Near-Infrared Light-Triggered Photodynamic Therapy and Apoptosis Using Upconversion Nanoparticles With Dual Photosensitizers

Abstract

Elucidation of upconversion nanoparticles (UCNPs) that can be excited by nearinfrared (NIR) light is an interesting topic in the field of photodynamic therapy (PDT). However, the PDT efficiency of conventional UCNPs is limited due to the low quantum yield and overheating effect of the 980 nm light source. In this study, a light source with a wavelength of 808 nm was used as an excitation source for Nddoped UCNPs to solve the overheating effect. UCNPs with a core@shell structure (NaYF 4 :Yb,Er,Nd@NaYF 4 :Yb,Nd) were synthesized to increase the upconversion emission efficiency. Dual-color emitting Er-doped UCNPs and dual photosensitizers (Chlorin e6 and Rose Bengal) were used for enhanced PDT. Each photosensitizer could absorb red and green emissions of the UCNPs to generate reactive oxygen species (ROS), respectively. The ROS generation in a dual photosensitizer system is significantly higher than that in a single photosensitizer system. Additionally, PDT induces immunogenic apoptosis. In this study, by utilizing a highly efficient PDT agent, PDT-induced apoptosis was studied by biomarker analysis.

Non-Oncologic Applications of Nanomedicine-Based Phototherapy

“…Therefore, UCNP-based PS was applied to the phototherapy to increase therapeutic efficacy [ 94 ]. Another recent study used the conjugation of UCNP with dual PSs (chlorin e6 and Rose Bengal) for greater ROS generation than single PS-based PDT [ 95 ].…”

Escherichia coliadhesin protein-conjugated thermal responsive hybrid nanoparticles for photothermal and immunotherapy against cancer and its metastasis

“…PDT uses light to excite the photosensitizer, which then forms cytotoxic reactive oxygen species that kill tumor cells. 43 In this study, we selected ICG for incorporation into the HNPs; it can be used to load photosensitizers for PDT in the HNPs.…”

Photoresponsive Hydrogels as Drug Delivery Systems

“…These upconversion nanoparticles have been studied and are continually being developed for photodynamic therapy in cancer due to their ability to deliver chemotherapeutic drugs in to the tumor microenvironment. 26,27 The use of light or laser to control the release and activation of chemotherapeutic drugs on site reducing the toxicity towards healthy surrounding cells or tissue have made such an impact on cancer research.…”