Science.gov

Sample records for nanomaterials inhibit phorbol

  1. Inhibition of insulin receptor binding by phorbol esters.

    PubMed

    Thomopoulos, P; Testa, U; Gourdin, M F; Hervy, C; Titeux, M; Vainchenker, W

    1982-12-15

    Phorbol esters inhibit the binding of insulin to its receptors on U-937 monocyte-like and HL-60 promyelocytic leukemia human cell lines. Within 20-30 min, exposure of these cells to 12-O-tetradecanoylphorbol 13-acetate (TPA) at 37 degrees C results in a 50% reduction of the specific binding of 125I-insulin. Half-maximal inhibition occurs at 1 nM TPA. Other tumor-promoting phorbol esters also inhibit 125I-insulin binding in a dose-dependent manner which parallels their known promoting activity in vivo. TPA does not alter the degradation of the hormone nor does it induce any shedding of its receptors in the medium. The effect of phorbol esters is dependent on temperature and cell type. It is less prominent at 22 degrees C than at 37 degrees C. It is reversible within 2 h at 37 degrees C. TPA reduces the binding of insulin predominantly by increasing its dissociation rate. This effect results in an accelerated turnover of the hormone on its receptors. PMID:6891320

  2. Phosphatidylinositol 4,5-bisphosphate competitively inhibits phorbol ester binding to protein kinase C

    SciTech Connect

    Chauhan, A.; Cauhan, V.P.S.; Deshmukh, D.S.; Brokerhoff, H. )

    1989-06-13

    Calcium phospholipid dependent protein kinase C (PKC) is activated by diacylglycerol (DG) and by phorbol esters and is recognized to be the phorbol ester receptor of cells; DG displaces phorbol ester competitively from PKC. A phospholipid, phosphatidylinositol 4,5-bisphosphate (PIP{sub 2}), can also activate PKC in the presence of phosphatidylserine (PS) and Ca{sup 2+} with a K{sub PIP{sub 2}} of 0.04 mol %. Preliminary experiments have suggested a common binding site for PIP{sub 2} and DG on PKC. Here, the authors investigate the effect of PIP{sub 2} on phorbol ester binding to PKC in a mixed micellar assay. In the presence of 20 mol % PS, PIP{sub 2} inhibited specific binding of ({sup 3}H)phorbol 12,13-dibutyrate (PDBu) in a dose-dependent fashion up to 85% at 1 mol %. Inhibition of binding was more pronounced with PIP{sub 2} than with DG. Scatchard analysis indicated that the decrease in binding of PDBu in the presence of PIP{sub 2} is the result of an altered affinity for the phorbol ester rather than of a change in maximal binding. The plot of apparent dissociation constants (K{sub d{prime}}) against PIP{sub 2} concentration was linear over a range of 0.01-1 mol % with a K{sub i} of 0.043 mol % and confirmed the competitive nature of inhibition between PDBu and PIP{sub 2}. Competition between PIP{sub 2} and phorbol ester could be determined in a liposomal assay system also. These results indicate that PIP{sub 2}, DG, and phorbol ester all compete for the same activator-receiving region on the regulatory moiety of protein kinase C, and they lend support to the suggestion that PIP{sub 2} is a primary activator of the enzyme.

  3. Inhibition of transferring binding and iron uptake of hematopoietic cell lines by phorbol esters.

    PubMed

    Pelicci, P G; Testa, U; Thomopoulos, P; Tabilio, A; Vainchenker, W; Titeux, M; Gourdin, M F; Rochant, H

    1984-01-01

    Phorbol esters inhibit cell growth and the binding of transferrin to receptors on K 562, HL 60 and U 937 human leukemic cell lines. Exposure of these cells to 12-0-tetradecanoyl phorbol-13-acetate (TPA) at 37 degrees C results in a 40% reduction of the specific binding of 125I-transferrin, which is apparent within 15 min. Half-maximal inhibition occurs at about 1 nM. Other tumor promoting phorbol esters also inhibit 125I-transferrin binding in a dose-dependent manner which parallels their known promoting activity in vivo. TPA reduces the number of transferrin receptors, and does not alter the degradation or the internalization of transferrin. In addition, TPA inhibits iron uptake by these cell lines. These effects are specific, since phorbol esters do not affect either cell growth or the binding of transferrin to Friend erythroleukemia cells and Raji cell line. On the basis of these findings it is suggested that the inhibition of transferrin binding may represent one of the mechanisms by which phorbol esters affect the growth and the differentiation of hematopoietic cell lines. PMID:6088899

  4. Phorbol myristate acetate and dioctanoylglycerol inhibit transport in rabbit proximal convoluted tubule

    SciTech Connect

    Baum, M.; Hays, S.R. )

    1988-01-01

    The present in vitro microperfusion study examined the effect of protein kinase C activation on transport in the rabbit proximal convoluted tubule (PCT). PCT were perfused with an ultrafiltrate-like solution and were bathed in a serumlike albumin solution. Addition of phorbol 12-myristate 13-acetate, an activator of protein kinase C, inhibited volume absorption from 1.06 {plus minus} 0.10 to 0.77 {plus minus} 0.07 nl{center dot}mm{sup {minus}1}min{sup {minus}1}, and 0.76 {plus minus} 0.14 to 0.48 {plus minus} 0.08 nl{center dot}mm{sup {minus}1}{center dot}min{sup {minus}1}, respectively. Bath phorbol 12-myristate 13-acetate had no effect on volume absorption. In contrast, bath 4{alpha}-phorbol, an inactive phorbol that does not activate protein kinase C, had no effect on J{sub v}. Bath L-{alpha}-dioctanoylglycerol, another known activator of protein kinase C, inhibited volume absorption. A 10-fold lower concentration of L-{alpha}-dioctanoylglycerol had no effect on J{sub v}. Both 5 x 10{sup {minus}8} M phorbol 12-myristate 13-acetate and 10{sup {minus}4} M L-{alpha}-dioctanoylglycerol inhibited glucose, bicarbonate, and chloride transport in the PCT. These data are consistent with protein kinase C activation playing a role in the modulation of proximal tubular transport.

  5. Inhibition of cytopathic effect of human immunodeficiency virus type-1 by various phorbol derivatives.

    PubMed

    El-Mekkawy, Sahar; Meselhy, Meselhy Ragab; Abdel-Hafez, Atef Abdel-Monem; Nakamura, Norio; Hattori, Masao; Kawahata, Takuya; Otake, Toru

    2002-04-01

    Forty-eight derivatives of phorbol (9) and isophorbol (14) were evaluated for their inhibition of human immunodeficiency virus (HIV)-1 induced cytopathic effects (CPE) on MT-4 cells, as well as their activation of protein kinase C (PKC), as indices of anti-HIV-1 and tumor promoting activities, respectively. Of these compounds, the most potent inhibition of CPE was observed in 12-O-tetradecanoylphorbol 13-acetate (8) and 12-O-acetylphorbol 13-decanoate (6). The former also showed the strongest PKC activation activity, while the latter showed no activity at 10 ng/ml. Both activities were generally observed in those phorbol derivatives with an A/B trans configuration, but not in the isophorbol derivatives with an A/B cis configuration. Acetylation of 20-OH in the phorbol derivatives significantly reduced the inhibition of CPE, as shown in 12-O-, 20-O-diacetylphorbol 13-decanoate (6a) (IC100=15.6 microg/ml) vs. compound 6 (IC100=0.0076 microg/ml), and 12-O-tetradecanoylphorbol 13,20-diacetate (8a) (IC100=15.6 microg/ml) vs. 12-O-tetradecanoylphorbol 13-acetate (8) (IC100=0.00048 microg/ml), except in the case of 12-O-decanoylphorbol 13-(2-methylbutyrate) (4) and phorbol 12,13-diacetate (9c). The reduction of a carbonyl group at C-3 abruptly reduced the inhibition of CPE, as observed in 3beta-hydroxyphorbol 12,13,20-triacetate (9f) (IC100=500 microg/ml) vs. phorbol 12,13,20-triacetate (9d) (IC100=62.5 microg/ml). Although 8 was equipotent in the inhibition of CPE, and activation of PKC, both activities were abruptly decreased by the acetylation of 20-OH and methylation of 4-OH [as in 8a and 4-O-methyl-12-O-tetradecanoylphorbol 13,20-diacetate (8b), respectively]. On the other hand, its positional isomer (12-O-acetylphorbol 13-tetradecanoate (8c) showed neither activities. The removal of a long acyl group in 8 led to a substantial loss of both activities, as shown in phorbol 13-acetate (9b). Of the 12-O-acetyl-13-O-acylphorbol derivatives, the highest inhibition of CPE

  6. Tumour-promoting phorbol esters increase basal and inhibit insulin-stimulated lipogenesis in rat adipocytes without decreasing insulin binding.

    PubMed Central

    van de Werve, G; Proietto, J; Jeanrenaud, B

    1985-01-01

    In isolated rat adipocytes, tumour-promoting phorbol esters caused (1) dose-dependent stimulation of lipogenesis in the absence of insulin and (2) inhibition of the lipogenic effect of submaximal concentrations of insulin, but without affecting insulin binding. The possible involvement of protein kinase C in insulin action is discussed. PMID:3883992

  7. Phorbol myristate acetate inhibits anti-IgM-mediated signaling in resting B cells.

    PubMed Central

    Mizuguchi, J; Beaven, M A; Li, J H; Paul, W E

    1986-01-01

    Cross-linking the membrane immunoglobulins of resting B cells leads to activation as judged by increased inositol phospholipid metabolism, intracellular free calcium concentration ([Ca2+]i), and cell volume. Such activated B cells enter S phase in the presence of B-cell stimulatory factor 1. Phorbol myristate acetate (PMA) is a potent inhibitor of anti-IgM- and anti-IgD-stimulated B-cell responses. In B cells concentrations of PMA ranging from 0.1 to 100 ng/ml completely inhibit anti-IgM-stimulated DNA synthesis and block anti-IgM-stimulated increases in inositol phospholipid metabolism and in [Ca2+]i. Preincubation periods as short as 4 min block these effects although longer preincubations are somewhat more effective in inhibiting increases in [Ca2+]i. Preincubation with PMA for 1.5 hr does not diminish expression of membrane IgM. This strongly suggests that PMA inhibits responses of resting B cells to anti-IgM by interrupting signal transmission rather than by diminishing cross-linking of membrane immunoglobulin on B cells. In contrast to resting B cells, B cells activated in vitro for 29 hr show enhanced responses to anti-IgM in the presence of PMA. PMID:3086884

  8. Phorbol ester-induced inhibition of. beta. -adrenergic - and vasopressin-mediated responses in an established smooth muscle cell line

    SciTech Connect

    Not Available

    1986-03-01

    A-10 cells which are derived from embryonic rat thoracic aorta contain a high density of vasopressin receptors and relatively fewer ..beta..-adrenergic receptors. The effects of vasopressin binding to these cells are two-fold: a) inhibition of isoproterenol-stimulated cAMP accumulation, and; b) stimulation of phosphatidyl inositol turnover. Incubation of these cells with phorbol dibutyrate leads to an attenuation of the responses mediated by ..beta..-adrenergic agonist as well as vasopressin. This effect of phorbol ester is concentration- and time-dependent and can be observed as early as five minutes. The inactive phorbol ester (4 ..cap alpha.. phorbol 12,13-didecanoate) is ineffective in inhibiting ..beta..-adrenergic agonist and vasopressin-mediated responses. Since present evidence indicates that the enzyme protein kinase C (PK-C) is involved in both short-term and long-term regulatory processes such as secretion, smooth muscle contraction and cell growth, these data suggest that both ..beta..-adrenergic and vasopressin receptors and/or some mediator(s) of ..beta..-adrenergic and/or vasopressin responses may be phosphorylated by protein kinase C resulting in an attenuated response of these two hormones.

  9. Inhibition of inflammatory arthritis using fullerene nanomaterials.

    PubMed

    Dellinger, Anthony L; Cunin, Pierre; Lee, David; Kung, Andrew L; Brooks, D Bradford; Zhou, Zhiguo; Nigrovic, Peter A; Kepley, Christopher L

    2015-01-01

    Inflammatory arthritis (e.g. rheumatoid arthritis; RA) is a complex disease driven by the interplay of multiple cellular lineages. Fullerene derivatives have previously been shown to have anti-inflammatory capabilities mediated, in part, by their ability to prevent inflammatory mediator release by mast cells (MC). Recognizing that MC can serve as a cellular link between autoantibodies, soluble mediators, and other effector populations in inflammatory arthritis, it was hypothesized that fullerene derivatives might be used to target this inflammatory disease. A panel of fullerene derivatives was tested for their ability to affect the function of human skin-derived MC as well as other lineages implicated in arthritis, synovial fibroblasts and osteoclasts. It is shown that certain fullerene derivatives blocked FcγR- and TNF-α-induced mediator release from MC; TNF-α-induced mediator release from RA synovial fibroblasts; and maturation of human osteoclasts. MC inhibition by fullerene derivatives was mediated through the reduction of mitochondrial membrane potential and FcγR-mediated increases in cellular reactive oxygen species and NF-κB activation. Based on these in vitro data, two fullerene derivatives (ALM and TGA) were selected for in vivo studies using K/BxN serum transfer arthritis in C57BL/6 mice and collagen-induced arthritis (CIA) in DBA/1 mice. Dye-conjugated fullerenes confirmed localization to affected joints in arthritic animals but not in healthy controls. In the K/BxN moldel, fullerenes attenuated arthritis, an effect accompanied by reduced histologic inflammation, cartilage/bone erosion, and serum levels of TNF-α. Fullerenes remained capable of attenuating K/BxN arthritis in mast cell-deficient mice Cre-Master mice, suggesting that lineages beyond the MC represent relevant targets in this system. These studies suggest that fullerene derivatives may hold promise both as an assessment tool and as anti-inflammatory therapy of arthritis.

  10. Inhibition of Inflammatory Arthritis Using Fullerene Nanomaterials

    PubMed Central

    Dellinger, Anthony L.; Cunin, Pierre; Lee, David; Kung, Andrew L.; Brooks, D. Bradford; Zhou, Zhiguo; Nigrovic, Peter A.; Kepley, Christopher L.

    2015-01-01

    Inflammatory arthritis (e.g. rheumatoid arthritis; RA) is a complex disease driven by the interplay of multiple cellular lineages. Fullerene derivatives have previously been shown to have anti-inflammatory capabilities mediated, in part, by their ability to prevent inflammatory mediator release by mast cells (MC). Recognizing that MC can serve as a cellular link between autoantibodies, soluble mediators, and other effector populations in inflammatory arthritis, it was hypothesized that fullerene derivatives might be used to target this inflammatory disease. A panel of fullerene derivatives was tested for their ability to affect the function of human skin-derived MC as well as other lineages implicated in arthritis, synovial fibroblasts and osteoclasts. It is shown that certain fullerene derivatives blocked FcγR- and TNF-α-induced mediator release from MC; TNF-α-induced mediator release from RA synovial fibroblasts; and maturation of human osteoclasts. MC inhibition by fullerene derivatives was mediated through the reduction of mitochondrial membrane potential and FcγR-mediated increases in cellular reactive oxygen species and NF-κB activation. Based on these in vitro data, two fullerene derivatives (ALM and TGA) were selected for in vivo studies using K/BxN serum transfer arthritis in C57BL/6 mice and collagen-induced arthritis (CIA) in DBA/1 mice. Dye-conjugated fullerenes confirmed localization to affected joints in arthritic animals but not in healthy controls. In the K/BxN moldel, fullerenes attenuated arthritis, an effect accompanied by reduced histologic inflammation, cartilage/bone erosion, and serum levels of TNF-α. Fullerenes remained capable of attenuating K/BxN arthritis in mast cell-deficient mice Cre-Master mice, suggesting that lineages beyond the MC represent relevant targets in this system. These studies suggest that fullerene derivatives may hold promise both as an assessment tool and as anti-inflammatory therapy of arthritis. PMID:25879437

  11. Thymoquinone inhibits phorbol ester-induced activation of NF-κB and expression of COX-2, and induces expression of cytoprotective enzymes in mouse skin in vivo

    SciTech Connect

    Kundu, Joydeb Kumar; Liu, Lijia; Shin, Jun-Wan; Surh, Young-Joon

    2013-09-06

    Highlights: •Thymoquinone inhibits phorbol ester-induced COX-2 expression in mouse skin. •Thymoquinone attenuates phosphorylation of IκBα and DNA binding of NF-κB in mouse skin. •Thymoquinone inhibits phosphorylation of p38 MAP kinase, JNK and Akt in mouse skin. •Thymoquinone induces the expression of cytoprotective proteins in mouse skin. -- Abstract: Thymoquinone (TQ), the active ingredient of Nigella sativa, has been reported to possess anti-inflammatory and chemopreventive properties. The present study was aimed at elucidating the molecular mechanisms of anti-inflammatory and antioxidative activities of thymoquinone in mouse skin. Pretreatment of female HR-1 hairless mouse skin with TQ attenuated 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced expression of cyclooxygenase-2 (COX-2). TQ diminished nuclear translocation and the DNA binding of nuclear factor-kappaB (NF-κB) via the blockade of phosphorylation and subsequent degradation of IκBα in TPA-treated mouse skin. Pretreatment with TQ attenuated the phosphorylation of Akt, c-Jun-N-terminal kinase and p38 mitogen-activated protein kinase, but not that of extracellular signal-regulated kinase-1/2. Moreover, topical application of TQ induced the expression of heme oxygenase-1, NAD(P)H-quinoneoxidoreductase-1, glutathione-S-transferase and glutamate cysteine ligase in mouse skin. Taken together, the inhibitory effects of TQ on TPA-induced COX-2 expression and NF-κB activation, and its ability to induce the expression of cytoprotective proteins provide a mechanistic basis of anti-inflammatory and antioxidative effects of TQ in hairless mouse skin.

  12. Inhibition of phorbol ester tumor promoter 12-O-tetradecanoylphorbol-13-acetate-caused inflammatory responses in SENCAR mouse skin by black tea polyphenols.

    PubMed

    Katiyar, S K; Mukhtar, H

    1997-10-01

    Over the past 10 years many studies from several laboratories defined anticarcinogenic and anti-inflammatory effects of tea, a widely consumed beverage by the human population. Much of such work has been conducted with green tea or its polyphenolic constituents. Regarding black tea, studies have shown that its water extract affords protection against tumor promotion caused by chemical carcinogens or ultraviolet B radiation in murine skin carcinogenesis models. Several studies have shown that topical application of chemical tumor promoters to murine skin results in the induction of epidermal edema, hyperplasia and ornithine decarboxylase (ODC) and cyclo-oxygenase activities, and interleukin-1 alpha (IL-1alpha) and ODC mRNA expression. In this study, we assessed whether topical application of polyphenols isolated from black tea leaves (hereafter referred to as BTP) mainly consisting of theaflavine gallates and (-)-epigallocatechin-3-gallate, inhibits phorbol ester tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-caused induction of these markers of inflammatory responses in murine skin. Topical application of BTP (6 mg in 0.2 ml acetone/animal) 30 min prior to TPA application on to the mouse skin resulted in significant inhibition against TPA-caused induction of epidermal edema (40%, P < 0.01), hyperplasia (57%, P < 0.005), leukocytes infiltration (50%), and induction of epidermal ODC (57%) and pro-inflammatory cytokine IL-1alpha mRNA expression (69%). Pre-application of BTP to that of TPA also resulted in significant inhibition of TPA-caused induction of epidermal ODC (23-73%, P < 0.005-0.0001), and cyclo-oxygenase, in terms of prostaglandins metabolites formation (38-65%, P < 0.01-0.0005), enzyme activities. Our data indicate that the inhibition of TPA-caused changes in these markers of inflammatory responses in murine skin by BTP may be one of the possible mechanisms of chemopreventive effects associated with black tea against tumorigenesis. The results

  13. Liganded thyroid hormone receptor inhibits phorbol 12-O-tetradecanoate-13-acetate-induced enhancer activity via firefly luciferase cDNA.

    PubMed

    Misawa, Hiroko; Sasaki, Shigekazu; Matsushita, Akio; Ohba, Kenji; Iwaki, Hiroyuki; Matsunaga, Hideyuki; Suzuki, Shingo; Ishizuka, Keiko; Oki, Yutaka; Nakamura, Hirotoshi

    2012-01-01

    Thyroid hormone receptor (TR) belongs to the nuclear hormone receptor (NHR) superfamily and regulates the transcription of its target genes in a thyroid hormone (T3)-dependent manner. While the detail of transcriptional activation by T3 (positive regulation) has been clarified, the mechanism of T3-dependent repression (negative regulation) remains to be determined. In addition to naturally occurring negative regulations typically found for the thyrotropin β gene, T3-bound TR (T3/TR) is known to cause artificial negative regulation in reporter assays with cultured cells. For example, T3/TR inhibits the transcriptional activity of the reporter plasmids harboring AP-1 site derived from pUC/pBR322-related plasmid (pUC/AP-1). Artificial negative regulation has also been suggested in the reporter assay with firefly luciferase (FFL) gene. However, identification of the DNA sequence of the FFL gene using deletion analysis was not performed because negative regulation was evaluated by measuring the enzymatic activity of FFL protein. Thus, there remains the possibility that the inhibition by T3 is mediated via a DNA sequence other than FFL cDNA, for instance, pUC/AP-1 site in plasmid backbone. To investigate the function of FFL cDNA as a transcriptional regulatory sequence, we generated pBL-FFL-CAT5 by ligating FFL cDNA in the 5' upstream region to heterologous thymidine kinase promoter in pBL-CAT5, a chloramphenicol acetyl transferase (CAT)-based reporter gene, which lacks pUC/AP-1 site. In kidney-derived CV1 and choriocarcinoma-derived JEG3 cells, pBL-FFL-CAT5, but not pBL-CAT5, was strongly activated by a protein kinase C activator, phorbol 12-O-tetradecanoate-13-acetate (TPA). TPA-induced activity of pBL-FFL-CAT5 was negatively regulated by T3/TR. Mutation of nt. 626/640 in FFL cDNA attenuated the TPA-induced activation and concomitantly abolished the T3-dependent repression. Our data demonstrate that FFL cDNA sequence mediates the TPA-induced transcriptional activity

  14. MDP(Lysyl)GDP, a nontoxic muramyl dipeptide derivative, inhibits cytokine production by activated macrophages and protects mice from phorbol ester- and oxazolone-induced inflammation.

    PubMed

    Zunic, M; Bahr, G M; Mudde, G C; Meingassner, J G; Lam, C

    1998-07-01

    High levels of pro-inflammatory cytokines and nitric oxide are proposed to orchestrate pathophysiologic mechanism(s) associated with various inflammatory dermatoses. This study examines whether a water soluble 3-O-[N-acetylmuramyl-L-lysyl-D-iso]-2-di-on-glycine [MDP(Lysyl)GDP], a nontoxic and nonpyrogenic derivative of muramyl dipeptide (MDP), can inhibit the in vitro production of inflammatory mediators by lipopolysaccharide- or interferon-gamma-activated macrophages, and whether such an inhibitory effect can translate into in vivo protection of mice from irritant and allergic contact dermatitis. Thioglycollate-elicited peritoneal macrophages cultured in medium alone or in medium supplemented with MDP(Lysyl)GDP (1-100 microg per ml) expressed neither mRNA transcripts for inducible nitric oxide synthase, interleukin-1beta, and tumor necrosis factor-alpha, nor cytokine proteins and nitric oxide activity. Incubation of the cells with either lipopolysaccharide or interferon-gamma for 6 h resulted in a significant induction of inducible nitric oxide synthase, interleukin-1beta, and tumor necrosis factor-alpha mRNA, and the accumulation of high levels of monokines and nitrites in cultures by 24 h. Co-incubation of the macrophages with lipopolysaccharide or interferon-gamma and MDP(Lysyl)GDP (1-100 microg per ml) resulted in a concentration-dependent suppression of the steady-state mRNA transcripts for inducible nitric oxide synthase, tumor necrosis factor-alpha, and interleukin-1beta, induced by lipopolysaccharide, but not by interferon-gamma. In mouse models of phorbol ester- and oxazolone-induced ear inflammation, topical application of MDP(Lysyl)GDP significantly suppressed ear swelling in a dose-dependent manner. Likewise, oral treatment with MDP(Lysyl)GDP at days -3, -2, and -1 before elicitation with oxazolone also significantly inhibited ear inflammation. Taken together, our findings suggest that MDP(Lysyl)GDP has the potential to be a therapeutic application in

  15. Inhibition of hormone-sensitive lipase gene expression by cAMP and phorbol esters in 3T3-F442A and BFC-1 adipocytes.

    PubMed

    Plée-Gautier, E; Grober, J; Duplus, E; Langin, D; Forest, C

    1996-09-15

    Hormone-sensitive lipase (HSL) catalyses the rate-limiting step in adipocyte lipolysis. Short-term hormonal regulation of HSL activity is well characterized, whereas little is known about the control of HSL gene expression. We have measured HSL mRNA content of 3T3-F442A and BFC-1 adipocytes in response to the cAMP analogue 8-(4-chlorophenylthio)-cAMP (8-CPT-cAMP) and to the phorbol ester phorbol 12-myristate 13-acetate (PMA) by Northern blot, using a specific mouse cDNA fragment. Treatment of the cells for 12 or 6 h with, respectively, 0.5 mM 8-CPT-cAMP or 1 microM PMA produced a maximal decrease of about 60% in HSL mRNA. These effects were unaffected by the protein-synthesis inhibitor anisomycin, suggesting that cAMP and PMA actions were direct. The reduction in HSL mRNA was accompanied by a reduction in HSL total activity. The intracellular routes that cAMP and PMA follow for inducing such an effect seemed clearly independent. (i) After desensitization of the protein kinase C regulation pathway by a 24 h treatment of the cells with 1 microM PMA, PMA action was abolished whereas cAMP was still fully active. (ii) Treatment with saturating concentrations of both agents produced an additive effect. (iii) The synthetic glucocorticoid dexamethasone had no proper effect on HSL gene expression but potentiated cAMP action without affecting PMA action. cAMP inhibitory action on HSL is unexpected. Indeed, the second messenger of catecholamines is the main activator of HSL by phosphorylation. We envision that a long-term cAMP treatment of adipocytes induces a counter-regulatory process that reduces HSL content and, ultimately, limits fatty acid depletion from stored triacylglycerols.

  16. Genistein inhibits phorbol ester-induced NF-κB transcriptional activity and COX-2 expression by blocking the phosphorylation of p65/RelA in human mammary epithelial cells.

    PubMed

    Chung, Myung-Hoon; Kim, Do-Hee; Na, Hye-Kyung; Kim, Jung-Hwan; Kim, Ha-Na; Haegeman, Guy; Surh, Young-Joon

    2014-10-01

    Genistein, an isoflavone present in soy products, has chemopreventive effects on mammary carcinogenesis. In the present study, we have investigated the effects of genistein on phorbol ester-induced expression of cyclooxygenase-2 (COX-2) that plays an important role in the pathophysiology of inflammation-associated carcinogenesis. Pretreatment of cultured human breast epithelial (MCF10A) cells with genistein reduced COX-2 expression induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). There are multiple lines of evidence supporting that the induction of COX-2 is regulated by the eukaryotic transcription factor NF-κB. Genistein failed to inhibit TPA-induced nuclear translocation and DNA binding of NF-κB as well as degradation of IκB. However, genistein abrogated the TPA-induced transcriptional activity of NF-κB as determined by the luciferase reporter gene assay. Genistein inhibited phosphorylation of the p65 subunit of NF-κB and its interaction with cAMP regulatory element-binding protein-binding protein (CBP)/p300 and TATA-binding protein (TBP). TPA-induced NF-κB phosphorylation was abolished by pharmacological inhibition of extracellular signal-regulated kinase (ERK). Likewise, pharmacologic inhibition or dominant negative mutation of ERK suppressed phosphorylation of p65. The above findings, taken together, suggest that genistein inhibits TPA-induced COX-2 expression in MCF10A cells by blocking ERK-mediated phosphorylation of p65 and its subsequent interaction with CBP and TBP.

  17. Cytotoxic phorbol esters of Croton tiglium.

    PubMed

    Zhang, Xiao-Long; Wang, Lun; Li, Fu; Yu, Kai; Wang, Ming-Kui

    2013-05-24

    Chemical investigation of the seeds of Croton tiglium afforded eight new phorbol diesters (three phorbol diesters, 1-3, and five 4-deoxy-4α-phorbol diesters, 4-8), together with 11 known phorbol diesters (nine phorbol diesters, 9-17, and two 4-deoxy-4α-phorbol diesters, 18 and 19). The structures of compounds 1-8 were determined by spectroscopic data information and chemical degradation experiments. The cytotoxic activities of the phorbol diesters were evaluated against the SNU387 hepatic tumor cell line, and compound 3 exhibited the most potent activity (IC50 1.2 μM).

  18. Chemosensitizing effects of carbon-based nanomaterials in cancer cells: enhanced apoptosis and inhibition of proliferation as underlying mechanisms

    NASA Astrophysics Data System (ADS)

    Erdmann, Kati; Ringel, Jessica; Hampel, Silke; Rieger, Christiane; Huebner, Doreen; Wirth, Manfred P.; Fuessel, Susanne

    2014-10-01

    Recent studies have shown that carbon nanomaterials such as carbon nanofibres (CNFs) and multi-walled carbon nanotubes (CNTs) can exert antitumor activities themselves and sensitize cancer cells to conventional chemotherapeutics such as carboplatin and cisplatin. In the present study, the chemosensitizing effect of CNFs and CNTs on cancer cells of urological origin was investigated regarding the underlying mechanisms. Prostate cancer (DU-145, PC-3) and bladder cancer (EJ28) cells were treated with carbon nanomaterials (CNFs, CNTs) and chemotherapeutics (carboplatin, cisplatin) alone as well as in combination for 24 h. Forty-eight (EJ28) or 72 h (DU-145, PC-3) after the end of treatment the effects on cellular proliferation, clonogenic survival, cell death rate and cell cycle distribution were evaluated. Depending on the cell line, simultaneous administration of chemotherapeutics and carbon nanomaterials produced an additional inhibition of cellular proliferation and clonogenic survival of up to 77% and 98%, respectively, compared to the inhibitory effects of the chemotherapeutics alone. These strongly enhanced antiproliferative effects were accompanied by an elevated cell death rate, which was predominantly mediated via apoptosis and not by necrosis. The antitumor effects of combinations with CNTs were less pronounced than those with CNFs. The enhanced effects of the combinatory treatments on cellular function were mostly of additive to partly synergistic nature. Furthermore, cell cycle analysis demonstrated an arrest at the G2/M phase mediated by a monotreatment with chemotherapeutics. Following combinatory treatments, mostly less than or nearly additive increases of cell fractions in the G2/M phase could be observed. In conclusion, the pronounced chemosensitizing effects of CNFs and CNTs were mediated by an enhanced apoptosis and inhibition of proliferation. The combination of carbon-based nanomaterials and conventional chemotherapeutics represents a novel

  19. Phorbol ester stimulates membrane association of protein kinase C and inhibits spontaneous Ca/sup 2 +/ dependent sarcoplasmic reticulum Ca/sup 2 +/ release in rat cardiac cells

    SciTech Connect

    Capogrossi, M.C.; Kaku, T.; Filburn, C.H.; Pelto, D.J.; Hansford, R.G.; Lakatta, E.G.

    1986-03-01

    Spontaneous oscillatory Ca/sup 2 +/ release from sarcoplasmic reticulum (SR) occurs in rat cardiac myocytes at hyperpolarized membrane potentials and is manifested as contractile waves (W). W frequency varies with SR functional status and cell Ca/sup 2 +/ loading. In myocyte suspensions (Hepes buffer, 37/sup 0/C (Ca/sup 2 +/) = 1.0mM) phorbol myristate acetate, PMA, (10/sup -7/ M) increased protein kinase C activity in membranes as a fraction of total (PKCAM) fivefold with a t 1/2 of < 30 sec (n = 3) and decreased W frequency in individual myocytes (n = 8). This effect varied directly and linearly with baseline W frequency, r = .94, p < .001). Dioctanoyl glycerol (10 ..mu.. M) had a similar effect on W. The PMA effect to decrease W frequency could be a direct one on SR or result from a reduction in cell Ca/sup 2 +/. The time course of PKCAM change is sufficiently rapid for it to mediate the effect on W. Thus, enhanced PKCAM may exert negative feedback control on Ca/sup 2 +/ mobilization during ..cap alpha..-adrenergic stimulation.

  20. Phorbol ester attenuates the KCl-induced increase in (Ca/sup 2 +/) and inhibits spontaneous sarcoplasmic reticulum Ca/sup 2 +/ release, in rat cardiac myocytes

    SciTech Connect

    Hansford, R.G.; Capogrossi, M.C.; Kaku, T.; Pelto, D.J.; Filburn, C.H.; Lakatta, E.G.

    1986-03-01

    Partial membrane depolarization induced by increasing the KCl concentration of the medium bathing cardiac myocytes leads to an increase in cell (Ca/sup 2 +/), and accelerates the frequency of spontaneous contractile waves (W) caused by periodic sarcoplasmic reticulum (SR) Ca/sup 2 +/ release. In suspensions of myocytes bathed in 1.0mM Ca/sup 2 +/ at 37 (pH 7.4) and loaded with the fluorescent Ca/sup 2 +/ - indicator Fura-2, by incubation with 2 ..mu..M acetoxymethyl ester for 30 min, the addition of KCl to raise (K/sup +/) from 5 to 30 mM is associated with a rapid (< 10 sec) increase in fluorescence, corresponding to an increased cell (Ca/sup 2 +/). Prior exposure (3 min) to 10/sup -7/ M phorbol myristate acetate (PMA) diminishes this response to 44 +/- 10% of that in control suspensions (n = 9). Under the same conditions W frequency (min/sup -1/) in individual cells in 30 mM KCl averaged 8.3 +/- 0.6. Addition of PMA abolished W within 1 min. Diacylglycerol (10 ..mu..M L..cap alpha..-1,2-dioctanoylglycerol, di C8) had a similar effect on W frequency. The thesis is that PMA attenuates cell Ca/sup 2 +/ overload and its associated potentiation of spontaneous SR Ca/sup 2 +/ oscillations. In view of the efficacy of PMA and di C8, it is suggested that the effect is mediated by protein kinase c, and it may involve an alteration in the intracellular distribution of this enzyme.

  1. Biological responsiveness to the phorbol esters and specific binding of (/sup 3/H)phorbol 12,13-dibutyrate in the nematode Caenorhabditis elegans, a manipulable genetic system

    SciTech Connect

    Lew, K.K.; Chritton, S.; Blumberg, P.M.

    1982-01-01

    Because of its suitability for genetic studies, the nematode Caenorhabditis elegans was examined for its responsiveness to the phorbol esters. Phorbol 12-myristate 13-acetate had three effects. It inhibited the increase in animal size during growth; it decreased the yield of progeny; and it caused uncoordinated movement of the adult. The effects on nematode size, progeny yield, and movement were quantitated. Concentrations of phorbol 12-myristate 13-acetate yielding half-maximal responses were 440, 460, and 170 nM, respectively. As was expected from the biological responsiveness of the nematodes, specific, saturable binding of phorbol ester to nematode extracts was found. (/sup 3/H)phorbol 12,13-dibutyrate bound with a dissociation constant of 26.8 +/- 3.9 nM. At saturation, 5.7 +/- 1.4 pmole/mg protein was bound.

