Intracellular synchrotron nanoimaging and DNA damage/genotoxicity screening of novel lanthanide-coated nanovectors.
OBJECTIVE
In cancer therapy, research has focused on the development of nanocarriers that can aid diagnosis, deliver therapeutic agents and monitor treatment progress. This study introduces high-resolution synchrotron x-ray fluorescence microscopy (SR-XFM) to investigate intracellular localization of novel lanthanide-coated nanoparticles in human cells and their genotoxicity screening after internalization.


METHODS
Noble metal nanoparticles coated with cerium and luminescent europium complexes have been developed as platforms for bioimaging and potential biodelivery applications. The intracellular distribution after internalization has been analyzed by ultrasensitive SR-XFM and genotoxicity evaluated using γ-H2AX DNA damage foci phosphorylation assay.


RESULTS
We demonstrate the unprecedented capability of SR-XFM for extremely sensitive nanoimaging and intracellular elemental distribution analysis of noble metal nanoparticles in cells. Furthermore, we show that, depending on the charge of the coating complex and the presence of the DNA cargo, the internalization of functionalized nanoparticles by human fibroblasts can cause elevated levels of DNA damage detected by histone H2AX phosphorylation.


CONCLUSIONS
The variable genotoxic impact of newly designed nanovectors emphasizes the need for careful and comprehensive testing of biological responses of all new nanoconstructs intended for future clinical applications. This can be greatly facilitated by SR-XFM nanoimaging of nanoparticles in cells at very low concentrations.
Lewis
David J
DJ
School of Chemistry, University of Birmingham, Edgbaston, Birmingham, UK.
Bruce
Christopher
C
Bohic
Sylvain
S
Cloetens
Peter
P
Hammond
Stephen P
SP
Arbon
Darren
D
Blair-Reid
Sarah
S
Pikramenou
Zoe
Z
Kysela
Boris
B
D002460:Cell Line; D004249:DNA Damage / Q000235:genetics / Q000502:physiology*; D003952:Diagnostic Imaging / Q000379:methods*; D006657:Histones / Q000378:metabolism; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods*; D010766:Phosphorylation; D017356:Synchrotrons
C468783:H2AX protein, human; D006657:Histones; D028581:Lanthanoid Series Elements