The use of magnetite nanoparticles for implant-assisted magnetic drug targeting in thrombolytic therapy.
Implant-assisted targeting of magnetic particles under the influence of an external magnetic field has previously been verified through mathematical modeling, in vitro studies, and in vivo studies on rat carotid arteries as a feasible method for localized drug delivery. The present study focuses on the development of nanoparticles for the treatment of in-stent thrombosis. Magnetic nanoparticles in the size-range 10-30 nm were synthesized in a one-pot procedure by precipitation of ferrous hydroxide followed by oxidation to magnetite. The nanoparticles were silanized with tetraethyl orthosilicate in the presence of triethylene glycol and/or polyethylene glycol. The surface coated magnetite nanoparticles were activated with either N-hydroxysulfosuccinimide or tresyl chloride for covalent immobilization of tissue plasminogen activator (tPA). Hysteresis loops showed saturation magnetizations of 55.8, 44.1, and 43.0 emu/g for the naked nanoparticles, the surface coated nanoparticles, and the tPA-nanoparticle conjugates, respectively. The hemolytic activity of the nanoparticles in blood was negligible. An initial in vivo biocompatibility test in pig, carried out by intravascular injection of the nanoparticles in a stented brachial artery, showed no short-term adverse effects. In vitro evaluation in a flow-through model proved that the nanoparticles were captured efficiently to the surface of a ferromagnetic coiled wire at the fluid velocities typical for human arteries. A preliminary test of the tPA-nanoparticle conjugates in a pig model suggested that the conjugates may be used for treatment of in-stent thrombosis in coronary arteries.
Kempe
Maria
M
Biomedical Polymer Technology, Department of Experimental Medical Science, Lund University, BMC D11, SE-22184 Lund, Sweden.
Kempe
Henrik
H
Snowball
Ian
I
Wallén
Rita
R
Arza
Carlos Rodriguez
CR
Götberg
Matthias
M
Olsson
Tommy
T
D000818:Animals; D016503:Drug Delivery Systems / Q000379:methods*; D004800:Enzymes, Immobilized / Q000378:metabolism; D004912:Erythrocytes / Q000473:pathology; D005260:Female; D006461:Hemolysis; D006801:Humans; D020007:Implants, Experimental; D008280:Magnetics / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000627:therapeutic use* / Q000648:ultrastructure; D008422:Materials Testing; D051381:Rats; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D034421:Sus scrofa; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000378:metabolism
D004800:Enzymes, Immobilized; D058185:Magnetite Nanoparticles; D010959:Tissue Plasminogen Activator