  2. Phorbol-ester-induced alterations of free calcium ion transients in single rat hepatocytes.

    PubMed Central

    Woods, N M; Cuthbertson, K S; Cobbold, P H

    1987-01-01

    The effect of the phorbol esters phorbol 12-myristate 13-acetate (TPA) and phorbol 12,13-dibutyrate (PDB) on changes in free Ca2+ concentration ([Ca2+]i) in single rat hepatocytes, microinjected with the photoprotein aequorin, were investigated. [Arg8]vasopressin and phenylephrine induced a series of repetitive [Ca2+]i transients. Phorbol esters inhibited the alpha 1-adrenoceptor-induced response; sub-nanomolar concentrations decreased the transient frequency, and higher concentrations abolished the transients. The inhibitory effect of PDB was readily reversible. Phorbol esters were less effective in decreasing the frequency of [Arg8]-vasopressin-induced transients, and the inhibition could be overcome by high [Arg8]vasopressin concentrations. PMID:3479980

  3. Identification of the phorbol ester receptor in human and avian erythrocytes

    SciTech Connect

    Kramer, C.M.; Sando, J.J.; Speizer, L.A.

    1986-05-01

    The ability of phorbol esters to inhibit the uptake of a fluorescent glucose analogue in goose but not human erythrocytes is consistent with earlier reports that the human red blood cell lacks the phorbol ester receptor. However, they have located specific phorbol 12,13-dibutyrate binding sites in both human and goose erythrocytes. Human and goose red blood cells contain 2 classes of phorbol ester receptors with similar affinities, however the human erythrocyte contains 1/3 as many phorbol ester receptors as does the goose red blood cell. An additional contrast in the binding of phorbol esters to human and goose red blood cells is the temperature-induced enhancement of binding to goose, but not human erythrocytes. Equilibrium phorbol ester binding to goose red blood cells at 37/sup 0/C is enhanced 3.3 +/- 0.4 times that amount bound at 4/sup 0/C. Equilibrium binding of phorbol esters to human erythrocytes is identical at both temperatures. In vivo and in vitro phosphorylation profiles of C-kinase substrates also differ between the human and goose erythrocyte.

  4. Resveratrol inhibits phorbol ester-induced expression of COX-2 and activation of NF-kappaB in mouse skin by blocking IkappaB kinase activity.

    PubMed

    Kundu, Joydeb Kumar; Shin, Young Kee; Kim, Sung Hoon; Surh, Young-Joon

    2006-07-01

    Aberrant expression of cyclooxygenase-2 (COX-2) has been implicated in tumor promotion. Resveratrol, a phytoalexin present in grapes, was reported to inhibit multistage mouse skin carcinogenesis. In the present study, we found that topically applied resveratrol significantly inhibited COX-2 expression induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Resveratrol-suppressed phosphorylation and subsequent degradation of IkappaBalpha, thereby inhibiting activation of nuclear factor-kappaB (NF-kappaB) in TPA-stimulated mouse skin. Pretreatment with resveratrol also suppressed TPA-induced phosphorylation of extracellular signal-regulated protein kinase (ERK) and p38 mitogen-activated protein (MAP) kinase. Resveratrol blunted TPA-induced phosphorylation of p65 and its interaction with CBP/p300, rendering NF-kappaB transcriptionally inactive. To get further insights into the molecular basis of NF-kappaB inactivation by resveratrol, we examined the role of IkappaB kinase (IKK) in mediating TPA-induced activation of NF-kappaB and COX-2 expression. TPA treatment led to rapid induction of IKK activity in mouse skin, which was abolished either by resveratrol or an IKK inhibitor Bay 11-7082. Topical application of Bay 11-7082 also abrogated TPA-induced NF-kappaB activation and COX-2 expression, supporting the involvement of IKK in TPA-induced COX-2 expression. Taken together, the above findings suggest that resveratrol targets IKK in blocking TPA-induced NF-kappaB activation and COX-2 expression in mouse skin in vivo.

  5. Thyrotropin inhibits while insulin, epidermal growth factor and tetradecanoyl phorbol acetate stimulate insulin-like growth factor binding protein secretion from sheep thyroid cells.

    PubMed

    Eggo, M C; Bachrach, L K; Brown, A L; Burrow, G N

    1991-01-01

    Six insulin-like growth factor binding proteins (IGFBP) have been identified in the conditioned medium from sheep thyroid cells cultured under serum-free conditions. IGFBPs of 32, 28, 23 and 19 kDa were secreted by cells cultured for 14 days in serum-free and hormone-free medium. The constitutive secretion of IGFBP was inhibited by thyrotropin (TSH, 0.3 mU per mL). The effect was most marked on the secretion of the 28 kDa BP. High insulin concentrations stimulated the secretion of this IGFBP. The stimulatory effects of insulin were inhibited by TSH. Growth hormone treatment decreased the secretion of the 28 kDa protein. Tetradecanoylphorbol-13 acetate (TPA) and epidermal growth factor (EGF) both of which stimulate thyroid cell growth but inhibit differentiated function, markedly stimulated IGFBP secretion and induced the appearance of a 46 and a 150 kDa IGFBP. The effects of EGF and TPA were not identical. A rat IGFBP-2 cDNA reacted with sheep thyroid RNA of approximate size 1.6 kb. TPA treatment increased IGFBP-2 mRNA. Other hormones used to enhance differentiation and growth in thyroid cells in culture i.e. transferrin, somatostatin, cortisol and glycyl-histidyl-lysine acetate had no marked effects on IGFBP secretion nor on TSH-dependent, insulin-mediated iodide uptake and organification and cell growth. We show a correlation between secretion of high molecular weight IGFBP with enhanced growth but decreased function. Conversely, we find a correlation between decreased secretion of the 28 kDa BP and increased growth and function. PMID:1722684

  6. [6]-Gingerol inhibits COX-2 expression by blocking the activation of p38 MAP kinase and NF-kappaB in phorbol ester-stimulated mouse skin.

    PubMed

    Kim, Sue Ok; Kundu, Joydeb Kumar; Shin, Young Kee; Park, Jin-Hong; Cho, Myung-Haing; Kim, Tae-Yoon; Surh, Young-Joon

    2005-04-01

    [6]-Gingerol, a pungent ingredient of ginger (Zingiber officinale Roscoe, Zingiberaceae), has a wide array of pharmacologic effects. The present study was aimed at unraveling the molecular mechanisms underlying previously reported antitumor promoting effects of [6]-gingerol in mouse skin in vivo. One of the well-recognized molecular targets for chemoprevention is cyclooxygenase-2 (COX-2) that is abnormally upregulated in many premalignant and malignant tissues and cells. In our present study, topical application of [6]-gingerol inhibited COX-2 expression in mouse skin stimulated with a prototype tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Since the transcription factor nuclear factor-kappaB (NF-kappaB) is known to regulate COX-2 induction, we attempted to determine the effect of [6]-gingerol on TPA-induced activation of NF-kappaB. Pretreatment with [6]-gingerol resulted in a decrease in both TPA-induced DNA binding and transcriptional activities of NF-kappaB through suppression of IkappaBalpha degradation and p65 nuclear translocation. Phosphorylation of both IkappaBalpha and p65 was substantially blocked by [6]-gingerol. In addition, [6]-gingerol inhibited TPA-stimulated interaction of phospho-p65-(Ser-536) with cAMP response element binding protein-binding protein, a transcriptional coactivator of NF-kappaB. Moreover, [6]-gingerol prevented TPA-induced phosphorylation and catalytic activity of p38 mitogen-activated protein (MAP) kinase that regulates COX-2 expression in mouse skin. The p38 MAP kinase inhibitor SB203580 attenuated NF-kappaB activation and subsequent COX-2 induction in TPA-treated mouse skin. Taken together, our data suggest that [6]-gingerol inhibits TPA-induced COX-2 expression in mouse skin in vivo by blocking the p38 MAP kinase-NF-kappaB signaling pathway. PMID:15735738

  7. Silver nanoparticles impede phorbol myristate acetate-induced monocyte-macrophage differentiation and autophagy

    NASA Astrophysics Data System (ADS)

    Xu, Yingying; Wang, Liming; Bai, Ru; Zhang, Tianlu; Chen, Chunying

    2015-09-01

    Monocytes/macrophages are important constituents of the innate immune system. Monocyte-macrophage differentiation is not only crucial for innate immune responses, but is also related to some cardiovascular diseases. Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials because of their broad-spectrum antimicrobial properties. However, the effect of AgNPs on the functions of blood monocytes is scarcely reported. Here, we report the impedance effect of AgNPs on THP-1 monocyte differentiation, and that this effect was mediated by autophagy blockade and lysosomal impairment. Firstly, AgNPs inhibit phorbol 12-myristate 13-acetate (PMA)-induced monocyte differentiation by down-regulating both expression of surface marker CD11b and response to lipopolysaccharide (LPS) stimulation. Secondly, autophagy is activated during PMA-induced THP-1 monocyte differentiation, and the autophagy inhibitor chloroquine (CQ) can inhibit this process. Thirdly, AgNPs block the degradation of the autophagy substrate p62 and induce autophagosome accumulation, which demonstrates the blockade of autophagic flux. Fourthly, lysosomal impairments including alkalization and decrease of lysosomal membrane stability were observed in AgNP-treated THP-1 cells. In conclusion, we demonstrate that the impedance of monocyte-macrophage differentiation by AgNPs is mediated by autophagy blockade and lysosomal dysfunction. Our results suggest that crosstalk exists in different biological effects induced by AgNPs.

  8. Silver nanoparticles impede phorbol myristate acetate-induced monocyte-macrophage differentiation and autophagy.

    PubMed

    Xu, Yingying; Wang, Liming; Bai, Ru; Zhang, Tianlu; Chen, Chunying

    2015-10-14

    Monocytes/macrophages are important constituents of the innate immune system. Monocyte-macrophage differentiation is not only crucial for innate immune responses, but is also related to some cardiovascular diseases. Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials because of their broad-spectrum antimicrobial properties. However, the effect of AgNPs on the functions of blood monocytes is scarcely reported. Here, we report the impedance effect of AgNPs on THP-1 monocyte differentiation, and that this effect was mediated by autophagy blockade and lysosomal impairment. Firstly, AgNPs inhibit phorbol 12-myristate 13-acetate (PMA)-induced monocyte differentiation by down-regulating both expression of surface marker CD11b and response to lipopolysaccharide (LPS) stimulation. Secondly, autophagy is activated during PMA-induced THP-1 monocyte differentiation, and the autophagy inhibitor chloroquine (CQ) can inhibit this process. Thirdly, AgNPs block the degradation of the autophagy substrate p62 and induce autophagosome accumulation, which demonstrates the blockade of autophagic flux. Fourthly, lysosomal impairments including alkalization and decrease of lysosomal membrane stability were observed in AgNP-treated THP-1 cells. In conclusion, we demonstrate that the impedance of monocyte-macrophage differentiation by AgNPs is mediated by autophagy blockade and lysosomal dysfunction. Our results suggest that crosstalk exists in different biological effects induced by AgNPs. PMID:26372376

  9. Phorbol ester-stimulated phosphorylation of basolateral membranes from canine kidney

    SciTech Connect

    Hammerman, M.R.; Rogers, S.; Morrissey, J.J.; Gavin, J.R. III

    1986-06-01

    To determine whether protein kinase C is present in the basolateral membrane of the renal proximal tubular cell, we performed experiments to ascertain whether specific binding of (/sup 3/H)phorbol 12,13-dibutyrate could be demonstrated in basolateral membranes isolated from canine kidney. Specific binding was demonstrable that was half maximal at between 10(-7) and 10(-8) M phorbol 12,13-dibutyrate. Binding was inhibited by 12-O-tetradecanoylphorbol-13-acetate (TPA) and other tumor-promoting phorbol esters, but not by inactive phorbol esters, including 4 alpha-phorbol. Incubation of basolateral membranes with TPA and phorbol 12,13-dibutyrate, but not with 4 alpha-phorbol, in the presence of submicromolar concentrations of free calcium, enhanced phosphorylation of several proteins demonstrable in autoradiograms of sodium dodecyl sulfate-polyacrylamide gels originating from membranes subsequently exposed to (gamma-32P)ATP for 30 s. Dephosphorylation of (/sup 32/P)phosphoproteins was observed in gels from membranes incubated with (gamma-32P)ATP over time. TPA-stimulated phosphorylation of one protein band with Mr 135,000 was quantitated and was found to increase as a function of (TPA). Half-maximal TPA-stimulated phosphorylation of this protein band occurred at slightly less than 10(-9) M TPA. Our findings are consistent with a role for protein kinase C-effected phosphorylation of basolateral membrane proteins in the mediation or modulation of hormonal actions in the proximal tubular cell.

  10. Purifying Nanomaterials

    NASA Technical Reports Server (NTRS)

    Hung, Ching-Cheh (Inventor); Hurst, Janet (Inventor)

    2014-01-01

    A method of purifying a nanomaterial and the resultant purified nanomaterial in which a salt, such as ferric chloride, at or near its liquid phase temperature, is used to penetrate and wet the internal surfaces of a nanomaterial to dissolve impurities that may be present, for example, from processes used in the manufacture of the nanomaterial.

  11. High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae.

    PubMed

    Mesarič, Tina; Gambardella, Chiara; Milivojević, Tamara; Faimali, Marco; Drobne, Damjana; Falugi, Carla; Makovec, Darko; Jemec, Anita; Sepčić, Kristina

    2015-06-01

    We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration-dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5mg/mL carbon black and 0.1mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change. PMID:25889088

  12. Extracellular biogenic nanomaterials inhibit pyoverdine production in Pseudomonas aeruginosa: a novel insight into impacts of metal(loid)s on environmental bacteria.

    PubMed

    Mohanty, Anee; Liu, Yang; Yang, Liang; Cao, Bin

    2015-02-01

    Anthropogenic activities such as mining, smelting, and industrial use have caused serious problems of metal(loid) pollution in nearly every country in the world. A wide range of environmental microorganisms are capable of transforming metal(loid)s into nanomaterials, i.e., biogenic nanomaterials (bio-NMs), in the environment. Although the impacts of various metal(loid)s on the ecosystems have been extensively studied, the potential influence of the bio-NMs generated in the environment to environmental organisms is largely unexplored. Using tellurium nanomaterials transformed from tellurite by a metal-reducing bacterium as model bio-NMs, we demonstrated that the bio-NMs significantly decreased siderophore production in an environmental bacterium Pseudomonas aeruginosa in both planktonic cultures and biofilms. Transcriptomic analysis revealed that the bio-NMs inhibited the expression of genes involved in biosynthesis and transport of siderophores. Siderophores secreted by certain bacteria in microbial communities can be considered as public goods that can be exploited by local communities, playing an important role in shaping microbial communities. The inhibition of siderophore production by the bio-NMs implies that bio-NMs may have an important influence on the ecosystems through altering specific functions of environmental bacteria. Taken together, this study provides a novel insight into the environmental impacts of metal(loid)s. PMID:25273177

  13. Specific binding and biological effects of tumor promoting phorbol esters on sponges.

    PubMed

    Mazzorana, M; Garrone, R; Martel, N; Yamasaki, H

    1984-01-01

    Sponges grown in the presence of 12-O-tetradecanoyl phorbol-13-acetate (TPA) show deep alterations of their structure and development. Their aquiferous system (flagellated cells and canals) is largely altered and the tissues show an unusually high cell density. This focalized effect of TPA on the aquiferous system seems specific and is reversible at low concentrations (100 ng/ml). A toxic, non-specific effect is also noted, particularly at high concentrations (5000 ng/ml). Using 3H-phorbol-12, 13-dibutyrate (3H-PDBu), we demonstrate a class of specific binding sites for phorbol esters in the homogenates of sponges. These binding sites have high affinity (Kd = 26.0 nM) for PDBu and at saturation about 20 pmoles of 3H-PDBu is bound per mg protein of sponge homogenates. The binding of 3H-PDBu was inhibited by other phorbol esters and their congeners, and there was a good correlation between their potency in binding inhibition and their tumor promoting activity. It is concluded that sponges have a class of specific saturable and high affinity receptors for phorbol esters and that there is a very high conservation of these receptors during evolution. Such specific binding may be responsible for subsequent biological effect of TPA on sponges.

  14. Effect of phorbol esters on guniea pig skin in vivo.

    PubMed

    Bourin, M C; Delescluse, C; Fürstenberger, G; Marks, F; Schweizer, J; Klein-Szanto, A J; Prunieras, M

    1982-01-01

    When topically applied to guniea pig ear skin the tumor promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induced inflammation and epidermal hyperproliferation which could be inhibited by indomethacin. This inhibition could be reversed both by prostaglandins E and F. Five minutes after TPA treatment an increase in the level of prostaglandin E but not of prostaglandin F was observed in the epidermis. The non-promoting phorbol ester 4-O-methyl-TPA also stimulated epidermal cell proliferation but this stimulation was not inhibited by indomethacin. The above results are in agreement with those already reported in the mouse system with these two compounds. Ornithine decarboxylase (ODC) activity has been evaluated in the epidermis of guniea pig ear after topical application of 20 nmol of TPA. No increase was noted. This is in contrast with the well documented activation of ODC in mouse skin treated with TPA. Since TPA acts as a promoter in the mouse whereas both croton oil and TPA have no promoting action in the guinea pig, the above result supports the view that ODC activationis related to promotion, and provides a possible explanation for the resistance of this animal species to promotion. This resistance is further documented by the fact that no "dark cells" were found in guinea pig ear skin.

  15. Nineteen-Step Total Synthesis of (+)-Phorbol

    PubMed Central

    Kawamura, Shuhei; Chu, Hang; Felding, Jakob; Baran, Phil S.

    2016-01-01

    Phorbol, the flagship member of the tigliane diterpene family, has been known for over 80 years and has attracted attention from scores of chemists and biologists due to its intriguing chemical structure and the medicinal potential of phorbol esters.1 Access to useful quantities of phorbol and related analogs has relied upon isolation from natural sources and semisynthesis. Despite relentless efforts spanning 40 years, chemical synthesis has been unable to compete with these strategies due to its sheer complexity and unusual oxidation pattern. In fact, purely synthetic enantiopure phorbol has remained elusive and efforts on the synthetic biology side have not led to even the simplest members of this terpene family. Recently the chemical syntheses of eudesmanes,2 germacrenes,3 taxanes,4,5 and ingenanes6-8 have all benefited from a strategy inspired by the logic of two-phase terpene biosynthesis where powerful C–C bond constructions and C–H bond oxidations go hand in hand. In this manuscript, we show how a two-phase terpene synthesis strategy can be enlisted to achieve the first enantiospecific total synthesis of (+)-phorbol in only 19 steps from the abundant monoterpene (+)-3-carene. The purpose of this route is not to displace isolation/semisynthesis as a means to generate the natural product per se, but rather to enable access to analogs containing unique oxidation patterns that are otherwise inaccessible. PMID:27007853

  16. Effect of phorbol and Bryostatin I on chondrogenic expression of chick limb bud, in vitro

    SciTech Connect

    Garrison, J.C.; Pettit, G.R.; Uyeki, E.M.

    1987-10-26

    The present paper describes the effects of PMA (phorbol 12-myristate 13 acetate) on in vitro chondrogenesis in non-passaged, embryonic limb bud cells, relative to the effects of Bryostatin I. This compound also activates C kinase and binds competitively to the phorbol ester receptor, yet does not affect cell differentiation. Levels of PMA as low as 10/sup -7/ M markedly reduced cartilage formation in 4-day cultures, as indicated by nodule count and Alcian blue staining for chondroitin sulfate. Coadministration of Bryostatin I at equimolar concentration prevented the PMA inhibitory effect on chondrocytic expression. This confirms other findings that phorbol activation of C kinase cannot exclusively account for the activity of phorbol on cell expression. Altering the time of PMA exposure demonstrated that PMA inhibited chondrocyte phenotypic expression, rather than cell commitment: early exposure to PMA had little inhibitor effect on the staining index, whereas, exposure from 49-96 h and 0-96 h had moderate and strong inhibitory effects, respectively, on cartilage synthesis. Further research on the phorbol/Bryostatin I interaction should add to their knowledge of the control processes involved in tumor promotion and cell differentiation. 21 references, 3 figures.

  17. Five new phorbol esters with cytotoxic and selective anti-inflammatory activities from Croton tiglium.

    PubMed

    Wang, Jun-Feng; Yang, Sheng-Hui; Liu, Yan-Qun; Li, Din-Xiang; He, Wei-Jun; Zhang, Xiao-Xiao; Liu, Yong-Hong; Zhou, Xiao-Jiang

    2015-05-01

    Five new phorbol esters, (four phorbol diesters, 1-4, and one 4-deoxy-4α-phorbol diester, 5), as well as four known phorbol esters analogues (6-9) were isolated and identified from the branches and leaves of Croton tiglium. Their structures were elucidated mainly by extensive NMR spectroscopic, and mass spectrometric analysis. Among them, compound (1) was the first example of a naturally occurring phorbol ester with the 20-aldehyde group. Compounds 2-5, and 7-9 showed potent cytotoxicity against the K562, A549, DU145, H1975, MCF-7, U937, SGC-7901, HL60, Hela, and MOLT-4 cell lines, with IC50 values ranging from 1.0 to 43 μM, while none of the compounds exhibited cytotoxic effects on normal human cell lines 293T and LX-2, respectively. In addition, compound 3 exhibited moderate COX-1 and COX-2 inhibition, with IC50 values of 0.14 and 8.5 μM, respectively.

  18. Receptor-mediated Modulation of Human Monocyte, Neutrophil, Lymphocyte, and Platelet Function by Phorbol Diesters

    PubMed Central

    Goodwin, Bonnie J.; Weinberg, J. Brice

    1982-01-01

    The tumor promoting phorbol diesters elicit a variety of responses from normal and leukemic blood cells in vitro by apparently interacting with cellular receptors. The biologically active ligand [20-3H] phorbol 12,13-dibutyrate ([3H]PDBu) bound specifically to intact human lymphocytes, monocytes, polymorphonuclear leukocytes (PMN), and platelets, but not to erythrocytes. Binding, which was comparable for all four blood cell types, occurred rapidly at 23° and 37°C, reaching a maximum by 20-30 min usually followed by a 30-40% decrease in cell associated radioactivity over the next 30-60 min. The time course for binding was temperature dependent with equilibrium binding occurring after 120-150 min at 4°C, with no subsequent loss of cell-associated radioactivity at this temperature. Bound [3H]PDBu could be eluted by addition of unlabeled PDBu. Scatchard analysis of data from 4°C binding studies revealed linear plots with high affinity receptors in these cell types with dissociation constants and receptors per cell of 60 nM and 7.8 × 105/cell for lymphocytes, 51 nM and 15.5 × 105/cell for monocytes, 38 nM and 4.0 × 105/cell for PMN, and 19 nM and 2.9 × 104/cell for platelets. Structure-activity studies using unlabeled phorbol-related compounds demonstrated a close correlation between their abilities to inhibit binding of [3H]PDBu to cells and their abilities to induce cellular responses (monocyte and PMN H2O2 secretion, lymphocyte 3HTdR incorporation, and platelet tritiated serotonin release); phorbol and 4-alpha phorbol were inactive while phorbol 12-myristate 13-acetate (PMA), PDBu, mezerein, and phorbol 12,13-diacetate (in decreasing order of potency) inhibited [3H]PDBu binding and elicited the various responses. Thus, these high affinity, specific receptors for the phorbol diesters, present on monocytes, lymphocytes, PMN, and platelets, mediate the pleiotypic effects induced by these ligands. PMID:6956584

  19. Phorbol esters induce multidrug resistance in human breast cancer cells

    SciTech Connect

    Fine, R.L.; Patel, J.; Chabner, B.A.

    1988-01-01

    Mechanisms responsible for broad-based resistance to antitumor drugs derived from natural products (multidrug resistance) are incompletely understood. Agents known to reverse the multidrug-resistant phenotype (verapamil and trifluoperazine) can also inhibit the activity of protein kinase C. When the authors assayed human breast cancer cell lines for protein kinase C activity, they found that enzyme activity was 7-fold higher in the multidrug-resistance cancer cells compared with the control, sensitive parent cells. Exposure of drug-sensitive cells to the phorbol ester phorbol 12,13-dibutyate (P(BtO)/sub 2/) led to an increase in protein kinase C activity and induced a drug-resistance phenotype, whereas exposure of drug-resistant cells to P(BtO)/sub 2/ further increased drug resistance. In sensitive cells, this increased resistance was accomplished by a 3.5-fold increased phosphorylation of a 20-kDa particulate protein and a 35-40% decreased intracellular accumulation of doxorubicin and vincristine. P(BtO)/sub 2/ induced resistance to agents involved in the multidrug-resistant phenotype (doxorubicin and vincristine) but did not affect sensitivity to an unrelated alkylating agent (melphalan). The increased resistance was partially or fully reversible by the calcium channel blocker verapamil and by the calmodulin-antagonist trifluoperazine. These data suggest that stimulation of protein kinase C playus a role in the drug-transport changes in multidrug-resistant cells. This may occur through modulation of an efflux pump by protein phosphorylation.

  20. Phorbol esters enhance attachment of NIH/3T3 cells to laminin and type IV collagen substrates

    SciTech Connect

    Kato, Shigemi; Ben, T.L.; De Luca, L.M. )

    1988-11-01

    The effect of phorbol esters on the adhesive properties of NIH/3T3 mouse fibroblasts was investigated using plastic substrates precoated with the extracellular matrix proteins fibronectin, collagen, and laminin. Treatment with phorbol 12-myristate 13-acetate (PMA) enhanced NIH/3T3 cell attachment to laminin and type IV collagen substrates but had little or no effect on attachment to fibronectin and type I collagen substrates. The effect of PMA in enhancing cell attachment to laminin and type IV collagen substrates was dose dependent between 10{sup {minus}9} and 10{sup {minus}7} M. PMA was effective as early as 30 min; the effect reached a maximum at 2 h and decreased gradually. Phorbol 12, 13-dibenzoate and phorbol 12, 13-diacetate were effective but to a lesser extent and phorbol 12-myristate and phorbol 13-acetate showed little or no effect. These results suggest that PMA may enhance NIH/3T3 cell adhesion through effects on laminin and type IV collagen receptors. Retinoic acid, which itself requires at least 6 h to show an effect on attachment, did not have any effect on cell attachment in 2 h and, if anything, slightly inhibited PMA-enhanced cell attachment to laminin and type IV collagen substrates.

  1. Stimulation of Paramecium phagocytosis by phorbol ester and forskolin.

    PubMed

    Wyroba, E

    1987-09-01

    Phorbol ester (PMA) exerted a dose- and time- dependent stimulating effect on phagocytosis in axenic Paramecium aurelia. When cells were exposed to 200-800 nM PMA in the presence of latex beads, the phagocytic coefficient was enhanced 2.25 to 3.14 times, during 10 min of continuous treatment and then rapidly declined. A similar effect was observed when the cells were exposed to a forskolin treatment, which resulted in nearly a twofold increase in phagocytic activity after a 10 min pulse. Both PMA and forskolin strongly stimulated phagocytosis (i.e. fivefold and threefold, respectively) in cells in which such activity had been completely inhibited by pre-exposure to the beta-receptor antagonist 1-propranolol.

  2. Tumor promoter 12-O-tetradecanoyl phorbol 13-acetate and regulatory diacylglycerols are substrates for the same carboxylesterase

    SciTech Connect

    Mentlein, R.

    1986-06-15

    Rat liver homogenate or cell fractions deacylate 12-O-tetradecanoyl phorbol 13-acetate (TPA) in vitro mainly by conversion to phorbol 13-acetate. The highest specific activity is located in the microsomal fraction. The deacylation is inhibited by bis-(4-nitrophenyl) phosphate, a selective inhibitor of nonspecific carboxylesterases. Only two of five purified esterases from rat liver endoplasmic reticulum deacylate TPA. These two esterases have formerly been characterized as acylcarnitine hydrolases and the more active one is also a potent diacylglycerol lipase. Its TPA-hydrolyzing activity is inhibited by other substrates like 1-naphthylacetate, lauroylcarnitine, or dioleoyl glycerol. The results support the view that phorbol esters act like structural analogs of diacylglycerols, not only with respect to their activating effect on protein kinase C, but also as substrates for the same lipases.

  3. Interactions between Carbon Nanomaterials and Biomolecules.

    PubMed

    Han, Xu; Li, Shanghao; Peng, Zhili; Al-Yuobi, Abdulrahman Obaid; Omar Bashammakh, Abdulaziz Saleh; El-Shahawi, M S; Leblanc, Roger M

    2016-01-01

    Interactions between carbon nanomaterials, including carbon dots, fullerene, carbon nanotube, graphene, and graphene oxide, and biomolecules play an important role in the field of nanobiotechnology. Due to the unique properties of carbon nanomaterials and the magnificent features of their colloids, it shows high potential in fibrillation inhibition, high sensitivity sensor fabrication, bioimaging, drug delivery, and other areas. Hereby, we will go over different families of carbon nanomaterials regarding to the interaction between carbon nanomaterials and biomolecules at the interface, and their applications will be reviewed as well.

  4. The peroxisome proliferator activated receptor delta is required for the differentiation of THP-1 monocytic cells by phorbol ester.

    PubMed

    Vosper, Helen; Khoudoli, Guennadi A; Palmer, Colin NA

    2003-12-11

    BACKGROUND: PPARdelta (NR1C2) promotes lipid accumulation in human macrophages in vitro and has been implicated in the response of macrophages to vLDL. We have investigated the role of PPARdelta in PMA-stimulated macrophage differentiation.The THP-1 monocytic cell line which displays macrophage like differentiation in response to phorbol esters was used as a model system. We manipulated the response to PMA using a potent synthetic agonist of PPARdelta, compound F. THP-1 sub-lines that either over-expressed PPARdelta protein, or expressed PPARdelta anti-sense RNA were generated. We then explored the effects of these genetic modulations on the differentiation process. RESULTS: The PPARdelta agonist, compound F, stimulated differentiation in the presence of sub-nanomolar concentrations of phorbol ester. Several markers of differentiation were induced by compound F in a synergistic fashion with phorbol ester, including CD68 and IL8. Over-expression of PPARdelta also sensitised THP-1 cells to phorbol ester and correspondingly, inhibition of PPARdelta by anti-sense RNA completely abolished this response. CONCLUSIONS: These data collectively demonstrate that PPARdelta plays a fundamental role in mediating a subset of cellular effects of phorbol ester and supports observations from mouse knockout models that PPARdelta is involved in macrophage-mediated inflammatory responses.

  5. Luminol-dependent photoemission from single neutrophil stimulated by phorbol ester and calcium ionophore--role of degranulation and myeloperoxidase

    SciTech Connect

    Suematsu, M.; Oshio, C.; Miura, S.; Suzuki, M.; Houzawa, S.; Tsuchiya, M.

    1988-08-30

    Luminol-dependent photonic burst from phorbol ester-treated single neutrophil was visually investigated by using an ultrasensitive photonic image intensifier microscope. Neutrophils stimulated by phorbol myristate acetate (0.1 microgram/ml) alone produced a negligible level of photonic activities in the presence of luminol (10 micrograms/ml). The additional application of 0.1 microM Ca2+ ionophore A23187 induced explosive changes of photonic burst corresponding to the distribution of neutrophils, and these photonic activities were gradually spread to extracellular space. Sodium azide, which prevents myeloperoxidase activity, inhibited Ca2+ ionophore-induced photonic burst from phorbol ester-treated neutrophil. These findings suggest a prerequisite role of degranulation and myeloperoxidase release in luminol-dependent photoemission from stimulated neutrophils.

  6. Impact of Carbon Nanomaterials on Actin Polymerization.

    PubMed

    Dong, Ying; Sun, Haiyan; Li, Xu; Li, Xin; Zhao, Lina

    2016-03-01

    Many nanomaterials have entered people's daily lives and impact the normal process of biological entities consequently. As one kind of the important nanomaterials, carbon based nanomaterials have invoked a lot of concerns from scientific researches because of their unique physicochemical properties. In eukaryotes, actin is the most abundantly distributed protein in both cytoplasm and cell nucleus, and closely controls the cell proliferation and mobility. Recently, many investigations have found some carbon based nanomaterials can affect actin cytoskeleton remarkably, including fullerenes derivatives, carbon nanotubes, graphene and its derivatives. However, these interaction processes are complicated and the underlying mechanism is far from being understood clearly. In this review, we discussed the different mechanisms of carbon nanomaterials impact on actin polymerization into three pathways, as triggering the signaling pathways from carbon nanomaterials outside of cells, increasing the production of reactive oxygen species from carbon nanomaterials inside of cells and direct interaction from carbon nanomaterials inside of cells. As a result, the dimension and size of carbon nanomaterials play a key role in regulation of actin cytoskeleton. Furthermore, we forecasted the possible investigation strategy for meeting the challenges of the future study on this topic. We hope the findings are helpful in understanding the molecular mechanism in carbon nanomaterials regulating actin polymerization, and provide new insight in novel nanomedicine development for inhibition tumor cell migration. PMID:27455649

  7. Effect of phorbol derivatives and staurosporine on gravitropic response of primary root of maize

    SciTech Connect

    Mulkey, T.J.; Kim, S.Y. ); Lee, J.S. )

    1991-05-01

    Time-lapse videography and computer-based, video image digitization were used to examine the effects of phorbol derivatives (phorbol 12-myristate 13-acetate, TPA; phorbol 12-myristate 13-acetate 4-O-methyl ether, mTPA) and staurosporine on the kinetics of gravicurvature of primary roots of maize (Zea mays L., Pioneer 3343 and Golden Cross Bantam). Pretreatment of roots with TPA (3 hr, 1 {mu}M) decreases the time lag prior to induction of positive gravicurvature in horizontally-oriented roots by > 60%. The rate of curvature is not significantly different than the rate observed in control roots. Wrongway curvature which is observed in 30-40% of control roots is not observed in TPA-pretreated roots. Oscillatory movements observed in control roots after completion of gravitropic reorientation is completely dampened in TPA-pretreated roots. Pretreatment of roots with mTPA(3hr,1{mu}M), the inactive analog of TPA, does not significantly alter the kinetics of gravicurvature of primary roots of maize. Staurosporine (10{sup {minus}8}M), a microbial alkaloid which has been reported to have antifungal activity and to inhibit phospholipid/Ca{sup ++} dependent protein kinase, completely inhibits TPA-induced alteration of the kinetics of gravitropism. DAG (1-oleoyl-2-acetyl-rac-glycerol), a synthetic diglyceride activator of protein kinase C, exhibits similar activity to TPA. TPA-induced alterations in tissue response to auxin are presented.

  8. Tumor-promoting phorbol esters support the in vitro proliferation of murine pluripotent hematopoietic stem cells.

    PubMed Central

    Spivak, J L; Hogans, B B; Stuart, R K

    1989-01-01

    The effect of tumor-promoting phorbol esters on the in vitro proliferation of mouse pluripotent hematopoietic stem cells (CFU-S) was examined using a short-term in vitro culture system and an 11-d spleen colony assay. Phorbol myristate acetate (PMA, 10(-7) M), but not the inert compound phorbol, supported the in vitro survival of day 11 CFU-S for 72 h in a manner similar to IL 3. PMA also enhanced the effect of IL 3 on the in vitro survival of day 11 CFU-S and as little as 1 h of exposure to PMA was sufficient for this purpose. The effect of PMA on CFU-S survival in vitro was not mediated by prostaglandins, did not require an established adherent cell population, and was observed at a concentration of 10(-9) M. PMA alone did not enhance the in vitro survival of day 11 CFU-S at very low concentrations of FCS but was still able to potentiate the effect of IL 3 on these cells. PMA also enhanced the in vitro survival of day 11 CFU-S from mice treated with 5-fluorouracil or from marrow cells exposed to merocyanine 540 and light. The interaction of PMA with day 11 CFU-S was not inhibited by a neutralizing antiserum to IL 3 but was inhibited by the protein kinase inhibitor H-7. Together, the data indicate that tumor-promoting phorbol esters interact with pluripotent hematopoietic stem cells. Like IL 3, their effect appears to be permissive and involves stem cells with marrow repopulating ability. PMID:2463264

  9. GLAST: gene expression regulation by phorbol esters.

    PubMed

    Espinoza-Rojo, M; López-Bayghen, E; Ortega, A

    2000-08-21

    The gene expression regulation of the Na+-dependent high affinity glutamate/aspartate transporter GLAST expressed in cultured Bergmann glia cells from chick cerebellum was studied. A 679 bp fragment of the chick GLAST cDNA was cloned and sequenced. Specific PCR primers were used to quantify chick GLAST mRNA levels. Treatment of the cells with the Ca2+/diacylglycerol dependent protein kinase C (PKC) activator, phorbol 12-tetradecanoyl-13-acetate (TPA) produced a decrease in transporter mRNA levels, without an effect in its mRNA half life, suggesting a transcriptional down regulation. Activation of the cAMP pathway results in a transient decrease in GLAST mRNA levels, in contrast with the TPA effect. These findings suggest that GLAST expression is under control of distinct signaling pathways.

