Nanoparticle Cytometrics: a quantitative analysis of the toxic effect of nanoparticles

Lead Research Organisation: Swansea University
Department Name: College of Engineering

Abstract

The last decade has seen an explosion in the development and use of nanoscale technologies and materials and this trend will undoubtedly continue for some time to come. It is clear therefore that human exposure to nanoscale particles will grow dramatically and this has triggered serious concerns over the safety of nanoparticles in relation to human health and the wider ecosystems within which we live. Much of this stems from the paradigm shift incorporated in the move to nano scales which invalidates current chemical risk assessments that are based on bulk properties and hence grossly inappropriate for nano-systems. A marked example of this is provided by noble metals such as Gold; these are traditionally viewed as inert and hence bio-compatible however in nano-particulate form the huge increase in their surface area makes them highly reactive. The issue of surface area has led to the realisation that the quantisation of potential toxins into nano-particulate form is important and that assessment of health risk must take account of specific particle number rather than gross measures of chemical solution based on weight per volume. There is also a growing realisation that the function of particles due to size, shape and chemistry is important. This gap in understanding of chemical hazard at the nanoscale has led to a number of reports from government agencies and royal commissions emphasising the need to develop new measurement techniques to quantify the level of nanoparticle dose and to assess potential toxicity. We propose to use flow cytometry, a laser-based technology, to optically track fluorescent nanoparticles within populations of living cells. This optical measurement approach will be linked to electron microscopy to image particles within cells at the nanoscale. Together these techniques will provide a fully calibrated metrology providing information on number of particles per cell for each and every cell within a measured set (typically a million cells). Our objective is to provide a fundamental understanding of the way in which nanoparticle dose is acquired by cells through natural uptake mechanisms (endocytosis) and then diluted within growing tissue as particles are divided between daughter cells upon cell division (mitosis). A range of cell types will be used to reflect the main exposure routes to nanoparticles, i.e. skin, lung and circulatory (blood) systems. A detailed study of any toxic effects of nanoparticles on the cells will be undertaken and this together with the absolute quantification of dose will allow us to correlate any potential nanotoxicity to the number and form of nanoparticle within a given cell type.

Publications

10 25 50
 
Description We have established that nanoparticle uptake into biological cells is a random process. Through detailed experimental studies we have shown that statistical mathematics can be used to describe the particle uptake and through this probability approach prediction of nanoparticle-cell interactions can be achieved.

In the context of nanotoxicology research we have shown that time dependent studies provide a more accurate assessment of the actual dose delivered to the cell than the standard end-point measurements.
Exploitation Route Using our findings researchers can now accurately predict the nanoparticle dose across a population of cells and the dilution of this dose as the cells divide. This will allow meaningful assessment of the potency of nanomedicines and the toxicity of nanoparticles.
Sectors Environment

Healthcare

Pharmaceuticals and Medical Biotechnology

 
Description EPSRC Platform
Amount £1,250,000 (GBP)
Funding ID EP/N013506/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 02/2016 
End 01/2021
 
Description Joint research programme and student exchange 
Organisation The Methodist Hospital, Houston
Country United States 
Sector Hospitals 
PI Contribution Development of time-mortality based dose-response assays appropriate for the assessment of nanomedicine potency
Collaborator Contribution hosting of students in the US, provision of facilities (EM, animal studies, RF treatment systems), performing experimental studies on nanomedicine-cell interactions in-vitro and in-vivo
Impact Papers published - entered in relevant section PhD student trained and now continuing career as a PDRA in Baylor College of Medicine in Houston
Start Year 2009