Technological study for medical application of TiO_2 photocatalysis

1. 为了更好地解决TiO_2在医学上的应用问题，例如癌症治疗，我们尝试在水溶液中构建稳定的TiO_2纳米复合材料。在这里，我们成功地研制并展示了TiO_2与聚丙烯酸聚合物（TiO_2- paa）的水溶性纳米级杂化颗粒。使用该TiO_2-PAA溶液，我们还在体外证实了TiO_2-PAA与UVA联合治疗对T-24膀胱癌细胞的杀伤作用，以及对裸鼠T-24肿瘤的抗肿瘤作用。此外，该TiO_2-PAA纳米复合材料可以通过多种生物重要化学物质（如抗癌药物）的共价附着进行修饰。这些混合纳米模型可以作为具有光开关能力的分子或作为药物载体分子之一。并分析了TiO_2 + UVA复合处理对细胞杀伤作用的几种机制。结果表明，这种光催化处理抑制了与癌症相关的新血管生成。我们还获得了新的发现，细胞Hsp90蛋白的表达被这种光催化处理特异性地抑制。

1. To provide the best resolution of the problem for applying of TiO_2 to medical use, for example cancer treatment, we tried to construct the stable nano composite of TiO_2 in water solution. Here, we have successfully developed and showed water soluble nano size hybrid particle of TiO_2 with polyacrylic acid polymer (TiO_2-PAA).2. Using this TiO_2-PAA solution, we also confirmed the cell killing effects to T-24 bladder cancer cells in vitro and the anti-tumor effects to the T-24 tumor on the nude mice by the combined treatment of TiO_2-PAA with UVA irradiation.3. Furthermore, this TiO_2-PAA nano composite can be modified by the covalent attachment of various biological important chemicals such as anti-cancer drug. These hybrid-nano-models can be allied as a molecule possessing photo-switch capacity or as one of the drug carrier molecules.4. We also analyzed the several mechanisms of cell killing effect of combined treatment TiO_2 Plus UVA. As results, we have shown that this photocatalytic treatment inhibit the neoangiogenesis associated with cancer. And we also obtained the novel finding that cellular Hsp90 protein expression was specifically inhibited by this photocatalytic treatment.