Pathologists and clinical laboratory managers may soon see this innovative combination of diagnostic technologies used in developing nations
There is now a technology that combines synthetic biomarkers with a paper-based urine test that can detect colorectal cancer and thrombosis in just a few minutes. Medical laboratory tests incorporating this diagnostic technology would be accurate, cheap, and simple enough to perform in developing countries.
Researchers at Massachusetts Institute of Technology (MIT) say that the new technology opens the door to development a cheap diagnostic tool for a range of noncommunicable diseases (NCD). This could revolutionize diagnostic testing of NCDs, with particular significance for developing countries.
Existing Diagnostic Technologies Used in a New Way
The new technique uses exogenous agents injected into the patient. These agents bind with tumor proteins. A paper strip test then easily detects the synthetic biomarkers in the patient’s urine. The molecular detection system brings a number of existing technologies together in a new way, reported a story published at gizmodo.com. The result is a new method of cancer signal amplification.
“This is a clever and inspired technology to develop new exogenous compounds that can detect clinical conditions with aberrantly high protease concentrations,” stated Samuel Sia, Ph.D., Associate Professor of Biological Engineering at Columbia University, in an MIT news release. “Extending this technology to detection by strip tests is a big leap forward in bringing its use to outpatient clinics and decentralized health settings,” he added. Sia was not involved in the research.
Synthetic Biomarkers Amplify Weak Signals from Diseased Tissue
Biomarkers produce very weak signals, according to the MIT study, which was published in the Proceedings of the National Academy of Sciences (PNAS). This makes tumors hard to detect with biomarkers. The MIT researchers sought to amplify these signals in a way that could lead to a detectable biomarker. They focused on one group of signals called matrix metalloproteinases (MMPs). MMPs function to help cancer cells to metastasize.
MIT graduate student Andrew Warren and his colleagues designed two synthetic biomarkers, according to a story published online by The Scientist Magazine. They coated nanoparticles with short protein fragments that bind with different MMPs. Each MMP molecule causes the release of hundreds of peptide fragments, which collect in the kidneys and clear in the urine.
The team directed one biomarker at colorectal cancer tumor proteins and the other biomarker was directed at thrombosis. Next, they injected mice with the target-specific nanoparticle solution. They then used a multiplexed paper lateral flow assay (LFA) to detect the presence of the biomarkers in the urine of the mice. (LFA is the same technology used in pregnancy tests.)
Previously, detection of such peptides in urine required the use of an expensive mass spectrometer, the study authors pointed out. “Together, the LFA and injectable synthetic biomarkers… form a generalized diagnostic platform for NCDs that can be applied in almost any setting without expensive equipment or trained medical personnel,” they wrote in PNAS.
New Approach Promises Better Diagnostics for Developing Countries
NDCs, such as cancer, stroke, and heart disease, constitute an increasing majority of global mortality, the authors pointed out in their paper. Further, in many parts of the world, people cannot afford expensive diagnostic tests to detect early-stage disease, noted a reporter in a story published on CNET.com. This means cheaper, faster, simpler diagnostic tools are of growing importance to global health.
“When we invented this new class of synthetic biomarker, we used a highly specialized instrument to do the analysis,” remarked senior MIT study author Sangeeta Bhatia, M.D., Ph.D., Director, Laboratory for Multiscale Regenerative Technologies, and Professor at MIT, in the news release. “For the developing world, we thought it would be exciting to adapt it instead to a paper test that could be performed on unprocessed samples in a rural setting, without the need for any specialized equipment. The simple readout could even be transmitted to a remote caregiver by a picture on a mobile phone,” she said.
Low-Cost Medical Laboratory Diagnostics on a Global Scale
The investigators expect that the new technology will be compatible with a broad variety of diagnostic technologies. In addition, the approach could be tailored to additional NCDs, along with infectious diseases, they wrote in PNAS. This would go a long way toward meeting the challenge of providing low-cost diagnostics on a global scale.
According to Bhatia, her team plans to develop biomarkers to detect breast and prostate cancers, CNET reported. “Eventually, we would hope that all solid tumors could be detected this way,” she stated.
As the push for increasingly faster, cheaper, simpler and more accurate diagnostic tests accelerates, pathologists and clinical laboratory managers can expect a growing number of medical laboratory and anatomic pathology tests for both noncommunicable and infectious diseases to be performed outside of traditional healthcare settings.
—by Pamela Scherer McLeod