With this study we evaluated the effects of the herb rosemary (Rosmarinus officinalis L. Lamiaceae) extract on the labeling of blood constituents with technetium-99m (99mTc) labeled sulphur colloid and on the biodistribution of 99mTc-Sulphur Colloid in Wistar albino rats. For this purpose, two groups of animals (male wistar rats, 130-140 g) were treated (1 mL) with a rosemary extract (750 mg/kg body wt.,n=9) and water (control, n=9) separately by gavage for five days. 99mTc-Sulphur Colloid was administrated by intravenous injection; organs/tissues were withdrawn and weighted. Blood was centrifuged, plasma and blood cells were isolated. The radioactivity was counted to calculate the percentage of activity per gram for each organ/tissue and percentage of activity in blood cells and plasma. A significant increase (p<0.05) in the uptake of 99mTc-Sulphur Colloid in the liver after the treatment with rosemary extract was observed. These results indicate that the substances or metabolites of the rosemary extract would change the biodistribution of99mTc-Sulphur Colloid.

Nanopartículas magnéticas oferecem novas oportunidades interessantes, incuindo a melhora da qualidade da imagem de ressonância magnética (MRI), no tratamento hipertérmico para células malignas, na administração de medicamentos sítio-específicos e também no recente interesse da manipulação de membranas celulares. As aplicações biológicas desses nanomateriais requer que essas nanopartículas tenham valores altos de magnetização, tamanho menor que 20 nm, partículas de dimensão de distribuição restrita e um revestimento especial de superfície para evitar a toxicidade e permitir o acoplamento de biomoléculas. Nessa revisão, focalizamos na viabilidade de nanopartículas magnéticas marcadas com radionuclídeos, como transportadoras de medicamentos, e resumimos os recentes avanços nesse campo.

Magnetic nanoparticles offer exciting new opportunities including the improvement of the quality of magnetic resonance imaging (MRI), hyperthermic treatment for malignant cells, site-specific drug delivery and also the recent research interest of manipulating cell membranes. The biological applications of these nanomaterials require these nanoparticles to have high magnetization values, size smaller than 20 nm, narrow particle size distribution and a special surface coating for both avoiding toxicity and allowing the coupling of biomolecules. In this review, we focus on the feasibility of radionuclide labeled magnetic nanoparticles, as drug carriers, and summarize recent advances in this field.