Surface modification of upconverting lanthanide-based nanoparticles for improved chemical and colloidal stability

Taras Vasylyshyn
Přednáška cyklu VIS
23.1.2025 10:30, Přednáškový sál A

The lanthanide-doped upconversion nanoparticles (UCNPs) represent a novel class of luminescent materials that recently received a great attention in various bioapplications, such as photodynamic therapy, drug delivery, in vitro/ in vivo imaging, etc. Unlike traditional fluorescent materials, UCNPs have great advantages that include ability to convert low-energy NIR photons into a higher energy visible one, excellent photostability, high signal-to-noise ratio, low autofluorescence and photodamage to biological tissues. However, the significant drawback of UCNPs application consists in their poor colloidal stability, and so called “dark” cytotoxicity, mainly due to a low chemical stability, particle matrix dissolution and subsequent release of lanthanide and fluorides ions in aqueous media. Therefore, there is a need to develop protective polymer coatings to ensure UCNP chemical and colloidal stability in buffers and biological fluids. Moreover, surface modification of the nanoparticle with polymers will also introduce reactive groups, expanding their scope of application. In this work, uniform UCNPs were synthesized via high temperature coprecipitation. The nanoparticles were than surface-modified with various biocompatible macromolecules using different approaches i.e. grafting to or miniemulsion polymerization. Resulting surface-modified particles were characterized in terms of their morphology, chemical and colloidal stability, luminescence, and in vitro/in vivo toxicity. Additionally obtained nanoparticles were loaded with active molecules, such as photosensitizers or fluorescent dyes so that they could be used in photodynamic therapy of cancer or multimodal bioimaging.

Přednáška je vedena v anglickém jazyce