Recent advances in innovative strategies for enhanced cancer photodynamic therapy

Abstract

Photodynamic therapy (PDT), a non-invasive therapeutic modality, has received increasing attention owing to its high selectivity and limited side effects. Although significant clinical research progress has been made in PDT, the breadth and depth of its clinical application have not been fully realized due to the limitations such as inadequate light penetration depth, non-targeting photosensitizers (PSs), and tumor hypoxia. Consequently, numerous investigations put their emphasis on innovative strategies to overcome the aforementioned limitations and enhance the therapeutic effect of PDT. Herein, up-to-date advances in these innovative methods for PDT are summarized by introducing the design of PS systems, their working mechanisms and application examples. In addition, current challenges of these innovative strategies for clinical application, and future perspectives on further improvement of PDT are also discussed.

Photodynamic Therapy: A Compendium of Latest Reviews

“…Oxygen self-sufficient [185] and oxygen-boosted PDT could be the solutions. Some strategies involve oxygen carriers or generators, such as nanoparticles based on perfluorocarbon or manganese dioxide (MnO 2 ) and haemoglobin-based nanostructures [186]. Another strategy could be the use of low-fluence light to avoid oxygen depletion.…”

Recent Advances in Photosensitizers as Multifunctional Theranostic Agents for Imaging-Guided Photodynamic Therapy of Cancer

“…The rationale designing of novel PS with desirable properties remains a big challenge. In recent years, several innovative PS designs and strategies are being explored to improve the treatment of deep-seated or thick tumors, stability and targeting ability of PSs, ROS production efficiency, tumor hypoxia, aPSs and nanosystem-based PS formulations for improving PDT efficacy 8 , 23 , 25 - 30 .…”

“…and hydrogen peroxides (H 2 O 2 ) via electron transfer. While type II is a highly O 2 -dependent process where the 3 PS* directly transfers its energy to molecular 3 O 2 to form highly reactive singlet oxygen ( 1 O 2 ) 8 - 10 . Generation of ROS causes complex PDT induced tumor response involving direct tumor cell killing, microvascular damage to activation of innate and adaptive immune responses which altogether enhances the therapeutic outcome as represented in Figure 2 .…”

“…In an effort to establish PDT as a frontline treatment modality and to enhance the therapeutic effect of PDT, innovative approaches are being exploited to circumvent the limitations in the currently used PDT model in clinics. The latest advancements of PDT for cancer therapy have been focused on improving light source to overcome penetration depth issues, stability and targeting ability of PSs, and tumor hypoxia (Figure 1 A) 8 , 12 - 14 .…”

Antibacterial and Anti-Inflammatory Coating Materials for Orthopedic Implants: A Review

“…A schematic diagram of the mechanism is shown in Figure 6. At present, PDT is mainly used to treat infections [32] and tumors [33,34]. In orthopedic surgery, PDT has been used in the treatment of osteosarcoma [35] and prosthetic joint infections [36], and its effect on the treatment of soft tissue injury has been studied in animal experiments [37].…”