Search

Molecular biomarkers can be used as objective indicators of pathologic processes. Although their levels often change over time, their measurement is often constrained to a single time point. Cumulative biomarker exposure would provide a fundamentally different kind of measurement to what is available in the clinic. Magnetic resonance relaxometry can be used to noninvasively monitor changes in the relaxation properties of antibody-coated magnetic particles when they aggregate upon exposure to a biomarker of interest. We used implantable devices containing such sensors to continuously profile changes in three clinically relevant cardiac biomarkers at physiological levels for up to 72 h. Sensor response differed between experimental and control groups in a mouse model of myocardial infarction and correlated with infarct size. Our prototype for a biomarker monitoring device also detected doxorubicin-induced cardiotoxicity and can be adapted to detect other molecular biomarkers with a sensitivity as low as the pg/ml range.

We explore the use of magnetic relaxation sensors as an in vitroassay platform. Functionalized magnetic nanoparticles that exhibit transverse relaxation time (T2) changes with the introduction of an analyte have previously been used to detect proteins, antibodies, receptor ligands, peptides, nucleic acids, oligonucleotides, and other small molecules. The standard procedure for sensitizing particles towards specific targets is, however, time-consuming and cumbersome. We report here a new approach that exploits primary–secondary antibody binding for easily derivatizing particles against specific targets. The assay is shown to be quantitative and a multiplexed assay against three target analytes is demonstrated. [ABSTRACT FROM AUTHOR]