8 research outputs found

    Tissue biodistribution and blood clearance rates of intravenously administered carbon nanotube radiotracers

    No full text
    Carbon nanotubes (CNT) are intensively being developed for biomedical applications including drug and gene delivery. Although all possible clinical applications will require compatibility of CNT with the biological milieu, their in vivo capabilities and limitations have not yet been explored. In this work, water-soluble, single-walled CNT (SWNT) have been functionalized with the chelating molecule diethylentriaminepentaacetic (DTPA) and labeled with indium ((111)In) for imaging purposes. Intravenous (i.v.) administration of these functionalized SWNT (f-SWNT) followed by radioactivity tracing using gamma scintigraphy indicated that f-SWNT are not retained in any of the reticuloendothelial system organs (liver or spleen) and are rapidly cleared from systemic blood circulation through the renal excretion route. The observed rapid blood clearance and half-life (3 h) of f-SWNT has major implications for all potential clinical uses of CNT. Moreover, urine excretion studies using both f-SWNT and functionalized multiwalled CNT followed by electron microscopy analysis of urine samples revealed that both types of nanotubes were excreted as intact nanotubes. This work describes the pharmacokinetic parameters of i.v. administered functionalized CNT relevant for various therapeutic and diagnostic applications

    Modulation of tumor necrosis factor-mediated cell death by fullerenes

    No full text
    Purpose. The fullerene (C-60/C-70 mixture-C-60/70) nanocrystalline suspension prepared by solvent exchange method using tetrahydrofyran (THF/nC(60/70)) and polyhydroxylated C-60/70 [C-60/70(OH)(n)] were compared for their ability to modulate cytotoxicity of the proinflammatory cytokine tumor necrosis factor (TNT). Materials and Methods. TNF-induced cytotoxicity was assessed in L929 fibrosarcoma cells by crystal violet assay. The type of cell death (apoptosis/necrosis), production of reactive oxygen species, mitochondrial depolarization and caspase activation were determined by flow cytometry using the appropriate reporter dyes. Results. THF/nC(60/70) augmented, while C-60/70(OH)(n) reduced the cytotoxicity of TNF. The numbers of cells undergoing apoptosis/necrosis, as well as of those displaying the activation of apoptosis-inducing enzymes of caspase family, were respectively increased or reduced by THF/nC(60/70) or C-60/70(OH)(n). The antioxidant N-acetylcysteine and mitochondrial permeability transition inhibitor cyclosporin A each partly blocked the cytotoxic action of TNF, indicating the involvement of oxidative stress and mitochondrial dysfunction in the TNF cytotoxicity. Accordingly, THF/nC(60/70) or C-60/70(OH)(n) potentiated or suppressed, respectively, TNF-triggered oxidative stress and mitochondrial depolarization. Conclusion. The ability of different fullerene preparations to modulate TNF-induced oxidative stress and subsequent cell death suggests their potential value in the TNF-based cancer therapy or prevention of TNF-dependent tissue damage
    corecore