title: Therapeutic magnetic microcarriers guided by magnetic resonance navigation for enhanced liver chemoembilization: a design review.
abstract: This review paper describes the past, present and future design of therapeutic magnetic carriers (TMMC) being guided in the vascular network using a novel technique known as magnetic resonance navigation (MRN). This targeting method is an extension of magnetic resonance imaging (MRI) technologies. MRN, based on magnetic gradient variation, aims to navigate carriers in real-time along a pre-planned trajectory from their injection site to a targeted area. As such, this approach should minimize systemic distribution of toxic agents loaded into the carriers and improve therapeutic efficacy by delivering a larger proportion of the drug injected. MRN-compatible carriers (shape, material, size, magnetic properties, biocompatibility) have to be designed by taking into consideration the constraints of the medical task and MRN. In the past, as a proof of concept of MRN feasibility, a 1.5-mm ferromagnetic bead was guided in the artery of a living swine with a clinical MRI system. Present day, to aim at medical applications, TMMC have been designed for targeted liver chemoembolization by MRN. TMMC are 50-μm biodegradable microparticles loaded with iron-cobalt nanoparticles and doxorubicin as an antitumor drug. TMMC were selectively guided to the right or left liver lobes in a rabbit model with a clinical MRI scanner upgraded with steering coils. To treat human liver tumor, according to the theoretical MRN model, future TMMC design should take into consideration magnetic nanoparticle properties (nature and loading), MRN platform performances (gradient amplitude and rise time) and vascular hepatic network properties (blood flow velocity and geometry) to optimize the carrier diameter for efficient chemoembolization.
authors.affiliation: NanoRobotics Laboratory, Department of Computer and Software Engineering and Institute of Biomedical Engineering, Ecole Polytechnique de Montréal (EPM), C.P. 6079, Succ. Centre-ville, Montreal, QC, H3C 3A7, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Pouponneau
authors.forename: Gaël
authors.initials: G
authors.lastname: Bringout
authors.forename: Sylvain
authors.initials: S
authors.lastname: Martel
mesh_terms: D000818:Animals; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D003035:Cobalt / Q000008:administration & dosage / Q000737:chemistry; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems; D006801:Humans; D007501:Iron / Q000008:administration & dosage / Q000737:chemistry; D008099:Liver / Q000378:metabolism; D060328:Magnetic Phenomena; D008279:Magnetic Resonance Imaging
chemical_list: D004337:Drug Carriers; D003035:Cobalt; D007501:Iron