Targeted Therapy of Cancer Using Photodynamic Therapy in Combination with Multi-faceted Anti-Tumor Modalities

Abstract

Photodynamic therapy (PDT) has emerged as one of the important therapeutic options in the management of cancer and other diseases. PDT involves a tumor-localized photosensitizer (PS), which when appropriately illuminated by visible light converts oxygen into cytotoxic reactive oxygen species (ROS), that attack key structural entities within the targeted cells, ultimately resulting in necrosis or apoptosis. Though PDT is a selective modality, it can be further enhanced by combining other targeted therapeutic strategies that include the use of synthetic peptides and nanoparticles for selective delivery of photosensitizers. Another potentially promising strategy is the application of targeted therapeutics that exploit a myriad of critical pathways involved in tumorigenesis and metastasis. Vascular disrupting agents that eradicate tumor vasculature during PDT and anti-angiogenic agents that targets specific molecular pathways and prevent the formation of new blood vessels are novel therapeutic approaches that have been shown to improve treatment outcome. In addition to the well-documented mechanisms of direct cell killing and damage to the tumor vasculature, PDT can also activate the body’s immune response against tumors. Numerous pre-clinical studies and clinical observations have demonstrated the immuno-stimulatory capability of PDT. Herein, we aim to integrate the most important findings with regard to the combination of PDT and other novel targeted therapy approaches, detailing its potential in cancer photomedicine.

Porphyrin-based cationic amphiphilic photosensitisers as potential anticancer, antimicrobial and immunosuppressive agents

“…A second important PDT target is the tumour vasculature. Activated PS can directly damage the existing vessels and/or inhibit the formation of new ones (Olivo et al 2010). The balance between these two executive Fig.…”

Novel water soluble dendrimer nanocarrier for enhanced photodynamic efficacy of protoporphyrin IX

“…Moreover nanoparticle based approach makes favour for the PS to deliver it more selectively at the tumor site, by reducing its toxicity and damage to the healthy tissues [10]. Nanoparticles carrying PS by different strategies (adsorption/covalent bonding) offer benefits of hydrophilicity and appropriate size for passive targeting to tumour tissues by the enhanced permeability and retention (EPR) effect [3].…”

Effect of photodynamic therapy combined with Celecoxib on expression of cyclooxygenase-2 protein in HeLa cells

“…The present study will provide novel ideas for the clinical prevention and treatment of CC and is therefore of important practical significance in improving the survival rates and decreasing the mortality rates of CC. With advances from previous studies and clinical studies, this combined therapy may have broad application prospects toward the prevention and treatment of early and advanced CC (16,17).…”