Nanocomposite material with enhanced photodynamic activity and preparation method thereof

Abstract

The invention provides a nanocomposite material with reinforced photodynamic activity and a preparation method thereof. The nanocomposite material is an up-converting nanocrystal @SiO2@TiO2 / Au, and iscomposed of an up-converting nanocrystal, SiO2 and TiO2 shells successively coated at the periphery of the up-converting nanocrystal, and Au nanoparticles deposited on the surface of the TiO2 shell,wherein the TiO2 shell is a porous TiO2 shell composed of nanoparticles; the nanocomposite material has a particle size of 40 to 98 nm; and the particle size of the Au nanoparticles is 3.0 to 20.2 nm.The preparation method comprises the following steps: (1) coating the TiO2 shell onto a SiO2 coated up-converting nanocrystal through a controlled hydrolysis method; and (2) loading the Au nanoparticles onto the surface of TiO2 through a photochemical method. The nanocomposite material provided by the invention has the following advantages: simple and highly-efficient preparation process, uniformproduct morphology, good controllability in constitution and sizes, strong ability of generating reactive oxygen species, excellent photodynamic activity, and good application prospect in the field of photodynamic therapy.

Description

technical field [0001] The invention relates to the technical field of nanomaterial preparation, in particular to a nanocomposite material with enhanced photodynamic activity and a preparation method thereof. Background technique [0002] In recent years, the increasing incidence of cancer has seriously threatened human health and life. Traditional cancer treatment methods have some disadvantages: surgery is difficult to deal with the spread of cancer cells and will cause serious body trauma, radiotherapy and chemotherapy have poor treatment selectivity for tumor cells and large side effects. In contrast, photodynamic therapy is a non-invasive cancer treatment method that uses incident light to irradiate photosensitizing drugs that are enriched in tumor tissues, and the photosensitizing drugs are generated in a series of photophysical and photochemical processes, including singlet oxygen. The reactive oxygen species (ROS) can kill tumor cells and realize the treatment of ca...

AI Technical Summary

Problems solved by technology

However, due to the generally low quantum yield of upconversion nanocrystal luminescence while TiO 2 The photogenerated electron-hole recombination is easy to occur, which leads to the energy conversion efficiency of this kind of inorganic photosensitizer is very low in general, which is manifested as the weak ROS generation ability and the photodynamic activity needs to be improved.

In addition, the surface modification of functional molecules is the upconversion nanocrystal-TiO 2 The premise of the in vivo application of composite particles, the above-mentioned literature uses the silane coupling modification of TiO 2 surface, and then coupling to modify molecules, but the modification of the silane coupling agent consumes TiO 2 Partial hydroxyl groups on the surface, closed TiO 2 Part of the photocatalytic active sites on the surface, resulting in further weakening of the photodynamic activity of the drug

In this case, in order to maintain the effective dose required for photodynamic therapy, the power density of the near-infrared excitation light must be increased, which will increase the risk of skin burns by the near-infrared light with significant thermal effects

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