title: Synthesis and in vitro evaluation of bone-seeking superparamagnetic iron oxide nanoparticles as contrast agents for imaging bone metabolic activity.
abstract: In this article, we report the synthesis and in vitro evaluation of a new class of nonionizing bone-targeting contrast agents based on bisphosphonate-conjugated superparamagnetic iron oxide nanoparticles (SPIONs), for use in imaging of bone turnover with magnetic resonance imaging (MRI). Similar to bone-targeting (99m)Technetium medronate, our novel contrast agent uses bisphosphonates to impart bone-seeking properties, but replaces the former radioisotope with nonionizing SPIONs which enables their subsequent detection using MRI. Our reported method is relatively simple, quick and cost-effective and results in BP-SPIONs with a final nanoparticle size of 17 nm under electron microscopy technique (i.e., TEM). In-vitro binding studies of our novel bone tracer have shown selective binding affinity (around 65%) for hydroxyapatite, the principal mineral of bone. Bone-targeting SPIONs offer the potential for use as nonionizing MRI contrast agents capable of imaging dynamic bone turnover, for use in the diagnosis and monitoring of metabolic bone diseases and related bone pathology.
authors.affiliation: Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Arash
authors.initials: A
authors.lastname: Panahifar
authors.forename: Morteza
authors.initials: M
authors.lastname: Mahmoudi
authors.forename: Michael R
authors.initials: MR
authors.lastname: Doschak
mesh_terms: D000328:Adult; D019386:Alendronate / Q000737:chemistry; D050071:Bone Density Conservation Agents / Q000737:chemistry; D001842:Bone and Bones / Q000378:metabolism; D003287:Contrast Media / Q000138:chemical synthesis; D003911:Dextrans / Q000138:chemical synthesis; D052203:Ferrosoferric Oxide / Q000138:chemical synthesis; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D010003:Osteoarthritis / Q000175:diagnosis* / Q000378:metabolism; D010024:Osteoporosis / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D050071:Bone Density Conservation Agents; D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides; D019386:Alendronate; D052203:Ferrosoferric Oxide