Development of Biotechnological Photosensitizers for Photodynamic Therapy: Cancer Research and Treatment—From Benchtop to Clinical Practice

Abstract

Photodynamic therapy (PDT) is a noninvasive therapeutic approach that has been applied in studies for the treatment of various diseases. In this context, PDT has been suggested as a new therapy or adjuvant therapy to traditional cancer therapy. The mode of action of PDT consists of the generation of singlet oxygen (¹O2) and reactive oxygen species (ROS) through the administration of a compound called photosensitizer (PS), a light source, and molecular oxygen (3O2). This combination generates controlled photochemical reactions (photodynamic mechanisms) that produce ROS, such as singlet oxygen (¹O2), which can induce apoptosis and/or cell death induced by necrosis, degeneration of the tumor vasculature, stimulation of the antitumor immune response, and induction of inflammatory reactions in the illuminated region. However, the traditional compounds used in PDT limit its application. In this context, compounds of biotechnological origin with photosensitizing activity in association with nanotechnology are being used in PDT, aiming at its application in several types of cancer but with less toxicity toward neighboring tissues and better absorption of light for more aggressive types of cancer. In this review, we present studies involving innovatively developed PS that aimed to improve the efficiency of PDT in cancer treatment. Specifically, we focused on the clinical translation and application of PS of natural origin on cancer.

Salvianolic acid B as a potent nano‐agent for enhanced ALA‐PDT of oral cancer and leukoplakia cells

“…The mechanism of action of PDT is the photoactivation of a particular photosensitizer in the TME in the presence of oxygen, and cancer cells produce ROS upon activation of photosensitizers by irradiation during PDT. There are two main types of reactions that can be triggered by this interaction: type I reaction, which can result in the production of hydrogen peroxide, superoxide anion and hydroxyl radical, and type II reaction, which is the photodynamic reaction, which results in singlet oxygen production (Aires-Fernandes et al, 2022).…”

Photodynamic Therapy for Eye, Ear, Laryngeal Area, and Nasal and Oral Cavity Diseases: A Review

“…PDT therapy is referred to as a safe and highly selective therapy [63][64][65]. Currently, photosensitizers are still being sought that will be more effective, safer, and less invasive to humans [66][67][68][69][70]. UV-Vis spectroscopy is one of the methods by which photosensitizers are analyzed [71].…”

Application of Cyclodextrin for Cancer Immunotherapy

“…Photodynamic therapy (PDT) has gained significant popularity in recent years as an effective therapeutic approach. Similar to photothermal therapy, PDT also involves the utilization of photosensitizers, but its primary focus lies in the generation of intracellular reactive oxygen species (ROS) [ 69 , 70 , 71 ]. However, the efficacy of photodynamic therapy is influenced by the penetration of near-infrared light within tissues and cells.…”