光動力治療於癌症之應用

Photodynamic Therapy for Cancer

光動力治療是近年來逐步發展成熟的一種癌症治療方式，主要原理是利用光感物質被特定波長光源激發後，產生單態氧及自由基，來造成腫瘤細胞死亡。影響光動力治療效果的主要因素為光感物質和光照效能。近年有許多研究者利用劑型設計及改變投藥途徑的方式，藉以改變光感物質的特性並將之送達至作用部位，以發揮最大療效並降低副作用的產生。

Photodynamic therapy (PDT), which is based on the uptake of a photosensitizer followed by the selective irradiation of light, is a therapeutic modality for cancer treatment. Since current photosensitizers are usually administrated intravenously, side effects such as skin hypersensitivity may be caused by the higher accumulation of photosensitizers in skin. Therefore, a variety of drug carriers have been used to enhance the effect of photosensitizers and decrease the side effect of PDT. Liposomes appeared to be the most promising carrier system among all, and higher cytotoxicity has been reported with the liposomal encapsulated photosensitizers.