Progress in Clinical Trials of Photodynamic Therapy for Solid Tumors and the Role of Nanomedicine

Abstract

Current research to find effective anticancer treatments is being performed on photodynamic therapy (PDT) with increasing attention. PDT is a very promising therapeutic way to combine a photosensitive drug with visible light to manage different intense malignancies. PDT has several benefits, including better safety and lower toxicity in the treatment of malignant tumors over traditional cancer therapy. This reasonably simple approach utilizes three integral elements: a photosensitizer (PS), a source of light, and oxygen. Upon light irradiation of a particular wavelength, the PS generates reactive oxygen species (ROS), beginning a cascade of cellular death transformations. The positive therapeutic impact of PDT may be limited because several factors of this therapy include low solubilities of PSs, restricting their effective administration, blood circulation, and poor tumor specificity. Therefore, utilizing nanocarrier systems that modulate PS pharmacokinetics (PK) and pharmacodynamics (PD) is a promising approach to bypassing these challenges. In the present paper, we review the latest clinical studies and preclinical in vivo studies on the use of PDT and progress made in the use of nanotherapeutics as delivery tools for PSs to improve their cancer cellular uptake and their toxic properties and, therefore, the therapeutic impact of PDT. We also discuss the effects that photoimmunotherapy (PIT) might have on solid tumor therapeutic strategies.

Nanomaterials for Antiangiogenic Therapies for Cancer: A Promising Tool for Personalized Medicine

“…Another challenge of the cancer TME is hypoxia, which plays a significant role in oxygen-dependent cancer therapies [92]. PDT functions by converting tumor oxygen to reactive singlet oxygen (ROS), which is able to activate the photosensitizer [93]. However, inadequate oxygen within the tumor site attenuates PDT efficiency.…”

“…In addition to the abovementioned PDT to overcome the cancer defense mechanism, PDT has been found to stimulate the suppressed immune system, as shown in Figure 5. Several nanoparticles strategies have been developed to enhance PDT's TME immunosuppressive nature [93]. Chen et al used a hemoglobin and HSA proteinaceous oxygen carrier loaded with a photosensitizer (Ce6).…”

Fibroblast activation protein targeted near infrared photoimmunotherapy (NIR PIT) overcomes therapeutic resistance in human esophageal cancer

“…Once the antibody-IR700 conjugate is bound to its target, subsequent local exposure to NIR light causes physical changes in the shape of antibody antigen complexes that are thought to induce physical stress within the cellular membrane leading to increases in transmembrane water flow that eventually lead to cell bursting, also known as an immunogenic cell death (ICD), in contrast to most other treatments that result in apoptosis. ICD rapidly mature dendritic cells adjacent to dying cancer cells, resulting in re-education and subsequent proliferation of CD8 + T cells against a variety of released cancer antigens, which amplifies the therapeutic effect of NIR-PIT 38 , 39 . NIR-PIT is quite different from the conventional photodynamic therapy (PDT), which uses porphyrin derivatives to produce reactive oxygen species in the cells to induce apoptosis and cytotoxic effect 40 .…”

Development of Non-Porous Silica Nanoparticles towards Cancer Photo-Theranostics

“…In addition to imaging, the application of optics is also being expanded to therapeutic techniques, such as photodynamic therapy (PDT). PDT is a breakthrough medical technique which irradiates only the lesion area with an optical laser, in order to treat cancer without resorting to surgery, further reducing complications [ 32 , 33 ]. Recent research in nanomedicine has been progressing toward the realization of the integration of diagnosis and therapy, termed “theranostics”.…”