Single-walled carbon nanotubes (CNTs) emit heat when they absorb energy from near-infrared (NIR) light. Tissue is relatively transparent to NIR, which suggests that targeting CNTs to tumor cells, followed by noninvasive exposure to NIR light, will ablate tumors within the range of NIR. In this study, we demonstrate the specific binding of antibody-coupled CNTs to tumor cells in vitro, followed by their highly specific ablation with NIR light. Biotinylated polar lipids were used to prepare stable, biocompatible, noncytotoxic CNT dispersions that were then attached to one of two different neutralite avidin-derivatized mAbs directed against either human CD22 or CD25. CD22 ؉ CD25 ؊ Daudi cells bound only CNTs coupled to the anti-CD22 mAb; CD22 ؊ CD25 ؉ activated peripheral blood mononuclear cells bound only to the CNTs coupled to the anti-CD25 mAb. Most importantly, only the specifically targeted cells were killed after exposure to NIR light.immunoconjugates ͉ lymphoma cells ͉ monoclonal antibodies ͉ nanotechnology ͉ near infrared light

This work concerns exposing cultured human epithelial-like HeLa cells to single-walled carbon nanotubes (SWNTs) dispersed in cell culture media supplemented with serum. First, the asreceived CoMoCAT SWNT-containing powder was characterized using scanning electron microscopy and thermal gravimetric analyses. Characterizations of the purified dispersions, termed DM-SWNTs, involved atomic force microscopy, inductively coupled plasma -mass spectrometry, and absorption and Raman spectroscopies. Confocal microRaman spectroscopy was used to demonstrate that DM-SWNTs were taken up by HeLa cells in a time-and temperature-dependent fashion. Transmission electron microscopy revealed SWNT-like material in intracellular vacuoles. The morphologies and growth rates of HeLa cells exposed to DM-SWNTs were statistically similar to control cells over the course of 4 d. Finally, flow cytometry was used to show that the fluorescence from MitoSOX™ Red, a selective indicator of superoxide in mitochondria, was statistically similar in both control cells and cells incubated in DM-SWNTs. The combined results indicate that under our sample preparation protocols and assay conditions, CoMoCAT DM-SWNT dispersions are not inherently cytotoxic to HeLa cells. We conclude with recommendations for improving the accuracy and comparability of carbon nanotube (CNT) cytotoxicity reports.

CD22 is broadly expressed on human B cell lymphomas. Monoclonal anti‐CD22 antibodies alone, or coupled to toxins, have been used to selectively target these tumors both in SCID mice with xenografted human lymphoma cell lines and in patients with B cell lymphomas. Single‐walled carbon nanotubes (CNTs) attached to antibodies or peptides represent another approach to targeting cancer cells. CNTs convert absorbed near‐infrared (NIR) light to heat, which can thermally ablate cells that have bound the CNTs. We have previously demonstrated that monoclonal antibodies (MAbs) noncovalently coupled to CNTs can specifically target and kill cells in vitro. Here, we describe the preparation of conjugates in which the MAbs are covalently conjugated to the CNTs. The specificity of both the binding and NIR‐mediated killing of the tumor cells by the MAb‐CNTs is demonstrated by using CD22+CD25− Daudi cells, CD22−CD25+ phytohemagglutinin‐activated normal human peripheral blood mononuclear cells, and CNTs covalently modified with either anti‐CD22 or anti‐CD25. We further demonstrate that the stability and specificity of the MAb‐CNT conjugates are preserved following incubation in either sodium dodecyl sulfate or mouse serum, indicating that they should be stable for in vivo use. © 2009 UICC

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A highly porous architecture of graphitic carbon nitride g-C3N4/Cu2O nanocomposite in the form of cubes with a side length of ≈ 1 μm, large pores of 1.5 nm, and a high surface area of 9.12 m2/g was realized by an optimized in situ synthesis protocol. The synthesis protocol involves dispersing a suitable “Cu” precursor into a highly exfoliated g-C3N4 suspension and initiating the reaction for the formation of Cu2O. Systematic optimization of the conditions and compositions resulted in a highly crystalline g-C3N4/Cu2O composite. In the absence of g-C3N4, the Cu2O particles assemble into cubes with a size of around 300 nm and are devoid of pores. Detailed structural and morphological evaluations by powder X-ray diffraction and field emission scanning electron microscopy revealed the presence of highly exfoliated g-C3N4, which is responsible for the formation of the porous architecture in the cube like assembly of the composite. The micrographs clearly reveal the porous structure of the composite that retains the cubic shape of Cu2O, and the energy-dispersive spectroscopy supports the presence of g-C3N4 within the cubic morphology. Among the different g-C3N4/Cu2O compositions, CN/Cu-5 with 10% of g-C3N4, which is also the optimum composition resulting in a porous cubic morphology, shows the best visible light photocatalytic performance. This has been supported by the ultraviolet diffuse reflectance spectroscopy (UV-DRS) studies of the composite which shows a band gap of around 2.05 eV. The improved photocatalytic performance of the composite could be attributed to the highly porous morphology along with the suitable optical band gap in the visible region of the solar spectrum. The optimized composite, CN/Cu-5, demonstrates a visible light degradation of 81% for Methylene Blue (MB) and 85.3% for Rhodamine-B (RhB) in 120 min. The decrease in the catalyst performance even after three repeated cycles is less than 5% for both MB and RhB dyes. The rate constant for MB and RhB degradation is six and eight times higher with CN/Cu-5 when compared with the pure Cu2O catalyst. To validate our claim that the dye degradation is not merely decolorization, liquid chromatography–mass spectroscopy studies were carried out, and the end products of the degraded dyes were identified.