SYNTHESIS OF LUMINESCENT THERANOSTIC NANOCOMPLEXES BASED ON UPCOVERSION NANOPARTICLES AND RECOMBINANT PROTEINS

Theranostics is a rapidly developing field of biomedicine, aimed at the development of multifunctional agents with diagnostic and therapeutic properties simultaneously. This work describes the production of HER2-specific theranostic nanocomplexes based on upconversion nanoparticles and bifunctional proteins. Inorganic nanocrystals of the NaY0.794Yb0.2Tm0.006F4/NaYF4 core/shell structure were used as a platform for the assembly of the multifunctional complex. Upconversion nanoparticles (UCNP) were shown to have pronounced maxima of photoluminescence emission in the visible and infrared regions of the spectrum, which provides effective in vivo imaging of cells and tissues by optical imaging methods. Covering UCNP with additional shells allows achieving their colloidal stability and attaching additional external modules to them. The recombinant targeting toxin DARPin-LoPE, which has specific toxicity against tumor cells expressing the HER2 receptor, was used as a therapeutic module of the nanocomplexes. The theranostic complex NAF-DARPin-LoPE was shown to be able to selectively bind to tumor cells hyperexpressing the HER2 receptor due to the DARPin guide module included in its composition.