title: Turning erythrocytes into functional micromotors.
abstract: Attempts to apply artificial nano/micromotors for diverse biomedical applications have inspired a variety of strategies for designing motors with diverse propulsion mechanisms and functions. However, existing artificial motors are made exclusively of synthetic materials, which are subject to serious immune attack and clearance upon entering the bloodstream. Herein we report an elegant approach that turns natural red blood cells (RBCs) into functional micromotors with the aid of ultrasound propulsion and magnetic guidance. Iron oxide nanoparticles are loaded into the RBCs, where their asymmetric distribution within the cells results in a net magnetization, thus enabling magnetic alignment and guidance under acoustic propulsion. The RBC motors display efficient guided and prolonged propulsion in various biological fluids, including undiluted whole blood. The stability and functionality of the RBC motors, as well as the tolerability of regular RBCs to the ultrasound operation, are carefully examined. Since the RBC motors preserve the biological and structural features of regular RBCs, these motors possess a wide range of antigenic, transport, and mechanical properties that common synthetic motors cannot achieve and thus hold considerable promise for a number of practical biomedical uses.
authors.affiliation: Department of Nanoengineering, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Wu
authors.forename: Tianlong
authors.initials: T
authors.lastname: Li
authors.forename: Jinxing
authors.initials: J
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Tailin
authors.initials: T
authors.lastname: Xu
authors.forename: Caleb
authors.initials: C
authors.lastname: Christianson
authors.forename: Weiwei
authors.initials: W
authors.lastname: Gao
authors.forename: Michael
authors.initials: M
authors.lastname: Galarnyk
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.forename: Liangfang
authors.initials: L
authors.lastname: Zhang
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D001692:Biological Transport; D032701:Biomimetics / Q000379:methods*; D002460:Cell Line; D004912:Erythrocytes / Q000166:cytology*; D008264:Macrophages / Q000166:cytology; D008297:Male; D051379:Mice; D055616:Microtechnology / Q000379:methods*
keywords: biocompatibility; magnetic guidance; red blood cells; synthetic motor; ultrasound; whole blood