Chizenga Elvin Peter, Abrahamse Heidi
Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2028, South Africa.
Pharmaceutics. 2020 Jul 6;12(7):632. doi: 10.3390/pharmaceutics12070632.
Photodynamic therapy (PDT) has emerged as a potential therapeutic option for most localized cancers. Its high measure of specificity and minimal risk of side effects compared to other therapies has put PDT on the forefront of cancer research in the current era. The primary cause of treatment failure and high mortality rates is the occurrence of cancer resistance to therapy. Hence, PDT is designed to be selective and tumor-specific. However, because of complex biological characteristics and cell signaling, cancer cells have shown a propensity to acquire cellular resistance to PDT by modulating the photosensitization process or its products. Fortunately, nanotechnology has provided many answers in biomedical and clinical applications, and modern PDT now employs the use of nanomaterials to enhance its efficacy and mitigate the effects of acquired resistance. This review, therefore, sought to scrutinize the mechanisms of cellular resistance that affect the therapeutic response with an emphasis on the use of nanomaterials as a way of overriding cancer cell resistance. The resistance mechanisms that have been reported are complex and photosensitizer (PS)-specific. We conclude that altering the structure of PSs using nanotechnology is an ideal paradigm for enhancing PDT efficacy in the presence of cellular resistance.
光动力疗法（PDT）已成为大多数局部癌症的一种潜在治疗选择。与其他疗法相比，其高度的特异性和极小的副作用风险使PDT在当前时代处于癌症研究的前沿。治疗失败和高死亡率的主要原因是癌症产生了对治疗的抗性。因此，PDT被设计为具有选择性且针对肿瘤特异性的。然而，由于癌细胞复杂的生物学特性和细胞信号传导，它们已表现出通过调节光敏化过程或其产物而获得对PDT的细胞抗性的倾向。幸运的是，纳米技术在生物医学和临床应用中提供了许多解决方案，现代PDT现在采用纳米材料来提高其疗效并减轻获得性抗性的影响。因此，本综述旨在仔细研究影响治疗反应的细胞抗性机制，重点关注使用纳米材料作为克服癌细胞抗性的一种方式。已报道的抗性机制是复杂且针对光敏剂（PS）特异性的。我们得出结论，在存在细胞抗性的情况下，利用纳米技术改变PS的结构是提高PDT疗效的理想模式。
