Grant: Project Grant

Laryngopharyngeal reflux (LPR), also known as "silent reflux", is the back flow of gastric juice into larynx and pharynx, and affects 20-60% of population in developed countries. Rapid quantification of the digestive enzyme, pepsin, in saliva or laryngeal surface secretion could allow accurate diagnosis and thus effective treatment of LPR. Currently, only lateral flow strip based tests are available for pepsin tests at the point of care (POC), which is limited in detection accuracy and sensitivity. This project aims to develop a novel paper-based microfluidic platform for rapid and accurate detection of LPR protein markers in an automated "sample-in-answer-out" fashion. The platform can perform multiplexed enzyme-linked immunosorbent arrays (ELISAs) of pepsin and two other LPR markers on a paper-based microfluidic chip, and automatically regulate the transport of reagent solutions on the chip, and accurately quantify colorimetric readout signals of the assays. It will be integrated into a handheld device, and does not require human intervention during operation. We will study the correlation of concentrations of LPR biomarkers in saliva and laryngeal surface secretion with conventional diagnostic outputs in individuals with and without LPR, and confirm the most relevant biomarkers for LPR diagnosis. We will evaluate the effectiveness of our microfluidic platform using patient samples, and compare it with the standard laboratory ELISA tests. This project will lead to the next generation of POC diagnostic technology for LPR with high sensitivity, which will facilitate doctors to identify LPR patients without going through time-consuming laboratory tests and thus improve the life quality of the large population of LPR patients.