Lab-on-Paper Developed for Rapid Inexpensive Medical Diagnostics

A new paper-based platform has been created for conducting a wide range of complex medical diagnostics including Lyme disease, human immunodeficiency virus, Ebolavirus disease and malaria.

The key development was the invention of fluid actuated valves embedded in the paper that allow for sequential manipulation of sample fluids and multiple reagents in a controlled manner to perform complex multistep immune-detection tests without human intervention.

A team of engineers at the University of Rhode Island (URI; Kingston, RI, USA) used the principle of paper-based lateral flow test strips where sample fluid wicks along a strip of paper, reacts with embedded reagents, and produces a colored signal result. However, more complex medical diagnostics such as enzymatic assay protocols require multiple reagents triggered at particular times during the process, which can only be accomplished autonomously using the proprietary microfluidic valve technology created by the engineers.

The lab-on-paper devices are constructed with multiple layers of paper printed with wax to create a three-dimensional structure of valves and channels along which the fluid travels, triggering the reagents at the appropriate time and generating a result. This new paper-based technology is the next generation of the lab-on-a-chip device the team reported in 2011, which has been further refined since then. That device is now smaller and employs an innovative micropump for precise fluid movement within the cartridge's microchannels.

The scientists have already succeeded in performing a feasibility study of their technology by detecting a biomarker for sepsis, a life-threatening complication from an infection. ProThera Biologics (East Providence, RI, USA) identified a biomarker that indicates a patient is going into shock from sepsis, and the company has collaborated with the URI engineers to develop a paper-based rapid test using this biomarker, and have established a startup company, Labonachip LLC (North Kingstown, RI, USA) to commercialize their technologies.

Mohammad Faghri, PhD, a professor of Mechanical Engineering and Applied Mechanics, and inventor of the platform said, “We combined the well-established test strip technology, micro-patterning techniques and our innovative paper-based valves to create a new class of strip tests that are capable of autonomously handling multiple reagents. The sample fluid activates the flow of reagents in a predetermined sequence and time. When combined with an optical reader, which could even be a conventional smart phone, the lab-on-paper device provides accurate quantitative results.”

Related Links:
University of Rhode Island
ProThera Biologics
Labonachip LLC