Local Photodynamic Therapy of Gastrointestinal Tumors by Water-soluble Polymerized Fullerene

富勒烯是众所周知的，可以有效地产生单氧化物，当被光辐射时。这将导致对肿瘤产生一种光动力效应，如果肿瘤组织中的首选累积是可见的。为了研究这个肿瘤的目标，我们化学地修改了水不溶的富勒烯与聚乙烯糖醇（PEG）不仅仅是为了使富勒烯溶于水中，但也能使富勒烯溶于其分子大小。当一个内向的老鼠携带一个肿瘤质量在后面的子管，一个大尺寸的，水-松的富勒尼-PEG聚合物展示了更高的累积和更长的富勒尼保留在比正常的问题。“”“一个幻觉是从一个特定的器官中创造出来的，而没有时间存在。在肿瘤站点暴露出可见光的情况下，将填充-PEG聚合物的内部注射到肿瘤-承载老鼠耦合上，肿瘤质量的体积增加了。历史学测试揭示了一种具有聚合物注射加上光辐射的强烈诱导的肿瘤坏死，而没有对正常皮肤造成任何损害。结合物因增加辐照功率和氟醚剂量而增加的拮抗剂的影响，以及结合物（424 g/kg）辐照功率为107 J/cm的固化肿瘤的治疗。这些发现表明，PEG-修饰的富勒烯是一种用于光动力肿瘤治疗的高潜力剂。

Fullerene is known to efficiently generate singlet oxygen when irradiated with light. This will facilitate to induce a photodynamic effect on tumor, if its preferential accumulation in the tumor tissue is attained. To explore this tumor targeting of Fullerene, we chemically modified the water-insoluble fullerene with polyethylene glycol (PEG) not only to make fullerene soluble in water but also to enlarge its molecular size. When injected intravenously to mice carrying a tumor mass in the back subcutis, the large-sized, water-soluble fullerene-PEG conjugate exhibited higher accumulation and more prolonged fullerene retention in the tumor tissue than in the normal tissue. The conjugate was excreted from the body with time without being accumulated in a specific organ. Following intravenous injection of fullerene-PEG conjugates to the tumor-bearing mice coupled with exposure of the tumor site to visible light, the volume increase of the tumor mass was suppressed. Histological examination revealed that conjugate injection plus light irradiation strongly induced tumor necrosis without any damage to the overlaying normal skin. The antitumor effect of the conjugates increased with the increasing irradiation power and the fullerene dose, and the treatment with fullerene in a conjugate (424 g/kg) cured tumor at an irradiation power of 107 J/cmィイD12ィエD1. These findings indicate that the PEG-modified fullerene is a high potential agent for photodynamic tumor therapy.