No more complicated than a pregnancy test
Cancer diagnosis simplified to paper test strips
Copper news based on MIT materials: A paper diagnostic for cancerSpecialists from the Massachusetts Institute of Technology (MIT) have developed a simple and cheap method of rapid testing for oncological diseases.
Cancer diagnosis, by analogy with a pregnancy test, is carried out using a urine sample and a paper test strip, and its result is ready in a few minutes. The work was published on February 24 in the journal Proceedings of the National Academy of Sciences (Warren et al., Point-of-care diagnostics for noncommunicable diseases using synthetic urinary biomarkers and paper microfluidics).
Illustration from the website web.mit.edu
In 2012, a group led by Sangeeta Bhatia presented a concept for the diagnosis of non–communicable diseases using synthetic biomarkers that amplify signals from proteases - enzymes that cleave the peptide bond between amino acids in proteins. In particular, we are talking about tumor matrix metalloproteinases (MMP), which ensure the destruction of extracellular matrix proteins and the migration of cancer cells.
Bhatia and her colleagues created nanoparticles coated with specific peptide substrates to which tumor MMP bind. Once in the body, such nanoparticles passively flock to the sites of accumulation of cancer cells, where tumor MMP cleave their surface peptides. Nanoparticles with cleavage products accumulate in the kidneys and are then excreted in the urine. They can be detected using a mass spectrometer, but scientists have simplified this process by adapting the particles so that they can be detected visually using a "sandwich" method used in test systems for enzyme immunoassay of various infections, as well as in paper pregnancy tests.
On the surface of the nitrocellulose test strips there are antibodies to the peptides covering the nanoparticles – products of cleavage by tumor proteases. After the strip is dipped into a urine sample containing the antigen, it binds with an antibody, and then, as the liquid is absorbed into the paper, reaches several invisible test lines containing specific antibodies to various labeled enzymes associated with peptides. If one of the lines becomes visible, it means that the desired peptide is present in the urine. The authors point out that this technology can be modified to identify different types of peptides characteristic of different types or stages of the disease.
The method was successfully tested on a mouse model using synthetic biomarkers adapted to detect colorectal cancer. In addition, with the help of such technology, the authors were able to diagnose blood vessel thrombosis, which suggests that the method, which does not require expensive equipment and trained personnel, but only the presence of a urine sample and paper test strips, can also be used for rapid diagnosis of cardiovascular diseases.
Bhatia believes that the proposed method has a great future in developing countries. Her group has already received a grant to develop a business plan for the commercialization of the method and the start of its clinical trials.
Portal "Eternal youth" http://vechnayamolodost.ru25.02.2014