Objectives: To analyze the effects of multilayer shielding coatings on cytotoxicity, cellular uptake and photoluminescent properties of UCNP-PEI.
Methods and results: UCNP-PEI were modified with additional two or three layers of various polymers and characterized by size, surface charge and photophysical properties. HaCaT keratinocytes were exposed to the particles for 24 or 120 h to study the cytotoxicity and cellular uptake. The results show that onion-like coatings of UCNP-PEI simultaneously decrease cytotoxicity and relative luminescence of the particles, depending on structure and method of formation of multilayer coating.
Conclusions: Rational design of UCNP-PEI using extra coatings layers can help to keep acceptable levels of biocompatibility and photoluminescence intensity.