The development of point-of-care tests – and as of late, for COVID-19 – has been the primary focus of Dr. Katerina Kourentzi, Research Associate Professor of Chemical and Biomolecular Engineering in the William A. Brookshire Department of Chemical and Biomolecular Engineering at the University of Houston's Cullen College of Engineering.
Kourentzi is not a newcomer to UH. After graduating with a degree in Chemical Engineering from the National Technical University of Athens in Greece, Kourentzi completed her doctoral studies in Chemical Engineering at UH in 2002. After a brief career in the biotech industry, she returned to UH and was promoted to Research Faculty in 2009.
“I was introduced to the fascinating and intellectually-stimulating nano-world of biomolecular recognition, and the science behind antibody-antigen interactions, during my graduate studies under Professor Richard C. Willson,” she said. “Beyond their natural role in the immune system, antibodies can be made ex-vivo [by chemical engineers] to be used as therapeutics but also as precise tools in diagnostics to target a specific antigen or pathogen.”
Kourentzi wants to put these antibodies to work to diagnose disease.
“My goal is to develop novel antibody-based diagnostic technologies and enable early disease detection,” she said. “As an engineer, I am very interested in using science and technology to solve society’s problems and help people live better.”
With the unfortunate onset of COVID-19, Kourentzi noted that many people are now much more familiar with terms like rapid point-of-care diagnostics, false positives and false negatives. When it came to her own work, she's interested in further development and improvement of rapid testing, with the home pregnancy test serving as the model.
“The home pregnancy test format – the lateral-flow test – is one of the most remarkable technical developments that anybody ever made,” she said. “After all, you can buy them inexpensively and they allow people at home, with no medical training, to measure human chorionic gonadotropin – the pregnancy hormone – with high reliability, at parts-per-billion concentrations.”
Kourentzi is taking this a step further, creating an inexpensive test for detecting SARS-CoV-2 virus in saliva by looking for the presence of the proteins of the virus.
“These tests can offer fast and scalable solutions,” she said. “Imagine schools and universities being able to test everybody cheaply, quickly and often.”
Kourentzi noted that the test needs to be reliable – not missing any positives – as well as specific – not misidentifying a negative as a positive. However, when it comes to COVID-19, the level of the proteins varies and they can be very low, at parts-per-trillion concentrations. Kourentzi said their team of researchers is up for the challenge.
“We use a novel type of reporter for the visualization of the test 'lines,” she said. “We use innocuous, naturally-occurring but manufacturable bacteriophage virus particles. Think of long, hair-like structures, with lengths of one-thousandth of a millimeter, and a diameter of five millionths of a millimeter. We chemically 'decorate' them with tens of antibodies for specific target recognition and hundreds of enzymes as catalysts for signal amplification. These reporters push the analytical sensitivity of the tests to being 100 to 1000-fold better than the typical reporters used for the visualization of the 'lines' on the home pregnancy test while having low non-specific stickiness. We can use color to see the lines by naked eye or light emission to see the lines by an inexpensive reader or even a smartphone. “
Kourentzi noted that she doesn't work in a vacuum, and she was quick to credit the other members of her research team.
“I am part of a great multi-disciplinary team focused on innovative point-of-care diagnostics together with my colleagues Professor Willson, Professor Jacinta Conrad and Dr. Binh Vu of Chemical Engineering, and a group of very talented graduate students from Chemical Engineering, Biomedical Engineering, Biology and Chemistry.”
Kourentzi stressed that while the current focus is on detecting the coronavirus, the testing platform could be used for other things as well.
“We expect the technology to be broadly useful in other areas of molecular diagnostics and biomedical research,” she said. “Over the last few months, the emphasis has been on SARS-CoV-2 detection, but our bacteriophage platform is going further than COVID-19 diagnosis. Think of a pregnancy test for cancer diagnostics. We are teaming up with Houston Methodist and the MD Anderson Cancer Center, and I hope to share our progress soon.”