Multidentate block-copolymer-stabilized ultrasmall superparamagnetic iron oxide nanoparticles with enhanced colloidal stability for magnetic resonance imaging.
Ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs) with diameters <5 nm hold great promise as T1-positive contrast agents for in vivo magnetic resonance imaging. However, control of the surface chemistry of USPIOs to ensure individual colloidal USPIOs with a ligand monolayer and to impart biocompatibility and enhanced colloidal stability is essential for successful clinical applications. Herein, an effective and versatile strategy enabling the development of aqueous colloidal USPIOs stabilized with well-defined multidentate block copolymers (MDBCs) is reported. The multifunctional MDBCs are designed to consist of an anchoring block possessing pendant carboxylates as multidentate anchoring groups strongly bound to USPIO surfaces and a hydrophilic block having pendant hydrophilic oligo(ethylene oxide) chains to confer water dispersibility and biocompatibility. The surface of USPIOs is saturated with multiple anchoring groups of MDBCs, thus exhibiting excellent long-term colloidal stability as well as enhanced colloidal stability at biologically relevant electrolyte, pH, and temperature conditions. Furthermore, relaxometric properties as well as in vitro and in vivo MR imaging results demonstrate that the MDBC-stabilized USPIO colloids hold great potential as an effective T1 contrast agent.
Department of Chemistry and Biochemistry and Center for Nanoscience Research, Concordia University , Montreal, Quebec H4B 1R6, Canada.
Nicky
N
Chan
Myriam
M
Laprise-Pelletier
Pascale
P
Chevallier
Andrea
A
Bianchi
Marc-André
MA
Fortin
Jung Kwon
JK
Oh
D000005:Abdomen / Q000098:blood supply / Q000502:physiology; D000818:Animals; D003102:Colloids / Q000737:chemistry* / Q000378:metabolism; D004355:Drug Stability; D005260:Female; D005290:Ferric Compounds / Q000737:chemistry* / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000737:chemistry* / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C
D003102:Colloids; D005290:Ferric Compounds; C427127:superparamagnetic blood pool agent; C000499:ferric oxide; D052203:Ferrosoferric Oxide