Onion-like surface design of upconverting nanophosphors modified with polyethylenimine

shielding toxicity versus keeping brightness?

Anna Guller, Annemarie Nadort, Alla Generalova, Inna Kornienko, Elena Petersen, Yi Qian, Anatoly Shekhter, Ewa Goldys, Andrei Zvyagin

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

Abstract

Background: Upconverting nanoparticles (UCNPs) represent a unique class of nanomaterials, able to convert infrared excitation light into long lifetime visible and infrared photoluminescence, within the "optical transparency window" of biological tissues. This makes UCNPs an attractive contrast agent for background-free bioimaging. However, assynthesized UCNPs are hydrophobic and need additional surface coating for stability in water-based solutions and further functionalization. Polyethylenimine (PEI), a polycationic amphiphilic polymer, is a well-known transfection agent for gene delivery and a popular material for UCNPs surface hydrophilization. Combining the functional properties of UCNPs and PEI is extremely useful for precise visualization of genetic manipulations and intracellular drug delivery. At the same time, PEI is toxic to cells, while the photoluminescent properties of UCNPs are very sensitive to surface chemistry and environment. Then, creation of hydrophilic, biocompatible and simultaneously bright UCNPs, modified by PEI (UCNP-PEI), is a challenging task. 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.

Original languageEnglish
Title of host publicationSPIE BioPhotonics Australasia
EditorsMark R. Hutchinson, Ewa M. Goldys
Place of PublicationBellingham, Washington
PublisherSPIE
Pages1-5
Number of pages5
ISBN (Electronic)9781510604353
ISBN (Print)9781510604346
DOIs
Publication statusPublished - 2016
EventSPIE BioPhotonics Australasia - Adelaide, Australia
Duration: 17 Oct 201619 Oct 2016

Publication series

NameProceedings of SPIE
PublisherSPIE
Volume10013
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Other

OtherSPIE BioPhotonics Australasia
CountryAustralia
CityAdelaide
Period17/10/1619/10/16

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Keywords

  • brightness
  • cytotoxicity
  • polyethylenimine
  • skin
  • surface modification
  • upconversion nanoparticles

Cite this

Guller, A., Nadort, A., Generalova, A., Kornienko, I., Petersen, E., Qian, Y., ... Zvyagin, A. (2016). Onion-like surface design of upconverting nanophosphors modified with polyethylenimine: shielding toxicity versus keeping brightness? In M. R. Hutchinson, & E. M. Goldys (Eds.), SPIE BioPhotonics Australasia (pp. 1-5). [100132Q] (Proceedings of SPIE; Vol. 10013). Bellingham, Washington: SPIE. https://doi.org/10.1117/12.2244636