Near-infrared-driven upconversion nanoparticles with photocatalysts through water-splitting towards cancer treatment.

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.

Synthesis of Methotrexate-Loaded Dumbbell-Shaped Titanium Dioxide/Gold Nanorods Coated with Mesoporous Silica and Decorated with Upconversion Nanoparticles for Near-Infrared-Driven Trimodal Cancer Treatment.

This study prepared dumbbell-shaped titanium dioxide (TiO)/gold nanorods (AuNRs) coated with mesoporous silica shells (mS) (AuNRs-TiO@mS). Methotrexate (MTX) was further loaded into the AuNRs-TiO@mS, and then upconversion nanoparticles (UCNPs) were decorated to form AuNRs-TiO@mS-MTX: UCNP nanocomposites. TiO is used as an intense photosensitizer (PS) to produce cytotoxic reactive oxygen species (ROS), leading to photodynamic therapy (PDT).