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Abstract: In the present study, boron nitride nanotubes (BNNTs) were synthesized from an innovative process and functionalized with a glycol chitosan polymer in CDTN (Centro de Desenvolvimento da Tecnologia Nuclear) laboratories. As a means of studying their in vivo biodistribution behavior, these nanotubes were radiolabeled with 99mTc and injected in mice. Their size, distribution, and homogeneity were determined by photon correlation spectroscopy (PCS), while their zeta potential was determined by laser Doppler anemometry. The morphology and structural organization were evaluated by scanning electron microscopy (SEM). The functionalization in the nanotubes was evaluated by thermogravimetry analysis (TGA) and Fourier transformer infrared spectroscopy. The results showed that BNNTs were obtained and functionalized successfully, reaching a mean size and dispersity deemed adequate for in vivo studies. The BNNTs were also evaluated by ex vivo biodistribution studies and scintigraphic imaging in healthy mice. The results showed that nanostructures, after 24h, having accumulated in the liver, spleen and gut, and eliminated via renal excretion. The findings from this study reveal a potential application of functionalized BNNTs as new potential drugs or radioisotope nanocarriers to be applied in therapeutic procedures. [Copyright &y& Elsevier]

Abstract: Several classes of antifungal have been employed in candidiasis treatment, but patients with advanced immunodeficiency can present unsatisfactory results after therapy. In these cases, high doses of drugs or the use of multiple agents are sometimes used, and hence increasing the risk of serious side effects. Considering theses difficulties, the encapsulation of antifungal agents in nanoparticulate carriers has been used with the objective of modifying the pharmacokinetic of drugs resulting in more efficient treatments with less side effects. The purpose of this work was the preparation, characterization and the investigation of the release profiles of radiolabeled fluconazole nanocapsules. The size, homogeneity and zeta potential of NC preparations were determined with a Zetasizer 3000HS. The morphology and the structural organization were evaluated by atomic force microscopy (AFM). The release study in vitro of NC was evaluated in physiologic solution with or without 70% mouse plasma. The labeling yield of fluconazole with 99mTc was 94% and the radiolabeled drug was stable within 24h period. The encapsulation percentage of 99mTc-fluconazole in PLA-POLOX NC and PLA-PEG NC was approximately of 30%. The average diameter calculated by photon correlation spectroscopy (PCS) varied from 236 to 356nm, while the average diameter determined by AFM varied from 238 to 411nm. The diameter/height relation decreased significantly when 25% glutaraldehyde was used for NC fixation on mica. The zeta potential varied from −55 to −69nm and surface-modified NC showed lower absolute values than conventional NC. The in vitro release of 99mTc-fluconazole in plasma medium of the conventional and surface-modified NC was greater than in saline. The drug release in plasma medium from conventional NC was faster than for surface-modified NC. The results obtained in this work suggest that the nanocapsules containing fluconazole could be used to identify infectious foci, due to the properties, such as size, zeta potential and controlled release of 99mTc-fluconazole. The surface-modified nanocapsules could constitute a long-circulating intravenous formulation of fluconazole for treating sepsis caused by disseminated form of candidiasis. However, in vivo studies should be considered and are under investigation. [Copyright &y& Elsevier]

In the present study, boron nitride nanotubes (BNNTs) were synthesized from an innovative process and functionalized with a glycol chitosan polymer in CDTN (Centro de Desenvolvimento da Tecnologia Nuclear) laboratories. As a means of studying their in vivo biodistribution behavior, these nanotubes were radiolabeled with (99m)Tc and injected in mice. Their size, distribution, and homogeneity were determined by photon correlation spectroscopy (PCS), while their zeta potential was determined by laser Doppler anemometry. The morphology and structural organization were evaluated by scanning electron microscopy (SEM). The functionalization in the nanotubes was evaluated by thermogravimetry analysis (TGA) and Fourier transformer infrared spectroscopy. The results showed that BNNTs were obtained and functionalized successfully, reaching a mean size and dispersity deemed adequate for in vivo studies. The BNNTs were also evaluated by ex vivo biodistribution studies and scintigraphic imaging in healthy mice. The results showed that nanostructures, after 24h, having accumulated in the liver, spleen and gut, and eliminated via renal excretion. The findings from this study reveal a potential application of functionalized BNNTs as new potential drugs or radioisotope nanocarriers to be applied in therapeutic procedures., (Copyright © 2011 Elsevier B.V. All rights reserved.)