Enabling standardized point-of-care tuberculosis diagnostics via rapid osmotic concentration

PROJECT SUMMARY/ABSTRACT Urine is an attractive biospecimen for point-of-care diagnostics because it can be collected in large quantities with noninvasive procedures. Urine-based lateral flow assays (LFAs) are low-cost devices suitable for point-of-care testing, particularly in low-resource settings. However, many urine-based LFAs exhibit sensitivity levels well below diagnostic utility due to the low concentration of diagnostic biomarkers present in urine. This is the case with LFAs for tuberculosis (TB) diagnostics and is a major barrier to rapid TB testing and treatment in endemic areas. Mainstream clinical and laboratory tests for diagnosing active TB, including bacterial culture, sputum smear microscopy and nucleic acid amplification tests, present limitations in speed, sensitivity, accessibility, respectively. These tests also require sputum samples that present additional difficulty and exposure risks for healthcare staff during the collection procedure. To address this, we developed an osmotic processor that statically and spontaneously concentrates urinary biomarkers for use in LFAs. Urea and small molecules that can interfere with downstream assays are removed in the concentration process. Using human chorionic gonadotropin (hCG) protein as a model analyte, we showed near 100-fold concentration of a 20 mL sample in an early prototype. By exploiting the principles of osmosis, recent prototypes developed by the company show promise in significantly reducing processing time to within 30 minutes. With its simplicity and flexibility, the device demonstrates a great potential to be interfaced with existing LFAs to enable highly sensitive detection of dilute target analytes in urine, while still retaining a diagnostic time suitable for point-of-care diagnostics. The project aims to validate molecule concentration quantitatively with mass spectrometry in newer prototypes, perform spike-and-recovery tests with simulated urine and lab-based LAM, and then test qualitatively with TB-positive clinical samples and LFAs. If awarded the Phase I SBIR grant, the team will hire another full time research scientist, register our device as a General Controls Device through the FDA, continue business collaborations with companies developing LFAs, research other applications of the device to process other biomarkers for diagnostic, disease monitoring and therapeutic purposes, and plan scale-up of device production for commercial distribution in preparation of Phase II.