  10. Phorbol esters and adenosine affect the readily releasable neurotransmitter pool by different mechanisms at amphibian motor nerve endings.

    PubMed

    Searl, T J; Silinsky, E M

    2003-12-01

    Phorbol esters and adenosine have been proposed to interact at common sites downstream of calcium entry at amphibian motor nerve endings. We thus studied the actions and interactions of phorbol esters and adenosine using electrophysiological recording techniques in conjunction with both binomial statistical analysis and high-frequency stimulation at the amphibian neuromuscular junction. To begin this study, we confirmed previous observations that synchronous evoked acetylcholine (ACh) release (reflected as endplate potentials, EPPs) is well described by a simple binomial distribution. We then used binomial analysis to study the effects of the phorbol ester phorbol dibutyrate (PDBu, 100 nM) and adenosine (50 microM) on the binomial parameters n (the number of calcium charged ACh quanta available for release) and p (the average probability of release), where the mean level of evoked ACh release (m) = np. We found that PDBu increased m by increasing the parameter n whilst adenosine reduced m by reducing n; neither agent affected the parameter p. PDBu had no effect on either the potency or efficacy of the inhibition produced by adenosine. Subtle differences between these two agents were revealed by the patterns of EPPs evoked by high-frequency trains of stimuli. Phorbol esters increased ACh release during the early phase of stimulation but not during the subsequent plateau phase. The inhibitory effect of adenosine was maximal at the beginning of the train and was still present with reduced efficacy during the plateau phase. When taken together with previous findings, these present results suggest that phorbol esters increase the immediately available store of synaptic vesicles by increasing the number of primed vesicles whilst adenosine acts at a later stage of the secretory process to decrease the number of calcium-charged primed vesicles.

  11. The effects of phorbol ester activation and reactive oxygen species scavengers on the macrophage-mediated foreign body reaction to polyurethanes.

    PubMed

    McBane, Joanne E; Matheson, Loren A; Santerre, J Paul; Labow, Rosalind S

    2009-12-15

    Phorbol myristate acetate, a protein kinase C activator, inhibited monocyte-derived macrophage (MDM)-mediated degradation of aliphatic (HDI) polycarbonate-based polyurethanes but not degradation of the aromatic polycarbonate-based polyurethane (MDI). The objectives of this study were to determine if reactive oxygen species are involved in the phorbol myristate acetate effect on esterase activity and MDM-mediated polycarbonate-based polyurethane degradation and to find a good marker of material-initiated activation of MDM. The phorbol myristate acetate-dependent effects of the material chemistry on cell activation and degradation were evaluated by adding reactive oxygen species scavengers, catalase plus superoxide dismutase to MDM and assaying possible markers of MDM activation: esterase activity, acid phosphatase activity, and high molecular weight group box 1 protein (HMGB1). All treatments reduced the esterase activity in MDM on HDI but not in MDM on MDI. Acid phosphatase was inhibited in MDM to varying degrees on all surfaces by phorbol myristate acetate or catalase plus superoxide dismutase either alone or together. Secretion of HMGB1 from MDM on HDI431 was higher than MDI; however only secretion from MDM on HDI was inhibited by phorbol myristate acetate. In MDM on HDI, catalase plus superoxide dismutase reduced intracellular HMGB1 levels +/- phorbol myristate acetate; whereas, catalase, superoxide dismutase plus phorbol myristate acetate increased intracellular HMGB1 in MDM on MDI, suggesting that esterase and HMGB1 are more specific markers of activation than acid phosphatase. Manipulation of signaling pathways may provide insight surrounding the mechanism of activation for oxidative and/or hydrolytic degradative pathways in the MDM response to material surface chemistry.

  12. Phorbol myristate acetate receptors in human polymorphonuclear neutrophils

    SciTech Connect

    Nishihira, J.; O'Flaherty, J.T.

    1985-11-01

    Resting or phorbol myristate acetate (PMA)-pretreated neutrophils were disrupted by nitrogen cavitation and were fractionated on Percoll density gradients to identify the subcellular location of PMA receptors. Receptors were found in the cytoplasm of resting cells; neither primary nor secondary granules bound (/sup 3/H)PMA, and the few binding sites located in non-granule membrane fractions appeared to reflect cytosolic contamination. Contrastingly, PMA-pretreated cells lost cytosolic receptors; > 80% of PMA-binding sites were associated with non-granule membranes. Protein kinase C activity similarly shifted from cytosol to membranes after PMA treatment. Indeed, protein kinase C and PMA receptors co-sedimented on Percoll gradients, co-eluted from Ultragel AcA 44 columns loaded with neutrophil cytoplasm, and were identically influenced by various phospholipids. Finally, PMA, mezerein, diacylglycerol, and dialkylglycerol activated protein kinase C with potencies that paralleled their respective abilities to stimulate neutrophil aggregation responses and inhibit (/sup 3/H)PMA binding to whole cells or cytosol. These results fit a model of stimulus-response coupling wherein exogenous PMA or endogenous diacylglycerol solvate in cellular membranes. Cytosolic protein kinase C binds to the intramembranous ligand, forming an active, membrane-associated complex that phosphorylates nearby elements involved in triggering aggregation and other responses.

  13. Tumor promoting phorbol diesters: substrates for diacylglycerol lipase

    SciTech Connect

    Cabot, M.C.

    1984-08-30

    Enzyme activity in rat serum was examined utilizing the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and various glycerolipids as substrates. The serum activity was specific for hydrolysis of the long chain tetradecanoate moiety of TPA, hydrolyzed mono- and diacylglycerols, but was not effective against triacylglycerols, cholesterylesters, or phospholipids. Heating the enzyme preparation at 56/sup 0/C for 1 min was dually effective in reducing the hydrolysis of both TPA and dioleoylglycerol by 83-86% of control levels. The potent diacylglycerol lipase inhibitor, RHC 80267, inhibited the hydrolysis of TPA in the 0.2-1.0 ..mu..M range and was also a potent blocker of monoacyl- and diacylglycerol hydrolysis. In substrate competition studies, exogenous unlabeled TPA was added to the (/sup 14/C)dioleoylglycerol-containing reaction mixture, however, this produced an approximate 3-fold stimulation of (/sup 14/)dioleoylglycerol hydrolysis. Although we have not established whether the hydrolysis of TPA and diacylglycerol is the work of one enzyme, the effectiveness of the specific lipase inhibitor, RHC 80267, demonstrates that diacylglycerol lipase can utilize TPA as substrate, a finding never before documented. This point is of interest in light of the theory that phorbol esters act by mimicry of the natural lipid mediator, diacylglycerols. 44 references, 3 figures, 1 table.

  14. Phorbol diesters and transferrin modulate lymphoblastoid cell transferrin receptor expression by two different mechanisms

    SciTech Connect

    Alcantara, O.; Phillips, J.L.; Boldt, D.H.

    1986-12-01

    Expression of transferrin receptors (TfR) by activated lymphocytes is necessary for lymphocyte DNA synthesis and proliferation. Regulation of TfR expression, therefore, is a mechanism by which the lymphocyte's proliferative potential may be directed and controlled. The authors studied mechanisms by which lymphoblastoid cells modulate TfR expression during treatment with phorbol diesters or iron transferrin (FeTf), agents which cause downregulation of cell surface TfR. Phorbol diester-induced TfR downregulation occurred rapidly, being detectable at 2 min and reaching maximal decreases of 50% by 15 min. It was inhibited by cold but not by agents that destabilize cytoskeletal elements. Furthermore, this downregulation was reversed rapidly by washing or by treatment with the membrane interactive agent, chlorpromazine. In contrast, FeTf-induced TfR downregulation occurred slowly. Decreased expression of TfR was detectable only after 15 min and maximal downregulation was achieved after 60 min. Although FeTf-induced downregulation also was inhibited by cold, it was inhibited in addition by a group of microtubule destabilizing agents (colchicine, vinblastine, podophyllotoxin) or cytochalasin B, a microfilament inhibitor. Furthermore, FeTf-induced downregulation was not reversed readily by washing or by treatment with chlorpromazine. Phorbol diesters cause TfR downregulation by a cytoskeleton-independent mechanism. These data indicate that TfR expression is regulated by two independent mechanisms in lymphoblastoid cells, and they provide the possibility that downregulation of TfR by different mechanisms may result in different effects in these cells.

  15. Phorbol ester phorbol-12-myristate-13-acetate promotes anchorage-independent growth and survival of melanomas through MEK-independent activation of ERK1/2

    SciTech Connect

    Jorgensen, Kjersti; Skrede, Martina; Cruciani, Veronique; Mikalsen, Svein-Ole; Slipicevic, Ana; Florenes, Vivi Ann . E-mail: v.a.florenes@labmed.uio.no

    2005-04-01

    The phorbol ester, phorbol-12-myristate-13-acetate (PMA), an activator of PKCs, is known to stimulate the in vitro growth of monolayer cultures of normal human melanocytes whereas it inhibits the growth of most malignant melanoma cell lines. We examined the effect of PMA on proliferation and survival of melanoma cells grown as multicellular aggregates in suspension (spheroids), and aimed to elucidate downstream targets of PKC signaling. In contrast to monolayer cultures, PMA increased cell proliferation as well as protected melanoma cells from suspension-mediated apoptosis (anoikis). Supporting the importance of PKC in anchorage-independent growth, treatment of anoikis-resistant melanoma cell lines with antisense oligonucleotides against PKC-{alpha}, or the PKC inhibitor Goe6976, strongly induced anoikis. PMA induced activation of ERK1/2, but this effect was not prevented by the MEK inhibitors PD98059 or by U0126. Whereas PD98059 treatment alone led to marked activation of the pro-apoptotic Bim and Bad proteins and significantly increased anoikis, these effects were clearly reversed by PMA. In conclusion, our results indicate that the protective effect of PMA on anchorage-independent survival of melanoma cells at least partly is mediated by MEK-independent activation of ERK1/2 and inactivation of downstream pro-apoptotic effector proteins.

  16. ECOTOXICOLOGY OF NANOMATERIALS

    EPA Science Inventory

    An overview of issues associated with potential ecological toxicity of nanomaterials with research needs outlined, current literature reviewed and discussion of nanomaterial toxicity relative to concerns that EPA and state risk assessors might have.

  17. Plasma application for detoxification of Jatropha phorbol esters

    NASA Astrophysics Data System (ADS)

    Kongmany, S.; Matsuura, H.; Furuta, M.; Okuda, S.; Imamura, K.; Maeda, Y.

    2013-06-01

    Atmospheric pressure non-thermal dielectric barrier discharge (DBD) plasma generated by helium gas at high voltage and input power of about 50 W was first applied to detoxification of Jatropha curcas phorbol esters (J. PEs) as well as standard phorbol ester (4β-12-O-tetradecanoyl phorbol-13-acetate, TPA) in water and methanol. Plasma irradiation on the solution sample was conducted for 15 min. In aqueous solution, only 16% of TPA was degraded and complete degradation of J. PEs was observed. On the contrary, complete degradation of both TPA and J. PEs in methanol was achieved by the same plasma irradiation condition. Hydroxyl radical (•OH) generated by plasma irradiation of the solution is expected as the main radical inducing the degradation of PEs.

  18. EDITORIAL: Whither nanomaterials? Whither nanomaterials?

    NASA Astrophysics Data System (ADS)

    Mallouk, Thomas E.; Pinkerton, Fred; Stetson, Ned

    2009-10-01

    As the journal Nanotechnology enters its third decade it is interesting to look back on the field and to think about where it may be headed in the future. The growth of the journal over the past twenty years mirrors that of the field, with exponentially rising numbers of citations and a widening diversity of topics that we identify as nanotechnology. In the early 1990s, Nanotechnology was focused primarily on nanoscale electronics and on scanning probe tools for fabricating and characterizing nanostructures. The synthesis and assembly of nanomaterials was already an active area in chemical research; however, it did not yet intersect strongly with the activities of the physics community, which was interested primarily in new phenomena that emerged on the nanoscale and on the devices that derived from them. In the 1990s there were several key advances that began to bridge this gap. Techniques were developed for making nanocrystals of compound semiconductors, oxides, and metals with very fine control over shape and superstructure. Carbon nanotubes were discovered and their unique electronic properties were demonstrated. Research on the self-assembly of organic molecules on surfaces led to the development of soft lithography and layer-by- layer assembly of materials. The potential to use DNA and then proteins as building blocks of precise assemblies of nanoparticles was explored. These bottom-up structures could not be made by top-down techniques, and their unique properties as components of sensors, electronic devices, biological imaging agents, and drug delivery vehicles began to change the definition of the field. Ten years ago, Inelke Malsch published a study on the scientific trends and organizational dynamics of nanotechology in Europe (1999 Nanotechnology 10 1-7). Scientists from a variety of disciplines were asked which areas of research they would include in the definition of nanotechnology. Although the article concluded with forward-looking thoughts in the

  19. Nanomaterial disposal by incineration.

    PubMed

    Holder, Amara L; Vejerano, Eric P; Zhou, Xinzhe; Marr, Linsey C

    2013-09-01

    As nanotechnology-based products enter into widespread use, nanomaterials will end up in disposal waste streams that are ultimately discharged to the environment. One possible end-of-life scenario is incineration. This review attempts to ascertain the potential pathways by which nanomaterials may enter incinerator waste streams and the fate of these nanomaterials during the incineration process. Although the literature on incineration of nanomaterials is scarce, results from studies of their behavior at high temperature or in combustion environments for other applications can help predict their fate within an incinerator. Preliminary evidence suggests nanomaterials may catalyze the formation or destruction of combustion by-products. Depending on their composition, nanomaterials may undergo physical and chemical transformations within the incinerator, impacting their partitioning within the incineration system (e.g., bottom ash, fly ash) and the effectiveness of control technology for removing them. These transformations may also drastically affect nanomaterial transport and impacts in the environment. Current regulations on incinerator emissions do not specifically address nanomaterials, but limits on particle and metal emissions may prove somewhat effective at reducing the release of nanomaterials in incinerator effluent. Control technology used to meet these regulations, such as fabric filters, electrostatic precipitators, and wet electrostatic scrubbers, are expected to be at least partially effective at removing nanomaterials from incinerator flue gas. PMID:23880913

  20. Nanomaterial disposal by incineration.

    PubMed

    Holder, Amara L; Vejerano, Eric P; Zhou, Xinzhe; Marr, Linsey C

    2013-09-01

    As nanotechnology-based products enter into widespread use, nanomaterials will end up in disposal waste streams that are ultimately discharged to the environment. One possible end-of-life scenario is incineration. This review attempts to ascertain the potential pathways by which nanomaterials may enter incinerator waste streams and the fate of these nanomaterials during the incineration process. Although the literature on incineration of nanomaterials is scarce, results from studies of their behavior at high temperature or in combustion environments for other applications can help predict their fate within an incinerator. Preliminary evidence suggests nanomaterials may catalyze the formation or destruction of combustion by-products. Depending on their composition, nanomaterials may undergo physical and chemical transformations within the incinerator, impacting their partitioning within the incineration system (e.g., bottom ash, fly ash) and the effectiveness of control technology for removing them. These transformations may also drastically affect nanomaterial transport and impacts in the environment. Current regulations on incinerator emissions do not specifically address nanomaterials, but limits on particle and metal emissions may prove somewhat effective at reducing the release of nanomaterials in incinerator effluent. Control technology used to meet these regulations, such as fabric filters, electrostatic precipitators, and wet electrostatic scrubbers, are expected to be at least partially effective at removing nanomaterials from incinerator flue gas.

  1. Degradation of phorbol 12,13-diacetate in aqueous solution by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kongmany, Santi; Furuta, Masakazu; Matsuura, Hiroto; Okuda, Shuichi; Imamura, Kiyoshi; Maeda, Yasuaki

    2014-12-01

    Phorbol esters (PEs) are highly toxic compounds that cause skin irritation, inflammation, and tumor promotion upon contact with humans or animals. These compounds are naturally present in Jatropha curcas L. To promote the use of J. curcas seed oil in bio-diesel production industries and reduce environmental concerns, it is necessary to find methods of degrading PEs. In this study, the degradation of phorbol 12,13-diacetate (PDA), as a representative PE, in aqueous solution at a concentration of 10 mg/L by 60Co-γ-irradiation was investigated. The results demonstrate that PDA was effectively degraded by this treatment and the degradation efficiency increased with the absorbed dose within the range of 0.5-3 kGy. Complete degradation of PDA was achieved at a dose of 3 kGy. In the presence of radical scavengers (i.e., methanol, tert-butanol, 2-propanol), reactive species from water radiolysis were scavenged, and significant inhibition of PDA degradation was observed at absorbed doses less than 1 kGy. In the presence of nitrous oxide, the generation of hydroxyl radicals (rad OH) was promoted during gamma irradiation and PDA degradation was drastically enhanced.

  2. Nanomaterials in preventive dentistry

    NASA Astrophysics Data System (ADS)

    Hannig, Matthias; Hannig, Christian

    2010-08-01

    The prevention of tooth decay and the treatment of lesions and cavities are ongoing challenges in dentistry. In recent years, biomimetic approaches have been used to develop nanomaterials for inclusion in a variety of oral health-care products. Examples include liquids and pastes that contain nano-apatites for biofilm management at the tooth surface, and products that contain nanomaterials for the remineralization of early submicrometre-sized enamel lesions. However, the treatment of larger visible cavities with nanomaterials is still at the research stage. Here, we review progress in the development of nanomaterials for different applications in preventive dentistry and research, including clinical trials.

  3. Nanomaterials meet microfluidics.

    PubMed

    Pumera, Martin

    2011-05-28

    Nanomaterials and lab-on-a-chip platforms have undergone enormous development during the past decade. Here, we present an overview of how microfluidics benefited from the use of nanomaterials for the enhanced separation and detection of analytes. We also discuss how nanomaterials benefit from microfluidics in terms of synthesis and in terms of the simulation of environments for nanomotors and nanorobots. In our opinion, the "marriage" of nanomaterials and microfluidics is highly beneficial and is expected to solve vital challenges in related fields.

  4. Electrodynamic Arrays Having Nanomaterial Electrodes

    NASA Technical Reports Server (NTRS)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  5. Effect of phorbol esters on iron uptake in human hematopoietic cell lines

    SciTech Connect

    Testa, U.; Titeux, M.; Louache, F.; Thomopoulos, P.; Rochant, H.

    1984-11-01

    We have investigated the effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) on iron uptake into human hematopoietic cell lines K562, U937, and HL-60. TPA inhibited both cell growth and iron uptake by these cell lines. This effect was rapid, which is typical of phorbol esters which are biologically active, and it occurred at very low concentrations of TPA. This effect of TPA was dependent upon an inhibition of the transferrin-binding capacity as estimated on intact cells. However, experiments with transferrin binding on cell samples dissolved in 1% Triton X-100 showed that TPA-treated cells exhibited a transferrin-binding capacity similar to that of control cells. On the basis of this result, it is suggested that TPA modified a part of transferrin receptors present in the cells; as a result of this modification, these receptors became unavailable for binding transferrin, but they remained physically present in the cell. Other compounds capable of inducing the differentiation of leukemic cells, such as dimethyl sulfoxide, butyrate, retinoic acid, and 1 alpha,25-dihydroxy-vitamin D3, did not acutely inhibit iron uptake. We also investigated the effect of TPA on transferrin receptors in a cellular system in which phorbol esters stimulate cell proliferation. At 16 X 10(-9) M, TPA markedly stimulated the proliferation of T-lymphocytes. However, in spite of this marked stimulation of cell proliferation, TPA-stimulated lymphocytes exhibited a transferrin-binding capacity much inferior to cells stimulated by other mitogens, such as phytohemagglutinin.

  6. Nanomaterials and Retinal Toxicity

    EPA Science Inventory

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  7. Phototoxicity of Selected Nanomaterials

    EPA Science Inventory

    Quantification of exposure to nanomaterials is critical for assessing their environmental hazard and risk. This is an immediate issue for nano-TiO2 because it is one of more common nanomaterials now in commerce, and is difficult to analyze using common acid-digestion techniques. ...

  8. Nanomaterials in Biosolids Inhibit Nodulation, Shift Microbial Community Composition, and Result in Increased Metal Uptake Relative to Bulk/Dissolved Metals.

    PubMed

    Judy, Jonathan D; McNear, David H; Chen, Chun; Lewis, Ricky W; Tsyusko, Olga V; Bertsch, Paul M; Rao, William; Stegemeier, John; Lowry, Gregory V; McGrath, Steve P; Durenkamp, Mark; Unrine, Jason M

    2015-07-21

    We examined the effects of amending soil with biosolids produced from a pilot-scale wastewater treatment plant containing a mixture of metal-based engineered nanomaterials (ENMs) on the growth of Medicago truncatula, its symbiosis with Sinorhizobium meliloti, and on soil microbial community structure. Treatments consisted of soils amended with biosolids generated with (1) Ag, ZnO, and TiO2 ENMs introduced into the influent wastewater (ENM biosolids), (2) AgNO3, Zn(SO4)2, and micron-sized TiO2 (dissolved/bulk metal biosolids) introduced into the influent wastewater stream, or (3) no metal added to influent wastewater (control). Soils were amended with biosolids to simulate 20 years of metal loading, which resulted in nominal metal concentrations of 1450, 100, and 2400 mg kg(-1) of Zn, Ag, and Ti, respectively, in the dissolved/bulk and ENM treatments. Tissue Zn concentrations were significantly higher in the plants grown in the ENM treatment (182 mg kg(-1)) compared to those from the bulk treatment (103 mg kg(-1)). Large reductions in nodulation frequency, plant growth, and significant shifts in soil microbial community composition were found for the ENM treatment compared to the bulk/dissolved metal treatment. These results suggest differences in metal bioavailability and toxicity between ENMs and bulk/dissolved metals at concentrations relevant to regulatory limits.

  9. Okadaic acid: An additional non-phorbol-12-tetradecanoate-13-acetate-type tumor promoter

    SciTech Connect

    Suganuma, Masami; Fujiki, Hirota; Suguri, Hiroko; Yoshizawa, Shigeru; Hirota, Mitsuru; Nakayasu, Michie ); Ojika, Makoto; Wakamatsu, Kazumasa; Yamada, Kiyoyuki ); Sugimura, Takashi )

    1988-03-01

    Okadaic acid is a polyether compound of a C{sub 38} fatty acid, isolated from a black sponge, Halichondria okadai. Previous studies showed that okadaic acid is a skin irritant and induces ornithine decarboxylase in mouse skin 4 hr after its application to the skin. This induction was strongly inhibited by pretreatment of the skin with 13-cis-retinoic acid. A two-stage carcinogenesis experiment in mouse skin initiated by a single application of 100 {mu}g of 7,12-dimethylbenz(a)anthracene (DMBA) and followed by application of 10 {mu}g of okadaic acid twice a week revealed that okadaic acid is a potent additional tumor promoter: tumors developed in 93% of the mice treated with DMBA and okadaic acid by week 16. In contrast, tumors were found in only one mouse each in the groups treated with DMBA alone or okadaic acid alone. An average of 2.6 tumors per mouse was found in week 30 in the group treated with DMBA and okadaic acid. Unlike phorbol 12-tetradecanoate 13-acetate (TPA), teleocidin, and aplysiatoxin, okadaic acid did not inhibit the specific binding of ({sup 3}H)TPA to a mouse skin particulate fraction when added up to 100 {mu}M or activate calcium-activated, phospholipid-dependent protein kinase (protein kinase C) in vitro when added up to 1.2 {mu}M. Therefore, the actions of okadaic acid and phorbol ester may be mediated in different ways. These results show that okadaic acid is a non-TPA-type tumor promoter in mouse skin carcinogenesis.

  10. Potential risks of nanomaterials

    NASA Astrophysics Data System (ADS)

    Bakalova, Totka; Louda, Petr

    2014-05-01

    Nanotechnology is the design and manipulation of materials at the nanometer scale such that novel or enhanced properties emerge. It is a new area of knowledge that promises a dazzling array of opportunities in areas as diverse as manufacturing, energy, health care, and waste treatment. But while the ability to develop nanomaterials and incorporate them into products is advancing rapidly, our understanding of the potential environmental, health, and safety effects of nanomaterials — and of the most effective ways to manage such effects — has proceeded at a much slower pace. Because of the novel properties that emerge at the nano scale, nanomaterials may require more and different information than called for under traditional risk management systems. And given the enormous commercial and societal benefits that may potentially come from this technology, it is likely that nanomaterials, and the products and other applications containing them, will be widely produced and used. Therefore it is especially important to understand and minimize the potential risks.

  11. Food decontamination using nanomaterials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The research indicates that nanomaterials including nanoemulsions are promising decontamination media for the reduction of food contaminating pathogens. The inhibitory effect of nanoparticles for pathogens could be due to deactivate cellular enzymes and DNA; disrupting of membrane permeability; and/...

  12. Phorbol Ester Effects on Neurotransmission: Interaction with Neurotransmitters and Calcium in Smooth Muscle

    NASA Astrophysics Data System (ADS)

    Baraban, Jay M.; Gould, Robert J.; Peroutka, Stephen J.; Snyder, Solomon H.

    1985-01-01

    Stimulation of the phosphatidylinositol cycle by neurotransmitters generates diacylglycerol, an activator of protein kinase C, which may regulate some forms of neurotransmission. Phorbol esters, potent inflammatory and tumorpromoting compounds, also activate protein kinase C. We demonstrate potent and selective effects of phorbol esters on smooth muscle, indicating a role for protein kinase C in neurotransmission. In rat vas deferens and dog basilar artery, phorbol esters synergize with calcium to mimic the contractile effects of neurotransmitters that act through the phosphatidylinositol cycle. In guinea pig ileum and rat uterus, phorbol esters block contractions produced by these neurotransmitters.

  13. Roles of phospholipase D in phorbol myristate acetate-stimulated neutrophil respiratory burst.

    PubMed

    Hu, Tianhui; Liu, Zhaoxia; Shen, Xun

    2011-03-01

    The phorbol myristate acetate (PMA) stimulated nutrophil respiratory burst has been considered to simply involve the activation of protein kinase C (PKC). However, the PLD activity was also increased by 10-fold in human neutrophils stimulated with 100 nM PMA. Unexpectedly, U73122, an inhibitor of phospholipase C, was found to significantly inhibit PMA-stimulated respiratory burst in human neutrophils. U73122 at the concentrations, which were sufficient to inhibit the respiratory burst completely, caused partial inhibition of the PLD activity but no inhibition on PKC translocation and activation, suggesting that PLD activity is also required in PMA-stimulated respiratory burst. Using 1-butanol, a PLD substrate, to block phosphatidic acid (PA) generation, the PMA-stimulated neutrophil respiratory burst was also partially inhibited, further indicating that PLD activation, possibly its hydrolytic product PA and diacylglycerol (DAG), is involved in PMA-stimulated respiratory burst. Since GF109203X, an inhibitor of PKC that could completely inhibit the respiratory burst in PMA-stimulated neutrophils, also caused certain suppression of PLD activation, it may suggest that PLD activation in PMA-stimulated neutrophils might be, to some extent, PKC dependent. To further study whether PLD contributes to the PMA stimulated respiratory burst through itself or its hydrolytic product, 1,2-dioctanoyl-sn-glycerol, an analogue of DAG , was used to prime cells at low concentration, and it reversed the inhibition of PMA-stimulated respiratory burst by U73122. The results indicate that U73122 may act as an inhibitor of PLD, and PLD activation is required in PMA-stimulated respiratory burst.

  14. Environmental implications and applications of nanomaterials

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Priyanka

    Recent advances in material science and nanotechnology have given rise to a myriad of developments, while in the meantime call for research into the impacts of nanomaterials on the environment and human health. Although considerable progress has been made in the past decade concerning the behavior of nanomaterials in biological systems, such understanding is critically lacking with respect to the fate of nanomaterials in ecosystems. Accordingly, this dissertation addresses the interactions between nanomaterials and algae---the major constituent of the aquatic food chain (Part I, Chapter two), and exploits the physicochemistry of nanoscaled synthetic dendritic polymers for environmental applications, especially for water purification that is a focused theme of the entire dossier (Part II, Chapters two--five). This dissertation is organized as follows. Chapter one presents a general review of the physical/physicochemical properties, characterizations, implications---especially ecological implication, and applications of a host of most produced and studied nanomaterials. In addition, advances in environmental applications of nanomaterials are discussed. Chapter two examines algal responses to two major types of engineered nanomaterials---quantum dots and polystyrene. Inhibited photosynthetic activities of green algae are observed as a result of the physical adsorption of the nanomaterials. Chapter three elucidates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- and amine-terminated dendrimers towards their applications in water remediation. Here, the capacities and mechanisms of the dendrimers in hosting cationic copper, anionic nitrate, polyaromatic phenanthrene, and the more heterogeneous humic acids are discussed. Based on the results of Chapter three, Chapter four presents a dendrimer-based novel optical scheme for improving the detection sensitivity and selectivity of environmental pollutants. Specifically, the surface plasmon

  15. Structural investigations of hybrid TiO2/CNTs nanomaterials.

    PubMed

    Lin, Kuan-Nan; Liou, Wei-Jen; Lin, Hong-Ming; Yang, Tsung-Yeh; Lin, Chung-Kwei

    2010-05-01

    In the present study, pure TiO2 and hybrid TiO2/CNTs nanomaterials are prepared by sol gel technique. Post heat treatment is performed at 600, 800, and 1000 degrees C, respectively. The structural characterizations are performed by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and synchrotron X-ray absorption spectroscopy techniques. Experimental results show that anatase to rutile transformation can be observed for pure TiO2 nanomaterials after heat treatment at 800 degrees C. The anatase to rutile transformation is inhibited by carbon nanotubes, and therefore only anatase phases for TiO2 nanomaterials can be observed in the hybrid nanomaterials. The 600 degrees C hybrid nanomaterials show a microstructure with CNTs covered by continuous TiO2 films of numerous small nanoparticles. After applying heat treatment on the hybrid nanomaterials at 1000 degrees C, only TiO2 nanoparticles adhere individually to the uncovered CNTs. Though all hybrid nanomaterials exhibit anatase TiO2, synchrotron X-ray absorption spectra investigations reveal that hybrid TiO2/CNTs exhibit different electronic properties as compared to those of pure TiO2 nanomaterials.

