Kontrastní látky na bázi upkonverzních nanočástic pro použití v biomedicíně

Mrázek, Jiří

Upconverting nanoparticles (UCNP) represent an interesting class of contrast agents for biomedical applications due to their ability to convert infrared light into the visible or even UV region of the spectrum. The aim of this work was to prepare UCNP with bound hyaluronan (HA), a natural polysaccharide, and to investigate their interaction with cells in vitro. The reproducibility of the synthesis of β-Na(RE)F4 UCNP was demonstrated in a series of 15 consecutive preparations. Particles with different ratios of RE elements (Yb, Gd, Y, Lu, Er, Tm) with emission spectra covering the range from NIR to UV and advanced core/shell type UCNP with different combinations of core/shell material were prepared. The layer-by-layer shell growth method allowed to control the particle size. Hydrophobic UCNP were incorporated into oleyl-HA micelles. The UCNP@oleyl-HA micelles were stable in buffers and in cell culture media, where they effectively limited the quenching of UCNP luminescence. The second method of UCNP modification consisted of sorption of HA-furanyl onto particles followed by photochemical crosslinking. The UCNP@HA-furanyl particles with a hydrodynamic diameter of ~180 nm formed stable colloids in cell culture media. UCNP@oleyl-HA micelles reduced the viability of MDA-MB-231 cancer cells but were...

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