Effect of External Magnetic Field on IV 99mTc-Labeled Aminosilane-Coated Iron Oxide Nanoparticles

Abstract

Among the most interesting applications of ferromagnetic nanoparticles (NPs) in medicine is the potential for localizing pharmacologically or radioactively tagged agents directly to selected tissues selected by an adjustable external magnetic field. This concept is demonstrated by the application external magnetic field on IV Tc-labeled aminosilane-coated iron oxide NPs in a rat model. In a model comparing a rat with a 0.3-T magnet over a hind paw versus a rat without a magnet, a static acquisition at 45 minutes showed that 27% of the administered radioactivity was in the area subtended by the magnet, whereas the liver displays a percentage of binding of 14% in the presence of the magnet and of 16% in the absence of an external magnetic field. These preliminary results suggest that the application of an external magnetic field may be a viable route for the development of methods for the confinement of magnetic NPs labeled with radioactive isotopes targeted for predetermined sites of the body.

Nanoparticles and radiotracers: advances toward radionanomedicine

“…74 For longer imaging studies, 111 In, 67 Ga, and various iodine species are used. 67 Ga (t 1/2 = 2.2d) and 111 In (t 1/2 = 2.8d) have been used to radiolabel NP via both chelator-free methods 40,41 as well as a diethylenetriamine-pentaacetic acid (DTPA) chelator. 75 D-Glucosamine-coated micelles were radiolabeled with 111 In using DTPA and showed 2.62% Id/g in a human epithelial carcinoma A-431 xenograft model at 24 h post injection, allowing tumor delineation.…”

“…99m Tc (t 1/2 = 6 h) allows SPECT imaging typically out to 1 day post injection, and has mature radiochemistry as the most widely used medical radiotracer. 99m Tc has been attached to IONP, [67][68][69] silver NP (AgNP), 70 AuNP, 71 and SNP 67,72 among others. Other 99m Tc tracers include a FDA-approved formulation of 99m Tc-sulfur nanocolloid filtered <100 nm for imaging of SLNs in prostate cancer.…”

“…A more in depth coverage of SLN mapping with ultra small SNPs can be found in this review. 74 For longer imaging studies, 111 In, 67 Ga, and various iodine species are used. 67 Ga (t 1/2 = 2.2d) and 111 In (t 1/2 = 2.8d) have been used to radiolabel NP via both chelator-free methods 40,41 as well as a diethylenetriamine-pentaacetic acid (DTPA) chelator.…”

Internalisation of core-shell superparamagnetic nanoparticles into human granulocytes

“…To overcome this drawback, superparamagnetic core can be protected by either metallic or polymeric functional shells [6]. In this field, our group has recently been interested in the use of core-shell superparamagnetic nanoparticles consisting of a nucleus of magnetite, a first shell of Cu and an additional housing of Au properly functionalised with drugs for application as theranostic agent [7,8]. However, moving from in vitro to in vivo environment, nanoparticles (NPs) normally undergo a strong interaction with the proteins contained in the blood (i.e., albumins and opsonins), which results in the formation of aggregates and their confinement in reservoir organs such as liver, spleen or kidneys.…”

New Synthesis and Biodistribution of the D-Amino Acid Oxidase-Magnetic Nanoparticle System

“…Besides considerable progress in cancer therapy and the many anticancer drugs available, the treatment of cancer has still a lot of side effects [13] and NPs could be an efficient alternative to conventional therapies, serving as carrier systems capable of enhancing efficacy, while simultaneously reducing side effects. Magnetic NPs can be functionalized with anticancer drugs and guided along an externally placed magnet into the tumor [14]. Moreover, magnetic NPs can produce heat through various energy losses under an external alternating magnetic field, causing cancer destruction by hyperthermia [15–20].…”