Quantitative determination of the biodistribution of nanoparticles: could radiolabelling be the answer?
In a recent article co-authored by CIC biomaGUNE (San Sebastian, Spain) and JRC, scientists from the two Institutions discuss the advantages of nanoparticle radiolabelling, the various strategies by which radiolabelling might be achieved, as well as the various difficulties and pitfalls of the technique.
Nanoparticles of different types have a wide range of applications and are incorporated into a number of consumer products, including some foods and cosmetics. Many new applications are under study, including in the field of nanomedicine, for example as targeted drug delivery systems. However, the increased use of nanoparticles has also raised concerns related to potential toxicological effects derived from long term workplace, environmental or consumer exposure. In the biomedical field, the development of nanoparticle applications requires a reliable and convenient strategy for their pharmacological evaluation, while in the field of nanotoxicology a method to quantitatively track the nanoparticles after incorporation or administration into animal models is highly desirable in order to study nanoparticle biokinetics, including nanoparticle passage across biological barriers and possible long term accumulation. In this context, using its MC40 Cyclotron facility, the JRC is researching methods for labelling nanoparticles with gamma emitting radioisotopes in order to facilitate such in vivo studies.
The JRC work on radiolabelling focuses on isotopes of a long enough half-life for tracing studies over several weeks or months, while CIC biomaGUNE up to now has focussed on labelling with shorter-lived isotopes suitable for PET imaging of nanoparticle biodistribution over several hours. Such nuclear imaging techniques require a certain activity concentration to be viable, and where studies over several days, weeks, or even months are required, or in cases where extremely low concentrations of nanoparticles need to be detected, non-imaging methods based on radioactivity measurements on individual organs constitute the most accurate approach. Radiolabelling of nanoparticles may also be used for sensitive and accurate in vitro studies, as well as for other tracing applications such as quantitative evaluation of the environmental transport of nanoparticles or for assessing their possible release from consumer products. European researchers can apply for funded access to the facilities of both JRC and CIC biomaGUNE through the European QualityNano Research Infrastructure: http://www.qualitynano.eu/access.html
Bibliographic reference: Llop J, Gómez-Vallejo V, Gibson P. Quantitative determination of the biodistribution of nanoparticles: could radiolabelling be the answer. NANOMEDICINE 8 (7); 2013. p. 1035-1038. JRC81805
Photo: The M40 Cyclotron at the JRC, Ispra. Copyright EU 2011.