  16. A Comparison Between Phorbol 12 Myristate 13 Acetate and Phorbol 12, 13 Dibutyrate in Human Melanocyte Culture

    PubMed Central

    Padma, Divya

    2016-01-01

    Introduction Melanocyte culture is an integral part of the studies of skin biology and cosmetic applications. After the introduction of selective medium for the culture of human melanocyte using Phorbol 12-myristate13-acetate (PMA) in 1982, a lot of methods of culturing were tried but till date PMA is a preferred mitogen because of its cost effectiveness compared to growth factors. We have tried to preliminarily evaluate the efficacy of another phorbol ester, Phorbol 12, 13-dibutyrate (PDBu) in melanocyte culture because of its less hydrophobic nature compared to PMA. This property minimizes the trace amount of mitogen in cell culture after washing off and hence does not interfere in other biological assays. Aim To evaluate the differences in the melanocyte survival rate, morphology and mitotic index when grown in media supplemented with PMA and PDBu. Materials and Methods Foreskins were collected from children undergoing circumcision. Epidermal cells were isolated from foreskin and cultured using PMA and PDBu. Melanocytes in culture were monitored for the better establishment and documented. In proliferative assay, melanocytes were treated with PMA and PDBu for 24, 48 and 72 hours and proliferation was measured using 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay method. Results When cultured, melanocytes acquired proliferative status and bipolar morphology quicker in PDBu medium than in PMA medium. Keratinocytes survived as contamination in PMA medium whereas PDBu medium had minimal keratinocytes. MTT assay showed that PDBu has higher proliferative induction capacity than PMA. In even lower concentration of PDBu in medium, melanocytes survived till 72 hours without significant cell loss in compared to PMA medium. Conclusion PDBu can be a valuable replacement for PMA in human melanocyte culture. Higher proliferation induction, unfavourable to keratinocyte survival and less hydrophobicity make PDBu a promising alternative for quicker

  17. Antiallergic Phorbol Ester from the Seeds of Aquilaria malaccensis.

    PubMed

    Korinek, Michal; Wagh, Vitthal D; Lo, I-Wen; Hsu, Yu-Ming; Hsu, Hsue-Yin; Hwang, Tsong-Long; Wu, Yang-Chang; Cheng, Yuan-Bin; Chen, Bing-Hung; Chang, Fang-Rong

    2016-01-01

    The Aquilaria malaccensis (Thymelaeaceae) tree is a source of precious fragrant resin, called agarwood, which is widely used in traditional medicines in East Asia against diseases such as asthma. In our continuous search for active natural products, A. malaccensis seeds ethanolic extract demonstrated antiallergic effect with an IC50 value less than 1 µg/mL. Therefore, the present research aimed to purify and identify the antiallergic principle of A. malaccensis through a bioactivity-guided fractionation approach. We found that phorbol ester-rich fraction was responsible for the antiallergic activity of A. malaccensis seeds. One new active phorbol ester, 12-O-(2Z,4E,6E)-tetradeca-2,4,6-trienoylphorbol-13-acetate, aquimavitalin (1) was isolated. The structure of 1 was assigned by means of 1D and 2D NMR data and high-resolution mass spectrometry (HR-MS). Aquimavitalin (1) showed strong inhibitory activity in A23187- and antigen-induced degranulation assay with IC50 values of 1.7 and 11 nM, respectively, with a therapeutic index up to 71,000. The antiallergic activities of A. malaccensis seeds and aquimavitalin (1) have never been revealed before. The results indicated that A. malaccensis seeds and the pure compound have the potential for use in the treatment of allergy. PMID:27007372

  18. Activities of Jatropha curcas phorbol esters in various bioassays.

    PubMed

    Devappa, Rakshit K; Rajesh, Sanjay K; Kumar, Vikas; Makkar, Harinder P S; Becker, Klaus

    2012-04-01

    Jatropha curcas seeds contain 30-35% oil, which can be converted to high quality biodiesel. However, Jatropha oil is toxic, ascribed to the presence of phorbol esters (PEs). In this study, isolated phorbol ester rich fraction (PEEF) was used to evaluate the activity of PEs using three aquatic species based bioassays (snail (Physa fontinalis), brine shrimp (Artemeia salina), daphnia (Daphnia magna)) and microorganisms. In all the bioassays tested, increase in concentration of PEs increased mortality with an EC(50) (48 h) of 0.33, 26.48 and 0.95 mg L(-1) PEs for snail, artemia and daphnia, respectively. The sensitivity of various microorganisms for PEs was also tested. Among the bacterial species tested, Streptococcus pyogenes and Proteus mirabilis were highly susceptible with a minimum inhibitory concentration (MIC) of 215 mg L(-1) PEs; and Pseudomonas putida were also sensitive with MIC of 251 mg L(-1) PEs. Similarly, Fusarium species of fungi exhibited EC(50) of 58 mg L(-1) PEs, while Aspergillus niger and Curvularia lunata had EC(50) of 70 mg L(-1). The snail bioassay was most sensitive with 100% snail mortality at 1 μg of PEs mL(-1). In conclusion, snail bioassay could be used to monitor PEs in Jatropha derived products such as oil, biodiesel, fatty acid distillate, kernel meal, cake, glycerol or for contamination in soil or other environmental matrices. In addition, PEs with molluscicidal/antimicrobial activities could be utilized for agricultural and pharmaceutical applications. PMID:22172520

  19. Antiallergic Phorbol Ester from the Seeds of Aquilaria malaccensis

    PubMed Central

    Korinek, Michal; Wagh, Vitthal D.; Lo, I-Wen; Hsu, Yu-Ming; Hsu, Hsue-Yin; Hwang, Tsong-Long; Wu, Yang-Chang; Cheng, Yuan-Bin; Chen, Bing-Hung; Chang, Fang-Rong

    2016-01-01

    The Aquilaria malaccensis (Thymelaeaceae) tree is a source of precious fragrant resin, called agarwood, which is widely used in traditional medicines in East Asia against diseases such as asthma. In our continuous search for active natural products, A. malaccensis seeds ethanolic extract demonstrated antiallergic effect with an IC50 value less than 1 µg/mL. Therefore, the present research aimed to purify and identify the antiallergic principle of A. malaccensis through a bioactivity-guided fractionation approach. We found that phorbol ester-rich fraction was responsible for the antiallergic activity of A. malaccensis seeds. One new active phorbol ester, 12-O-(2Z,4E,6E)-tetradeca-2,4,6-trienoylphorbol-13-acetate, aquimavitalin (1) was isolated. The structure of 1 was assigned by means of 1D and 2D NMR data and high-resolution mass spectrometry (HR-MS). Aquimavitalin (1) showed strong inhibitory activity in A23187- and antigen-induced degranulation assay with IC50 values of 1.7 and 11 nM, respectively, with a therapeutic index up to 71,000. The antiallergic activities of A. malaccensis seeds and aquimavitalin (1) have never been revealed before. The results indicated that A. malaccensis seeds and the pure compound have the potential for use in the treatment of allergy. PMID:27007372

  20. Nanomaterials and bone regeneration

    PubMed Central

    Gong, Tao; Xie, Jing; Liao, Jinfeng; Zhang, Tao; Lin, Shiyu; Lin, Yunfeng

    2015-01-01

    The worldwide incidence of bone disorders and conditions has been increasing. Bone is a nanomaterials composed of organic (mainly collagen) and inorganic (mainly nano-hydroxyapatite) components, with a hierarchical structure ranging from nanoscale to macroscale. In consideration of the serious limitation in traditional therapies, nanomaterials provide some new strategy in bone regeneration. Nanostructured scaffolds provide a closer structural support approximation to native bone architecture for the cells and regulate cell proliferation, differentiation, and migration, which results in the formation of functional tissues. In this article, we focused on reviewing the classification and design of nanostructured materials and nanocarrier materials for bone regeneration, their cell interaction properties, and their application in bone tissue engineering and regeneration. Furthermore, some new challenges about the future research on the application of nanomaterials for bone regeneration are described in the conclusion and perspectives part. PMID:26558141

  1. Phorbol esters stimulate the phosphorylation of receptors for insulin and somatomedin C.

    PubMed Central

    Jacobs, S; Sahyoun, N E; Saltiel, A R; Cuatrecasas, P

    1983-01-01

    The effect of phorbol esters on the extent of phosphorylation of receptors for insulin and somatomedin C (insulin-like growth factor I) was studied in intact IM-9 cells that were labeled by incubation with H332PO4. The tumor-promoting phorbol esters phorbol tetradecanoate acetate (TPA) and phorbol dibutyrate, but not the inactive 4 alpha-phorbol, enhanced phosphorylation of the beta subunit of both receptors approximately 4-fold; 70 nM TPA maximally stimulated phosphorylation of both receptors, whereas concentrations less than or equal to 0.7 nM had no observable effect. Insulin also enhanced the phosphorylation of the beta subunit of the insulin receptor, and its effects appeared to be additive to those of TPA. Peptide maps indicated that at least some of the residues phosphorylated by these two agents are distinct. These results suggest a possible role of protein kinase C in regulating insulin and somatomedin C receptors. Images PMID:6312447

  2. Perovskite ferroelectric nanomaterials

    NASA Astrophysics Data System (ADS)

    Nuraje, Nurxat; Su, Kai

    2013-09-01

    In this review, the main concept of ferroelectricity of perovskite oxides and related materials at nanometer scale and existing difficulties in the synthesis of those nanocrystals are discussed. Important effects, such as depolarization field and size effect, on the existence of ferroelectricity in perovskite nanocrystals are deliberated. In the discussion of modeling works, different theoretical calculations are pinpointed focusing on their studies of lattice dynamics, phase transitions, new origin of ferroelectricity in nanostructures, etc. As the major part of this review, recent research progress in the facile synthesis, characterization and various applications of perovskite ferroelectric nanomaterials, such as BaTiO3, PbTiO3, PbZrO3, and BiFeO3, are also scrutinized. Perspectives concerning the future direction of ferroelectric nanomaterials research and its potential applications in renewable energy, etc., are presented. This review provides an overview in this area and guidance for further studies in perovskite ferroelectric nanomaterials and their applications.In this review, the main concept of ferroelectricity of perovskite oxides and related materials at nanometer scale and existing difficulties in the synthesis of those nanocrystals are discussed. Important effects, such as depolarization field and size effect, on the existence of ferroelectricity in perovskite nanocrystals are deliberated. In the discussion of modeling works, different theoretical calculations are pinpointed focusing on their studies of lattice dynamics, phase transitions, new origin of ferroelectricity in nanostructures, etc. As the major part of this review, recent research progress in the facile synthesis, characterization and various applications of perovskite ferroelectric nanomaterials, such as BaTiO3, PbTiO3, PbZrO3, and BiFeO3, are also scrutinized. Perspectives concerning the future direction of ferroelectric nanomaterials research and its potential applications in renewable

  3. Nanobiotechnology: protein-nanomaterial interactions.

    PubMed

    Kane, Ravi S; Stroock, Abraham D

    2007-01-01

    We review recent research that involves the interaction of nanomaterials such as nanoparticles, nanowires, and carbon nanotubes with proteins. We begin with a focus on the fundamentals of the structure and function of proteins on nanomaterials. We then review work in three areas that exploit these interactions: (1) sensing, (2) assembly of nanomaterials by proteins and proteins by nanomaterials, and (3) interactions with cells. We conclude with the identification of challenges and opportunities for the future. PMID:17335286

  4. Biological and Pharmaceutical Nanomaterials

    NASA Astrophysics Data System (ADS)

    Kumar, Challa S. S. R.

    2006-01-01

    This first comprehensive yet concise overview of all important classes of biological and pharmaceutical nanomaterials presents in one volume the different kinds of natural biological compounds that form nanomaterials or that may be used to purposefully create them. This unique single source of information brings together the many articles published in specialized journals, which often remain unseen by members of other, related disciplines. Covering pharmaceutical, nucleic acid, peptide and DNA-Chitosan nanoparticles, the book focuses on those innovative materials and technologies needed for the continued growth of medicine, healthcare, pharmaceuticals and human wellness. For chemists, biochemists, cell biologists, materials scientists, biologists, and those working in the pharmaceutical and chemical industries.

  5. Nanomaterials for Defense Applications

    NASA Astrophysics Data System (ADS)

    Turaga, Uday; Singh, Vinitkumar; Lalagiri, Muralidhar; Kiekens, Paul; Ramkumar, Seshadri S.

    Nanotechnology has found a number of applications in electronics and healthcare. Within the textile field, applications of nanotechnology have been limited to filters, protective liners for chemical and biological clothing and nanocoatings. This chapter presents an overview of the applications of nanomaterials such as nanofibers and nanoparticles that are of use to military and industrial sectors. An effort has been made to categorize nanofibers based on the method of production. This chapter particularly focuses on a few latest developments that have taken place with regard to the application of nanomaterials such as metal oxides in the defense arena.

  6. Dietary lipid varying in corn and coconut oil influences protein kinase C in phorbol ester-treated mouse skin.

    PubMed

    Mouat, M F; Locniskar, M F

    1998-01-01

    An earlier study indicated that increased levels of corn oil in the diet resulted in decreased tumor yield after promotion by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate in Sencar mouse epidermis (J Leyton, ML Lee, M Locniskar, MA Belury, TJ Slaga, et al. Cancer Res 51, 907-915, 1991). In the present study we investigated whether corn oil diets could alter the subcellular distribution and activity of protein kinase C (PKC), which is part of an important signaling pathway in carcinogenesis. We used three 15% (wt/wt) fat semipurified diets containing three ratios of corn oil to coconut oil: 1.0%:14.0% (Diet L), 7.9%:7.1% (Diet M), and 15.0%:0.0% (Diet H). The translocation to the membrane fraction of epidermal PKC by 12-O-tetradecanoylphorbol-13-acetate was decreased as the corn oil content of the diet was increased, and this correlates with the decrease in tumor yield. The translocation to the membrane fraction of specific isoforms of PKC was affected by increased dietary corn oil: the largest decreases were in cytosolic PKC-alpha and -beta, and the smallest change was in PKC-epsilon. The other isoforms, PKC-delta and -zeta, were unaffected. The major constituent of corn oil is linoleic acid, which did not affect the binding of phorbol ester to PKC, which suggests that inhibition of such binding was not responsible for the effects of increased dietary corn oil. Products of linoleic acid metabolism, i.e., arachidonic acid and 13-hydroxyoctadecadienoic acid, also did not affect the binding of phorbol ester to PKC. Thus the results of these studies suggest that the subcellular distributions of PKC and its isoforms can be modulated by dietary lipids.

  7. Intracellular Signal Modulation by Nanomaterials

    PubMed Central

    Hussain, Salik; Garantziotis, Stavros; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Baeza-Squiban, Armelle; Boland, Sonja

    2016-01-01

    A thorough understanding of the interactions of nanomaterials with biological systems and the resulting activation of signal transduction pathways is essential for the development of safe and consumer friendly nanotechnology. Here we present an overview of signaling pathways induced by nanomaterial exposures and describe the possible correlation of their physicochemical characteristics with biological outcomes. In addition to the hierarchical oxidative stress model and a review of the intrinsic and cell-mediated mechanisms of reactive Oxygen species (ROS) generating capacities of nanomaterials, we also discuss other oxidative stress dependent and independent cellular signaling pathways. Induction of the inflammasome, calcium signaling, and endoplasmic reticulum stress are reviewed. Furthermore, the uptake mechanisms can crucially affect the cytotoxicity of nanomaterials and membrane-dependent signaling pathways can be responsible for cellular effects of nanomaterials. Epigenetic regulation by nanomaterials effects of nanoparticle-protein interactions on cell signaling pathways, and the induction of various cell death modalities by nanomaterials are described. We describe the common trigger mechanisms shared by various nanomaterials to induce cell death pathways and describe the interplay of different modalities in orchestrating the final outcome after nanomaterial exposures. A better understanding of signal modulations induced by nanomaterials is not only essential for the synthesis and design of safer nanomaterials but will also help to discover potential nanomedical applications of these materials. Several biomedical applications based on the different signaling pathways induced by nanomaterials are already proposed and will certainly gain a great deal of attraction in the near future. PMID:24683030

  8. Comparative effects of endothelin and phorbol 12-13 dibutyrate in rat aorta

    SciTech Connect

    Auguet, M.; Delaflotte, S.; Chabrier, P.E.; Braquet, P. )

    1989-01-01

    The vasoconstrictive properties of endothelin (ET-1) and the protein kinase C activator, phorbol 12-13 dibutyrate (PDB) were comparatively investigated in isolated rat aorta. ET-1 and PDB induced a slowly developing sustained contraction in endothelium denuded aorta. Maximal contractions induced by ET-1 and PDB were unaffected by diltiazem. Substantial contraction to ET-1 and PDB remained in calcium-free medium. Contractions of ET-1 and PDB in calcium-free medium were unaffected by intracellular calcium depletion induced by phenylephrine. Following the response to ET-1 and PDB in a calcium-free medium, an additional sustained was observed after calcium was added to the bath. The protein kinase C inhibitor, H7 was more potent in inhibiting contractions induced by phenylephrine and KCl than the ones elicited by ET-1 and PDB. The other protein kinase C inhibitors i.e. staurosporine and phloretin inhibited to a similar extent all the agonists tested. These results suggest that protein kinase C may play an important role in mediating the contraction to ET-1 in rat aorta.

  9. Nanomaterial disposal by incineration

    EPA Science Inventory

    As nanotechnology-based products enter into widespread use, nanomaterials will end up in disposal waste streams that are ultimately discharged to the environment. One possible end-of-life scenario is incineration. This review attempts to ascertain the potential pathways by which ...

  10. Toxicity of nanomaterials

    PubMed Central

    Sharifi, Shahriar; Behzadi, Shahed; Laurent, Sophie; Forrest, M. Laird; Stroeve, Pieter

    2015-01-01

    Nanoscience has matured significantly during the last decade as it has transitioned from bench top science to applied technology. Presently, nanomaterials are used in a wide variety of commercial products such as electronic components, sports equipment, sun creams and biomedical applications. There are few studies of the long-term consequences of nanoparticles on human health, but governmental agencies, including the United States National Institute for Occupational Safety and Health and Japan’s Ministry of Health, have recently raised the question of whether seemingly innocuous materials such as carbon-based nanotubes should be treated with the same caution afforded known carcinogens such as asbestos. Since nanomaterials are increasing a part of everyday consumer products, manufacturing processes, and medical products, it is imperative that both workers and end-users be protected from inhalation of potentially toxic NPs. It also suggests that NPs may need to be sequestered into products so that the NPs are not released into the atmosphere during the product’s life or during recycling. Further, non-inhalation routes of NP absorption, including dermal and medical injectables, must be studied in order to understand possible toxic effects. Fewer studies to date have addressed whether the body can eventually eliminate nanomaterials to prevent particle build-up in tissues or organs. This critical review discusses the biophysicochemical properties of various nanomaterials with emphasis on currently available toxicology data and methodologies for evaluating nanoparticle toxicity. PMID:22170510

  11. Nanomaterials in Consumer Products

    NASA Astrophysics Data System (ADS)

    Hansen, S. Foss; Baun, A.; Michelson, E. S.; Kamper, A.; Borling, P.; Stuer-Lauridsen, F.

    Exposure assessment is crucial for risk assessment for nanomaterials. We propose a framework to aid exposure assessment in consumer products. We determined the location of the nanomaterials and the chemical identify of the 580 products listed in the inventory maintained by the Woodrow Wilson International Center for Scholars. It was found that in 19% of the products the nanomaterial were nanoparticles bound to the surfaces. Nanoparticles suspended in liquids were used in 37% of the products, whereas 13% used nanoparticles suspended in solids. One percent were powders containing free potentially airborne nanoparticles. Based on the location of the nanostructure we were able to further group the products into categories of: (1) Expected to cause exposure; (2) May cause exposure; and (3) No expected exposure to the consumer. Most products fall into the category of expected exposure, but we were not able to complete the quantitative exposure assessment mainly due to the lack of information on the concentration of the nanomaterial in the products — a problem that regulators and industry will have to address if we are to have realistic exposure assessment in the future. To illustrate the workability of our procedure, we applied it to a product scenario — the application of sun lotion — using best estimates available and/or worst case assumptions.

  12. Effects of 1-beta-D-arabinofuranosylcytosine and phorbol ester on differentiation of human K562 erythroleukemia cells.

    PubMed

    Watanabe, T; Mitchell, T; Sariban, E; Sabbath, K; Griffin, J; Kufe, D

    1985-06-01

    We have previously demonstrated that 1-beta-D-arabinofuranosylcytosine (ara-C) induces hemoglobin synthesis in human K562 erythroleukemia cells. The present study extends these findings by demonstrating that ara-C treatment of K562 cells results in both increased heme synthesis and accumulation of alpha-, gamma-, epsilon-, and zeta-globin RNA. The results also demonstrate that ara-C enhances K562 cell surface expression of glycophorin. Furthermore, we demonstrate that phorbol ester (12-O-tetradecanoylphorbol-13-acetate; TPA) inhibits the effects of ara-C on heme production, accumulation of globin RNA, and glycophorin expression. The inhibitory effect occurs maximally when K562 cells are treated with TPA before undergoing ara-C-induced commitment to erythroid differentiation. These findings suggest that TPA inhibits an early step in the process required for ara-C to enhance expression of genes involved in the erythroid program.

  13. Phorbol ester stimulates calcium sequestration in saponized human platelets

    SciTech Connect

    Yoshida, K.; Nachmias, V.T.

    1987-11-25

    When platelets are activated by agonists, calcium (Ca2+) is released from an intracellular storage site. Recent studies using fura-2 show that, after thrombin stimulation, the rise in free calcium is transient and returns to base-line levels in 2-3 min, while the transient following ADP stimulation lasts only 15-20 s. We reported previously that the phorbol ester 12,13-phorbol myristate acetate (PMA), added at nanomolar levels after thrombin, immediately accelerated the rate of return of calcium to the base line severalfold. In the present study, we used both intact and saponized platelets to determine whether this is due to stimulation of calcium sequestration. Using fura-2 and intact platelets, we found 1) that PMA stimulated the restoration of free Ca2+ levels after ADP as well as after thrombin, and 2) that H-7, an inhibitor of protein kinase C (Ca2+/phospholipid-dependent enzyme), slowed the return of Ca2+ to baseline levels. Using saponized platelets, we also found 3) that pretreatment of platelets with PMA before saponin treatment increased the ATP-dependent /sup 45/Ca2+ uptake 2-fold, with a half-maximal effect at 5 nm; 4) that most of the Ca2+ released by ionomycin or by myoinositol 1,4,5-trisphosphate; and 5) that a GTP-binding protein inhibitor, guanosine 5'-O-(2-thiodiphosphate), decreased basal or PMA-stimulated /sup 45/Ca2+ uptake in saponin-treated platelets. Our data suggest that activation of protein kinase C stimulates the sequestration of Ca2+ independently of cAMP or myoinositol 1,4,5-trisphosphate.

  14. Phorbol ester-induced activation of protein kinase C leads to increased formation of diacylglycerol in human neutrophils

    SciTech Connect

    Faellman, M.; Stendahl, O.; Andersson, T. )

    1989-03-01

    Human neutrophils stimulated with a phorbol ester (phorbol 12-myristate 13-acetate or phorbol 12,13-dibutyrate) responded with an increase in diacylglycerol, considered the natural activator of protein kinase C. The amounts of diacylglycerol formed were considerable, reaching 700-900% of basal after 20 minutes. In contrast, 4-{alpha}-phorbol 12-myristate 13-acetate did not induce any detectable formation of diacylglycerol. Simultaneously, phorbol 12-myristate 13-acetate exposure caused increased breakdown of both phosphatidylcholine and phosphatidylinositol 4,5-bisphosphate. These results suggest that once activated, protein kinase C can positively modulate its own activity by inducing additional formation of diacylglycerol from at least two different sources.

  15. Regulatory elements involved in constitutive and phorbol ester-inducible expression of the plasminogen activator inhibitor type 2 gene promoter.

    PubMed Central

    Cousin, E; Medcalf, R L; Bergonzelli, G E; Kruithof, E K

    1991-01-01

    Gene transcription rates and mRNA levels of plasminogen activator inhibitor type 2 (PAI-2) are markedly induced by the tumor promoting agent phorbol 12-myristate 13-acetate (PMA) in human HT1080 fibrosarcoma cells. To identify promoter elements required for basal-, and phorbol ester-inducible expression, deletion mutants of the PAI-1 promoter fused to the chloramphenicol acetyl transferase (CAT) reporter gene, were transiently expressed in HT1080 cells. Constitutive CAT activity was expressed from constructs containing more than 215 bp of promoter sequence, whereas deletion to position -91 bp abolished CAT gene expression. Treatment of transfected cells with PMA resulted in a three- to ten-fold increase in CAT expression from all constructs except from the construct shortened to position -91. DNAse1 protection analysis of the promoter region between -215 and the transcription initiation site revealed numerous protected regions, including two AP1-like binding sites (AP1a and AP1b) and one CRE-like element. Site-directed mutagenesis of the AP1a site or of the CRE-like site resulted in the loss of basal CAT activity and abolished the PMA effect, whereas mutagenesis of AP1b only partially inhibited basal and PMA-mediated expression. Our results suggest that the PAI-2 promoter contains at least two elements required for basal gene transcription and PMA-mediated induction. Images PMID:1650454

  16. The structural requirements for phorbol esters to enhance serotonin and acetylcholine release from rat brain cortex

    PubMed Central

    Iannazzo, L; Kotsonis, P; Majewski, H

    1999-01-01

    The effects of various phorbol-based protein kinase C (PKC) activators on the electrical stimulation-induced (S-I) release of serotonin and acetylcholine was studied in rat brain cortical slices pre-incubated with [3H]-serotonin or [3H]-choline to investigate possible structure-activity relationships. 4β-Phorbol 12,13-dibutyrate (4βPDB, 0.1–3.0 μM), enhanced S-I release of serotonin in a concentration-dependent manner whereas the structurally related inactive isomer 4α-phorbol 12, 13-dibutyrate (4αPDB) and phorbol 13-acetate (PA) were without effect. Another group of phorbol esters containing a common 13-ester substituent (phorbol 12,13-diacetate, PDA; phorbol 12-myristate 13-acetate, PMA; phorbol 12-methylaminobenzoate 13-acetate, PMBA) also enhanced S-I serotonin release with PMA being least potent. The deoxyphorbol monoesters, 12-deoxyphorbol 13-acetate (dPA), 12-deoxyphorbol 13-angelate (dPAng), 12-deoxyphorbol 13-phenylacetate (dPPhen) and 12-deoxyphorbol 13-isobutyrate (dPiB) enhanced S-I serotonin release but 12-deoxyphorbol 13-tetradecanoate (dPT) was without effect. The 20-acetate derivatives of dPPhen and dPAng were less effective in enhancing S-I serotonin release compared to the parent compounds. With acetylcholine release all phorbol esters tested had a far lesser effect when compared to their facilitatory action on serotonin release with only 4βPDB, PDA, dPA, dPAng and dPiB having significant effects. The effects of the phorbol esters on serotonin release were not correlated with their reported in vitro affinity and isozyme selectivity for PKC. A comparison across three transmitter systems (noradrenaline, dopamine, serotonin) suggests basic similarities in the structural requirements of phorbol esters to enhance transmitter release with short chain substituted mono- and diesters of phorbol being more potent facilitators of release than the long chain esters. Some compounds notably PDA, PMBA, dPPhen, dPPhenA had different potencies across

  17. Neutrophil beta-adrenergic receptor responses are potentiated by acute exposure to phorbol ester without changes in receptor distribution or coupling

    SciTech Connect

    Kilfeather, S.A.; Stein, M.; O'Malley, K. )

    1991-01-01

    Exposure to the phorbol ester, phorbol 12-myristate, 13-acetate for 10 minutes enhanced cyclic AMP accumulation in human neutrophils under basal conditions and in response to the beta-adrenergic receptor agonist isoproterenol (ISO, 1{mu}M) and the adenylate cyclase activator forskolin (FSK, 10mM). Potentiation of responses to ISO by PMA was dose-dependent between 0.1 and 100nM PMA. The diacylglycerol analogue, 1-oleoyl-2-actylgylcerol (OAG) (50 {mu}M) also elevated beta-receptor responses, but 4beta-phorbol (100nM), lacking the capacity to activate PMA, was ineffective. Short-term exposure to the peptide n-formylmethionine leucyl-phenylalanine (FMLP, 1 {mu}M) also elevated neutrophil cyclic AMP accumulation. All potentiating effects of PMA on cyclic AMP production were inhibited by the protein kinase inhibitor 1-(5-isoquinolinylsulphonyl)-2-methylpiperazine (H{sub 7}). PMA had no apparent effect on beta-receptor agonist-affinity, distribution between cell-surface and internalized compartments, or the capacity of ISO to induce beta-receptor internalization. Responses to FSK or ISO in terms of fold-stimulation of basal cyclic AMP accumulation int he presence of PMA were not elevated by PMA.

  18. Center for Functional Nanomaterials

    SciTech Connect

    BNL

    2008-08-12

    Staff from Brookhaven's new Center for Functional Nanomaterials (CFN) describe how this advanced facility will focus on the development and understanding of nanoscale materials. The CFN provides state-of-the-art capabilities for the fabrication and study of nanoscale materials, with an emphasis on atomic-level tailoring to achieve desired properties and functions. The overarching scientific theme of the CFN is the development and understanding of nanoscale materials that address the Nation's challenges in energy security.

  19. Center for Functional Nanomaterials

    ScienceCinema

    BNL

    2016-07-12

    Staff from Brookhaven's new Center for Functional Nanomaterials (CFN) describe how this advanced facility will focus on the development and understanding of nanoscale materials. The CFN provides state-of-the-art capabilities for the fabrication and study of nanoscale materials, with an emphasis on atomic-level tailoring to achieve desired properties and functions. The overarching scientific theme of the CFN is the development and understanding of nanoscale materials that address the Nation's challenges in energy security.

  20. Smart nanomaterials for biomedics.

    PubMed

    Choi, Soonmo; Tripathi, Anuj; Singh, Deepti

    2014-10-01

    Nanotechnology has become important in various disciplines of technology and science. It has proven to be a potential candidate for various applications ranging from biosensors to the delivery of genes and therapeutic agents to tissue engineering. Scaffolds for every application can be tailor made to have the appropriate physicochemical properties that will influence the in vivo system in the desired way. For highly sensitive and precise detection of specific signals or pathogenic markers, or for sensing the levels of particular analytes, fabricating target-specific nanomaterials can be very useful. Multi-functional nano-devices can be fabricated using different approaches to achieve multi-directional patterning in a scaffold with the ability to alter topographical cues at scale of less than or equal to 100 nm. Smart nanomaterials are made to understand the surrounding environment and act accordingly by either protecting the drug in hostile conditions or releasing the "payload" at the intended intracellular target site. All of this is achieved by exploiting polymers for their functional groups or incorporating conducting materials into a natural biopolymer to obtain a "smart material" that can be used for detection of circulating tumor cells, detection of differences in the body analytes, or repair of damaged tissue by acting as a cell culture scaffold. Nanotechnology has changed the nature of diagnosis and treatment in the biomedical field, and this review aims to bring together the most recent advances in smart nanomaterials. PMID:25992434

  1. Protection against apoptosis in chicken bursa and thymus cells by phorbol ester in vitro

    SciTech Connect

    Asakawa, J.; Thorbecke, G.J. )

    1991-03-15

    Programmed suicide or apoptosis, due to activation of endogenous nucleases, occurs in immature CD4{sup {minus}}85{sup {minus}} mammalian thymus cells. Like the thymus, the bursa of Fabricius is a site of massive lymphopoiesis accompanied by cell death in vivo. In the present study the authors have, therefore, examined whether chicken bursa and thymus cells exhibit apoptosis. Bursa and thymus cells from SC chickens, 4-10 weeks of age, were incubated for 8-24 hrs with various reagents. Genomic DNA was isolated, electrophoresed in 3% Nusieve agarose gels, and examined for patterns of DNA fragmentation. A laddering of DNA in multiples of 200 base pairs, indicative of apoptosis, was observed with both bursa and thymus cells. These patterns of DNA fragmentation from bursa cells could be prevented by adding phorbol myristic acetate during culture and, more effectively, by PMA plus ionomycin, but not by ionomycin alone or by anti-{mu}. PMA did not affect the patterns of DNA fragmentation seen with spleen cells. Addition of the protein kinase C inhibitor staurosporin inhibited the preventive effect of PMA on apoptosis. PMA also greatly promoted the survival of bursa cells in culture, as assayed by percentage cell death and by {sup 3}H-thymidine incorporation. It is concluded that bursa and thymus cells from the chicken exhibit apoptosis. The data further suggest that protein kinase C activation protects apoptosis in cultured bursa cells.

  2. Characterization of phorbol ester-stimulated serine phosphorylation of the human insulin receptor.

    PubMed Central

    Feener, E P; Shiba, T; Hu, K Q; Wilden, P A; White, M F; King, G L

    1994-01-01

    Phorbol 12-myristate 13-acetate (PMA)-stimulated phosphorylation of the human insulin receptor (IR) was characterized and compared in two cell types of different lineage: normal rat kidney epithelial (NRK) cells and Chinese hamster ovary (CHO) fibroblasts. PMA stimulation increased IR beta-subunit phosphorylation to 252 +/- 43 and 25- +/- 47% (+/- S.D.) of the unstimulated control in NRK and CHO cells respectively. Tryptic phosphopeptide analysis by Tricine/SDS/PAGE revealed significant differences in the PMA-stimulated phosphorylation of the IR in these two cell types. This phosphorylation of the IR was predominantly located in two tryptic phosphopeptides, and these phosphopeptides were absent in an IR mutant truncated by 43 C-terminal amino acids. The major PMA-stimulated tryptic phosphopeptide from in vivo-labelled CHO/IR was immunoprecipitated with an antibody against residues Ser1315 to Lys1329, and this precipitation was blocked with excess unlabelled peptide containing this sequence. Radiosequencing by manual Edman degradation revealed that this tryptic phosphopeptide was phosphorylated at Ser1315. This PMA-stimulated phosphorylation did not inhibit autophosphorylation of the IR in vivo. These results demonstrate that PMA-stimulated phosphorylation of the IR can exhibit significant differences when expressed in different cell types, and that Ser1315 is a major PMA-stimulated phosphorylation site on the human IR. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:7945263

  3. GM-CSF and phorbol esters modulate GM-CSF receptor expression by independent mechanisms.

    PubMed

    Brizzi, M F; Arduino, C; Avanzi, G C; Bussolino, F; Pegoraro, L

    1991-07-01

    Human granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.1 nM) down-modulates its receptor in IL-3/GM-CSF dependent M-07e cells, in KG-1 cells and normal granulocytes, whereas phorbol esters 12-O-tetradecanoylphorbol-13-acetate (TPA) (2 nM) down-modulates the GM-CSF receptor in M-07e cells and granulocytes but not in KG-1 cells. As data analysis shows by nonlinear regression, the decreased binding ability depends on a reduction of the binding sites with no significant change of their dissociation constant. To gain insight into the mechanisms involved in the GM-CSF receptor regulation, we investigated the role of protein kinase C (PKC). GM-CSF, unlike TPA, was unable to activate PKC in all the cells studied. Moreover, unlike TPA, GM-CSF was still able to down-modulate its receptor in cells where PKC was inhibited by 1-(5-isoquinolonesulphonyl)-2-methylpiperazine (H7) and staurosporine or in cells where PKC was exhausted by prolonged incubation with 1 microM TPA. Finally, the receptor re-expression rate was accelerated by protein kinases inhibitors. These results, taken together, indicate the presence of a PKC-dependent and -independent down-modulation mechanism and a negative role of the endogeneous protein kinases in GM-CSF receptor re-expression.

  4. Multianalyte Microphysiometry of Macrophage Responses to Phorbol Myristate Acetate, Lipopolysaccharide, and Lipoarabinomannan

    PubMed Central

    Kimmel, Danielle W.; Meschievitz, Mika E.; Hiatt, Leslie A.; Cliffel, David E.

    2015-01-01

    This study examined the hypothesis that mycobacterial antigens generate different metabolic responses in macrophages as compared to gram-negative effectors and macrophage activators. The metabolic activation of macrophages by PMA is a useful tool for studying virulent agents and can be compared to other effectors. While phorbol myristate acetate (PMA) is commonly used to study macrophage activation, the concentration used to create this physiological response varies. The response of RAW-264.7 macrophages is concentration-dependent, where the metabolic response to high concentrations of PMA decreases suggesting deactivation. The gram-negative effector, lipopolysaccharide (LPS), was seen to promote glucose and oxygen production which were used to produce a delayed onset of oxidative burst. Pre-incubation with interferon-γ (IFN-γ) increased the effect on cell metabolism, where the synergistic effects of IFN-γ and LPS immediately initiated oxidative burst. These studies exhibited a stark contrast with lipoarabinomannan (LAM), an antigenic glycolipid component associated with the bacterial genus Mycobacterium. The presence of LAM effectively inhibits any metabolic response preventing consumption of glucose and oxygen for the promotion of oxidative burst and to ensure pathogenic proliferation. This study demonstrates for the first time the immediate inhibitory metabolic effects LAM has on macrophages, suggesting implications for future intervention studies with Mycobacterium tuberculosis. PMID:25798034

  5. Effects of phorbol esters on fluid transport and blood flow in the small intestine

    SciTech Connect

    Sjoeqvist, A.; Henderson, L.S.; Fondacaro, J.D.

    1986-07-01

    Studies were designed to examine the effects of phorbol esters on intestinal fluid transport and blood flow in the anesthetized cat and enteropooling in the conscious rat. Intraluminal administration of phorbol ester into a segment of isolated small bowel produced a copious intestinal secretion and a concomitant mesenteric hyperemia in the cat. Net fluid movement in the intestine was converted from absorption in the control state to secretion following phorbol ester administration. Intravenous atropine reduced the phorbol ester-induced secretion by 56%; clonidine abolished the remaining secretory response. In the rat, intragastric administration of phorbol ester produced enteropooling comparable to that of other potent intestinal secretagogues. Since phorbol esters are known to activate protein kinase C, these suggest that activation of protein kinase C in the small intestine may lead to a full secretory response. The evidence suggests that this secretion is accompanied by a metabolic hyperemia. These results suggest that protein kinase C plays an important role in the regulation of intestinal fluid transport.

  6. Phorbol esters modulate cyclic AMP accumulation in porcine thyroid cells

    SciTech Connect

    Emoto, T.; Kasai, K.; Hiraiwa, M.; Shimoda, S.

    1988-01-01

    In cultured porcine thyroid cells, during 60 min incubation phorbol 12-myristate 13-acetate (PMA) had no effect on basal cyclic AMP accumulation and slightly stimulated cyclic AMP accumulation evoked by thyroid stimulating hormone (TSH) or forskolin. Cholera toxin-induced cyclic AMP accumulation was significantly stimulated by PMA. On the other hand, cyclic AMP accumulation evoked by prostaglandin E/sub 1/ or E/sub 2/ (PGE/sub 1/ and PGE/sub 2/) was markedly depressed by simultaneous addition of PMA. These opposing effects of PMA on cyclic AMP accumulation evoked by PGE and cholera toxin were observed in a dose-related fashion, with half-maximal effect of around 10/sup -9/ M in either case. The almost same effects of PMA on cyclic AMP accumulation in basal and stimulated conditions were also observed in freshly prepared thyroid cells. The present study was performed in the presence of phosphodiesterase inhibitor, 3-iso-butyl-1-methylxanthine (IBMX), indicating that PMA affected adenylate cyclase activity. Therefore, it is suggested that PMA may modulate the production of cyclic AMP in response to different stimuli, possibly by affecting several sites in the adenylate cyclase complex in thyroid cells.

  7. Phorbol ester and spontaneous activity in SHR aorta

    SciTech Connect

    Moisey, D.M.; Cox, R.H.

