Conventional cancer treatment modalities are often associated with major therapeutic limitations and severe side effects. Photodynamic therapy is a localized noninvasive mode of treatment that has given a different direction to cancer research due to its effectivity against a wide range of cancers and minimal side effects. A photosensitizer is the key component of photodynamic therapy (PDT) that generates cytotoxic reactive oxygen species to eradicate cancer cells. As the therapeutic effectivity of PDT greatly depends upon the photosensitizer, great efforts have been made to search for an ideal photosensitizer. Chlorin e6 is a FDA approved second generation photosensitizer that meets the desired clinical properties for PDT. It is known for its high reactive oxygen species (ROS) generation ability and anticancer potency against many types of cancer. Hydrophobicity is a major drawback of Ce6 that leads to its poor biodistribution and rapid clearance from the circulatory system. To overcome this drawback, researchers have designed and fabricated several types of nanosystems, which can enhance Ce6 solubility and thereby enhance its bioavailability. These nanosystems also improve tumor accumulation of Ce6 by selectively targeting the cancer cells through passive and active targeting. In addition, Ce6 has been employed in many combination therapies like chemo-photodynamic therapy, photoimmunotherapy, and combined photodynamic–photothermal therapy. A combination therapy is more curative than a single therapy due to the synergistic effects of individual therapies. Ce6-based nanosystems for combination therapies have shown excellent results in various studies and provide a promising platform for cancer treatment.

中文翻译：

---

Chlorin e6：基于光的癌症纳米医学中一种有前途的光敏剂

传统的癌症治疗方式通常与主要的治疗限制和严重的副作用有关。光动力疗法是一种局部无创治疗模式，由于其对多种癌症的有效性和最小的副作用，它为癌症研究指明了不同的方向。光敏剂是光动力疗法 (PDT) 的关键组成部分，可产生细胞毒性活性氧来根除癌细胞。由于PDT的治疗效果在很大程度上取决于光敏剂，因此人们努力寻找理想的光敏剂。Chlorin e6 是 FDA 批准的第二代光敏剂，符合 PDT 所需的临床特性。它以其高活性氧 (ROS) 生成能力和针对多种癌症的抗癌效力而闻名。疏水性是 Ce6 的主要缺点，导致其生物分布差和从循环系统中快速清除。为了克服这个缺点，研究人员设计并制造了几种类型的纳米系统，可以提高 Ce6 的溶解度，从而提高其生物利用度。这些纳米系统还通过被动和主动靶向选择性靶向癌细胞来改善 Ce6 的肿瘤积累。此外，Ce6 已被用于许多联合疗法，如化学-光动力疗法、光免疫疗法和联合光动力-光热疗法。由于个体疗法的协同作用，联合疗法比单一疗法更有效。