Photodynamic Therapy and Its Role in Combined Modality Anticancer Treatment

Abstract

Photodynamic therapy (PDT) is a relatively new modality for anticancer treatment and although the interest has increased greatly in the recent years, it is still far from clinical routine. As PDT consists of administering a nontoxic photosensitizing chemical and subsequently illuminating the tumor with visible light, the treatment is not subject to dose-limiting toxicity, which is the case for established anticancer treatments like radiation therapy or chemotherapy. This makes PDT an attractive adjuvant therapy in a combined modality treatment regimen, as PDT provides an antitumor immune response through its ability to elicit the release of damage-associated molecular patterns and tumor antigens, thus providing an increased antitumor efficacy, potentially without increasing the risk of treatment-related toxicity. There is great interest in the elicited immune response after PDT and the potential of combining PDT with other forms of treatment to provide potent antitumor vaccines. This review summarizes recent studies investigating PDT as part of combined modality treatment, hopefully providing an accessible overview of the current knowledge that may act as a basis for new ideas or systematic evaluations of already promising results.

Encapsulating pH‐Responsive Doxorubicin–Phthalocyanine Conjugates in Mesoporous Silica Nanoparticles for Combined Photodynamic Therapy and Controlled Chemotherapy

“…It utilizes the combined action of a photosensitive drug, light with appropriate wavelength, and molecular oxygen to produce cytotoxic reactive oxygen species (ROS), such as singlet oxygen, causing damage to tumor cells and tissues. While PDT can be a stand‐alone anticancer modality, combining PDT with other therapeutic methods could induce different cytotoxic pathways, resulting in enhanced therapeutic efficacy . The recent advances in nanotechnology enable the incorporation of various pharmaceutical components in a single nanoplatform, which has greatly promoted the development of “combo” nanomedicine .…”

“…While PDT can be as tand-alone anticancer modality, combining PDT with other therapeutic methods could induce different cytotoxic pathways, resulting in enhanced therapeutic efficacy. [3] The recent advances in nanotechnology enable the incorporation of various pharmaceutical components in as ingle nanoplatform, which has greatlyp romoted the development of "combo" nanomedicine. [4] Photonanomedicine, in particular, is of much current interest.…”

Zinc phthalocyanines attached to gold nanorods for simultaneous hyperthermic and photodynamic therapies against melanoma in vitro

“…The authors found that PDT was more effective than hyperthermia when applied separately, but the combination of treatments reduced the viability of B16F10 cells to about half that of PDT alone [23]. Other authors observed similar results for the combination of both therapies, and their results can be found in Brodin's review study [24]. …”

A safety study of a novel photosensitizer, sinoporphyrin sodium, for photodynamic therapy in Beagle dogs

“…40 Recently, photoimmunotherapy (PIT) has become a research topic of interest, such as PDT in combination with immunostimulants. 41,42 Additionally, another promising option is anticancer vaccination using immature DCs that have been treated with PDT. 43 …”