Magnetization of hydrogel particles: a novel urine tuberculosis antigen test

L. Paris, A. Cox, E. Petricoin, L. Liotta, A. Luchini
George Mason University, US

Keywords: tuberculosis, nanoparticles, magnet, hydrogel, urine, diagnostics


This study aims at developing a nanotechnology-based screening test that would reliably detect early stage tuberculosis (TB) infection and discriminate active from latent infections. The use of urine in TB testing has been hampered by 1) extremely low concentration analytes and 2) protein lability. A novel urine collection system is developed that in few instants concentrates the analytes present in a large volume of urine (e.g. 30 mL) in a small volume of hydrogel particles (e.g. 50 ul) and protects the captured analytes from degradation. Hydrogel particles can be shipped to the analysis laboratory at room temperature without the need of costly freezing preservation. When mixed with urine, bait functionalized hydrogel particles harvest, preserve and concentrate fluid phase analytes. A novel separation method based on magnetic nanoparticle tags permits the harvesting of hydrogel particles in few seconds without using high speed centrifugation. Hydrogel particles, separated with magnetic tags, achieved complete capture of target analytes from solution and recovery yield higher than 95%. Magnetized hydrogel particles massively increased the effective concentration of target analytes. This novel technology permitted the detection of TB antigens and host inflammation factors in the urine using clinical grade tests.