    1986-03-01

    Thoracic aortas (TA) were excised from 6-week old SHR and WKY. 2mm rings were mounted isometrically at optimum preload. Spontaneous rhythmical activity developed in TA from SHR and had a frequency of 3-4/min with varying periods of quiescence between bursts of activity. The spontaneous activity often produced an increase in tension development which was associated with increased frequency of oscillations. Verapamil (10/sup -7/ M) or Ca/sup + +/-free solution added during the contractile phase resulted in an immediate loss of tension and spontaneous activity. Addition of ouabain (10/sup -4/ M) during the contractile phase of spontaneous activity, increased the frequency of oscillations which appeared to fuse into a tetanus. Spontaneous rhythmical activity was infrequently observed in TA from WKY. However, addition of phorbol 12-myristate-13 acetate (TPA), frequently induced spontaneous rhythmic oscillations associated with tension development in TA from WKY. TPA contracted the SHR TA and increased the frequency of oscillations. SHR TA were more sensitive to TPA than WKY. This study demonstrates (1) spontaneous rhythmical activity, independent of agonist stimulation in TA from 6-week old SHR and (2) TPA induced spontaneous oscillatory activity. The mechanism underlying the spontaneous oscillatory activity may involve membrane coupling events and Na-pump difference between SHR and WKY.

  8. Electrocatalysis at metal nanomaterials

    NASA Astrophysics Data System (ADS)

    Dai, Lin

    Direct liquid fuel cells, such as direct methanol fuel cells and direct formic acid fuel cells, have attracted much attention in the past decades due to the need of clean and efficient power sources. One of the most critical issues in the development of highly efficient fuel cells is to increase the rates of fuel-cell reactions as a commercial product. As a result, the topic of electrocatalysis plays a significant role in the investigations of fuel cell reactions. For methanol oxidation, platinum based nanomaterials are the most important catalysts. For formic acid oxidation, both platinum and palladium based nanomaterials are widely employed as the catalysts. Recently, shape-control of the nanoparticles has become an imperative task due to the fact that most of the reactions in fuel cells are sensitive to the surface structure of the catalysts. Though numerous studies have been conducted in past to elucidate the catalytic activity on the nanomaterials with different shapes, the results are inconclusive. Herein, systematic comparison of catalytic activity toward methanol and formic acid oxidation on shape-controlled cubic platinum-based alloy nanoparticles with different alloy element are reported in this dissertation. Methanol and formic acid oxidation reactions on spherical and cubic Pt-Cu nanoparticles are also studied. Cu-Pd nanoparticles are synthesized through galvanic redox reactions to provide significantly higher and much more stable formic acid oxidation activities. Interparticle distance effect is investigated on two dimensional nanoparticle array electrodes with controlled particle size, which is ideal model system for exploring the interparticle distance effects on the voltammetric behavior and reaction mechanisms.

  9. Superconductivity in carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Dlugon, Katarzyna

    The purpose of this thesis is to explain the phenomenon of superconductivity in carbon nanomaterials such as graphene, fullerenes and carbon nanotubes. In the introductory chapter, there is a description of superconductivity and how it occurs at critical temperature (Tc) that is characteristic and different to every superconducting material. The discovery of superconductivity in mercury in 1911 by Dutch physicist Heike Kamerlingh Onnes is also mentioned. Different types of superconductors, type I and type II, low and high temperatures superconductors, as well as the BCS theory that was developed in 1957 by Bardeen, Cooper, and Schrieffer, are also described in detail. The BCS theory explains how Cooper's pairs are formed and how they are responsible for the superconducting properties of many materials. The following chapters explain superconductivity in doped fullerenes, graphene and carbon nanotubes, respectively. There is a thorough explanation followed by many examples of different types of carbon nanomaterials in which small changes in chemical structure cause significant changes in superconducting properties. The goal of this research was not only to take into consideration well known carbon based superconductors but also to search for the newest available materials such as the fullerene nanowhiskers discovered quite recently. There is also a presentation of fairly new ideas about inducing superconductivity in a monolayer of graphene which is more challenging than inducing superconductivity in graphite by simply intercalating metal atoms between its graphene sheets. An effort has been taken to look for any available information about carbon nanomaterials that have the potential to superconduct at room temperature, mainly because discovery of such materials would be a real revolution in the modern world, although no such materials have been discovered yet.

  10. Nanomaterial-Based Electrochemical Biosensors and Bioassays

    SciTech Connect

    Liu, Guodong; Mao, Xun; Gurung, Anant; Baloda, Meenu; Lin, Yuehe; He, Yuqing

    2010-08-31

    This book chapter summarizes the recent advance in nanomaterials for electrochemical biosensors and bioassays. Biofunctionalization of nanomaterials for biosensors fabrication and their biomedical applications are discussed.

  11. Nanomaterials, Inflammation and Tissue Engineering

    PubMed Central

    Padmanabhan, Jagannath

    2014-01-01

    Nanomaterials exhibit unique properties that are absent in the bulk material because decreasing material size leads to an exponential increase in surface area, surface area to volume ratio, and effective stiffness, resulting in altered physiochemical properties. Diverse categories of nanomaterials such as nanoparticles, nanoporous scaffolds, nanopatterned surfaces, nanofibers and carbon nanotubes can be generated using advanced fabrication and processing techniques. These materials are being increasingly incorporated in tissue engineering scaffolds to facilitate the development of biomimetic substitutes to replace damaged tissues and organs. Long term success of nanomaterials in tissue engineering is contingent upon the inflammatory responses they elicit in vivo. This review seeks to summarize the recent developments in our understanding of biochemical and biophysical attributes of nanomaterials and the inflammatory responses they elicit, with a focus on strategies for nanomaterial design in tissue engineering applications. PMID:25421333

  12. Detoxification of toxic phorbol esters from Malaysian Jatropha curcas Linn. kernel by Trichoderma spp. and endophytic fungi.

    PubMed

    Najjar, Azhar; Abdullah, Norhani; Saad, Wan Zuhainis; Ahmad, Syahida; Oskoueian, Ehsan; Abas, Faridah; Gherbawy, Youssuf

    2014-01-01

    The presence of phorbol esters (PEs) with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1) was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS) and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05) removed PEs with percentage losses of 96.9%-99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%-92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%-96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs.

  13. Detoxification of Toxic Phorbol Esters from Malaysian Jatropha curcas Linn. Kernel by Trichoderma spp. and Endophytic Fungi

    PubMed Central

    Najjar, Azhar; Abdullah, Norhani; Saad, Wan Zuhainis; Ahmad, Syahida; Oskoueian, Ehsan; Abas, Faridah; Gherbawy, Youssuf

    2014-01-01

    The presence of phorbol esters (PEs) with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1) was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS) and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05) removed PEs with percentage losses of 96.9%–99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%–92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%–96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs. PMID:24504029

  14. Detoxification of toxic phorbol esters from Malaysian Jatropha curcas Linn. kernel by Trichoderma spp. and endophytic fungi.

    PubMed

    Najjar, Azhar; Abdullah, Norhani; Saad, Wan Zuhainis; Ahmad, Syahida; Oskoueian, Ehsan; Abas, Faridah; Gherbawy, Youssuf

    2014-01-01

    The presence of phorbol esters (PEs) with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1) was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS) and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05) removed PEs with percentage losses of 96.9%-99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%-92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%-96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs. PMID:24504029

  15. Biofunctionalization of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Kumar, Challa S. S. R.

    2005-11-01

    The new book series 'Nanotechnologies for the Life Sciences' is the first comprehensive source on the topics where materials science and life sciences meet on the nanoscale. Each volume provides a concise overview of the underlying nanotechnologies for the design, creation and characterization of biomedical applications, collating the many articles found in the relevant specialized journals but as yet unseen by those working in other disciplines. Written by international experts describing the various facets of nanofabrication, the ten volumes of this single source of information cover the complete range of synthetic methods, tools and techniques being developed towards medical, biological and cybernetic applications. This volume covers the synthetic and materials aspects of instilling biocompatibility into nanomaterials with properties desirable for advanced medical and biological applications. Essential reading for anyone working in the various related disciplines: from medicine and biology through chemistry, materials science and physics to engineering.

  16. Nanomaterials for renewable energy

    DOE PAGES

    Chen, Shimou; Li, Liang; Sun, Hanwen; Sun, Jian; Lu, Baowang

    2015-05-19

    With demand for sustainable energy, resource, and environment protection, new material technologies are constantly expanding during the last few couple of decades. An intensive attention has been given by the scientific communities. In particular, nanomaterials are increasingly playing an active role either by increasing the efficiency of the energy storage and conversion processes or by improving the device design and performance. This special issue presents recent research advances in various aspects of energy storage technologies, advanced batteries, fuel cells, solar cell, biofuels, and so on. Design and synthesis of novel materials have demonstrated great impact on the utilization of themore » sustainable energy, which need to solve the increasing shortage of resource and the issues of environmental pollution.« less

  17. Nanomaterials for renewable energy

    SciTech Connect

    Chen, Shimou; Li, Liang; Sun, Hanwen; Sun, Jian; Lu, Baowang

    2015-05-19

    With demand for sustainable energy, resource, and environment protection, new material technologies are constantly expanding during the last few couple of decades. An intensive attention has been given by the scientific communities. In particular, nanomaterials are increasingly playing an active role either by increasing the efficiency of the energy storage and conversion processes or by improving the device design and performance. This special issue presents recent research advances in various aspects of energy storage technologies, advanced batteries, fuel cells, solar cell, biofuels, and so on. Design and synthesis of novel materials have demonstrated great impact on the utilization of the sustainable energy, which need to solve the increasing shortage of resource and the issues of environmental pollution.

  18. Nanomaterials for Space Exploration Applications

    NASA Technical Reports Server (NTRS)

    Moloney, Padraig G.

    2006-01-01

    Nano-engineered materials are multi-functional materials with superior mechanical, thermal and electrical properties. Nanomaterials may be used for a variety of space exploration applications, including ultracapacitors, active/passive thermal management materials, and nanofiltration for water recovery. Additional applications include electrical power/energy storage systems, hybrid systems power generation, advanced proton exchange membrane fuel cells, and air revitalization. The need for nanomaterials and their growth, characterization, processing and space exploration applications is discussed. Data is presented for developing solid-supported amine adsorbents based on carbon nanotube materials and functionalization of nanomaterials is examined.

  19. Insulin reverses the growth retardation effect of phorbol ester in chicken embryos during organogenesis

    SciTech Connect

    Girbau, M.; Bassas, L.; Roth, J.; de Pablo, F. )

    1989-01-01

    The tumor promoting phorbol esters can affect early embryonic development by causing interference with the normal pathways of cellular growth and differentiation. The present study was designed to: (a) define a time in organogenesis when a vertebrate embryo model, the chicken, was sensitive to the phorbol ester 12-0-tetradecanoil-13-acetate (TPA), and (b) attempt a rescue of the embryos disturbed by TPA with simultaneous addition of insulin. In embryos treated at days 2 and 3 of development, TPA caused dose-dependent mortality. Survivors were biochemically retarded as indicated by their decreased weight, protein, DNA, RNA, total creatine kinase, triglycerides, phospholipids and cholesterol contents. When intermediated doses of TPA were applied together with insulin the embryonic growth disturbance was largely antagonized. These data, generated with an in vivo whole embryo, support the strong link between the mode of action of insulin and signal transduction mechanisms typical of phorbol esters.

  20. Potentiation of specific association of insulin with HepG2 cells by phorbol esters.

    PubMed Central

    Blake, A D; Strader, C D

    1986-01-01

    The effects of tumour-promoting phorbol esters on the receptor-mediated endocytosis of insulin were investigated in the human hepatoma cell line HepG2. Treatment of these cells with the biologically active phorbol 12-O-tetradecanoylphorbol 13-acetate (TPA), but not with the non-tumour-promoting analogue 4 alpha-phorbol 12,13-didecanoate, resulted in dramatic morphological changes, which were accompanied by a 1.5-2.5-fold increase in specific 125I-insulin association with the cells at 37 degrees C. This increase in insulin binding was not observed when the binding reaction was performed at 4 degrees C. The potentiation of 125I-insulin association with TPA-treated cells at 37 degrees C could be completely accounted for by an increase in the intracellular pool of internalized insulin; there was no concomitant increase in cell-surface insulin binding. Dissociation studies showed that the enhanced internalization of insulin by cells after treatment with TPA resulted from a decrease in the rate of intracellular processing of the insulin after receptor-mediated endocytosis. The phorbol-ester-induced enhancement of internalized insulin in HepG2 cells was additive with the potentiation of endocytosed insulin induced by both the lysosomotropic reagent chloroquine and the ionophore monensin; this indicates that TPA affects the intracellular processing of the insulin receptor at a point other than those disrupted by either of these two reagents. The potentiation of insulin receptor internalization by tumour-promoting phorbol esters could be completely mimicked by treatment with phospholipase C, but not with phospholipase A, and partially mimicked by treatment with the synthetic diacylglycerol 1-oleoyl-2-acetylglycerol. By these criteria, the effects of phorbol esters on the insulin receptor in HepG2 cells appear to be mediated through protein kinase C. These results support the concept that the activation of protein kinase C by treatment with phorbol esters causes a

  1. Environmental Risk Assessment of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Bayramov, A. A.

    In this paper, various aspects of modern nanotechnologies and, as a result, risks of nanomaterials impact on an environment are considered. This very brief review of the First International Conference on Material and Information Sciences in High Technologies (2007, Baku, Azerbaijan) is given. The conference presented many reports that were devoted to nanotechnology in biology and business for the developing World, formation of charged nanoparticles for creation of functional nanostructures, nanoprocessing of carbon nanotubes, magnetic and optical properties of manganese-phosphorus nanowires, ultra-nanocrystalline diamond films, and nanophotonics communications in Azerbaijan. The mathematical methods of simulation of the group, individual and social risks are considered for the purpose of nanomaterials risk reduction and remediation. Lastly, we have conducted studies at a plant of polymeric materials (and nanomaterials), located near Baku. Assessments have been conducted on the individual risk of person affection and constructed the map of equal isolines and zones of individual risk for a plant of polymeric materials (and nanomaterials).

  2. Radioactive Nanomaterials for Multimodality Imaging

    PubMed Central

    Chen, Daiqin; Dougherty, Casey A.; Yang, Dongzhi; Wu, Hongwei; Hong, Hao

    2016-01-01

    Nuclear imaging techniques, including primarily positron emission tomography (PET) and single-photon emission computed tomography (SPECT), can provide quantitative information for a biological event in vivo with ultra-high sensitivity, however, the comparatively low spatial resolution is their major limitation in clinical application. By convergence of nuclear imaging with other imaging modalities like computed tomography (CT), magnetic resonance imaging (MRI) and optical imaging, the hybrid imaging platforms can overcome the limitations from each individual imaging technique. Possessing versatile chemical linking ability and good cargo-loading capacity, radioactive nanomaterials can serve as ideal imaging contrast agents. In this review, we provide a brief overview about current state-of-the-art applications of radioactive nanomaterials in the circumstances of multimodality imaging. We present strategies for incorporation of radioisotope(s) into nanomaterials along with applications of radioactive nanomaterials in multimodal imaging. Advantages and limitations of radioactive nanomaterials for multimodal imaging applications are discussed. Finally, a future perspective of possible radioactive nanomaterial utilization is presented for improving diagnosis and patient management in a variety of diseases. PMID:27227167

  3. Plasma nanofabrication and nanomaterials safety

    NASA Astrophysics Data System (ADS)

    Han, Z. J.; Levchenko, I.; Kumar, S.; Yajadda, M. M. A.; Yick, S.; Seo, D. H.; Martin, P. J.; Peel, S.; Kuncic, Z.; Ostrikov, K.

    2011-05-01

    The fast advances in nanotechnology have raised increasing concerns related to the safety of nanomaterials when exposed to humans, animals and the environment. However, despite several years of research, the nanomaterials safety field is still in its infancy owing to the complexities of structural and surface properties of these nanomaterials and organism-specific responses to them. Recently, plasma-based technology has been demonstrated as a versatile and effective way for nanofabrication, yet its health and environment-benign nature has not been widely recognized. Here we address the environmental and occupational health and safety effects of various zero- and one-dimensional nanomaterials and elaborate the advantages of using plasmas as a safe nanofabrication tool. These advantages include but are not limited to the production of substrate-bound nanomaterials, the isolation of humans from harmful nanomaterials, and the effective reforming of toxic and flammable gases. It is concluded that plasma nanofabrication can minimize the hazards in the workplace and represents a safe way for future nanofabrication technologies.

  4. ROCK mediates phorbol ester-induced apoptosis in prostate cancer cells via p21Cip1 up-regulation and JNK.

    PubMed

    Xiao, Liqing; Eto, Masumi; Kazanietz, Marcelo G

    2009-10-23

    It is established that androgen-dependent prostate cancer cells undergo apoptosis upon treatment with phorbol esters and related analogs, an effect primarily mediated by PKCdelta. Treatment of LNCaP prostate cancer cells with phorbol 12-myristate 13-acetate (PMA) causes a strong and sustained activation of RhoA and its downstream effector ROCK (Rho kinase) as well as the formation of stress fibers. These effects are impaired in cells subjected to PKCdelta RNA interference depletion. Functional studies revealed that expression of a dominant negative RhoA mutant or treatment with the ROCK inhibitor Y-27632 inhibits the apoptotic effect of PMA in LNCaP cells. Remarkably, the cytoskeleton inhibitors cytochalasin B and blebbistatin blocked not only PMA-induced apoptosis but also the activation of JNK, a mediator of the cell death effect by the phorbol ester. In addition, we found that up-regulation of the cell cycle inhibitor p21(Cip1) is required for PMA-induced apoptosis and that inhibitors of ROCK or the cytoskeleton organization prevent p21(Cip1) induction. Real time PCR analysis and reporter gene assay revealed that PMA induces p21(Cip1) transcriptionally in a ROCK- and cytoskeleton-dependent manner. p21(Cip1) promoter analysis revealed that PMA induction is dependent on Sp1 elements in the p21(Cip1) promoter but independent of p53. Taken together, our studies implicate ROCK-mediated up-regulation of p21(Cip1) and the cytoskeleton in PKCdelta-dependent apoptosis in prostate cancer cells.

  5. Energetics of Nanomaterials

    SciTech Connect

    Alexandra Navrotsky; Brian Woodfield; Juliana Boerio-Goates; Frances Hellman

    2005-01-28

    This project, "Energetics of Nanomaterials," represents a three-year collaboration among Alexandra Navrotsky (UC Davis), Brian Woodfield and Juliana Boerio-Goates (BYU), and Frances Hellman (UC Berkeley). It's purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in term of their thermodynamic properties, with an emphasis on heat capaacities and entropies, as well as enthalpies. the three groups have brought very different expertise and capabilities to the project. Navrotsky is a solid-state chemist and geochemist, with a unique Thermochemistry Facility emphasizing enthalpy of formation measurements by high temperature oxide melt and room temperatue acid solution calorimetry. Boerio-Goates and Woodfield are calorimetry. Hellman is a physicist with expertise in magnetism and heat capacity measurements using microscale "detector on a chip" calorimetric technology that she pioneered. The overarching question of our work is "How does the free energy play out in nanoparticles?", or "How do differences in free energy affect overall nanoparticle behavior?" Because the free energy represents the temperature-dependent balance between the enthalpy of a system and its entropy, there are two separate, but related, components to the experimental investigations: Solution calorimetric measurements provide the energetics and two types of heat capacity measurements the entropy. We use materials that are well characterized in other ways (structurally, magnetically, and chemically), and samples are shared across the collaboration.

  6. Vascular Distribution of Nanomaterials

    PubMed Central

    Stapleton, Phoebe A.; Nurkiewicz, Timothy R.

    2014-01-01

    Once considered primarily occupational, novel nanotechnology innovation and application has led to widespread domestic use and intentional biomedical exposures. With these exciting advances, the breadth and depth of toxicological considerations must also be expanded. The vascular system interacts with every tissue in the body, striving to homeostasis. Engineered nanomaterials (ENM) have been reported to distribute in many different organs and tissues. However, these observations have tended to use approaches requiring tissue homogenization and/or gross organ analyses. These techniques, while effective in establishing presence, preclude an exact determination of where ENM are deposited within a tissue. It is necessary to identify this exact distribution and deposition of ENM throughout the cardiovascular system, with respect to vascular hemodynamics and in vivo/ in vitro ENM modifications taken into account if nanotechnology is to achieve its full potential. Distinct levels of the vasculature will first be described as individual compartments. Then the vasculature will be considered as a whole. These unique compartments and biophysical conditions will be discussed in terms of their propensity to favor ENM deposition. Understanding levels of the vasculature will also be discussed. Ultimately, future studies must verify the mechanisms speculated on and presented herein. PMID:24777845

  7. The potential of protein-nanomaterial interaction for advanced drug delivery.

    PubMed

    Peng, Qiang; Mu, Huiling

    2016-03-10

    Nanomaterials, like nanoparticles, micelles, nano-sheets, nanotubes and quantum dots, have great potentials in biomedical fields. However, their delivery is highly limited by the formation of protein corona upon interaction with endogenous proteins. This new identity, instead of nanomaterial itself, would be the real substance the organs and cells firstly encounter. Consequently, the behavior of nanomaterials in vivo is uncontrollable and some undesired effects may occur, like rapid clearance from blood stream; risk of capillary blockage; loss of targeting capacity; and potential toxicity. Therefore, protein-nanomaterial interaction is a great challenge for nanomaterial systems and should be inhibited. However, this interaction can also be used to functionalize nanomaterials by forming a selected protein corona. Unlike other decoration using exogenous molecules, nanomaterials functionalized by selected protein corona using endogenous proteins would have greater promise for clinical use. In this review, we aim to provide a comprehensive understanding of protein-nanomaterial interaction. Importantly, a discussion about how to use such interaction is launched and some possible applications of such interaction for advanced drug delivery are presented.

  8. Carbamylcholine and phorbol esters desensitize muscarinic receptors by different mechanisms in rat pancreatic acini.

    PubMed

    Blanchard, L M; Paquette, B; Larose, L; Morisset, J

    1990-01-01

    Pretreatment of rat pancreatic acini with phorbol 12-myristate, 13-acetate (PMA), a protein kinase C (PK-C) activator, caused the desensitization of carbamylcholine (CBC)-induced amylase release in a concentration- and time-dependent fashion. The less potent phorbol-12, 13-dibutyrate (PDBu) also provoked a desensitization, but the inactive 4-alpha-phorbol-12,13-didecanoate had no effect. PMA or PDBu also significantly reduced subsequent amylase release induced by caerulein or secretin in contrast to CBC, which only reduced amylase release induced by CBC or secretin. Preincubation of acini with PMA did not lead to a decrease in PMA or A23187-stimulated amylase release. A 3 h resting period did not restore the desensitization induced by PMA or PDBu. Pretreatment with PMA did not cause changes in muscarinic receptor high- and low-affinity populations as observed with CBC pretreatment. The PK-C inhibitor H-7 completely prevented the desensitization induced by PDBu but not that induced by CBC. TMB-8, another PK-C inhibitor, also completely prevented the desensitization induced by PDBu but only partially that induced by CBC. These results suggest that phorbol esters can induce desensitization of muscarinic receptor-stimulated amylase release by a different mechanism than that involved in muscarinic agonist-induced desensitization.

  9. Method of phorbol ester degradation in Jatropha curcas L. seed cake using rice bran lipase.

    PubMed

    Hidayat, Chusnul; Hastuti, Pudji; Wardhani, Avita Kusuma; Nadia, Lana Santika

    2014-03-01

    A novel enzymatic degradation of phorbol esters (PE) in the jatropha seed cake was developed using lipase. Cihera rice bran lipase had the highest ability to hydrolyze PE, and reduced PE to a safe level after 8 h of incubation. Enzymatic degradation may be a promising method for PE degradation.

  10. Human brain n-chimaerin cDNA encodes a novel phorbol ester receptor.

    PubMed Central

    Ahmed, S; Kozma, R; Monfries, C; Hall, C; Lim, H H; Smith, P; Lim, L

    1990-01-01

    A human brain-specific cDNA encoding n-chimaerin, a protein of predicted molecular mass 34 kDa, has sequence identity with two different proteins: protein kinase C (PKC) at the N-terminus and BCR protein [product of the breakpoint-cluster-region (BCR) gene, involved in Philadelphia chromosome translocation] at the C-terminus [Hall, Monfries, Smith, Lim, Kozma, Ahmed, Vannaisungham, Leung & Lim (1990) J. Mol. Biol. 211, 11-16]. The sequence identity of n-chimaerin with PKC includes the cysteine-rich motif CX2CX13CX2CX7CX7C, and amino acids upstream of the first cysteine residue, but not the kinase domain. This region of PKC has been implicated in the binding of diacylglycerol and phorbol esters in a phospholipid-dependent fashion. Part of this cysteine-rich motif (CX2CX13CX2C) has the potential of forming a 'Zn-finger' structure. Phorbol esters cause a variety of physiological changes and are among the most potent tumour promoters that have been described. PKC is the only known protein target for these compounds. We now report that n-chimaerin cDNA encodes a novel phospholipid-dependent phorbol ester receptor, with the cysteine-rich region being responsible for this activity. This finding has wide implications for previous studies equating phorbol ester binding with the presence of PKC in the brain. Images Fig. 4. PMID:2268301

  11. Phorbol esters promote alpha 1-adrenergic receptor phosphorylation and receptor uncoupling from inositol phospholipid metabolism.

    PubMed Central

    Leeb-Lundberg, L M; Cotecchia, S; Lomasney, J W; DeBernardis, J F; Lefkowitz, R J; Caron, M G

    1985-01-01

    DDT1 MF-2 cells, which are derived from hamster vas deferens smooth muscle, contain alpha 1-adrenergic receptors (54,800 +/- 2700 sites per cell) that are coupled to stimulation of inositol phospholipid metabolism. Incubation of these cells with tumor-promoting phorbol esters, which stimulate calcium- and phospholipid-dependent protein kinase, leads to a marked attenuation of the ability of alpha 1-receptor agonists such as norepinephrine to stimulate the turnover of inositol phospholipids. This turnover was measured by determining the 32P content of phosphatidylinositol and phosphatidic acid after prelabeling of the cellular ATP pool with 32Pi. These phorbol ester-treated cells also displayed a decrease in binding affinity of cellular alpha 1 receptors for agonists with no change in antagonist affinity. By using affinity chromatography on the affinity resin Affi-Gel-A55414, the alpha 1 receptors were purified approximately equal to 300-fold from control and phorbol ester-treated 32Pi-prelabeled cells. As assessed by NaDodSO4/polyacrylamide gel electrophoresis, the Mr 80,000 alpha 1-receptor ligand-binding subunit is a phosphopeptide containing 1.2 mol of phosphate per mol of alpha 1 receptor. After phorbol ester treatment this increased to 3.6 mol of phosphate per mol of alpha 1 receptor. The effect of phorbol esters on norepinephrine-stimulated inositol phospholipid turnover and alpha 1-receptor phosphorylation showed the same rapid time course with a t1/2 less than 2 min. These results indicate that calcium- and phospholipid-dependent protein kinase may play an important role in regulating the function of receptors that are coupled to the inositol phospholipid cycle by phosphorylating and deactivating them. Images PMID:2994039

  12. Photoinduced toxicity of engineered nanomaterials

    NASA Astrophysics Data System (ADS)

    Jones, Philip Scott

    Engineered nanomaterials including metal, metal oxide and carbon based nanomaterials are extensively used in a wide variety of applications to the extent that their presence in the environment is expected to increase dramatically over the next century. These nanomaterials may be photodegraded by solar radiation and thereby release metal ions into the environment that can produce cytotoxic and genotoxic effects. Photoinduced toxicity experiments are performed exposing human lung epithelial carcinoma cells [H1650] to engineered semiconductor nanoparticles such as CdSe quantum dots and ZnO nanoparticles after exposure to 3, 6, and 9 hours of solar simulated radiation. Cytotoxicity and genotoxicity of the metal ions are evaluated using ZnSO4 and CdCl2 solutions for the MTT assay and Comet assay respectively. The objective of the dissertation is to obtain quantitative information about the environmental transformation of engineered nanomaterials and their mechanism of toxicity. This information is critical for addressing the environmental health and safety risks of engineered nanomaterials to workers, consumers and the environment.

  13. Inhibition of protein kinase C by calphostin C is light-dependent

    SciTech Connect

    Bruns, R.F.; Miller, F.D.; Merriman, R.L.; Howbert, J.J.; Heath, W.F.; Kobayashi, E.; Takahashi, I.; Tamaoki, T.; Nakano, H. )

    1991-04-15

    Calphostin C, a secondary metabolite of the fungus Cladosporium cladosporioides, inhibits protein kinase C by competing at the binding site for diacylglycerol and phorbol esters. Calphostin C is a polycyclic hydrocarbon with strong absorbance in the visible and ultraviolet ranges. In characterizing the activity of this compound, we unexpectedly found that the inhibition of ({sup 3}H)phorbol dibutyrate binding was dependent on exposure to light. Ordinary fluorescent light was sufficient for full activation. The inhibition of protein kinase C activity in cell-free systems and intact cells also required light. Light-dependent cytotoxicity was seen at concentrations about 5-fold higher than those inhibiting protein kinase C.

  14. Degradation of Jatropha curcas phorbol esters derived from Jatropha oil cake and their tumor-promoting activity.

    PubMed

    Nakao, Motoyuki; Hasegawa, Go; Yasuhara, Tadashi; Ishihara, Yoko

    2015-04-01

    Large amount of oil cake is generated during biodiesel production from Jatropha seeds. Although Jatropha oil cake is rich in plant nutrients, presence of toxic phorbol esters restricts the usage of oil cake as a fertilizer. The objective of this study is to evaluate the components and tumor promoting activity of phorbol esters in Jatropha oil cake-supplemented soil and plants grown in the treated soil. Contents and their biological activity of Jatropha phorbol esters in soil and plants were sequentially analyzed by high-performance liquid chromatography (HPLC) and in vitro cell transformation assay, respectively. Disappearance of Jatropha phorbol-ester-specific peaks were followed with HPLC during incubation of Jatropha oil cake with soil for five weeks. Along with the degradation of Jatropha phorbol ester in soil, tumor-promoting activity in the sample was also attenuated and ultimately disappeared. Jatropha phorbol esters and tumor promoting activity were not detected from mustard spinach grown in the Jatropha oil cake-supplemented soil. In addition, the esterase KM109 degrades DHPB (see definition below; Jatropha phorbol ester) and reduced its tumor-promoting activity. From these data, we conclude: (1) components and tumor promoting activity of Jatropha phorbol esters in the oil cake disappeared completely by incubation with soil for five-week, (2) Jatropha phorbol esters did not transfer into plants grown in the Jatropha oil cake-supplemented soil, and (3) DHPB can be degraded by esterase from soil bacterium. These observations are useful for utilization of Jatropha oil cake as a fertilizer. PMID:25066610

  15. Degradation of Jatropha curcas phorbol esters derived from Jatropha oil cake and their tumor-promoting activity.

    PubMed

    Nakao, Motoyuki; Hasegawa, Go; Yasuhara, Tadashi; Ishihara, Yoko

    2015-04-01

    Large amount of oil cake is generated during biodiesel production from Jatropha seeds. Although Jatropha oil cake is rich in plant nutrients, presence of toxic phorbol esters restricts the usage of oil cake as a fertilizer. The objective of this study is to evaluate the components and tumor promoting activity of phorbol esters in Jatropha oil cake-supplemented soil and plants grown in the treated soil. Contents and their biological activity of Jatropha phorbol esters in soil and plants were sequentially analyzed by high-performance liquid chromatography (HPLC) and in vitro cell transformation assay, respectively. Disappearance of Jatropha phorbol-ester-specific peaks were followed with HPLC during incubation of Jatropha oil cake with soil for five weeks. Along with the degradation of Jatropha phorbol ester in soil, tumor-promoting activity in the sample was also attenuated and ultimately disappeared. Jatropha phorbol esters and tumor promoting activity were not detected from mustard spinach grown in the Jatropha oil cake-supplemented soil. In addition, the esterase KM109 degrades DHPB (see definition below; Jatropha phorbol ester) and reduced its tumor-promoting activity. From these data, we conclude: (1) components and tumor promoting activity of Jatropha phorbol esters in the oil cake disappeared completely by incubation with soil for five-week, (2) Jatropha phorbol esters did not transfer into plants grown in the Jatropha oil cake-supplemented soil, and (3) DHPB can be degraded by esterase from soil bacterium. These observations are useful for utilization of Jatropha oil cake as a fertilizer.

  16. Porous substrates filled with nanomaterials

    SciTech Connect

    Worsley, Marcus A.; Baumann, Theodore F.; Satcher, Jr., Joe H.; Stadermann, Michael

    2014-08-19

    A composition comprising: at least one porous carbon monolith, such as a carbon aerogel, comprising internal pores, and at least one nanomaterial, such as carbon nanotubes, disposed uniformly throughout the internal pores. The nanomaterial can be disposed in the middle of the monolith. In addition, a method for making a monolithic solid with both high surface area and good bulk electrical conductivity is provided. A porous substrate having a thickness of 100 microns or more and comprising macropores throughout its thickness is prepared. At least one catalyst is deposited inside the porous substrate. Subsequently, chemical vapor deposition is used to uniformly deposit a nanomaterial in the macropores throughout the thickness of the porous substrate. Applications include electrical energy storage, such as batteries and capacitors, and hydrogen storage.

  17. An activator of protein kinase C (phorbol dibutyrate) attenuates atrial-natriuretic-factor-stimulated cyclic GMP accumulation in smooth-muscle cells.

    PubMed Central

    Nambi, P; Whitman, M; Aiyar, N; Stassen, F; Crooke, S T

    1987-01-01

    Rat thoracic aortic smooth-muscle cells (A-10; A.T.C.C. CRL 1476) displays a high density of vasopressin and atrial-natriuretic-factor (ANF) receptors and a low density of beta-adrenergic receptors. ANF stimulates cGMP (cyclic GMP) accumulation in a time- and dose-dependent fashion. Pretreatment of these cells with phorbol dibutyrate (PDBu), a known activator of protein kinase C, attenuated ANF-stimulated cGMP accumulation without affecting basal cGMP concentrations. This effect was concentration-dependent and was observed as early as 2 min after treatment. 4 alpha-Phorbol 12, 13-didecanoate (alpha PDD), which does not activate protein kinase C, did not inhibit the cGMP accumulation. PDBu pretreatment did not affect the density and affinity of ANF receptors. These data suggest that PDBu, presumably via activation of protein kinase C, might stimulate phosphorylation of a key regulatory protein in the ANF/cGMP pathway. PMID:2822009

  18. Cellular Stress Responses Elicited by Engineered Nanomaterials

    EPA Science Inventory

    Engineered nanomaterials are being incorporated continuously into consumer products, resulting in increased human exposures. The study of engineered nanomaterials has focused largely on oxidative stress and inflammation endpoints without further investigation of underlying pathwa...

  19. Engineered Nanomaterials Elicit Cellular Stress Responses

    EPA Science Inventory

    Engineered nanomaterials are being developed continuously and incorporated into consumer products, resulting in increased human exposures. The study of engineered nanomaterials has focused largely on toxicity endpoints without further investigating potential mechanisms or pathway...

  20. NANOMATERIALS, NANOTECHNOLOGY: APPLICATIONS, CONSUMER PRODUCTS, AND BENEFITS

    EPA Science Inventory

    Nanotechnology is a platform technology that is finding more and more applications daily. Today over 600 consumer products are available globally that utilize nanomaterials. This chapter explores the use of nanomaterials and nanotechnology in three areas, namely Medicine, Environ...

