Imagine what it would look like if carrying out a disease or cancer test was as simple as carrying out a home pregnancy or blood sugar test, well this might be possible in a few years’ time.
Ongoing research by a team of chemists at The Ohio State University is aimed towards the invention of paper strips that make the detection of diseases such as malaria and cancer possible at a meager price of 50 cents for each strip.
Abraham Badu-Tawiah stated that the process involved the application of a single drop of blood by the user, which was then sent regularly to a laboratory. The users visited a doctor only in cases where the test returned positive results. Up to one month after blood samples were collected and the test conducted, the results were found to be valid, leaving the possibility for these strips to be utilized in rural areas.
The Ohio State University Assistant Professor of chemistry and biochemistry saw the strips as a means to offer affordable malaria diagnostic tool to people in remote areas of Southeast Asia and Africa where thousands of people have been infected and subsequently killed by the disease yearly.
However, alongside his colleagues, in the American Chemical Society journal, it was asserted that strips could be doctored to identify diseases such as cancer of the large intestine and ovarian cancer.
According to Badu-Tawiah the technology, waiting to be patented, could make the diagnosis of diseases available to the most vulnerable people – people who were unable to afford personal medical examination or without direct access to health officials or medical practitioners.
He further stated that the motive behind the development of the strips was to equip people. People could test themselves at home, thereby eradicating the need for frequent visits to the hospital at the onset of any symptoms of ill health.
A similar technology to that used in the strip can be found on the diagnostics commonly referred to as “lab-on-a-chip“, but in the case of the strips plain sheets of white paper were glued on either side by adhesive tape prior to running them through a regular ink jet printer, in contrast to the plastic used in “lab-on-a-chip”.
The researchers sketched reservoirs and channel outlines using wax ink, as opposed to conventional ink. Upon piercing the paper, the wax stores blood samples in between different layers through the formation of a waterproof barrier. Dozens of separate tests can be conducted on a sheet of paper with a dimension of 8.5 x 11-inch, which could then split into strips more or less equal in size to a postage stamp.
According to Badu-Tawiah, a drop of blood had to be placed on the strip, followed by the folding of the strip into two equal parts which were then enclosed in an envelope and sent to a the laboratory for the test to be conducted.
The principle behind the operation of the strips varied with medical diagnostics that involved the use of paper strips such as DIY pregnancy tests where paper strips were overlaid with gold nanoparticles or enzymes that made their color to change. Rather tiny, positively charged artificial chemical probes were contained in the paper strips. The presence of these ionic probes made for impeccable detection using a handheld mass spectrometer.
Badu-Tawiah stated that enzymes, being selective, couldn’t be stored in a moist state and needed to be protected from light exposure and have just the right temperature. As opposed to the enzymes, ionic probes were durable, able to resist the impact of temperature, humidity and light – they could even endure the heat in Africa. This gave the assurance that they could be sent to hospitals without fear of them being compromised and not readable at the arrival to the hospital.
The ionic probes were designed in such a way that they were able to tag precise antibodies responsible for disease extraction onto the paper strip directly from the blood. Once that was done, the paper retained its color, and the color could only be changed at the laboratory by inserting it into a solution of ammonia. The layers between the paper strips were then removed before a mass spectrometer which had the ability to spot the existence of biomarkers in the blood of an infected individual through the detection of the probes, which is carried out by analyzing their atomic features.
A team of postdoctoral researchers, Qiongqiong Wan, Suming Chen and Badu-Tawiah was able to show that the paper strips could successfully detect the presence of protein biomarkers from Plasmodium falciparum, which happened to be the most widely occurring malaria parasite in Africa.
The team was also able to detect, inter alia, the marker for cancer of the large intestine, the carcinoembryonic antigen, and cancer antigen 125 which is the protein biomarker responsible for ovarian cancer.
They collaborated with Yang Song, an ex-doctoral student, in the laboratory of chemistry and biochemistry professor, Vicki Wysocki, managing director of the Ohio Campus Chemical Instrument Center and is also a distinguished Macromolecular Structure scholar in Ohio University. With the aid of a high-resolution mass spectrometer they examined the process through which the antibodies were attached to the probes.
The team of researchers led by Badu-Tawiah, after asserting that the tests were successful, safely put aside the strips, only testing them several days apart to observe whether there was a deterioration in the signal the mass spectrometer had previously detected. The signal remained the same, implying the disease proteins were steady and could be detected up to one month later.
According to Badu-Tawiah, since the antibody strips were unaffected by the duration it took for the strips to get in to the laboratories, they have the possibility of revolutionizing healthcare not only for residents in remote places, but also for those living in the United States. The paper strips would also be beneficial to those in urban areas, as it would provide a cheap means of testing oneself without the hassle of going to the hospital.
He further stated that the tests would be a huge plus for residents of the United States who were already treated for cancer, or whose families had a record of cancer. They now had the means to regularly test themselves at home, rather than waiting for bi-annual remission confirmation from their physicians upon visiting the hospital.
The financial and personnel requirements needed to tackle malaria are huge, particularly in Africa. Parasites cause malaria, but mosquitoes are the vectors of malaria. Infection usually begin with symptoms that mimic flu, but that could possibly spiral into other complications such as kidney failure. It is estimated by the Centers for Disease Control and Prevention that 214 million incidents of malaria took place in 2015 on a global scale, with a majority of the 438,000 fatalities being mainly African children. Badu-Tawiah stated that malaria was so prevalent in Africa that any incidence of fever is commonly thought to be a symptom of malaria.
Adding that test models of the strips were produced with a unit cost of 50 cents per strip, but large scale production is expected to drive the figures further downwards. Healthcare facilities in urban centers would have to bear the major financial burden associated with using the strips, as mass spectrometers would have to be purchased in order to read test results. Cheaper handheld versions are currently at the developmental stage, but some mass spectrometers of about $100,000 are already available in the market.
However, Badu-Tawiah opined that any investment in production or purchase of mass spectrometers would be compensated for by the benefits it would bring to the economy of Africa. It is estimated by UNICEF that malaria is responsible for loss in the productivity of workers amounting to $12 billion annually.
The availability of mass spectrometers in the United States will lead to reduction in personal expense on healthcare and insurance.
Badu-Tawiah stated that the sustainable paper strips are worthy investment, despite their cost implication. Furthermore, he said portable mass spectrometers could be installed at shops where groceries are sold, and users would have to pay only 50 cents for a test. A similar, perhaps less expensive, approach will be implemented in Africa.
Medical diagnostics companies could obtain license from the university in order to improve the technology. Badu-Tawiah said he was optimistic that he would be able to test people with the strips in a hospital environment in less than three years. For now he is working with his colleagues to increase the sensitivity of the tests, so that people could be tested using urine or saliva, as against blood that is currently needed for test.