ABSTRACT
Water splitting is promising, especially for energy and environmental applications; however, there are limited studies on the link between water splitting and cancer treatment. Upconversion nanoparticles (UCNPs) can be used to convert near-infrared (NIR) light to ultraviolet (UV) or visible (Vis) light and have great potential for biomedical applications because of their profound penetration ability, theranostic approaches, low self-fluorescence background, reduced damage to biological tissue, and low toxicity. UCNPs with photocatalytic materials can enhance the photocatalytic activities that generate a shorter wavelength to increase the tissue penetration depth in the biological microenvironment under NIR light irradiation. Moreover, UCNPs with a photosensitizer can absorb NIR light and convert it into UV/vis light and emit upconverted photons, which excite the photoinitiator to create H2, O2, and/or OHË via water splitting processes when exposed to NIR irradiation. Therefore, combining UCNPs with intensified photocatalytic and photoinitiator materials may be a promising therapeutic approach for cancer treatment. This review provides a novel strategy for explaining the principles and mechanisms of UCNPs and NIR-driven UCNPs with photocatalytic materials through water splitting to achieve therapeutic outcomes for clinical applications. Moreover, the challenges and future perspectives of UCNP-based photocatalytic materials for water splitting for cancer treatment are discussed in this review.
Subject(s)
Infrared Rays , Nanoparticles , Neoplasms , Water , Humans , Nanoparticles/chemistry , Catalysis , Water/chemistry , Neoplasms/drug therapy , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Animals , Photochemical ProcessesABSTRACT
This study prepared dumbbell-shaped titanium dioxide (TiO2)/gold nanorods (AuNRs) coated with mesoporous silica shells (mS) (AuNRs-TiO2@mS). Methotrexate (MTX) was further loaded into the AuNRs-TiO2@mS, and then upconversion nanoparticles (UCNPs) were decorated to form AuNRs-TiO2@mS-MTX: UCNP nanocomposites. TiO2 is used as an intense photosensitizer (PS) to produce cytotoxic reactive oxygen species (ROS), leading to photodynamic therapy (PDT). Concurrently, AuNRs exhibited intense photothermal therapy (PTT) effects and photothermal conversion efficiency. In vitro results suggested that these nanocomposites can kill oral cancer cells (HSC-3) without toxicity through irradiation of NIR laser, owing to the synergistic effect. The in vivo studies indicated that these nanocomposites exhibited excellent antitumor effects through synergistic PDT/PTT/chemotherapy under a near-infrared (NIR) 808 nm laser irradiation. Thus, these AuNRs-TiO2@mS: UCNP nanocomposites have great potential to undergo deep tissue penetration with enhanced synergistic effects through NIR-triggered light for cancer treatment.
