Intracellular Synchrotron Nanoimaging and DNA Damage/Genotoxicity Screening of Novel Lanthanide-Coated Nanovectors

Abstract

Aims: 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. Materials & 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. Conclusion: 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.

Keywords::

• DNA damage
• functionalized nanovector
• lanthanide
• nanoimaging
• nanoparticle genotoxicity
• synchrotron x-ray fluorescence microscopy

Financial & competing interests disclosure

This work has been supported by UK Medical Research Council (MRC) and Engineering and Physical Sciences Council (EPSRC) Institutional Discipline Bridging Award, Birmingham Children‘s Hospital Research Foundation grant, EPSRC project grant and MRC project grant. The spectrometers used in this research were obtained through Birmingham Science City: Innovative Uses for Advanced Materials in the Modern World (West Midlands Centre for Advanced Materials Project 2), with support from Advantage West Midlands (AWM) and part funded by the European Regional Development Fund (ERDF) The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Additional information

Funding

This work has been supported by UK Medical Research Council (MRC) and Engineering and Physical Sciences Council (EPSRC) Institutional Discipline Bridging Award, Birmingham Children‘s Hospital Research Foundation grant, EPSRC project grant and MRC project grant. The spectrometers used in this research were obtained through Birmingham Science City: Innovative Uses for Advanced Materials in the Modern World (West Midlands Centre for Advanced Materials Project 2), with support from Advantage West Midlands (AWM) and part funded by the European Regional Development Fund (ERDF) The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.