  1. Sphingosine and phorbol ester preferentially stimulate phosphatidylethanolamine hydrolysis

    SciTech Connect

    Kiss, Z.; Chattopadhyay, J. )

    1991-03-11

    It is generally accepted that agonist-stimulated phosphoinositide-specific phospholipase C and phosphatidyl-choline (PrdCho)-specific phospholipase D are the major systems to produce the lipid messengers phosphatidic acid (PtdOH) and 1,2-diacylglycerol (DAG). Here the authors show that simultaneous treatment of ({sup 14}C)palmitate-prelabeled NIH 3T3 fibroblasts with two synergistically acting mitogens, sphingosine and 12-O-tetradecanoylphorbol 13-acetate (TPA), resulted in about a two-fold increase in the cellular level of PtdOH, and that both sphingosine, and to a lesser extent, TPA preferentially stimulated phosphatidyl-ethanolamine (PtdEtn) hydrolysis. This latter point was demonstrated by using NIG 3T3 cells prelabeled with {sup 14}C-labeled bases, {sup 32}P-labeled phospholipids or ({sup 14}C)palmitate. Treatment of ({sup 14}C)palmitate-prelabeled cells with TPA alone did not result in significant accumulation of PtdOH, due to rapid metabolism of this phospholipid. On the other hand, sphingosine inhibited the rapid metabolism of the PtdOH pool, formed through the action of phospholipase D, by inhibiting PtdCho synthesis. Since PtdOH is a potent mitogen in these cells, it is possible that these effects of sphingosine on PtdOH metabolism are related to its recently reported co-mitogenic effects.

  2. Energetics of Nanomaterials

    SciTech Connect

    Hellman, Frances

    2004-12-13

    This project, ''Energetics of Nanomaterials'', represents a three-year collaboration among Alexandra Navrotsky (University of California at Davis), Brian Woodfield and Juliana Boerio-Goates (Brigham Young University) and Frances Hellman (University of California at San Diego). Its purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in terms of their thermodynamic properties, with an emphasis on heat capacities and entropies, as well as enthalpies. We used our combined experimental techniques to address the following questions: How does energy and entropy depend on particle size and crystal structure? Do entropic differences have their origins in changes in vibrational densities of states or configurational (including surface configuration) effects? Do material preparation and sample geometry, i.e., nanoparticles versus thin films, change these quantities? How do the thermodynamics of magnetic and structural transitions change in nanoparticles and thin films? Are different crystal structures stabilized for a given composition at the nanoscale, and are the responsible factors energetic, entropic, or both? How do adsorption energies (for water and other gases) depend on particle size and crystal structure in the nanoregime? What are the energetics of formation and strain energies in artificially layered thin films? Do the differing structures of grain boundaries in films and nanocomposites alter the energetics of nanoscale materials? Of the several directions we first proposed, we initially concentrated on a few systems: TiO(sub 2), CoO, and CoO-MgO. In these systems, we were able to clearly identify particle size-dependent effects on energy and vibrational entropy, and to separate out the effect of particle size and water content on the enthalpy of formation of the various TiO(sub 2) polymorphs. With CoO, we were able to directly compare nanoparticle films and bulk materials; this comparison is important because films can

  3. Phorbol 12-myristate 13-acetate prevents isoproterenol-induced morphological change in cultured vascular smooth muscle cells

    SciTech Connect

    Nabika, Toru; Chaldakov, G.N.; Nara, Yasuo; Endo, Jiro; Yamori, Yukio )

    1988-10-01

    The effect of phorbol 12-myristate 13-acetate (PMA) on isoproterenol (ISO)- and dibutyryl cAMP (dBcAMP)-induced morphological change and cytoskeletal reorganization was studied in cultured vascular smooth muscle cells (VSMC) using the fluorescence staining of actin and microtubules. The treatment of VSMC with 1.0 {mu}M of ISO or with 1.0 mM of dBcAMP for 90 min induced the disruption of actin-containing stress fibers followed by cytoplasmic arborization. The addition of 100 nM of PMA prevented both the destruction of actin fibers and cell arborization induced either by ISO or by dBcAMP. These results indicated that the inhibition of arborization by PMA was mediated through the activation of protein kinase C. Colchicine at 5.0 {mu}M also had an inhibitory effect on ISO- and dBcAMP-induced cell arborization. However, immunofluorescence studies revealed that colchicine but not PMA elicited the reorganization of microtubules, suggesting that the effect of PMA was mediated through a mechanism different from that of colchicine. The observations indicated that the morphology of VSMC was regulated through the alteration of cytoskeletal organization induced by cAMP-mediated and by protein kinase C-dependent systems.

  4. Acute effects of Fe₂O₃, TiO₂, ZnO and CuO nanomaterials on Xenopus laevis.

    PubMed

    Nations, Shawna; Wages, Mike; Cañas, Jaclyn E; Maul, Jonathan; Theodorakis, Chris; Cobb, George P

    2011-05-01

    Metal oxide nanomaterials have exhibited toxicity to a variety of aquatic organisms, especially microbes and invertebrates. To date, few studies have evaluated the toxicity of metal oxide nanomaterials on aquatic vertebrates. Therefore, this study examined effects of ZnO, TiO(2), Fe(2)O(3), and CuO nanomaterials (20-100 nm) on amphibians utilizing the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol, a 96 h exposure with daily solution exchanges. Nanomaterials were dispersed in reconstituted moderately hard test medium. These exposures did not increase mortality in static renewal exposures containing up to 1,000 mg L(-1) for TiO(2), Fe(2)O(3), CuO, and ZnO, but did induce developmental abnormalities. Gastrointestinal, spinal, and other abnormalities were observed in CuO and ZnO nanomaterial exposures at concentrations as low as 3.16 mg L(-1) (ZnO). An EC(50) of 10.3 mg L(-1) ZnO was observed for total malformations. The minimum concentration to inhibit growth of tadpoles exposed to CuO or ZnO nanomaterials was 10 mg L(-1). The results indicate that select nanomaterials can negatively affect amphibians during development. Evaluation of nanomaterial exposure on vertebrate organisms are imperative to responsible production and introduction of nanomaterials in everyday products to ensure human and environmental safety. PMID:21345480

  5. Novel type of phorbol ester-dependent protein phosphorylation in the particulate fraction of mouse epidermis

    SciTech Connect

    Gschwendt, M.; Kittstein, W.; Marks, F.

    1986-06-13

    In a Triton X100-extract from the particulate fraction of mouse epidermis but also of other murine tissues, the phosphorylation of a protein with the relative molecular mass of 82,000 (p82) is found to be dependent on phosphatidyl serine and the tumor promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). Unlike protein kinase C-catalyzed phosphorylation, p82 phosphorylation is neither observed in the presence of high concentrations of Ca/sup 2 +/ and phosphatidyl serine alone nor after addition of exogenous protein kinase C. Dioctanoylglycerol and the incomplete promoter 12-O-retinoylphorbol-13-acetate are also capable of stimulating p82 phosphorylation, whereas the non-promoting phorbol ester 4-O-methyl-TPA is at least 100-fold less active in this respect.

  6. Cellulose nanomaterials in water treatment technologies.

    PubMed

    Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

    2015-05-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

  7. Engineering Nanomaterial Surfaces for Biomedical Applications

    PubMed Central

    Wang, Xin; Liu, Li-Hong; Ramström, Olof; Yan, Mingdi

    2014-01-01

    Nanomaterials, possessing unique physical and chemical properties, have attracted much interest and generated wide varieties of applications. Recent investigations of functionalized nanomaterials have expanded into the biological area, providing a versatile platform in biomedical applications such as biomolecular sensing, biological imaging, drug delivery and disease therapy. Bio-functions and bio-compatibility of nanomaterials are realized by introducing synthetic ligands or natural biomolecules onto nanomaterials, and combining ligand-receptor biological interactions with intrinsic nanomaterial properties. Common strategies of engineering nanomaterial surfaces involve physisorption or chemisorption of desired ligands. We developed a photochemically initiated surface coupling chemistry, bringing versatility and simplicity to nanomaterial functionalization. The method was applied to attach underivatized carbohydrates efficiently on gold and iron oxide nanoparticles, and the resulting glyconanoparticles were successfully used as a sensitive biosensing system probing specific interactions between carbohydrates and proteins as well as bacteria. PMID:19596820

  8. Cellulose nanomaterials in water treatment technologies.

    PubMed

    Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

    2015-05-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

  9. Formation of a phorbol ester-binding fragment from protein kinase C by proteolytic digestion

    SciTech Connect

    Hoshijima, M.; Kikuchi, A.; Tanimoto, T.; Kaibuchi, K.; Takai, Y.

    1986-06-01

    When washed human platelets were disrupted by sonication in the presence of ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, both the catalytic and (/sup 3/H)phorbol-12,13-dibutyrate (PDBu)-binding activities of protein kinase C were recovered in the soluble fraction and were not separable from each other upon several column chromatographies. Platelet protein kinase C required diacylglycerol, Ca2+, and phospholipid for its activation and showed a molecular weight of about 87,000 as estimated by gel filtration analysis. However, when platelets were first incubated with 2 microM Ca2+-ionophore A23187 for 5 min at 37 degrees C in the medium containing 3 mM CaCl/sub 2/ and then disrupted under the same conditions, the catalytic and (/sup 3/H)phorbol-12,13-dibutyrate-binding activities were separately recovered in the soluble and particulate fractions, respectively; moreover, the catalytic activity recovered in the soluble fraction became independent of diacylglycerol, Ca2+, and phospholipid, and showed a molecular weight of about 50,000 as estimated by gel filtration analysis. The kinetic properties of this Mr 50,000 enzyme were similar to those of the catalytic fragment of rat brain protein kinase C described previously. In a cell-free system, digestion with trypsin of protein kinase C highly purified from rat brain caused the generation of a fragment which had no catalytic activity but showed full (/sup 3/H)phorbol-12,13-dibutyrate-binding activity. The molecular weight of this fragment was estimated to be about 35,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results indicate that protein kinase C consists of at least two functionally different domains, a hydrophobic phorbol ester- or diacylglycerol-binding and hydrophilic catalytic domains.

  10. Effect of phorbol esters on contractile state and calcium flux in cultured chick heart cells

    SciTech Connect

    Leatherman, G.F.; Kim, D.; Smith, T.W.

    1987-07-01

    Phorbol esters are potent tumor promoters that have been widely used in studies of transmembrane signaling because of their ability to activate protein kinase C. To study the effect of phorbol esters (and indirectly, the role of protein kinase C) on the cardiac muscle contractility, the authors examined the effects of phorbol myristate acetate (PMA) on contractile state, transmembrane /sup 45/Ca fluxes, and cytosolic free Ca concentration ((Ca)/sub i/) using spontaneously contracting cultured chick ventricular cells. PMA produced a concentration- and time-dependent decrease in the amplitude of cell motion (half maximum inhibitory concentration) with maximal effect observed at 1 ..mu..M. PMA (1 ..mu..M) reduced /sup 45/Ca uptake rate by 16 /plus minus/ 4% and the size of the rapidly exchangeable Ca pool by 11 /plus minus/ 2%, but did not alter the /sup 45/Ca efflux rate. In fura-2-loaded cells. PMA produced a decrease in (Ca)/sub i/ from 96 /plus minus/ 7 to 72 /plus minus/ 5 nM with a time course similar to that of alteration in contractile amplitude. These results indicate that PMA influences transsarcolemmal Ca uptake, and thus the excitation-contraction process, and suggest that protein kinase C may modulate myocardial Ca homeostassis and contractile state.

  11. Involvement of Ca/sup 2 +//phospholipid-dependent C-kinase in phorbol ester-mediated activation of normal human T cell

    SciTech Connect

    Dirienzo, W.; Nel, A.E.; Lattanze, G.R.; Galbraith, R.M.

    1986-03-01

    C-kinase appears to be involved in biological responses of T cells, and phorbol myristate acetate (PMA) is a direct activator of this enzyme. In this study, reaction of T cells with PMA (0.1-50 ng/ml) showed a dose-dependent increase in /sup 3/H-thymidine incorporation; higher concentrations were toxic. C-kinase assays performed in parallel demonstrated sustained translocation of >99% of C-kinase activity from the cytosol to the detergent-soluble membrane fraction. Experiments were done in the presence of cyclosporine (CSA), and of polymyxin B (PMB) which also inhibits C-kinase. Both PMA and CSA caused profound and dose-dependent reduction in proliferation, with maximal inhibition of >70% and >90% respectively. Moreover, addition of PMB showed coordinate inhibition of C-kinase activity (>80% at 10 ..mu..M), whereas at similar concentrations inhibiting cell proliferation CSA had no detectable effect. These results indicate that PMA initiates activation and proliferation by stimulation of at least two distinct pathways, one of which involves C-kinase activation and is inhibited by PMB.

  12. Tyrosine hydroxylase is activated and phosphorylated at different sites in rat pheochromocytoma PC 12 cells treated with phorbol ester and forskolin

    SciTech Connect

    Tachikawa, E.; Tank, A.W.; Weiner, D.H.; Mosimann, W.F.; Yanagihara, N.; Weiner, N.

    1986-03-01

    The effects of phorbol ester (4..beta..-phorbol, 12..beta..-myristate, 13..cap alpha..-acetate; TPA), an activator of Ca/sup + +//phospholipid-dependent protein kinase (PK-C), and forskolin, which stimulates adenylate cyclase and cyclic AMP-dependent protein kinase (cAMP-PK), on the activation and phosphorylation of tyrosine hydroxylase (TH) in rat pheochromocytoma (PC 12) cells were examined. Incubation of the cells with TPA (0.01-1 ..mu..M) or forskolin (0.01-0.1 ..mu..M) produces increases in activation and phosphorylation of TH in a concentration-dependent manner. The stimulatory effects of TPA are dependent on extracellular Ca/sup + +/ and are inhibited by pretreatment of the cells with trifluoperazine (TFP). The effects of forskolin are independent of Ca/sup + +/ and are not inhibited by TFP. In cells treated with forskolin, the time course of the increase in cAMP correlates with the increases in TH activity and phosphorylation. cAMP levels do not increase in cells treated with TPA. There is an increase in the phosphorylation of only one tryptic phosphopeptide derived from TH in cells treated with either forskolin or TPA. The peptide phosphorylated in TPA-treated cells exhibits different elution characteristics on HPLC from that in forskolin-treated cells. The authors conclude that TH in PC 12 cells is phosphorylated on different sites by cAMP-PK and PK-C. Phosphorylation of either of these sites is associated with enzyme activation.

  13. Enzyme-catalyzed degradation of carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Kotchey, Gregg P.

    Carbon nanotubes and graphene, the nanoscale sp 2 allotropes of carbon, have garnered widespread attention as a result of their remarkable electrical, mechanical, and optical properties and the promise of new technologies that harness these properties. Consequently, these carbon nanomaterials (CNMs) have been employed for diverse applications such as electronics, sensors, composite materials, energy conversion devices, and nanomedicine. The manufacture and eventual disposal of these products may result in the release of CNMs into the environment and subsequent exposure to humans, animals, and vegetation. Given the possible pro-inflammatory and toxic effects of CNMs, much attention has been focused on the distribution, toxicity, and persistence of CNMs both in living systems and the environment. This dissertation will guide the reader though recent studies aimed at elucidating fundamental insight into the persistence of CNMs such as carbon nanotubes (CNTs) and graphene derivatives (i.e., graphene oxide and reduced graphene oxide). In particular, in-testtube oxidation/degradation of CNMs catalyzed by peroxidase enzymes will be examined, and the current understanding of the mechanisms underlying these processes will be discussed. Finally, an outlook of the current field including in vitro and in vivo biodegradation experiments, which have benefits in terms of human health and environmental safety, and future directions that could have implications for nanomedical applications such as imaging and drug delivery will be presented. Armed with an understanding of how and why CNMs undergo enzyme-catalyzed oxidation/biodegradation, researchers can tailor the structure of CNMs to either promote or inhibit these processes. For example, in nanomedical applications such as drug delivery, the incorporation of carboxylate functional groups could facilitate biodegradation of the nanomaterial after delivery of the cargo. Also, the incorporation of CNMs with defect sites in consumer

  14. Nanomaterials-based optical techniques for the detection of acetylcholinesterase and pesticides.

    PubMed

    Xia, Ning; Wang, Qinglong; Liu, Lin

    2015-01-01

    The large amount of pesticide residues in the environment is a threat to global health by inhibition of acetylcholinesterase (AChE). Biosensors for inhibition of AChE have been thus developed for the detection of pesticides. In line with the rapid development of nanotechnology, nanomaterials have attracted great attention and have been intensively studied in biological analysis due to their unique chemical, physical and size properties. The aim of this review is to provide insight into nanomaterial-based optical techniques for the determination of AChE and pesticides, including colorimetric and fluorescent assays and surface plasmon resonance.

  15. Nanomaterials-Based Optical Techniques for the Detection of Acetylcholinesterase and Pesticides

    PubMed Central

    Xia, Ning; Wang, Qinglong; Liu, Lin

    2015-01-01

    The large amount of pesticide residues in the environment is a threat to global health by inhibition of acetylcholinesterase (AChE). Biosensors for inhibition of AChE have been thus developed for the detection of pesticides. In line with the rapid development of nanotechnology, nanomaterials have attracted great attention and have been intensively studied in biological analysis due to their unique chemical, physical and size properties. The aim of this review is to provide insight into nanomaterial-based optical techniques for the determination of AChE and pesticides, including colorimetric and fluorescent assays and surface plasmon resonance. PMID:25558991

  16. Pathophysiologic mechanisms of biomedical nanomaterials.

    PubMed

    Wang, Liming; Chen, Chunying

    2016-05-15

    Nanomaterials (NMs) have been widespread used in biomedical fields, daily consuming, and even food industry. It is crucial to understand the safety and biomedical efficacy of NMs. In this review, we summarized the recent progress about the physiological and pathological effects of NMs from several levels: protein-nano interface, NM-subcellular structures, and cell-cell interaction. We focused on the detailed information of nano-bio interaction, especially about protein adsorption, intracellular trafficking, biological barriers, and signaling pathways as well as the associated mechanism mediated by nanomaterials. We also introduced related analytical methods that are meaningful and helpful for biomedical effect studies in the future. We believe that knowledge about pathophysiologic effects of NMs is not only significant for rational design of medical NMs but also helps predict their safety and further improve their applications in the future.

  17. Final Report: "Energetics of Nanomaterials

    SciTech Connect

    Navrotsky, Alexandra; Ross, Nancy; Woodfield, Brian

    2015-02-14

    Nanomaterials, solids with very small particle size, form the basis of new technologies that are revolutionizing fields such as energy, lighting, electronics, medical diagnostics, and drug delivery. These nanoparticles are different from conventional bulk materials in many ways we do not yet fully understand. This project focused on their structure and thermodynamics and emphasized the role of water in nanoparticle surfaces. Using a unique and synergistic combination of high-tech techniques—namely oxide melt solution calorimetry, cryogenic heat capacity measurements, and inelastic neutron scattering—this work has identified differences in structure, thermodynamic stability, and water behavior on nanoparticles as a function of composition and particle size. The systematics obtained increase the fundamental understanding needed to synthesize, retain, and apply these technologically important nanomaterials and to predict and tailor new materials for enhanced functionality, eventually leading to a more sustainable way of life.

  18. Nanomaterial-Enabled Neural Stimulation.

    PubMed

    Wang, Yongchen; Guo, Liang

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed.

  19. Nanomaterial-Enabled Neural Stimulation

    PubMed Central

    Wang, Yongchen; Guo, Liang

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed. PMID:27013938

  20. Nano-material and method of fabrication

    DOEpatents

    Menchhofer, Paul A; Seals, Roland D; Howe, Jane Y; Wang, Wei

    2015-02-03

    A fluffy nano-material and method of manufacture are described. At 2000.times. magnification the fluffy nanomaterial has the appearance of raw, uncarded wool, with individual fiber lengths ranging from approximately four microns to twenty microns. Powder-based nanocatalysts are dispersed in the fluffy nanomaterial. The production of fluffy nanomaterial typically involves flowing about 125 cc/min of organic vapor at a pressure of about 400 torr over powder-based nano-catalysts for a period of time that may range from approximately thirty minutes to twenty-four hours.

  1. Nitric oxide and nitric oxide-generating agents induce a reversible inactivation of protein kinase C activity and phorbol ester binding.

    PubMed

    Gopalakrishna, R; Chen, Z H; Gundimeda, U

    1993-12-25

    Since S-nitrosylation of protein thiols is one of the cellular regulatory mechanisms induced by nitric oxide (NO), and since protein kinase C (PKC) has critical thiol residues which influence its kinase activity, we have determined whether NO could regulate this enzyme. Initial studies were carried out with purified PKC and the NO-generating agent S-nitrosocysteine. This agent decreased phosphotransferase activity of PKC in a Ca(2+)- and oxygen-dependent manner with an IC50 of 75 microM. Phorbol ester binding was affected partially only at higher concentrations (> 100 microM) of S-nitrosocysteine. This inactivation of PKC was blocked by the NO scavenger oxyhemoglobin or reversed by dithiothreitol. It is likely that NO initially induced an S-nitrosylation of vicinal thiols, which were then oxidized to form an intramolecular disulfide. Other NO-generating agents such as S-nitroso-N-acetylpenicillamine and sodium nitroprusside, as well as authentic NO gas, induced similar types of PKC modifications. In intact B16 melanoma cells treated with S-nitrosocysteine a rapid decrease in PKC activity in both cytosol and membrane was observed. Unlike in experiments with purified PKC, in intact cells treated with S-nitrosocysteine the phorbol ester binding also decreased to a rate equal to that of PKC activity. These modifications were readily reversed by treating the homogenates with dithiothreitol in test tubes or by removing the NO-generating source from intact cells. To determine whether the limited amounts of NO generated within the intact cells could induce this type of PKC modification, the macrophage cell line IC-21 was treated with lipopolysacharide and Ca2+ ionophore A23187 to induce the NO production. With an increase in generation of NO (3-12-h period) in these cells, a parallel and irreversible decrease in PKC activity and phorbol ester binding was observed. A specific inhibitor for NO synthase, NG-monomethyl-L-arginine, inhibited both the production of NO and PKC

  2. Nanometallomics: an emerging field studying the biological effects of metal-related nanomaterials.

    PubMed

    Li, Yu-Feng; Gao, Yuxi; Chai, Zhifang; Chen, Chunying

    2014-02-01

    Metallomics, focusing on the global and systematic understanding of the metal uptake, trafficking, role and excretion in biological systems, has attracted more and more attention. Metal-related nanomaterials, including metallic and metal-containing nanomaterials, have unique properties compared to their micro-scaled counterparts and therefore require special attention. The small size effect, surface effect, and quantum size effect directly influence the physicochemical properties of nanostructured materials and their fate and behavior in biota. However, to our knowledge, the metallomics itself did not touch this special category of materials yet. Therefore, the term "nanometallomics" is proposed and the systematic study on the absorption, distribution, metabolism, excretion (ADME) behavior of metal-related nanomaterials in biological systems and their interactions with genes, proteins and other biomolecules will be reviewed. The ADME behavior of metal-related nanomaterials in the biological systems is influenced by their physicochemical properties, the exposure route, and the microenvironment of the deposition site. Nanomaterials may not only interact directly or indirectly with genes, proteins and other molecules to cause DNA damage, genotoxicity, immunotoxicity, and cytotoxicity, but also stimulate the immune responses, circumvent tumor resistance and inhibit tumor metastasis. Nanometallomics needs to be integrated with other omics sciences, such as genomics, proteomics and metabolomics, to explore the biomedical data and obtain the overall knowledge of underlying mechanisms, and therefore to improve the application performance and to reduce the potential risk of metal-related nanomaterials.

  3. Screening for toxic phorbol esters in jerky pet treat products using LC-MS.

    PubMed

    Nishshanka, Upul; Jayasuriya, Hiranthi; Chattopadhaya, Chaitali; Kijak, Philip J; Chu, Pak-Sin; Reimschuessel, Renate; Tkachenko, Andriy; Ceric, Olgica; De Alwis, Hemakanthi G

    2016-05-01

    Since 2007, the U.S. FDA's Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats. Jerky used in pet treats contains glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Because some biodiesel is produced using oil from Jatropha curcas, a plant that contains toxic compounds including phorbol esters, CVM developed a liquid chromatography-mass spectrometry (LC-MS) screening method to evaluate investigational jerky samples for the presence of these toxins. Results indicated that the samples analyzed with the new method did not contain Jatropha toxins at or above the lowest concentration tested. PMID:27038400

  4. The insulin-like effects of phorbol myristate acetate (PMA) in the isolated fat cell

    SciTech Connect

    Solomon, S.S.; Palazzolo, M. )

    1989-01-01

    Recent data from many laboratories suggest that insulin stimulates diacylglycerol formation. Data presented in this manuscript demonstrate an insulin-like effect of PMA, a tumor promoting agent that mimics the action of diacylglycerol, in isolated adipocytes on; (a) glucose oxidation using uniformly labelled, C-1-labelled and C-6-labelled glucose, (b) epinephrine-induced lipolysis and (c) low Km cAMP phosphodiesterase activity. Additionally, a lipolytic effect of PMA is identified when unopposed by epinephrine. These data not only demonstrate an insulin-like effect of phorbol esters in adipose tissue but they lend support to the concept of diacylglycerol involvement in the mechanism of insulin action.

  5. Evaluation of effects of various drugs on platelet functions using phorbol 12-myristate 13-acetate-induced megakaryocytic human erythroid leukemia cells

    PubMed Central

    Tada, Tomoki; Aki, Kensaku; Oboshi, Wataru; Kawazoe, Kazuyoshi; Yasui, Toshiyuki; Hosoi, Eiji

    2016-01-01

    Background The hyperfunction and activation of platelets have been strongly implicated in the development and recurrence of arterial occlusive disease, and various antiplatelet drugs are used to treat and prevent such diseases. New antiplatelet drugs and many other drugs have been developed, but some drugs may have adverse effects on platelet functions. Objective The aim of this study was to establish an evaluation method for evaluating the effect and adverse effect of various drugs on platelet functions. Materials and methods Human erythroid leukemia (HEL) cells were used after megakaryocytic differentiation with phorbol 12-myristate 13-acetate as an alternative to platelets. Drugs were evaluated by changes in intracellular Ca2+ concentration ([Ca2+]i) mobilization in Fura2-loaded phorbol 12-myristate 13-acetate-induced HEL cells. Aspirin and cilostazol were selected as antiplatelet drugs and ibuprofen and sodium valproate as other drugs. Results There was a positive correlation between [Ca2+]i and platelet aggregation induced by thrombin. Aspirin (5.6–560 µM) and cilostazol (5–10 µM) significantly inhibited thrombin-induced increases in [Ca2+]i in a concentration-dependent manner. On the other hand, ibuprofen (8–200 µM) and sodium valproate (50–1,000 µg/mL) also significantly inhibited thrombin-induced increases in [Ca2+]i in a concentration-dependent manner. Furthermore, the interaction effects of the simultaneous combined use of aspirin and ibuprofen or sodium valproate were evaluated. When the inhibitory effect of aspirin was higher than that of ibuprofen, the effect of aspirin was reduced, whereas when the inhibitory effect of aspirin was lower than that of ibuprofen, the effect of ibuprofen was reduced. The combination of aspirin and sodium valproate synergistically inhibited thrombin-induced [Ca2+]i. Conclusion It is possible to induce HEL cells to differentiate into megakaryocytes, which are a useful model for the study of platelet functions

  6. Multi-metal oxide ceramic nanomaterial

    DOEpatents

    O'Brien, Stephen; Liu, Shuangyi; Huang, Limin

    2016-06-07

    A convenient and versatile method for preparing complex metal oxides is disclosed. The method uses a low temperature, environmentally friendly gel-collection method to form a single phase nanomaterial. In one embodiment, the nanomaterial consists of Ba.sub.AMn.sub.BTi.sub.CO.sub.D in a controlled stoichiometry.

  7. Nanomaterials Toxicity and Cell Death Modalities

    PubMed Central

    De Stefano, Daniela; Carnuccio, Rosa; Maiuri, Maria Chiara

    2012-01-01

    In the last decade, the nanotechnology advancement has developed a plethora of novel and intriguing nanomaterial application in many sectors, including research and medicine. However, many risks have been highlighted in their use, particularly related to their unexpected toxicity in vitro and in vivo experimental models. This paper proposes an overview concerning the cell death modalities induced by the major nanomaterials. PMID:23304518

  8. Self-assembled nanomaterials for photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Yang, Pei-Pei; Zhao, Xiao-Xiao; Wang, Hao

    2016-01-01

    In recent years, extensive endeavors have been paid to construct functional self-assembled nanomaterials for various applications such as catalysis, separation, energy and biomedicines. To date, different strategies have been developed for preparing nanomaterials with diversified structures and functionalities via fine tuning of self-assembled building blocks. In terms of biomedical applications, bioimaging technologies are urgently calling for high-efficient probes/contrast agents for high-performance bioimaging. Photoacoustic (PA) imaging is an emerging whole-body imaging modality offering high spatial resolution, deep penetration and high contrast in vivo. The self-assembled nanomaterials show high stability in vivo, specific tolerance to sterilization and prolonged half-life stability and desirable targeting properties, which is a kind of promising PA contrast agents for biomedical imaging. Herein, we focus on summarizing recent advances in smart self-assembled nanomaterials with NIR absorption as PA contrast agents for biomedical imaging. According to the preparation strategy of the contrast agents, the self-assembled nanomaterials are categorized into two groups, i.e., the ex situ and in situ self-assembled nanomaterials. The driving forces, assembly modes and regulation of PA properties of self-assembled nanomaterials and their applications for long-term imaging, enzyme activity detection and aggregation-induced retention (AIR) effect for diagnosis and therapy are emphasized. Finally, we conclude with an outlook towards future developments of self-assembled nanomaterials for PA imaging.

  9. Nanomaterial Toxicity Screening in Developing Zebrafish Embryos

    EPA Science Inventory

    To assess nanomaterial vertebrate toxicity, a high-content screening assay was created using developing zebrafish, Danio rerio. This included a diverse group of nanomaterials (n=42 total) ranging from metallic (Ag, Au) and metal oxide (CeO2, CuO, TiO2, ZnO) nanoparticles, to non...

  10. Cellulose Nanomaterials in Water Treatment Technologies

    PubMed Central

    Carpenter, Alexis Wells; de Lannoy, Charles François; Wiesner, Mark R.

    2015-01-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials’ potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials’ beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

  11. Nanomaterial Based Sensors for NASA Missions

    NASA Technical Reports Server (NTRS)

    Koehne, Jessica E.

    2016-01-01

    Nanomaterials such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene and metal nanowires have shown interesting electronic properties and therefore have been pursued for a variety of space applications requiring ultrasensitive and light-weight sensor and electronic devices. We have been pursuing development of chemical and biosensors using carbon nanotubes and carbon nanofibers for the last several years and this talk will present the benefits of nanomaterials these applications. More recently, printing approaches to manufacturing these devices have been explored as a strategy that is compatible to a microgravity environment. Nanomaterials are either grown in house or purchased and processed as electrical inks. Chemical modification or coatings are added to the nanomaterials to tailor the nanomaterial to the exact application. The development of printed chemical sensors and biosensors will be discussed for applications ranging from crew life support to exploration missions.

  12. Nanochemistry and nanomaterials for photovoltaics.

    PubMed

    Chen, Guanying; Seo, Jangwon; Yang, Chunhui; Prasad, Paras N

    2013-11-01

    Nanochemistry and nanomaterials provide numerous opportunities for a new generation of photovoltaics with high solar energy conversion efficiencies at low fabrication cost. Quantum-confined nanomaterials and polymer-inorganic nanocomposites can be tailored to harvest sun light over a broad range of the spectrum, while plasmonic structures offer effective ways to reduce the thickness of light-absorbing layers. Multiple exciton generation, singlet exciton fission, photon down-conversion, and photon up-conversion realized in nanostructures, create significant interest for harvesting underutilized ultraviolet and currently unutilized infrared photons. Nanochemical interface engineering of nanoparticle surfaces and junction-interfaces enable enhanced charge separation and collection. In this review, we survey these recent advances employed to introduce new concepts for improving the solar energy conversion efficiency, and reduce the device fabrication cost in photovoltaic technologies. The review concludes with a summary of contributions already made by nanochemistry. It then describes the challenges and opportunities in photovoltaics where the chemical community can play a vital role.

  13. [Pulmonary toxicity of manufactured nanomaterials].

    PubMed

    Morimoto, Yasuo

    2012-05-01

    We introduced the report on the pulmonary toxicity of manufactured nanomaterials as a national project in Japan conducted by the New Energy and Industrial Technology Development Organization (NEDO project). Well-characterized and well-dispersed industrial nanomaterials were used in this project. Using multiwall carbon nanotubes (MWCNTs), we conducted intratracheal instillation and inhalation studies. At a low dose (0.2 mg/rat) and a high dose (1 mg/rat) of almost individual MWCNTs, transient and persistent inflammatory responses were induced in the lungs following intratracheal instillation. Well-dispersed MWCNTs at a low concentration (0.37 mg/m3) did not induce pulmonary inflammation. Using single-wall carbon nanotubes (SWCNTs), we also conducted both studies. At low (0.2 mg/rat) and high doses (0.4 mg/rat) of well-dispersed SWCNTs, persistent inflammatory responses were induced in the lungs following intratracheal instillation. Well-dispersed MWCNTs at low and high concentrations (0.03 mg/m3 and 0.13 mg/m3, respectively) did not induce pulmonary inflammation. On the basis of these data from mainly inhalation studies, the acceptable exposure concentration of carbon nanotubes is proposed to be 0.03 mg/m3 in Japan.

  14. Tumor-promoting phorbol ester stimulates tyrosine phosphorylation in U-937 monocytes.

    PubMed Central

    Grunberger, G; Zick, Y; Taylor, S I; Gorden, P

    1984-01-01

    Solubilized lectin-purified extracts from human monocyte-like cells (U-937) and freshly isolated human mononuclear cells preincubated in the presence of phorbol 12-myristate 13-acetate (PMA) stimulated phosphorylation of synthetic tyrosine-containing polymers and of casein. Tyrosine phosphorylation was confirmed by phospho amino acid analysis. PMA stimulated phosphorylation of exogenous substrates in a time- and concentration-dependent manner. This phosphorylation reaction did not require addition of phospholipid, diolein, or calcium. Biologically inactive phorbol compounds did not stimulate phosphorylation in this system. In addition, PMA enhanced phosphorylation of a Mr approximately equal to 140,000 protein as well as several other endogenous proteins in the U-937 extracts. PMA treatment stimulated predominantly phosphorylation on tyrosine residues of the Mr 140,000 protein. Tyrosine phosphorylation, typical of growth-promoting peptides such as insulin or epidermal growth factor, is believed to play a role in regulating normal and disordered cellular growth and proliferation. The demonstration of PMA-stimulated tyrosine phosphorylation might provide a clue to the mechanism of cellular differentiation and proliferation induced by the tumor promoter. Images PMID:6201862

  15. Oncogene transcription in normal human IMR-90 fibroblasts: induction by serum and tetradecanoyl phorbol acetate

    SciTech Connect

    Bower, E.A.; Kaji, H.

    1988-01-01

    The authors report studies of oncogene transcription induced by the addition of serum to quiescent cultures of human IMR-90 fibroblasts. Oncogene messenger RNAs for c-myc, c-erbB and c-ras were increased in a specific temporal sequence after the addition of serum. Compounds that are proposed to exert their actions by the stimulation of cell growth were tested for their effect on oncogene transcription in IMR-90 fibroblasts. The tumor promoter tetradecanoyl phorbol acetate (TPA) was found to selectively induce the transcription of c-myc without observable effect on the transcription of the other oncogenes studied, and without inducing cell division. The inactive analog, phorbol didecanoate (PDD), and two complete carcinogens dimethylbenzanthracene (DMBA) and 4-nitro quinoline-1-oxide (4NQO) were without effect on the transcription of the genes studied. These results suggest that the complete ordered sequence of gene transcription is necessary to achieve the physiologic response of cell division, and that classical promoters and complete carcinogens achieve their effects through different pathways.

  16. An AP-2 element acts synergistically with the cyclic AMP- and Phorbol ester-inducible enhancer of the human proenkephalin gene

    SciTech Connect

    Hyman, S.E.; Comb, M.; Pearlberg, J.; Goodman, H.M.

