Detection of DNA Nanoparticulate Biomarkers and Drug Delivery Nanoparticles in Whole Blood
M.J. Heller, R. Krishnan, J.Y. Marciniak, A.P. Hsiao, D.A. Carson, S.C. Esener
University of California San Diego, US
Keywords: dielectrophoresis, nanoparticles, high molecular weight DNA, whole blood, AC electrokinetics, biosensors, nanomedicine
Abstract:The rapid detection of rare cells, novel nanoparticulate disease biomarkers (high molecular weight DNA, cellular organelles, etc.) and drug delivery nanoparticles will be critically important for new molecular diagnostics, personalized medicine and monitoring therapeutic responses. The detection of high molecular weight DNA and bioderivatized nanoparticles from whole blood has been achieved using a microarray dielectrophoretic (DEP) device. Both fluorescent nanoparticles and hmw DNA in undiluted whole blood samples were separated and held in DEP high field regions and then detected after the blood cells were removed by a fluidic wash. In buffy coat blood, with reduced cell numbers, 40nm nanoparticles concentrated into the DEP high field regions while the blood cells concentrated into the DEP low field regions. A fluidic wash then selectively removed the cells while the nanoparticles remained trapped. Unlabeled hmw DNA was also isolated into the high field regions, and then stained with a fluorescent dye for subsequent detection, demonstrating an intrinsic DEP advantage of separating unlabeled analytes. The present work now sets the stage for a new generation of “seamless” sample to answer molecular diagnostic systems, where complex biological samples like blood can be directly analyzed for disease related biomarkers and drug delivery nanoparticles.