WaterSoluble Upconversion Nanoparticles by Micell

Authors: Sounderya Nagarajan Victor Roullier Marian Amela Cortes Muthu Kumara Gnanasamandham Aurélien Dif Fabien Grasset Yong Zhang Valerie Marchi

Publish Date: 2013/04/23

Volume: 3, Issue: 2, Pages: 208-215

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Abstract

Upconversion nanoparticles UCNs have been of interest in applications such as biological imaging and sensing because of properties like low autofluorescence and negligible photobleaching In this paper a micellar encapsulation route was worked upon to make hydrophilic UCNs that are compatible with biological systems and enable conjugation of biomolecules Phospholipid micelles cannot be easily synthesized with chemical recognition groups of biological interest so synthetic amphiphiles with suitable functional head groups were used to encapsulate and solubilize the hydrophobic UCNs The encapsulated nanoparticles were characterized using transmission electron microscopy fluorescence spectroscopy and dynamic light scattering The micelleencapsulated UCNs had an average diameter of 125 nm and the fluorescence emission at 540/660 nm of the bare UCNs did not show any shift after encapsulation The cytotoxicity of the micelleencapsulated UCNs was tested using lactose dehydrogenase/MTS tetrazole salt assays The cell viability was estimated to be 80  at the working concentration of the micelleencapsulated UCNs Finally the micelleencapsulated UCNs bearing ArgGlyAsp tripeptidic RGD surface functionalization were tested on cancer cells expressing integrins for specificity The micelleencapsulated UCNs were found to be suitable for cellular targeting and imaging

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