    1989-01-01

    An enhancer with two DNA elements, one containing the sequence CGTCA, is required for cyclic AMP-and phorbol ester-inducible transcription of the human proenkephalin gene. The authors report that an AP-2 element located adjacent to the enhancer acts synergistically with it to confer maximal response to cyclic AMP and phorbol esters.

  17. Nanomaterials for Engineering Stem Cell Responses.

    PubMed

    Kerativitayanan, Punyavee; Carrow, James K; Gaharwar, Akhilesh K

    2015-08-01

    Recent progress in nanotechnology has stimulated the development of multifunctional biomaterials for tissue engineering applications. Synergistic interactions between nanomaterials and stem cell engineering offer numerous possibilities to address some of the daunting challenges in regenerative medicine, such as controlling trigger differentiation, immune reactions, limited supply of stem cells, and engineering complex tissue structures. Specifically, the interactions between stem cells and their microenvironment play key roles in controlling stem cell fate, which underlines therapeutic success. However, the interactions between nanomaterials and stem cells are not well understood, and the effects of the nanomaterials shape, surface morphology, and chemical functionality on cellular processes need critical evaluation. In this Review, focus is put on recent development in nanomaterial-stem cell interactions, with specific emphasis on their application in regenerative medicine. Further, the emerging technologies based on nanomaterials developed over the past decade for stem cell engineering are reviewed, as well as the potential applications of these nanomaterials in tissue regeneration, stem cell isolation, and drug/gene delivery. It is anticipated that the enhanced understanding of nanomaterial-stem cell interactions will facilitate improved biomaterial design for a range of biomedical and biotechnological applications.

  18. Phorbol esters from Jatropha meal triggered apoptosis, activated PKC-δ, caspase-3 proteins and down-regulated the proto-oncogenes in MCF-7 and HeLa cancer cell lines.

    PubMed

    Oskoueian, Ehsan; Abdullah, Norhani; Ahmad, Syahida

    2012-09-10

    Jatropha meal produced from the kernel of Jatropha curcas Linn. grown in Malaysia contains phorbol esters (PEs). The potential benefits of PEs present in the meal as anticancer agent are still not well understood. Hence, this study was conducted to evaluate the cytotoxic effects and mode of actions of PEs isolated from Jatropha meal against breast (MCF-7) and cervical (HeLa) cancer cell lines. Isolated PEs inhibited cells proliferation in a dose-dependent manner of both MCF-7 and HeLa cell lines with the IC₅₀ of 128.6 ± 2.51 and 133.0 ± 1.96 µg PMA equivalents/mL respectively, while the values for the phorbol 12-myristate 13-acetate (PMA) as positive control were 114.7 ± 1.73 and 119.6 ± 3.73 µg/mL, respectively. Microscopic examination showed significant morphological changes that resemble apoptosis in both cell lines when treated with PEs and PMA at IC₅₀ concentration after 24 h. Flow cytometry analysis and DNA fragmentation results confirmed the apoptosis induction of PEs and PMA in both cell lines. The PEs isolated from Jatropha meal activated the PKC-δ and down-regulated the proto-oncogenes (c-Myc, c-Fos and c-Jun). These changes probably led to the activation of Caspase-3 protein and apoptosis cell death occurred in MCF-7 and HeLa cell lines upon 24 h treatment with PEs and PMA. Phorbol esters of Jatropha meal were found to be promising as an alternative to replace the chemotherapeutic drugs for cancer therapy.

  19. Nanomaterials for Electronics and Optoelectronics

    NASA Technical Reports Server (NTRS)

    Koehne, Jessica E.; Meyyappan, M.

    2011-01-01

    Nanomaterials such as carbon nanotubes(CNTs), graphene, and inorganic nanowires(INWs) have shown interesting electronic, mechanical, optical, thermal, and other properties and therefore have been pursued for a variety of applications by the nanotechnology community ranging from electronics to nanocomposites. While the first two are carbon-based materials, the INWs in the literature include silicon, germanium, III-V, II-VI, a variety of oxides, nitrides, antimonides and others. In this talk, first an overview of growth of these three classes of materials by CVD and PECVD will be presented along with results from characterization. Then applications in development of chemical sensors, biosensors, energy storage devices and novel memory architectures will be discussed.

  20. Nanomaterial-based cocaine aptasensors.

    PubMed

    Mokhtarzadeh, Ahad; Dolatabadi, Jafar Ezzati Nazhad; Abnous, Khalil; de la Guardia, Miguel; Ramezani, Mohammad

    2015-06-15

    Up to now, many different methods have been developed for detection of cocaine, but most of these methods are usually time-consuming, tedious and require special or expensive equipment. Therefore, the development of simple, sensitive and rapid detection methods is necessary. In the last decade, aptamers have been used as a new biosensor platform for detection of cocaine in different samples. Aptamers are artificial single-stranded DNA or RNA oligonucleotides capable of binding to specific molecular targets with high affinity and if integrated to nanomaterials, it may lead in precise methods for cocaine detection in the common laboratories. In this review, recent advances and applications of aptamer-based biosensors and nanobiosensors, have been updated, paying attention to the use of fluorescence, colorimetric and electrochemical techniques for the detection and quantitative determination of cocaine.

  1. Assembly of ordered carbon shells on semiconducting nanomaterials

    DOEpatents

    Sutter, Eli Anguelova; Sutter, Peter Werner

    2012-10-02

    In some embodiments of the invention, encapsulated semiconducting nanomaterials are described. In certain embodiments the nanostructures described are semiconducting nanomaterials encapsulated with ordered carbon shells. In some aspects a method for producing encapsulated semiconducting nanomaterials is disclosed. In some embodiments applications of encapsulated semiconducting nanomaterials are described.

  2. Assembly of ordered carbon shells on semiconducting nanomaterials

    DOEpatents

    Sutter, Eli Anguelova; Sutter, Peter Werner

    2010-05-11

    In some embodiments of the invention, encapsulated semiconducting nanomaterials are described. In certain embodiments the nanostructures described are semiconducting nanomaterials encapsulated with ordered carbon shells. In some aspects a method for producing encapsulated semiconducting nanomaterials is disclosed. In some embodiments applications of encapsulated semiconducting nanomaterials are described.

  3. Green chemistry of carbon nanomaterials.

    PubMed

    Basiuk, Elena V; Basiuk, Vladimir A

    2014-01-01

    The global trend of looking for more ecologically friendly, "green" techniques manifested itself in the chemistry of carbon nanomaterials. The main principles of green chemistry emphasize how important it is to avoid the use, or at least to reduce the consumption, of organic solvents for a chemical process. And it is precisely this aspect that was systematically addressed and emphasized by our research group since the very beginning of our work on the chemistry of carbon nanomaterials in early 2000s. The present review focuses on the results obtained to date on solvent-free techniques for (mainly covalent) functionalization of fullerene C60, single-walled and multi-walled carbon nanotubes (SWNTs and MWNTs, respectively), as well as nanodiamonds (NDs). We designed a series of simple and fast functionalization protocols based on thermally activated reactions with chemical compounds stable and volatile at 150-200 degrees C under reduced pressure, when not only the reactions take place at a high rate, but also excess reagents are spontaneously removed from the functionalized material, thus making its purification unnecessary. The main two classes of reagents are organic amines and thiols, including bifunctional ones, which can be used in conjunction with different forms of nanocarbons. The resulting chemical processes comprise nucleophilic addition of amines and thiols to fullerene C60 and to defect sites of pristine MWNTs, as well as direct amidation of carboxylic groups of oxidized nanotubes (mainly SWNTs) and ND. In the case of bifunctional amines and thiols, reactions of the second functional group can give rise to cross-linking effects, or be employed for further derivatization steps. PMID:24730288

  4. Green chemistry of carbon nanomaterials.

    PubMed

    Basiuk, Elena V; Basiuk, Vladimir A

    2014-01-01

    The global trend of looking for more ecologically friendly, "green" techniques manifested itself in the chemistry of carbon nanomaterials. The main principles of green chemistry emphasize how important it is to avoid the use, or at least to reduce the consumption, of organic solvents for a chemical process. And it is precisely this aspect that was systematically addressed and emphasized by our research group since the very beginning of our work on the chemistry of carbon nanomaterials in early 2000s. The present review focuses on the results obtained to date on solvent-free techniques for (mainly covalent) functionalization of fullerene C60, single-walled and multi-walled carbon nanotubes (SWNTs and MWNTs, respectively), as well as nanodiamonds (NDs). We designed a series of simple and fast functionalization protocols based on thermally activated reactions with chemical compounds stable and volatile at 150-200 degrees C under reduced pressure, when not only the reactions take place at a high rate, but also excess reagents are spontaneously removed from the functionalized material, thus making its purification unnecessary. The main two classes of reagents are organic amines and thiols, including bifunctional ones, which can be used in conjunction with different forms of nanocarbons. The resulting chemical processes comprise nucleophilic addition of amines and thiols to fullerene C60 and to defect sites of pristine MWNTs, as well as direct amidation of carboxylic groups of oxidized nanotubes (mainly SWNTs) and ND. In the case of bifunctional amines and thiols, reactions of the second functional group can give rise to cross-linking effects, or be employed for further derivatization steps.

  5. Aptamer-conjugated nanomaterials and their applications.

    PubMed

    Yang, Liu; Zhang, Xiaobing; Ye, Mao; Jiang, Jianhui; Yang, Ronghua; Fu, Ting; Chen, Yan; Wang, Kemin; Liu, Chen; Tan, Weihong

    2011-11-01

    The combination of aptamers with novel nanomaterials, including nanomaterial-based aptamer bioconjugates has attracted considerable interest and has led to a wide variety of applications. In this review, we discuss how a variety of nanomaterials, including gold, silica and magnetic nanoparticles, as well as carbon nanotubes, hydrogels, liposomes and micelles, have been used to functionalize aptamers for a variety of applications. These aptamer functionalized materials have led to advances in amplified biosensing, cancer cell-specific recognition, high-efficiency separation, and targeted drug delivery. PMID:22016112

  6. Reproductive toxicity of carbon nanomaterials: a review

    NASA Astrophysics Data System (ADS)

    Vasyukova, I.; Gusev, A.; Tkachev, A.

    2015-11-01

    In the current review, we assembled the experimental evidences of an association between carbon nanomaterials including carbon black, graphite nanoplatelets, graphene, single- and multi-walled carbon nanotubes, and fullerene exposure and adverse reproductive and developmental effects, in vitro and in vivo studies. It is shown that carbon nanomaterials reveal toxic effect on reproductive system and offspring development of the animals of various system groups to a certain degree depending on carbon crystal structure. Although this paper provides initial information about the potential male and female reproductive toxicity of carbon nanomaterials, further studies, using characterized nanoparticles, relevant routes of administration, and doses closely reflecting all the expected levels of exposure are needed.

  7. Aptamer-conjugated nanomaterials and their applications

    PubMed Central

    Yang, Liu; Ye, Mao; Yang, Ronghua; Fu, Ting; Chen, Yan; Wang, Kemin

    2011-01-01

    The combination of aptamers with novel nanomaterials, including nanomaterial-based aptamer bioconjugates. has attracted considerable interest and has led to a wide variety of applications. In this review, we discuss how a variety of nanomaterials, including gold, silica and magnetic nanoparticles, as well as carbon nanotubes, hydrogels, liposomes and micelles, have been used to functionalize aptamers for a variety of applications. These aptamer functionalized materials have led to advances in amplified biosensing, cancer cell-specific recognition, high-efficiency separation, and targeted drug delivery. PMID:22016112

  8. Graphene-based nanomaterials and their electrochemistry.

    PubMed

    Pumera, Martin

    2010-11-01

    Graphene-based nanomaterials are in the forefront of chemical research. This tutorial review provides an introduction to their electrochemistry, its fundamentals and applications. Selected examples of applications in energy storage and sensing are presented. The synthetic methods for preparing graphenes as well as their materials chemistry are thoroughly discussed, as they have a profound influence on the electronic and electrochemical behavior of graphene-related nanomaterials. Inherent electrochemistry and spectroelectrochemistry of graphene nanomaterials is discussed thoroughly. Important application in sensing and energy storage areas are highlighted.

  9. Accelerating the Translation of Nanomaterials in Biomedicine.

    PubMed

    Mitragotri, Samir; Anderson, Daniel G; Chen, Xiaoyuan; Chow, Edward K; Ho, Dean; Kabanov, Alexander V; Karp, Jeffrey M; Kataoka, Kazunori; Mirkin, Chad A; Petrosko, Sarah Hurst; Shi, Jinjun; Stevens, Molly M; Sun, Shouheng; Teoh, Sweehin; Venkatraman, Subbu S; Xia, Younan; Wang, Shutao; Gu, Zhen; Xu, Chenjie

    2015-07-28

    Due to their size and tailorable physicochemical properties, nanomaterials are an emerging class of structures utilized in biomedical applications. There are now many prominent examples of nanomaterials being used to improve human health, in areas ranging from imaging and diagnostics to therapeutics and regenerative medicine. An overview of these examples reveals several common areas of synergy and future challenges. This Nano Focus discusses the current status and future potential of promising nanomaterials and their translation from the laboratory to the clinic, by highlighting a handful of successful examples.

  10. Toxicology and cellular effect of manufactured nanomaterials

    DOEpatents

    Chen, Fanqing

    2014-07-22

    The increasing use of nanotechnology in consumer products and medical applications underlies the importance of understanding its potential toxic effects to people and the environment. Herein are described methods and assays to predict and evaluate the cellular effects of nanomaterial exposure. Exposing cells to nanomaterials at cytotoxic doses induces cell cycle arrest and increases apoptosis/necrosis, activates genes involved in cellular transport, metabolism, cell cycle regulation, and stress response. Certain nanomaterials induce genes indicative of a strong immune and inflammatory response within skin fibroblasts. Furthermore, the described multiwall carbon nanoonions (MWCNOs) can be used as a therapeutic in the treatment of cancer due to its cytotoxicity.

  11. A requirement for extracellular signal-regulated kinase (ERK) function in the activation of AP-1 by Ha-Ras, phorbol 12-myristate 13-acetate, and serum.

    PubMed Central

    Frost, J A; Geppert, T D; Cobb, M H; Feramisco, J R

    1994-01-01

    The role of ERK-1 and ERK-2 in wild-type (wt) Ha-Ras, phorbol 12-myristate 13-acetate (PMA), and serum-induced AP-1 activity was studied. Microinjection of ERK-specific substrate peptides inhibited the induction of AP-1 activity by all three stimuli, whereas a control peptide had no effect. By using eukaryotic expression constructs encoding wt ERK-1 and kinase-deficient mutants of ERKs 1 and 2, it was found that ERK-1 and ERK-2 activities are required for AP-1 activation stimulated by either wt Ha-Ras, PMA, or serum. Overexpression of ERK-1 augmented wt Ha-Ras stimulation of AP-1, while having no effect upon PMA or serum stimulation. Overexpression of either kinase-deficient ERK-1 or kinase-deficient ERK-2 partially inhibited AP-1 activation by wt Ha-Ras but had no effect on PMA or serum-induced activation. Coexpression of both interfering mutants abolished AP-1 induction by wt Ha-Ras, PMA, or serum. We conclude that ERKs are necessary components in the pathway leading to the activation of AP-1 stimulated by these agents. Images PMID:8170999

  12. Biophysical influence of airborne carbon nanomaterials on natural pulmonary surfactant.

    PubMed

    Valle, Russell P; Wu, Tony; Zuo, Yi Y

    2015-05-26

    Inhalation of nanoparticles (NP), including lightweight airborne carbonaceous nanomaterials (CNM), poses a direct and systemic health threat to those who handle them. Inhaled NP penetrate deep pulmonary structures in which they first interact with the pulmonary surfactant (PS) lining at the alveolar air-water interface. In spite of many research efforts, there is a gap of knowledge between in vitro biophysical study and in vivo inhalation toxicology since all existing biophysical models handle NP-PS interactions in the liquid phase. This technical limitation, inherent in current in vitro methodologies, makes it impossible to simulate how airborne NP deposit at the PS film and interact with it. Existing in vitro NP-PS studies using liquid-suspended particles have been shown to artificially inflate the no-observed adverse effect level of NP exposure when compared to in vivo inhalation studies and international occupational exposure limits (OELs). Here, we developed an in vitro methodology called the constrained drop surfactometer (CDS) to quantitatively study PS inhibition by airborne CNM. We show that airborne multiwalled carbon nanotubes and graphene nanoplatelets induce a concentration-dependent PS inhibition under physiologically relevant conditions. The CNM aerosol concentrations controlled in the CDS are comparable to those defined in international OELs. Development of the CDS has the potential to advance our understanding of how submicron airborne nanomaterials affect the PS lining of the lung.

  13. Effect of phorbol ester on the release of atrial natriuretic peptide from the hypertrophied rat myocardium.

    PubMed Central

    Kinnunen, P.; Taskinen, T.; Järvinen, M.; Ruskoaho, H.

    1991-01-01

    1. To determine the cellular mechanisms of atrial natriuretic peptide (ANP) release from ventricular cardiomyocytes, the secretory and the cardiac effects of a phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), known to stimulate protein kinase C activity in heart cells, were studied in isolated, perfused heart preparations from 2- and 21-month-old Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. TPA was added to the perfusion fluid for 30 min at a concentration of 46 nM after removal of atrial tissue. Additionally, atrial and ventricular levels of immunoreactive ANP (IR-ANP) and ANP mRNA, the distribution of ANP within ventricles as well as the relative contribution of atria and ventricles in the release of ANP were studied. 2. Ventricular hypertrophy that gradually developed in hypertensive rats resulted in remarkable augmentation of ANP gene expression, as reflected by elevated levels of immunoreactive ANP and ANP mRNA. The total amount of IR-ANP in the ventricles of the SHR rats increased 41 fold and ANP mRNA levels 12.9 fold from the age of 2 to 21 months. At the age of 21 months, levels of IR-ANP and ANP mRNA in the ventricles of SHR rats were 5.4 fold and 3.7 fold higher, respectively, than in the normotensive WKY rats. Immunohistochemical studies demonstrated ANP granules within the hypertrophic ventricles of the old SHR rats, but not within normal ventricular tissue. 3. In isolated perfused heart preparations, the severely hypertrophied ventricular tissue of SHR rats after atrialectomy secreted more ANP into the perfusate than did the control hearts.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 2 PMID:1826618

  14. Regulation of osteosarcoma EGF receptor affinity by phorbol ester and cyclic AMP

    SciTech Connect

    Borst, S.E.; Catherwood, B.D. )

    1989-04-01

    We studied the binding and degradation of 125I-labeled epidermal growth factor (EGF) by UMR-106 osteosarcoma cells and the regulation of EGF receptor affinity for EGF by the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and by treatments that raise intracellular levels of cyclic AMP. Cell surface binding of (125I)EGF to A431 cells reached a plateau after a 30 minute incubation at 37 degrees C but was undetectable in UMR-106 cells. Degradation of (125I)EGF proceeded at a 50-fold higher rate in A431 cells on a per cell basis, but receptor-bound (125I)EGF was internalized and degraded at a 3.5-fold higher rate by UMR-106 cells on a per receptor basis. At 4 degrees C, (125I)EGF labeled a single class of surface binding sites in the UMR-106 cell. Treatment with TPA at 37 degrees C reduced subsequent cell surface binding of (125I)EGF at 4 degrees C a maximum of 80% with an IC50 of 1.25 ng/ml. Maximal TPA reduction of (125I)EGF binding was observed within 5-15 minutes and was due to a reduction in the affinity of cell surface receptors of (125I)EGF without a change in receptor density. Pretreatment of the cells for 4 h with 30 microM forskolin, 1 mM isobutylmethylxanthine (IBMX) plus 30 microM forskolin, or 1 mM IBMX plus 100 ng/ml parathyroid hormone (PTH) attenuated the loss in (125I)EGF binding caused by a subsequent dose of 10 ng/ml of TPA by 17% (p less than 0.0005), 39% (p less than 0.0002), and 35% (p less than 0.002), respectively.

  15. Nanomaterials - Acetylcholinesterase Enzyme Matrices for Organophosphorus Pesticides Electrochemical Sensors: A Review

    PubMed Central

    Periasamy, Arun Prakash; Umasankar, Yogeswaran; Chen, Shen-Ming

    2009-01-01

    Acetylcholinesterase (AChE) is an important cholinesterase enzyme present in the synaptic clefts of living organisms. It maintains the levels of the neurotransmitter acetylcholine by catalyzing the hydrolysis reaction of acetylcholine to thiocholine. This catalytic activity of AChE is drastically inhibited by trace amounts of organophosphorus (OP) pesticides present in the environment. As a result, effective monitoring of OP pesticides in the environment is very desirable and has been done successfully in recent years with the use of nanomaterial-based AChE sensors. In such sensors, the enzyme AChE has been immobilized onto nanomaterials like multiwalled carbon nanotubes, gold nanoparticles, zirconia nanoparticles, cadmium sulphide nano particles or quantum dots. These nanomaterial matrices promote significant enhancements of OP pesticide determinations, with the thiocholine oxidation occurring at much lower oxidation potentials. Moreover, nanomaterial-based AChE sensors with rapid response, increased operational and long storage stability are extremely well suited for OP pesticide determination over a wide concentration range. In this review, the unique advantages of using nanomaterials as AChE immobilization matrices are discussed. Further, detection limits, sensitivities and correlation coefficients obtained using various electroanalytical techniques have also been compared with chromatographic techniques. PMID:22408512

  16. Assessing the Environmental Safety of Engineered Nanomaterials

    EPA Science Inventory

    Nanotechnology research in the United States is coordinated under the National Nano-technology Initiative with the goal of fostering development and implementation of nanomaterials and products that incorporate them and assuring that they are environmentally safe. The environmen...

  17. Tissue engineering - nanomaterials in the musculoskeletal system.

    PubMed

    Egli, Rainer J; Luginbuehl, Reto

    2012-01-01

    The musculoskeletal tissues bone, cartilage and ligament/tendon are highly structured nanocomposites consisting of nanofibres embedded in a matrix of different composition. Thus, it was a logical step that during the hype of nano in the last decade, nanotechnology and nanomaterials became a hot topic in the field of musculoskeletal repair. Especially the fact that using nanomaterials would encompass a biomimetic approach, thus copying nature, was promising. However, it became evident that using nanomaterials in the repair of musculoskeletal tissues had a longer history than initially thought and its way was paved with failures, which are important to remember when applying current ideas. This current opinion paper summarises some fundamental aspects of nanomaterials to be used for musculoskeletal application and discusses where this field might move to in the near future.

  18. TOPICAL REVIEW: Carbon nanomaterials in biological systems

    NASA Astrophysics Data System (ADS)

    Ke, Pu Chun; Qiao, Rui

    2007-09-01

    This paper intends to reflect, from the biophysical viewpoint, our current understanding on interfacing nanomaterials, such as carbon nanotubes and fullerenes, with biological systems. Strategies for improving the solubility, and therefore, the bioavailability of nanomaterials in aqueous solutions are summarized. In particular, the underlining mechanisms of attaching biomacromolecules (DNA, RNA, proteins) and lysophospholipids onto carbon nanotubes and gallic acids onto fullerenes are analyzed. The diffusion and the cellular delivery of RNA-coated carbon nanotubes are characterized using fluorescence microscopy. The translocation of fullerenes across cell membranes is simulated using molecular dynamics to offer new insight into the complex issue of nanotoxicity. To assess the fate of nanomaterials in the environment, the biomodification of lipid-coated carbon nanotubes by the aquatic organism Daphnia magna is discussed. The aim of this paper is to illuminate the need for adopting multidisciplinary approaches in the field study of nanomaterials in biological systems and in the environment.

  19. The Neurotoxic Potential of Engineered Nanomaterials

    EPA Science Inventory

    The expanding development and production of engineered nanomaterials (ENMs) have diverse and far-reaching potential benefits in consumer products, food, drugs, medical devices and for enhancing environmental cleanup and remediation. The knowledge of potential implications of ENMs...

  20. Engineered nanomaterials: Exposures, hazards and risk prevention.

    EPA Science Inventory

    Nanotechnology presents the possibility of revolutionizing many aspects of our lives. People in many settings (academic, small and large industrial, and the general public) are either developing or using engineered nanomaterials (ENMs). However, understanding of the health and sa...

  1. Toxicity of Engineered Nanomaterials: A Physicochemical Perspective

    PubMed Central

    Podila, Ramakrishna; Brown, Jared M.

    2013-01-01

    The global market for nanomaterial-based products was forecasted to reach 100 billion dollars per annum for 2011–2015. Extensive manufacturing and the use of engineered nanomaterials (ENM) have raised concerns regarding their impact on biological response in living organisms, and the environment at large. The fundamental properties of nanomaterials exhibit a complex dependence upon several factors such as their morphology, size, defects, chemical stability, etc. Therefore, it is exceedingly difficult to correlate their biological response with their intricate physicochemical properties. For example, varying toxic response may ensue due to different methods of nanomaterial preparation, dissimilar impurities and defects. In this review, we surveyed the existing literature on the dependence of cytotoxicity on physicochemical properties. We found that ENM size, shape, defect density, physicochemical stability and surface modification to be the main causes that elicit altered physiological response or cytotoxicity. PMID:23129019

  2. Techniques for physicochemical characterization of nanomaterials

    PubMed Central

    Lin, Ping-Chang; Lin, Stephen; Wang, Paul C.; Sridhar, Rajagopalan

    2014-01-01

    Advances in nanotechnology have opened up a new era of diagnosis, prevention and treatment of diseases and traumatic injuries. Nanomaterials, including those with potential for clinical applications, possess novel physicochemical properties that have an impact on their physiological interactions, from the molecular level to the systemic level. There is a lack of standardized methodologies or regulatory protocols for detection or characterization of nanomaterials. This review summarizes the techniques that are commonly used to study the size, shape, surface properties, composition, purity and stability of nanomaterials, along with their advantages and disadvantages. At present there are no FDA guidelines that have been developed specifically for nanomaterial based formulations for diagnostic or therapeutic use. There is an urgent need for standardized protocols and procedures for the characterization of nanoparticles, especially those that are intended for use as theranostics. PMID:24252561

  3. Electrochemical nanomaterial-based nucleic acid aptasensors.

    PubMed

    Palchetti, Ilaria; Mascini, Marco

    2012-04-01

    Recent progress in the development of electrochemical nanomaterial-aptamer-based biosensors is summarized. Aptamers are nucleic acid ligands that can be generated against amino acids, drugs, proteins, and other molecules. They are isolated from a large random library of synthetic nucleic acids by an iterative process of binding, separation, and amplification, called systematic evolution of ligands by exponential enrichment (SELEX). In this review, different methods of integrating aptamers with different nanomaterials and nanoparticles for electrochemical biosensing application are described.

  4. Nanomaterial-mediated Biosensors for Monitoring Glucose

    PubMed Central

    Taguchi, Masashige; Ptitsyn, Andre; McLamore, Eric S.

    2014-01-01

    Real-time monitoring of physiological glucose transport is crucial for gaining new understanding of diabetes. Many techniques and equipment currently exist for measuring glucose, but these techniques are limited by complexity of the measurement, requirement of bulky equipment, and low temporal/spatial resolution. The development of various types of biosensors (eg, electrochemical, optical sensors) for laboratory and/or clinical applications will provide new insights into the cause(s) and possible treatments of diabetes. State-of-the-art biosensors are improved by incorporating catalytic nanomaterials such as carbon nanotubes, graphene, electrospun nanofibers, and quantum dots. These nanomaterials greatly enhance biosensor performance, namely sensitivity, response time, and limit of detection. A wide range of new biosensors that incorporate nanomaterials such as lab-on-chip and nanosensor devices are currently being developed for in vivo and in vitro glucose sensing. These real-time monitoring tools represent a powerful diagnostic and monitoring tool for measuring glucose in diabetes research and point of care diagnostics. However, concerns over the possible toxicity of some nanomaterials limit the application of these devices for in vivo sensing. This review provides a general overview of the state of the art in nanomaterial-mediated biosensors for in vivo and in vitro glucose sensing, and discusses some of the challenges associated with nanomaterial toxicity. PMID:24876594

  5. Nanomaterial Induced Immune Responses and Cytotoxicity.

    PubMed

    Ali, Ashraf; Suhail, Mohd; Mathew, Shilu; Shah, Muhammad Ali; Harakeh, Steve M; Ahmad, Sultan; Kazmi, Zulqarnain; Alhamdan, Mohammed Abdul Rahman; Chaudhary, Adeel; Damanhouri, Ghazi Abdullah; Qadri, Ishtiaq

    2016-01-01

    Nanomaterials are utilized in a wide array of end user products such as pharmaceuticals, electronics, clothes and cosmetic products. Due to its size (< 100 nm), nanoparticles have the propensity to enter through the airway and skin, making its path perilous with the potential to cause damages of varying severity. Once within the body, these particles have unconstrained access to different tissues and organs including the brain, liver, and kidney. As a result, nanomaterials may cause the perturbation of the immune system eliciting an inflammatory response and cytotoxicity. This potential role is dependent on many factors such as the characteristics of the nanomaterials, presence or absence of diseases, and genetic predisposition. Cobalt and nickel nanoparticles, for example, were shown to have inflammogenic properties, while silver nanoparticles were shown to reduce allergic inflammation. Just as asbestos fibers, carbon nanotubes were shown to cause lungs damage. Some nanomaterials were shown, based on animal studies, to result in cell damage, leading to the formation of pre-cancerous lesions. This review highlights the impact of nanomaterials on immune system and its effect on human health with toxicity consideration. It recommends the development of suitable animal models to study the toxicity and bio-clearance of nanomaterials and propose safety guidelines.

  6. Nanomaterial Induced Immune Responses and Cytotoxicity.

    PubMed

    Ali, Ashraf; Suhail, Mohd; Mathew, Shilu; Shah, Muhammad Ali; Harakeh, Steve M; Ahmad, Sultan; Kazmi, Zulqarnain; Alhamdan, Mohammed Abdul Rahman; Chaudhary, Adeel; Damanhouri, Ghazi Abdullah; Qadri, Ishtiaq

    2016-01-01

    Nanomaterials are utilized in a wide array of end user products such as pharmaceuticals, electronics, clothes and cosmetic products. Due to its size (< 100 nm), nanoparticles have the propensity to enter through the airway and skin, making its path perilous with the potential to cause damages of varying severity. Once within the body, these particles have unconstrained access to different tissues and organs including the brain, liver, and kidney. As a result, nanomaterials may cause the perturbation of the immune system eliciting an inflammatory response and cytotoxicity. This potential role is dependent on many factors such as the characteristics of the nanomaterials, presence or absence of diseases, and genetic predisposition. Cobalt and nickel nanoparticles, for example, were shown to have inflammogenic properties, while silver nanoparticles were shown to reduce allergic inflammation. Just as asbestos fibers, carbon nanotubes were shown to cause lungs damage. Some nanomaterials were shown, based on animal studies, to result in cell damage, leading to the formation of pre-cancerous lesions. This review highlights the impact of nanomaterials on immune system and its effect on human health with toxicity consideration. It recommends the development of suitable animal models to study the toxicity and bio-clearance of nanomaterials and propose safety guidelines. PMID:27398432

  7. Rational design of nanomaterials for water treatment

    NASA Astrophysics Data System (ADS)

    Li, Renyuan; Zhang, Lianbin; Wang, Peng

    2015-10-01

    The ever-increasing human demand for safe and clean water is gradually pushing conventional water treatment technologies to their limits. It is now a popular perception that the solutions to the existing and future water challenges will hinge upon further developments in nanomaterial sciences. The concept of rational design emphasizes on `design-for-purpose' and it necessitates a scientifically clear problem definition to initiate the nanomaterial design. The field of rational design of nanomaterials for water treatment has experienced a significant growth in the past decade and is poised to make its contribution in creating advanced next-generation water treatment technologies in the years to come. Within the water treatment context, this review offers a comprehensive and in-depth overview of the latest progress in rational design, synthesis and applications of nanomaterials in adsorption, chemical oxidation and reduction reactions, membrane-based separation, oil-water separation, and synergistic multifunctional all-in-one nanomaterials/nanodevices. Special attention is paid to the chemical concepts related to nanomaterial design throughout the review.

  8. Rational design of nanomaterials for water treatment.

    PubMed

    Li, Renyuan; Zhang, Lianbin; Wang, Peng

    2015-11-01

    The ever-increasing human demand for safe and clean water is gradually pushing conventional water treatment technologies to their limits. It is now a popular perception that the solutions to the existing and future water challenges will hinge upon further developments in nanomaterial sciences. The concept of rational design emphasizes on 'design-for-purpose' and it necessitates a scientifically clear problem definition to initiate the nanomaterial design. The field of rational design of nanomaterials for water treatment has experienced a significant growth in the past decade and is poised to make its contribution in creating advanced next-generation water treatment technologies in the years to come. Within the water treatment context, this review offers a comprehensive and in-depth overview of the latest progress in rational design, synthesis and applications of nanomaterials in adsorption, chemical oxidation and reduction reactions, membrane-based separation, oil-water separation, and synergistic multifunctional all-in-one nanomaterials/nanodevices. Special attention is paid to the chemical concepts related to nanomaterial design throughout the review.

  9. Synthesis and device applications of graphitic nanomaterials

    NASA Astrophysics Data System (ADS)

    Umair, Ahmad

    This thesis is focused on two topics: (i) synthesis and characterization of bilayer graphene and pyrolytic carbon by atmospheric pressure chemical vapor deposition, and (ii) application of graphene in the fabrication of a buckyball memory device. Monolayer and bilayer graphene are semi-metal with zero bandgap. One can induce a bandgap in bilayer graphene by applying a gate voltage in the stacking direction. Thus, bandgap and Fermi level in bilayer graphene can be controlled simultaneously with a double-gate device, making it a useful material for future semiconducting applications. Controlled synthesis of bilayer graphene would be the first step to fabricate bilayer graphene based devices. In this context, we report a uniform and low-defect synthesis of bilayer graphene on evaporated nickel films. Ultra-fast cooling is employed to control the number of layers and sample uniformity. The process is self-limiting, which leads to bilayer graphene synthesis over a wide range of growth-time and precursor flow-rate. Pryolytic carbon is another important carbon nanomaterial, due to its diverse applications in electronic and biomedicalengineering. We employ chemical vapor deposition with ultra-fast cooling technique to synthesize pyrolytic carbon. Furthermore, we elucidate a method to calculate the in-plane crystal size by using Raman spectroscopy. Finally, the use of bilayer graphene in a write-once read-many memory device has been demonstrated. The device showed irreversible switching from low-resistance to high-resistance state, with hysteresis in the transport characteristics. The control sample showed random switching and hysteresis due to electromigration of metal atoms into the active material of the device. We attribute the reliability and performance of the reported device to the ultra-smooth graphene contacts, which additionally inhibits electromigration from the underlying metallic film. Moreover, the memory device showed excellent endurance and retention

  10. Calcium-independent binding to interfacial phorbol esters causes protein kinase C to associate with membranes in the absence of acidic lipids.

