title: Implantable magnetic relaxation sensors measure cumulative exposure to cardiac biomarkers.
abstract: 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.
authors.affiliation: Harvard-MIT Division of Health Sciences & Technology, Cambridge, Massachusetts, USA.
authors.forename: Yibo
authors.initials: Y
authors.lastname: Ling
authors.forename: Terrence
authors.initials: T
authors.lastname: Pong
authors.forename: Christophoros C
authors.initials: CC
authors.lastname: Vassiliou
authors.forename: Paul L
authors.initials: PL
authors.lastname: Huang
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Cima
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D001798:Blood Proteins / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D051379:Mice; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000378:metabolism*; D019736:Prostheses and Implants
chemical_list: D015415:Biomarkers; D001798:Blood Proteins