The use of photodynamic therapy in medical practice

Abstract

Cancer therapy, especially for tumors near sensitive areas, demands precise treatment. This review explores photodynamic therapy (PDT), a method leveraging photosensitizers (PS), specific wavelength light, and oxygen to target cancer effectively. Recent advancements affirm PDT's efficacy, utilizing ROS generation to induce cancer cell death. With a history spanning over decades, PDT's dynamic evolution has expanded its application across dermatology, oncology, and dentistry. This review aims to dissect PDT's principles, from its inception to contemporary medical applications, highlighting its role in modern cancer treatment strategies.

Keywords: medical practice; oncology; photodynamic therapy (PDT); photosensitizers; treatment cancer.

Figure 1

Types of PS used for PDT. PS with hydrophilic and amphipathic properties have a greater affinity for the endoplasmic reticulum than hydrophilic PS.

Figure 2

Classification of PS by generation, which differ in structure, selectivity of action, or accumulation in tissues.

Figure 3

Application of PDT in various fields of medicine. The development of PDT is aimed at many different areas of medicine. Currently, the three most developed trends are those related to oncology, dermatology and dentistry. Photodynamic therapy is becoming increasingly important in ophthalmology, gastroenterology, cardiovascular diseases, neurology, rheumatology, and in combating bacteria, viruses and fungi thanks to photodynamic inactivation of microorganisms (PDI).

Figure 4

The cellular effect of PDT combined with chemotherapy. By generating ROS, an introduced PS can lead to cell death. The association of PDT with chemotherapy, which includes the use of various substances, including alkylating drugs, antimetabolites, natural products, and hormones and antagonists, can act favorably on the effect of anticancer therapy.

Figure 5

PDT combined with radiation therapy. The association of PDT with radiation therapy, includes the use of X-rays that can lead to the generation of free radicals, can act favorably on the effect of anticancer therapy.

Figure 6

PDT combined with immunotherapy. The association of PDT with immunotherapy, which may include, among other things, the use of an anti-PD-1 antibody directed against receptors on T lymphocytes, has a beneficial effect on the effect of anticancer therapy.