UNIFORM CORE-SHELL TIO2 COATED UPCONVERSION NANOPARTICLES AND USE THEREOF

摘要

An upconversion nanoparticle (UCN) coated with a layer of semiconductor material is disclosed. The UCN core acts as a nanotransducer to convert near infrared (NIR) to visible and/or ultraviolet (UV) light while the semiconductor shell serves as a photocatalyst. Upon excitation by NIR light, the UCN upconverts NIR light to UV and/or visible light of different wavelengths. Spectral overlap between the emitted UV and absorption wavelength of the coated TiO2 activates the TiO2 layer to generate cytotoxic reactive oxygen species (ROS), which can be used in photodynamic therapy for the treatment of cancer cells. Stability and uptake of the nanoparticles can be increased by altering the coating of the nanoparticle, such as by a polymer and a dispersion stabilizer.

主权项

1. A nanocomposite for photodynamic therapy, comprising:
an upconversion nanoparticle, wherein the nanoparticle, upon excitation by near infrared light, emits light of a wavelength from about 330 nm to about 675 nm; and a continuous and uniform outer coating on the outer surface of the nanoparticle, the coating comprising a semiconductor material, wherein the light emitted from the nanoparticle is of a wavelength sufficient to excite one or more electrons from a valence band of the semiconductor material to the conduction band of the semiconductor material, and the semiconductor material, after excitation, is of an energy sufficient to generate at least one reactive oxygen species.