by two-step method. On this basis, nanoparticles with core-shell structure of Ag@ TiO2 were prepared by sol-gel method. By adjusting the reaction time and the amount of sol-gel precursor, the thickness of oxide shell can be adjusted from 1-15 nm to 15 nm. The photothermal conversion efficiency properties of silver nanoparticles were measured by direct irradiation of 808rnm near infrared light with 2W cm-2 power density in quartz cell with different mass fraction aqueous solution. The in vitro toxicity of silver nanoparticles was evaluated by co-culture of B16F10 and OCM-1 cells with different concentrations of silver nanoparticles. The photothermal effect of silver nanoparticles was evaluated by 808nm near infrared laser irradiation of silver nanoparticles co-cultured in different concentrations. The animal models of subcutaneous melanoma and anterior chamber iris melanoma were constructed in vivo. A certain concentration of silver nanoparticles was injected into local tissues and immediately irradiated with near-infrared laser. The volume of solid tumor was then recorded and evaluated at different time points. In addition, the changes of organs were examined by histological examination after injecting silver nanoparticles into tail vein of mice for one month. Results: we developed a simple sol-gel method for the synthesis of Ag@ TiO2 nanostructures, and the thickness of Ag@ TiO2 nanostructures was adjustable. Because of the protective effect of oxide shell, the nanoparticles showed good biocompatibility and stability in vivo and in vitro. The localized surface plasmon resonance (plasmon resonance,) absorption band of the nanoparticles can be adjusted to the near infrared window (808 nm). When the incident light at the wavelength of 808 nm irradiates on the surface of the nanoparticles, the ambient temperature will increase obviously, which will lead to the death of B16F10 (p0.01) and OCM-1 cells (p0.01). After PTT treatment, melanoma became smaller, subcutaneous tumor model gradually disappeared 16 days after treatment, and the volume of tumor began to decrease three days after the treatment of iris melanoma model. The biotoxicity test showed that the cells showed good tolerance to silver nanoparticles, and still had strong activity in 200 渭 g/ml cells, and all the animals survived one month after treatment. Conclusion: we confirm that Ag@ TiO2 is an effective PTT medium for local treatment of solid tumors.
【学位授予单位】：中国人民解放军医学院
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R739.5;R739.7

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