ИСТИНА

The development of photosensitizers for photodynamic therapy of tumors is a promising area of high-tech industry. Photosensitizers (PS) are compounds that contain a molecule that generates reactive oxygen species (ROS) when absorbing a quantum of light. When the tumor tissue is illuminated, the PS in it produce ROS, which leads to cell death. Modern PSs belong to the second generation and are organic dyes of a certain configuration, there are some drugs based on them (Photofrin, Photosens, Radachlorin, Verteporfin, etc.) recommended for clinical use. The most significant challenges in this technology are a) delivery of PS to the target of therapy and b) increasing the ability of PS to produce ROS. As a result, third-generation PS with high specificity and efficiency of photodynamic action can be created. Various nanoparticles (NPs) are usually considered as platforms for the delivery of photosensitizer molecules. The most significant problem associated with the use of nanoparticles in biology is nonspecific cytotoxicity, which reduces the biocompatibility and bioavailability of materials based on nanoparticles. In addition, in vivo NPs are covered by the so-called protein crown, which leads to a change in the surface properties of NPs and can cause autoimmune processes. To create a third-generation PSs, we propose to use carbon-based nanoparticles - carbon nanodots (cND). cNDs are synthesized by the hydrothermal method using low molecular weight organic precursors. The source material can be any organic molecule; unlimited possibilities for selecting combinations of materials and their ratios make it possible to obtain cNDs with a wide range of properties, to perform screening with the selection of nanoparticles with the highest biocompatibility. In this aspect, cND potentially outperform not only metal and semiconductor analogs, but also the most studied carbon nanoparticles (nanotubes, fullerenes). In addition, cNDs exhibit luminescence, the parameters of which (quantum yield, luminescence duration) are comparable to those of semiconductor quantum dots. Thus, cNDs can act as a light-harvesting antenna for PS molecules, enhancing their photodynamic activity. The NP must transfer the received energy to the acceptor (PS) nonradiatively, for example, using an inductive-resonance mechanism. Broader opportunities open up for using the infrared region of the spectrum for PS pumping due to the greater penetration depth of infrared light into biological tissues.