Nanoparticle-Based Photodynamic Therapy: Current Status and Future Application to Improve Outcomes of Cancer Treatment

Abstract

Photodynamic therapy (PDT) is an emerging cancer treatment that uses photosensitizers (PS), along with light to activate them, resulting in oxidation of various biological components in cancer tissues. However, since most potential PS are solubilized and given as aqueous solution, PS is non-specifically distributed in the body, leading to the induction of various side effects in normal tissues that are exposed to daylight such as skin and eyes. To overcome the problem associated with non-specific in vivo disposition of PS, various approaches have been applied to develop safer dosage forms for PS with more efficient tumor delivery and lower disposition to normal tissues. Passive drug targeting to tumors with nanoparticulate formulations has been recognized as one of the potentially useful approaches to improve the poor tissue specificity of conventional cancer chemotherapy and this approach should also be applicable for more efficient tumor delivery of PS. In this review article, several issues concerning the efficacy of PDT using nanoparticle-based formulations are discussed and our recent attempts to temporally enhance the vascular permeability within tumors with photodynamic treatment for the better therapeutic outcome of nanoparticle-based therapy are introduced.

Recent Advances in Nanotheranostics for Treat‐to‐Target of Rheumatoid Arthritis

“…Research shows near‐infrared (NIR) light can efficiently penetrate inflamed joints affected by RA, thus phototherapy based on nanomaterials may provide new opportunities for the treatment of RA 119. In PDT, photosensitizers generate ROS such as singlet oxygen ( 1 O 2 ), superoxide, hydrogen peroxide, and hydroxyl radical under light stimulation to kill cancer or inflammatory cells 120–122. In parallel, the photothermal conversion agents covert NIR light into localized heat for destroying disease regions 123,124.…”

Near Infrared-Activated Dye-Linked ZnO Nanoparticles Release Reactive Oxygen Species for Potential Use in Photodynamic Therapy

“…Confluent HUVEC were exposed to ZnO NPs, Dye 847-ZnO NPs, or Dye 847 alone at varying concentrations (10,20,30,40,50,100, 300 and 500 µg/mL) for 24 h to test their cytotoxicity ( Figure 1). HUVEC viability in the presence of ZnO NPs was concentration-dependent, with significant losses in viability above 100 µg/mL.…”

“…The biggest drop in viability for these dye-linked NPs occurred at 100 μg/mL, followed by sudden increases thereafter from 300 to 500 μg/mL, which may be due to aggregation of the NPs that resulted in a limited uptake of large aggregates into cells. Since the viability of HUVEC showed minimal change upon exposure to lower concentrations (10,20, and 30 μg/mL) of Dye 847-ZnO NPs but decreased as the concentration increased, particle surface modification with the hydrophilic polymer PEG was hypothesized to increase Dye 847-ZnO particle biocompatibility. .…”

“…Photodynamic therapy (PDT) requires the production of these cytotoxic reactive species after activation of the photosensitizer by wavelength-matched light to initiate cell killing [7][8][9]. After excitement of the photosensitizer upon light irradiation, electrons return to the ground state and release the excess energy, which reacts with available molecular oxygen, generating ROS such as singlet oxygen ( 1 O 2 ), hydrogen peroxide, or superoxide anions [10][11][12][13]. PDT can be harnessed to kill unwanted cells, such as those in cancerous tumors.…”

An insight on the role of photosensitizer nanocarriers for Photodynamic Therapy

“…Master et al 2013). NPs, with a size ranging from 1 to 100 nm, reveal unique physical and chemical properties and are being exploited to deliver PSs, in order to improve the current treatment regimens in PDT (Chatterjee et al 2008, Konan et al 2002, Master et al 2013, Ogawara and Higaki 2017.…”