Point-of-care quantification of serum cellular fibronectin levels for stratification of ischemic stroke patients.

The abundance of cellular fibronectin (c-Fn) for ischemic stroke patients and the narrow time-window (<4.5 h) for the decision to administer the thrombolytic treatment with recombinant tissue plasminogen activator (rtPA) are challenging for the development of a point-of-care (PoC) diagnostic platform. We report a case of stratification of ischemic stroke patients based on a magnetoresistive biosensor platform that quantifies the c-Fn levels in a small volume of serum, within the clinically relevant time-window. Our PoC platform uses different ratios of biofunctionalized magnetic nanoparticles (MNPs) as immunoassay labels to adjust the sensitivity within the clinically relevant ranges for c-Fn (1-4 μg/mL). After optimizing the detection range, resolution, and sensitivity, our device was able to stratify ischemic stroke patients who developed hemorrhagic transformation, the main side-effect of rtPA, from those (both non-treated and treated with rtPA) who did not. Cellular fibronectin (c-Fn) is a predictive biomarker for evaluating the risk–benefit of the thrombolytic treatment for ischemic stroke. Present in abundance in the serum of stroke patients, c-Fn is used in this work as a model of challenges encountered in developing biosensors for clinical assays. The systematic optimization of the detection range, resolution, and sensitivity of the assay according to the clinical needs is demonstrated in this investigation. The use of magnetic labels and their versatility when coupled with a portable point-of-care magnetoresistive platform allowed patient stratification in less than 2 h. Unlabelled Image [ABSTRACT FROM AUTHOR]