Au@TiO_2纳米核壳与HMME结合体的制备及其光动力疗效初探

Preparation of Au@TiO_2-HMME and Its Photodynamic Efficiency

光动力疗法(PDT)是一种高效、安全、微创的新型治疗方法,国产光敏剂血卟啉单甲醚(HMME)介导的光动力疗法由于其成分单一、单态氧产量高及光敏周期短,临床上已用于脑胶质瘤和鲜红斑痣的治疗。为了进一步提高光动力疗效,本研究基于晶种生长法制备稳定粒径均一的吸收峰在530nm的阳离子金纳米球。采用毒性低且阴离子电解活化作用强的聚(四-苯乙烯磺酸钠)(PSS)进行修饰。利用静电吸引力将钛源TiCl_3水解的TiOH^(2+)与其结合并氧化制备AuNP@TiO_2核壳,通过改变NaHCO_3量制得不同TiO_2壳层厚度的AuNP@TiO_2核壳,并进一步将其与HMME结合制备结合体。采用紫外-可见吸收光谱、红外光谱、激光纳米粒度仪和透射电镜对所制样品进行表征。结果表明新型的光敏剂粒径均匀,结构稳定。最后采用细胞实验验证了其光动力疗效。总之,该研究合成了新型的Au@TiO_2-HMME纳米光敏剂,通过人口腔表皮样癌细胞系KB细胞与新型核壳纳米结构的光动力作用,与纯HMME相比,在最优条件下可提高约35%的细胞杀伤率。

Photodynamic therapy （PDT ） is a potential treatment method that has proven to be an efficient ,safe ,and minimally invasive technique .The technique mainly depends on photosensitizes to produce reactive oxygen species underthe irradiation of specific wavelengthlight ,therefore causing specific killing to tumor cells and tissues .Among them ,hematoporphyrinmonometh-yl ether （HMME） mediated PDT has been used in clinical treatment of port wine stain （PWS） due to its single component ,high yield of singlet oxygen and short light-sensitive period .In order to improve the efficiency of the PDT ,we synthesized stable , monodispersecation Au nanospheres with absorption peak of 530 nm based on seed-growth .Poly-（sodium 4-styrenesulfonate） （PSS） was employed to modify Au nanospheres owing to its low toxicity and strong anion electrolytic activation .Then TiOH2＋coming from TiCl3 hydrolysis could be closely attached to negatively charged Au nanospheres through electrostatic attraction and further oxidation to obtain AuNP@ TiO2 core-shell nanostructure .The TiO2 shell thickness could be adjusted by changing the NaHCO3 amount ,then further mixing AuNP@ TiO2 core-shell and HMME to form the conjugate .The obtained samples were characterized by UV-visible absorption spectroscopy ,infrared spectroscopy ,laser nanoparticle size analyzer and transmission e-lectron microscope （TEM） .The results showed that the core-shell nanostructures were stable and well-distributed .Otherwise , the cell killing experiments were performed with KB cells and LED array of 510 nm light source ,and CKK-8 was used to evalu-ate the cell viability .The results showed that the conjugate improved PDT efficiency about 35% higher than that of HMME a-lo ne .