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Findings from University of California Broaden Understanding of Nanoparticles (Potential Toxicity of Up-Converting Nanoparticles Encapsulated with a...

August 22, 2014



Findings from University of California Broaden Understanding of Nanoparticles (Potential Toxicity of Up-Converting Nanoparticles Encapsulated with a Bilayer Formed by Ligand Attraction)

By a News Reporter-Staff News Editor at Science Letter -- Investigators discuss new findings in Nanoparticles. According to news reporting originating from Davis, California, by NewsRx correspondents, research stated, "The cellular toxicity of nanoparticles that were capped with a bilayered ligand was studied using an up-converting (UC) phosphor material as a representative nanoparticle (NP). The results indicate that although UC NPs are known to be nontoxic, the toxicity of the NPs depends strongly on ligand coordination conditions, in addition to the other commonly known parameters such as size, structure, surface charge etc."

Our news editors obtained a quote from the research from the University of California, "Oleate-capped hydrophobic NaYF4:Yb,Er NPs were surface modified to yield three extreme conditions: bare particles that were stripped of the oleate ligands; particles with covalently bound poly(ethylene glycol) (PEG) ligands; and particles with an bilayer of PEG-oleate ligands using the oleate surface group that was remained after synthesis. It was found that the bare particles and the covalent PEG NPs induced little toxicity. However, particles that were rendered biocompatible by forming a bilayer with an amphiphilic ligand (i.e., PEG-oleate) resulted in significant cell toxicity. These findings strongly suggest that the PEG-oleate group dissociated from the bilayered oleate-capped NPs, resulting in significant toxicity by exposing the hydrophobic oleate-capped NPs to the cell. Based on results with bare particles, the NaLnF(4):Yb,Er (Ln = Y, Gd) up-converting phosphors are essentially less-toxic."

According to the news editors, the research concluded: "Capping and functionalizing these particles with ligand intercalation may, however, not be a suitable method for rendering the NPs suitable for bioapplication as the ligand can potentially dissociate upon cellular interaction, leading to significant toxicity."

For more information on this research see: Potential Toxicity of Up-Converting Nanoparticles Encapsulated with a Bilayer Formed by Ligand Attraction. Langmuir, 2014;30(27):8167-8176. Langmuir can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Langmuir - www.pubs.acs.org/journal/langd5)

The news editors report that additional information may be obtained by contacting G.K. Das, University of California, Dept. of Mech & Aerosp Engn, Davis, CA 95616, United States. Additional authors for this research include D.T. Stark and I.M. Kennedy (see also Nanoparticles).

Keywords for this news article include: Davis, California, United States, Nanotechnology, Emerging Technologies, North and Central America

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Science Letter


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