Research staff at the University of Oviedo have evaluated the latest methods for detecting individual cells and measuring their elemental content, with the aim of being able to differentiate between healthy and tumour cells and the response to certain therapies - for example, with platinum compounds. The work brings together advances in the use of inductively coupled plasma source mass spectrometry (ICP-MS) for measuring individual cells. The research has led to the conclusion that the most efficient methods for feeding cells into the ICP-MS for measurement are those that work with an aerosol that ensures that the cells do not break, and can therefore be introduced intact. In this way, the more cells that are introduced into the ICP-MS, the more likely it is that they will be correctly detected. That is to say, distinguishing one cell from another and observing possible differences in the behaviour of some of them - for example, when a tumour is developing or in response to a drug. The conclusions have been published in an article in the journal "Trends in Analytical Chemistry" and signed by Mario Corte Rodríguez, Roberto Álvarez-Fernández García, Paula García Cancela, María Montes Bayón and Jörg Bettmer, from the Asturian academic institution's Research Group on Mass Spectrometry and Biomedical Analysis ("EMAB" by its Spanish acronym). 

 

One of the lines of work of this research group consists in the detection of each of the cells from a sample by means of the ICP-MS technique, which is capable of measuring the quantity of many biologically interesting elements (such as phosphorus, copper, iron, zinc etc) there are in each cell. It also enables metals present in some drugs to be measured - such as platinum in the anti-tumour cisplatin. In addition, by using markers such as antibodies, the presence of specific types of cells can be detected, which could allow early detection and identification of some types of tumours. 

 

This technique has also been used by the EMAB group to detect metallic nanoparticles, which are in the order of 100 times smaller than a cell. The use of artificial nanoparticles is increasingly widespread in industry, technology, food and medicine. They are found in uses as varied as preventing bacterial growth (silver nanoparticles in textiles), providing a white colour to food (titanium dioxide nanoparticles in chewing gum and sweets, for example) or as a carrier for medicines (iron nanoparticles for the treatment of anaemia). However, certain nanoparticles are also naturally produced in some microorganisms as a means of detoxification. 

 

The research team has used the ICP-MS technique to detect each of the individual nanoparticles generated inside yeast cells exposed to a selenium-rich environment, which is a common technique for producing selenium nutritional supplements. In combination with other techniques, this study has concluded that yeasts exposed to selenium generate nanoparticles as a means of accumulation and to reduce their toxicity. This technique has also been shown to be useful in detecting counterfeits of these dietary supplements, as it allows for the differentiation between the addition of types of selenium that are poorly bioavailable and yeasts actually grown in selenium-rich environments, which incorporate selenium and produce compounds that are actually beneficial to the body.