    PubMed

    Mosior, M; Newton, A C

    1996-02-01

    The mechanism of interaction of phorbol esters with conventional protein kinase Cs was addressed by examining the direct binding of this class of activators to protein kinase C beta II. Binding measurements reveal that the major role of phorbol esters is to increase the affinity of protein kinase C for membranes by several orders of magnitude. The relative increase depends linearly on the mole fraction of phorbol esters in membranes, with the potency illustrated by the finding that 1 mol% phorbol 12-myristate 13-acetate (PMA) increases protein kinase C's membrane association by approximately 4 orders of magnitude. For comparison, diacylglycerol (DG), which also activates protein kinase C by increasing the enzyme's membrane affinity, is 2 orders of magnitude less effective than PMA in altering protein kinase C's membrane affinity. The remarkably high-affinity interaction with phorbol esters allowed us to measure the direct binding of protein kinase C to PMA in neutral membranes and, thus, to evaluate the effect of Ca2+ on the phorbol ester interaction in the absence of Ca2+ effects on the enzyme's interaction with acidic lipids. Changing the Ca2+ concentration over 5 orders of magnitude had no effect on the direct interaction of protein kinase C with PMA immobilized in phosphatidylcholine membranes. Thus, the Ca(2+)-binding site for membrane association and the phorbol ester-binding site do not interact allosterically. Lastly, a method that does not have the limitations of the Scatchard plot for analysis of amphitropic proteins was used to determine the dissociation constant of protein kinase C from phorbol esters: expressed relative to membrane lipids, the dissociation constant is 1.5 x 10(-5) mol %. In summary, our data reveal that (1) the direct binding of protein kinase C to phorbol esters, in the absence of interactions with acidic lipids, provides a major contribution to the free energy change involved in the association of protein kinase C with membranes and

  11. Quantum modeling of bioconjugated nanomaterials

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Saikat

    In recent years, the bio-conjugated nanostructured materials have emerged as a new class of materials for the bio-sensing and medical diagnostics applications. In spite of their multi-directional applications, interfacing nanomaterials with bio-molecules has been a challenge due to somewhat limited knowledge about the underlying physics and chemistry behind these interactions and also for the complexity of biomolecules. The main objective of this dissertation is to provide such a detailed knowledge on bioconjugated nanomaterials toward their applications in designing the next generation of sensing devices. Specifically, we investigate the changes in the electronic properties of a boron nitride nanotube (BNNT) due to the adsorption of different bio-molecules, ranging from neutral (DNA/RNA nucleobases) to polar (amino acid molecules). BNNT is a typical member of III-V compounds semiconductors with morphology similar to that of carbon nanotubes (CNTs) but with its own distinct properties. More specifically, the natural affinity of BNNTs toward living cells with no apparent toxicity instigates the applications of BNNTs in drug delivery and cell therapy. Our results predict that the adsorption of DNA/RNA nucleobases on BNNTs amounts to different degrees of modulation in the band gap of BNNTs, which can be exploited for distinguishing these nucleobases from each other. Interestingly, for the polar amino acid molecules, the nature of interaction appeared to vary ranging from Coulombic, van der Waals and covalent depending on the polarity of the individual molecules, each with a different binding strength and amount of charge transfer involved in the interaction. The strong binding of amino acid molecules on the BNNTs explains the observed protein wrapping onto BNNTs without any linkers, unlike carbon nanotubes (CNTs). Additionally, the widely varying binding energies corresponding to different amino acid molecules toward BNNTs indicate to the suitability of BNNTs for the

  12. Inhibition of the differentiation of human myeloid cell lines by redox changes induced through glutathione depletion.

    PubMed Central

    Esposito, F; Agosti, V; Morrone, G; Morra, F; Cuomo, C; Russo, T; Venuta, S; Cimino, F

    1994-01-01

    We have investigated the effect of redox changes in vivo on the differentiation of two human myeloid cell lines, HL-60 and KG-1. The glutathione-depleting agent diethyl maleate (DEM) prevented the development of differentiated features in response to phorbol esters, including adherence of the cells to plastic surfaces and repression of the myeloperoxidase and CD34 genes. Moreover, DEM abolished phorbol 12-myristate 13-acetate-induced activation of the transcription factors AP-1 and Egr-1, suggesting that inhibition of differentiation may be due, at least in part, to redox modifications of these proteins. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:7519845

  13. Health implications of engineered nanomaterials

    NASA Astrophysics Data System (ADS)

    Pietroiusti, Antonio

    2012-02-01

    With the development of nanotechnology, a growing number of people are expected to be exposed to its products, the engineered nanomaterials (ENMs). Some physico-chemical properties of ENMs, linked to their size in the nanoscale (1-100 nm), make them potentially more reactive, and therefore raise concern about possible adverse effects in humans. In this article, I discuss human diseases which may be predicted after exposure to ENMs, and how their pathogenetic mechanisms may be linked to exposure; in this regard, special emphasis has been given to the triad of oxidative stress/inflammation/genotoxicity and to the interaction of ENMs/proteins in different biological compartments. The analysis of possible adverse effects has been made on an organ-by-organ basis, starting from the skin, respiratory system and gastrointestinal tract. These sites are in fact not only those exposed to the highest amounts of ENMs, but are also the portals of entry to internal organs for possible systemic effects. Although the list and the relevance of possible human disorders linked to ENM exposure are at least as impressive as that of their direct or indirect beneficial effects for human health, we must be clear that ENM-linked diseases belong to the realm of possible risk (i.e. cannot be excluded, but are unlikely), whereas ENMs with proven beneficial effects are on the market. Therefore, the mandatory awareness about possible adverse effects of ENMs should in no way be interpreted as a motivation to disregard the great opportunity represented by nanotechnology.

  14. Signal Amplification of Bioassay Using Zinc Nanomaterials

    NASA Astrophysics Data System (ADS)

    Cowles, Chad L.

    An emerging trend in the analytical detection sciences is the employment of nanomaterials for bioassay signal transduction to identify analytes critical to public health. These nanomaterials have been specifically investigated for applications which require identification of trace levels of cells, proteins, or other molecules that can have broad ranging impacts to human health in fields such as clinical diagnostics, environmental monitoring, food and drink control, and the prevention of bioterrorism. Oftentimes these nanoparticle-based signal transduction or amplification approaches offer distinct advantages over conventional methods such as increased sensitivity, rapidity, or stability. The biological application of nanoparticles however, does suffer from drawbacks that have limited more widespread adoption of these techniques. Some of these drawbacks are, high cost and toxicity, arduous synthesis methods, functionalization and bioconjugation challenges, and laboratory disposal and environmental hazard issues, all of which have impeded the progression of this technology in some way or another. This work aims at developing novel techniques that offer solutions to a number of these hurdles through the development of new nanoparticle-based signal transduction approaches and the description of a previously undescribed nanomaterial. Zinc-based nanomaterials offer the opportunity to overcome some of the limitations that are encountered when other nanomaterials are employed for bioassay signal transduction. On the other hand, the biological application of zinc nanomaterials has been difficult because in general their fluorescence is in the blue range and the reported quantum yields are usually too low for highly sensitive applications. The advantages of using zinc nanomaterials for biological applications, such as reduced toxicity, simple synthesis, low cost, and straightforward functionalization strategies contribute to the research interest in their application as

  15. Hybrid upconversion nanomaterials for optogenetic neuronal control

    NASA Astrophysics Data System (ADS)

    Shah, Shreyas; Liu, Jing-Jing; Pasquale, Nicholas; Lai, Jinping; McGowan, Heather; Pang, Zhiping P.; Lee, Ki-Bum

    2015-10-01

    Nanotechnology-based approaches offer the chemical control required to develop precision tools suitable for applications in neuroscience. We report a novel approach employing hybrid upconversion nanomaterials, combined with the photoresponsive ion channel channelrhodopsin-2 (ChR2), to achieve near-infrared light (NIR)-mediated optogenetic control of neuronal activity. Current optogenetic methodologies rely on using visible light (e.g. 470 nm blue light), which tends to exhibit high scattering and low tissue penetration, to activate ChR2. In contrast, our approach enables the use of 980 nm NIR light, which addresses the short-comings of visible light as an excitation source. This was facilitated by embedding upconversion nanomaterials, which can convert NIR light to blue luminescence, into polymeric scaffolds. These hybrid nanomaterial scaffolds allowed for NIR-mediated neuronal stimulation, with comparable efficiency as that of 470 nm blue light. Our platform was optimized for NIR-mediated optogenetic control by balancing multiple physicochemical properties of the nanomaterial (e.g. size, morphology, structure, emission spectra, concentration), thus providing an early demonstration of rationally-designing nanomaterial-based strategies for advanced neural applications.Nanotechnology-based approaches offer the chemical control required to develop precision tools suitable for applications in neuroscience. We report a novel approach employing hybrid upconversion nanomaterials, combined with the photoresponsive ion channel channelrhodopsin-2 (ChR2), to achieve near-infrared light (NIR)-mediated optogenetic control of neuronal activity. Current optogenetic methodologies rely on using visible light (e.g. 470 nm blue light), which tends to exhibit high scattering and low tissue penetration, to activate ChR2. In contrast, our approach enables the use of 980 nm NIR light, which addresses the short-comings of visible light as an excitation source. This was facilitated by

  16. Screw dislocation driven growth of nanomaterials.

    PubMed

    Meng, Fei; Morin, Stephen A; Forticaux, Audrey; Jin, Song

    2013-07-16

    Nanoscience and nanotechnology impact our lives in many ways, from electronic and photonic devices to biosensors. They also hold the promise of tackling the renewable energy challenges facing us. However, one limiting scientific challenge is the effective and efficient bottom-up synthesis of nanomaterials. We can approach this core challenge in nanoscience and nanotechnology from two perspectives: (a) how to controllably grow high-quality nanomaterials with desired dimensions, morphologies, and material compositions and (b) how to produce them in a large quantity at reasonable cost. Because many chemical and physical properties of nanomaterials are size- and shape-dependent, rational syntheses of nanomaterials to achieve desirable dimensionalities and morphologies are essential to exploit their utilities. In this Account, we show that the dislocation-driven growth mechanism, where screw dislocation defects provide self-perpetuating growth steps to enable the anisotropic growth of various nanomaterials at low supersaturation, can be a powerful and versatile synthetic method for a wide variety of nanomaterials. Despite significant progress in the last two decades, nanomaterial synthesis has often remained an "art", and except for a few well-studied model systems, the growth mechanisms of many anisotropic nanostructures remain poorly understood. We strive to go beyond the empirical science ("cook-and-look") and adopt a fundamental and mechanistic perspective to the anisotropic growth of nanomaterials by first understanding the kinetics of the crystal growth process. Since most functional nanomaterials are in single-crystal form, insights from the classical crystal growth theories are crucial. We pay attention to how screw dislocations impact the growth kinetics along different crystallographic directions and how the strain energy of defected crystals influences their equilibrium shapes. Furthermore, such inquiries are supported by detailed structural investigation to

  17. Potential treatments to reduce phorbol esters levels in jatropha seed cake for improving the value added product.

    PubMed

    Sadubthummarak, Umapron; Parkpian, Preeda; Ruchirawat, Mathuros; Kongchum, Manoch; Delaune, R D

    2013-01-01

    Jatropha seed cake contains high amounts of protein and other nutrients, however it has a drawback due to toxic compounds. The aim of this study was to investigate the methods applied to detoxify the main toxin, phorbol esters in jatropha seed cake, to a safe and acceptable level by maintaining the nutritional values. Phorbol esters are tetracyclic diterpenoids-polycyclic compounds that are known as tumor promoters and hence exhibited the toxicity within a broad range of species. Mismanagement of the jatropha waste from jatropha oil industries would lead to contamination of the environment, affecting living organisms and human health through the food chain, so several methods were tested for reducing the toxicity of the seed cake. The results from this investigation showed that heat treatments at either 120°C or 220°C for 1 hour and then mixing with adsorbing bentonite (10%), nanoparticles of zinc oxide (100 μg/g) plus NaHCO3 at 4%, followed by a 4-week incubation period yielded the best final product. The remaining phorbol esters concentration (0.05-0.04 mg/g) from this treatment was less than that reported for the nontoxic jatropha varieties (0.11-0.27 mg/g). Nutritional values of the seed cake after treatment remained at the same levels found in the control group and these values were crude protein (20.47-21.40 + 0.17-0.25%), crude lipid (14.27-14.68 + 0.13-0.14%) and crude fiber (27.33-29.67 + 0.58%). A cytotoxicity test conducted using L929 and normal human dermal fibroblast cell lines confirmed that most of the toxic compounds, especially phorbol esters, were shown as completely eliminated. The results suggested that the detoxification of phorbol esters residues in the jatropha seed cake was possible while it also retained nutritional values. Therefore, the methods to detoxify phorbol esters are necessary to minimize the toxicity of jatropha seed cake. Further, it is essential to reduce the possible environmental impacts that may be generated

  18. Envelopment-Internalization Synergistic Effects and Metabolic Mechanisms of Graphene Oxide on Single-Cell Chlorella vulgaris Are Dependent on the Nanomaterial Particle Size.

    PubMed

    Ouyang, Shaohu; Hu, Xiangang; Zhou, Qixing

    2015-08-19

    The interactions between nanomaterials and cells are fundamental in biological responses to nanomaterials. However, the size-dependent synergistic effects of envelopment and internalization as well as the metabolic mechanisms of nanomaterials have remained unknown. The nanomaterials tested here were larger graphene oxide nanosheets (GONS) and small graphene oxide quantum dots (GOQD). GONS intensively entrapped single-celled Chlorella vulgaris, and envelopment by GONS reduced the cell permeability. In contrast, GOQD-induced remarkable shrinkage of the plasma membrane and then enhanced cell permeability through strong internalization effects such as plasmolysis, uptake of nanomaterials, an oxidative stress increase, and inhibition of cell division and chlorophyll biosynthesis. Metabolomics analysis showed that amino acid metabolism was sensitive to nanomaterial exposure. Shrinkage of the plasma membrane is proposed to be linked to increases in the isoleucine levels. The inhibition of cell division and chlorophyll a biosynthesis was associated with decreases in aspartic acid and serine, the precursors of chlorophyll a. The increases in mitochondrial membrane potential loss and oxidative stress were correlated with an increase in linolenic acid. The above metabolites can be used as indicators of the corresponding biological responses. These results enhance our systemic understanding of the size-dependent biological effects of nanomaterials. PMID:26221973

  19. Biological and ecological responses to carbon-based nanomaterials

    NASA Astrophysics Data System (ADS)

    Ratnikova, Tatsiana A.

    This dissertation examines the biological and ecological responses to carbon nanoparticles, a major class of nanomaterials which have been mass produced and extensively studied for their rich physical properties and commercial values. Chapter I of this dissertation offers a comprehensive review on the structures, properties, applications, and implications of carbon nanomaterials, especially related to the perspectives of biological and ecosystems. Given that there are many types of carbon nanomaterials available, this chapter is focused on three major types of carbon-based nanomaterials only, namely, fullerenes, single walled and multi-walled carbon nanotubes. On the whole organism level, specifically, Chapter II presents a first study on the fate of fullerenes and multiwalled carbon nanotubes in rice plants, which was facilitated by the self assembly of these nanomaterials with NOM. The aspects of fullerene uptake, translocation, biodistribution, and generational transfer in the plants were examined and quantified using bright field and electron microscopy, FT-Raman, and FTIR spectroscopy. The uptake and transport of fullerene in the plant vascular system were attributed to water transpiration, convection, capillary force, and the fullerene concentration gradient from the roots to the leaves of the plants. On the cellular level, Chapter III documents the differential uptake of hydrophilic C60(OH)20 vs. amphiphilic C70-NOM complex in Allium cepa plant cells and HT-29 colon carcinoma cells. This study was conducted using a plant cell viability assay, and complemented by bright field, fluorescence and electron microscopy imaging. In particular, C60(OH)20 and C70-NOM showed contrasting uptake in both the plant and mammalian cells, due to their significant differences in physicochemistry and the presence of an extra hydrophobic plant cell wall in the plant cells. Consequently, C60(OH)20 was found to induce toxicity in Allium cepa cells but not in HT-29 cells, while C70

  20. A Metabolic Shift toward Pentose Phosphate Pathway Is Necessary for Amyloid Fibril- and Phorbol 12-Myristate 13-Acetate-induced Neutrophil Extracellular Trap (NET) Formation.

    PubMed

    Azevedo, Estefania P; Rochael, Natalia C; Guimarães-Costa, Anderson B; de Souza-Vieira, Thiago S; Ganilho, Juliana; Saraiva, Elvira M; Palhano, Fernando L; Foguel, Debora

    2015-09-01

    Neutrophils are the main defense cells of the innate immune system. Upon stimulation, neutrophils release their chromosomal DNA to trap and kill microorganisms and inhibit their dissemination. These chromatin traps are termed neutrophil extracellular traps (NETs) and are decorated with granular and cytoplasm proteins. NET release can be induced by several microorganism membrane components, phorbol 12-myristate 13-acetate as well as by amyloid fibrils, insoluble proteinaceous molecules associated with more than 40 different pathologies among other stimuli. The intracellular signaling involved in NET formation is complex and remains unclear for most tested stimuli. Herein we demonstrate that a metabolic shift toward the pentose phosphate pathway (PPP) is necessary for NET release because glucose-6-phosphate dehydrogenase (G6PD), an important enzyme from PPP, fuels NADPH oxidase with NADPH to produce superoxide and thus induce NETs. In addition, we observed that mitochondrial reactive oxygen species, which are NADPH-independent, are not effective in producing NETs. These data shed new light on how the PPP and glucose metabolism contributes to NET formation.

  1. A Metabolic Shift toward Pentose Phosphate Pathway Is Necessary for Amyloid Fibril- and Phorbol 12-Myristate 13-Acetate-induced Neutrophil Extracellular Trap (NET) Formation*

    PubMed Central

    Azevedo, Estefania P.; Rochael, Natalia C.; Guimarães-Costa, Anderson B.; de Souza-Vieira, Thiago S.; Ganilho, Juliana; Saraiva, Elvira M.; Palhano, Fernando L.; Foguel, Debora

    2015-01-01

    Neutrophils are the main defense cells of the innate immune system. Upon stimulation, neutrophils release their chromosomal DNA to trap and kill microorganisms and inhibit their dissemination. These chromatin traps are termed neutrophil extracellular traps (NETs) and are decorated with granular and cytoplasm proteins. NET release can be induced by several microorganism membrane components, phorbol 12-myristate 13-acetate as well as by amyloid fibrils, insoluble proteinaceous molecules associated with more than 40 different pathologies among other stimuli. The intracellular signaling involved in NET formation is complex and remains unclear for most tested stimuli. Herein we demonstrate that a metabolic shift toward the pentose phosphate pathway (PPP) is necessary for NET release because glucose-6-phosphate dehydrogenase (G6PD), an important enzyme from PPP, fuels NADPH oxidase with NADPH to produce superoxide and thus induce NETs. In addition, we observed that mitochondrial reactive oxygen species, which are NADPH-independent, are not effective in producing NETs. These data shed new light on how the PPP and glucose metabolism contributes to NET formation. PMID:26198639

  2. Amphiregulin: A bifunctional growth-modulating glycoprotein produced by the phorbol 12-myristate 13-acetate-treated human breast adenocarcinoma cell line MCF-7

    SciTech Connect

    Shoyab, M.; McDonald, V.L.; Bradley, G.; Todaro, G.J. )

    1988-09-01

    A glycoprotein, termed amphiregulin (AR), inhibits growth of several human carcinoma cells in culture and stimulates proliferation of human fibroblasts and certain other tumor cells. It has been purified to apparent homogeneity from serum-free conditioned medium of MCF-7 human breast carcinoma cells that had been treated with phorbol 12-myristate 13-acetate. AR is a single-chain extremely hydrophilic glycoprotein containing cysteines in disulfide linkage(s) that are essential for biological activity; it is stable between pH2 and pH12 and after heating for 30 min at 56{degree}C but unstable at 100{degree}C. The apparent molecular weights of AR and N-Glycanase-treated AR are 14,000 and 15,000, respectively, as assessed by gel chromatography, and {approx}22,500 and {approx}14,000, respectively, as determined by polyacrylamide gel electrophoresis. A growth modulatory assay was performed with {sup 125}I-labeled deoxyuridine incorporation into DNA. The amino-terminal amino acid sequence of AR has been determined, and no significant sequence homology between AR and other proteins was found. The molecule thus appears to be a distinct growth regulatory protein.

  3. Ric-8A gene deletion or phorbol ester suppresses tumorigenesis in a mouse model of GNAQQ209L-driven melanoma

    PubMed Central

    Patel, B R; Tall, G G

    2016-01-01

    Ric-8A alleles. Our work defines two new rational targets that may be developed as potential uveal melanoma therapies through reduction of Gαq/11-Q209L oncoprotein abundance: (1) Ric-8A inhibition and (2) phorbol ester treatment. PMID:27348266

  4. Ric-8A gene deletion or phorbol ester suppresses tumorigenesis in a mouse model of GNAQ(Q209L)-driven melanoma.

    PubMed

    Patel, B R; Tall, G G

    2016-01-01

    rescue the floxed Ric-8A alleles. Our work defines two new rational targets that may be developed as potential uveal melanoma therapies through reduction of Gαq/11-Q209L oncoprotein abundance: (1) Ric-8A inhibition and (2) phorbol ester treatment. PMID:27348266

  5. Low affinity binding of phorbol esters to protein kinase C and its recombinant cysteine-rich region in the absence of phospholipids.

    PubMed

    Kazanietz, M G; Barchi, J J; Omichinski, J G; Blumberg, P M

    1995-06-16

    Binding of phorbol esters to protein kinase C (PKC) has been regarded as dependent on phospholipids, with phosphatidylserine being the most effective for reconstituting binding. By using a purified single cysteine-rich region from PKC delta expressed in Escherichia coli we were able to demonstrate that specific binding of [3H]phorbol 12,13-dibutyrate to the receptor still takes place in the absence of the phospholipid cofactor. However, [3H]phorbol 12,13-dibutyrate bound to the cysteine-rich region with 80-fold lower affinity in the absence than in the presence of 100 micrograms/ml phosphatidylserine. Similar results were observed with the intact recombinant PKC delta isolated from insect cells. When different phorbol derivatives were examined, distinct structure-activity relations for the cysteine-rich region were found in the presence and absence of phospholipid. Our results have potential implications for PKC translocation, for inhibitor design, and for PKC structural determination. PMID:7782331

  6. Nanomaterials and future aerospace technologies: opportunities and challenges

    NASA Astrophysics Data System (ADS)

    Vaia, Richard A.

    2012-06-01

    Two decades of extensive investment in nanomaterials, nanofabrication and nanometrology have provided the global engineering community a vast array of new technologies. These technologies not only promise radical change to traditional industries, such as transportation, information and aerospace, but may create whole new industries, such as personalized medicine and personalized energy harvesting and storage. The challenge today for the defense aerospace community is determining how to accelerate the conversion of these technical opportunities into concrete benefits with quantifiable impact, in conjunction with identifying the most important outstanding scientific questions that are limiting their utilization. For example, nanomaterial fabrication delivers substantial tailorablity beyond a traditional material data sheet. How can we integrate this tailorability into agile manufacturing and design methods to further optimize the performance, cost and durability of future resilient aerospace systems? The intersection of nano-based metamaterials and nanostructured devices with biotechnology epitomizes the technological promise of autonomous systems and enhanced human-machine interfaces. What then are the key materials and processes challenges that are inhibiting current lab-scale innovation from being integrated into functioning systems to increase effectiveness and productivity of our human resources? Where innovation is global, accelerating the use of breakthroughs, both for commercial and defense, is essential. Exploitation of these opportunities and finding solutions to the associated challenges for defense aerospace will rely on highly effective partnerships between commercial development, scientific innovation, systems engineering, design and manufacturing.

  7. Characterization of nanomaterials with transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Anjum, D. H.

    2016-08-01

    The field of nanotechnology is about research and development on materials whose at least one dimension is in the range of 1 to 100 nanometers. In recent years, the research activity for developing nano-materials has grown exponentially owing to the fact that they offer better solutions to the challenges faced by various fields such as energy, food, and environment. In this paper, the importance of transmission electron microscopy (TEM) based techniques is demonstrated for investigating the properties of nano-materials. Specifically the nano-materials that are investigated in this report include gold nano-particles (Au-NPs), silver atom-clusters (Ag-ACs), tantalum single-atoms (Ta-SAs), carbon materials functionalized with iron cobalt (Fe-Co) NPs and titania (TiO2) NPs, and platinum loaded Ceria (Pt-CeO2) Nano composite. TEM techniques that are employed to investigate nano-materials include aberration corrected bright-field TEM (BF-TEM), high-angle dark-field scanning TEM (HAADF-STEM), electron energy-loss spectroscopy (EELS), and BF-TEM electron tomography (ET). With the help presented of results in this report, it is proved herein that as many TEM techniques as available in a given instrument are essential for a comprehensive nano-scale analysis of nanomaterials.

  8. Describing Nanomaterials: A Uniform Description System

    NASA Astrophysics Data System (ADS)

    Rumble, John; Freiman, Steve; Teague, Clayton

    2014-03-01

    Products involving nanomaterials are growing rapidly and nanoparticles also occur naturally. Materials, scientists, engineers, health officials, and regulators have realized they need a common description system. Led by CODATA and VAMAS, a Uniform Description System (UDS) for nanomaterials is being developed to meet the requirements of a broad range of scientific and technical disciplines and different user communities. The goal of the CODATA/VAMAS effort is the creation of a complete set of descriptors that can be used by all communities, e.g., materials, physics, chemistry, agricultural, medical, etc., interested in nanomaterials. The description system must be relevant to researchers, manufacturers of nanomaterials, materials selectors, and regulators. The purpose of the UDS for materials on the nanoscale is twofold: Uniqueness and Equivalency. The first step in the development of the UDS has been the creation of a Framework that will be used by the different communities to guide in the selection of descriptors relevant to their needs. This talk is a brief description of the draft of such a Framework, and how the framework will be translated into a robust description system with input from many scientific communities including physics. A contribution from the CODATA/VAMAS Working Group on the Description of Nanomaterials.

  9. Applications of Nanomaterials in Food Packaging.

    PubMed

    Bumbudsanpharoke, Nattinee; Choi, Jungwook; Ko, Seonghyuk

    2015-09-01

    Nanomaterials have drawn great interest in recent years due to their extraordinary properties that make them advantageous in food packaging applications. Specifically, nanoparticles can impart significant barrier properties, as well as mechanical, optical, catalytic, and antimicrobial properties into packaging. Silver nanoparticles (AgNPs) and nanoclay account for the majority of the nano-enabled food packaging on the market, while others, such as nano-zinc oxide (ZnO) and titanium, share less of the current market. In current food packaging, these nanomaterials are primarily used to impart antimicrobial function and to improve barrier properties, thereby extending the shelf life and freshness of packaged food. On the other hand, there is growing concern about the migration of nanomaterials from food contact materials to foodstuffs and its associated potential risks. Indeed, insufficient data about environmental and human safety assessments of migration and exposure of nanomaterials are hindering their market growth. To overcome this barrier, the public believes that legislation from government agencies is critical. This review provides an overview of the characteristics and functions of major nanomaterials that are commonly applied to food packaging, including available and near- future products. Migration research, safety issues, and public concerns are also discussed. PMID:26716190

  10. Biopharmaceutics and Therapeutic Potential of Engineered Nanomaterials

    PubMed Central

    Liang, Xing-Jie; Chen, Chunying; Zhao, Yuliang; Jia, Lee; Wang, Paul C.

    2009-01-01

    Engineered nanomaterials are at the leading edge of the rapidly developing nanosciences and are founding an important class of new materials with specific physicochemical properties different from bulk materials with the same compositions. The potential for nanomaterials is rapidly expanding with novel applications constantly being explored in different areas. The unique size-dependent properties of nanomaterials make them very attractive for pharmaceutical applications. Investigations of physical, chemical and biological properties of engineered nanomaterials have yielded valuable information. Cytotoxic effects of certain engineered nanomaterials towards malignant cells form the basis for one aspect of nanomedicine. It is inferred that size, three dimensional shape, hydrophobicity and electronic configurations make them an appealing subject in medicinal chemistry. Their unique structure coupled with immense scope for derivatization forms a base for exciting developments in therapeutics. This review article addresses the fate of absorption, distribution, metabolism and excretion (ADME) of engineered nanoparticles in vitro and in vivo. It updates the distinctive methodology used for studying the biopharmaceutics of nanoparticles. This review addresses the future potential and safety concerns and genotoxicity of nanoparticle formulations in general. It particularly emphasizes the effects of nanoparticles on metabolic enzymes as well as the parenteral or inhalation administration routes of nanoparticle formulations. This paper illustrates the potential of nanomedicine by discussing biopharmaceutics of fullerene derivatives and their suitability for diagnostic and therapeutic purposes. Future direction is discussed as well. PMID:18855608

  11. Special type of morphological reorganization induced by phorbol ester: reversible partition of cell into motile and stable domains

    SciTech Connect

    Dugina, V.B.; Svitkina, T.M.; Vasiliev, J.M.; Gelfand, I.M.

    1987-06-01

    The phorbol ester phorbol 12-myristate 13-acetate (PMA) induced reversible alteration of the shape of fibroblastic cells of certain transformed lines-namely, partition of the cells into two types of domains: motile body actively extending large lamellas and stable narrow cytoplasmic processes. Dynamic observations have shown that stable processes are formed from partially retracted lamellas and from contracted tail parts of cell bodies. Immunofluorescence microscopy and electron microscopy of platinum replicas of cytoskeleton have shown that PMA-induced narrow processes are rich in microtubules and intermediate filaments but relatively poor in actin microfilaments; in contrast, lamellas and cell bodies contained numerous microfilaments. Colcemid-induced depolymerization of microtubules led to contraction of PMA-induced processes; cytochalasin B prevented this contraction. It is suggested that PMA-induced separation of cell into motile and stable parts is due to directional movement of actin structures along the microtubular framework. Similar movements may play an important role in various normal morphogenetic processes.

  12. Alterations in polyamine levels induced by phorbol diesters and other agents that promote differentiation in human promyelocytic leukemia cells

    SciTech Connect

    Huberman, E.; Weeks, C.; Herrmann, A.; Callaham, M.; Slaga, T.

    1981-02-01

    Polyamine levels were evaluated in human HL-60 promyelocytic leukemia cells after treatment with inducers of terminal differentiation. Differentiation in these cells was determined by increases in the percentage of morphologically mature cells and in lysozyme activity. Treatment of the HL-60 cells with phorbol 12-myristate-13-acetate (PMA), phorbol 12,13-didecanoate or other inducers of terminal differentiation such as dimethylsulfoxide and retinoic acid resulted in increased levels of putrescine. However, no increase in putrescine could be detected after PMA treatment of a HL-60 cell variant that exhibited a decreased susceptibility to PMA-induced terminal differentiation. Similarly, no increase in putrescine was observed with two nontumor-promoters (phorbol 12,13-diacetate and 4-O-methyl-PMA) or with anthralin, a non-phorbol tumor promoter. In addition to enhancing putrescine levels, PMA also increased the amount of spermidine and decreased the amount of spermine. The increase in putrescine and spermidine preceded the expression of the various differentiation markers. Unlike the changes observed in the polyamine levels after PMA treatment, the activities of ornithine and S-adenosylmethionine decarboxylases, which are polyamine biosynthetic enzymes, did not significantly change. ..cap alpha..-Methylornithine and ..cap alpha..-difluoromethylornithine and methylglyoxal bis(guanylhydrazone), which are inhibitors of the polyamine biosynthetic enzymes, did not affect differentiation in control or PMA-treated cells. Because of these observations, we suggest that the change in polyamine levels involve biochemical pathways other than the known biosynthetic ones. By-products of these pathways may perhaps be the controlling factors involved in the induction of terminal differentiation in the HL-60 and other cell types as well.

  13. Ice Nucleation Properties of Oxidized Carbon Nanomaterials.

    PubMed

    Whale, Thomas F; Rosillo-Lopez, Martin; Murray, Benjamin J; Salzmann, Christoph G

    2015-08-01

    Heterogeneous ice nucleation is an important process in many fields, particularly atmospheric science, but is still poorly understood. All known inorganic ice nucleating particles are relatively large in size and tend to be hydrophilic. Hence it is not obvious that carbon nanomaterials should nucleate ice. However, in this paper we show that four different readily water-dispersible carbon nanomaterials are capable of nucleating ice. The tested materials were carboxylated graphene nanoflakes, graphene oxide, oxidized single walled carbon nanotubes and oxidized multiwalled carbon nanotubes. The carboxylated graphene nanoflakes have a diameter of ∼30 nm and are among the smallest entities observed so far to nucleate ice. Overall, carbon nanotubes were found to nucleate ice more efficiently than flat graphene species, and less oxidized materials nucleated ice more efficiently than more oxidized species. These well-defined carbon nanomaterials may pave the way to bridging the gap between experimental and computational studies of ice nucleation. PMID:26267196

  14. Hierarchically Structured Nanomaterials for Electrochemical Energy Conversion.

    PubMed

    Trogadas, Panagiotis; Ramani, Vijay; Strasser, Peter; Fuller, Thomas F; Coppens, Marc-Olivier

    2016-01-01

    Hierarchical nanomaterials are highly suitable as electrocatalysts and electrocatalyst supports in electrochemical energy conversion devices. The intrinsic kinetics of an electrocatalyst are associated with the nanostructure of the active phase and the support, while the overall properties are also affected by the mesostructure. Therefore, both structures need to be controlled. A comparative state-of-the-art review of catalysts and supports is provided along with detailed synthesis methods. To further improve the design of these hierarchical nanomaterials, in-depth research on the effect of materials architecture on reaction and transport kinetics is necessary. Inspiration can be derived from nature, which is full of very effective hierarchical structures. Developing fundamental understanding of how desired properties of biological systems are related to their hierarchical architecture can guide the development of novel catalytic nanomaterials and nature-inspired electrochemical devices. PMID:26549054

  15. Nanomaterials as Analytical Tools for Genosensors

    PubMed Central

    Abu-Salah, Khalid M.; Alrokyan, Salman A.; Khan, Muhammad Naziruddin; Ansari, Anees Ahmad

    2010-01-01

    Nanomaterials are being increasingly used for the development of electrochemical DNA biosensors, due to the unique electrocatalytic properties found in nanoscale materials. They offer excellent prospects for interfacing biological recognition events with electronic signal transduction and for designing a new generation of bioelectronic devices exhibiting novel functions. In particular, nanomaterials such as noble metal nanoparticles (Au, Pt), carbon nanotubes (CNTs), magnetic nanoparticles, quantum dots and metal oxide nanoparticles have been actively investigated for their applications in DNA biosensors, which have become a new interdisciplinary frontier between biological detection and material science. In this article, we address some of the main advances in this field over the past few years, discussing the issues and challenges with the aim of stimulating a broader interest in developing nanomaterial-based biosensors and improving their applications in disease diagnosis and food safety examination. PMID:22315580

  16. In Vitro Cytotoxicity of Silver Nanomaterials in Murine Macrophages

    EPA Science Inventory

    Silver nanomaterials are increasingly used as antimicrobial agents in a variety of products. Although there is considerable potential for human exposure to these nanomaterials, little is known about the health risks associated with their use. Macrophages are prominent immune cell...

  17. Assessing the Implications of Modified Nanomaterials in Bioassay Testing

    EPA Science Inventory

    As nanotechnology advances to product development, filling environmental health and safety knowledge gaps is critical. Nanotoxicology is over-generalized, provided the permutations of nanomaterial variants created by the classes of nanomaterials (carbonaceous, metals, quantum dot...

  18. Development and In Vitro Toxicity Evaluation of Alternative Sustainable Nanomaterials

    EPA Science Inventory

    Novel nanomaterial types are rapidly being developed for the value they may add to consumer products without sufficient evaluation of implications for human health, toxicity, environmental impact and long-term sustainability. Nanomaterials made of metals, semiconductors and vario...

  19. Development and In Vitro Bioactivity Profiling of Alternative Sustainable Nanomaterials

    EPA Science Inventory

    Sustainable, environmentally benign nanomaterials (NMs) are being designed as alternatives based on functionality to conventional metal-based nanomaterials (NMs) in order to minimize potential risk to human health and the environment. Development of rapid methods to evaluate the ...

  20. The Nanomaterial Registry: facilitating the sharing and analysis of data in the diverse nanomaterial community.

    PubMed

    Ostraat, Michele L; Mills, Karmann C; Guzan, Kimberly A; Murry, Damaris

    2013-01-01

    The amount of data being generated in the nanotechnology research space is significant, and the coordination, sharing, and downstream analysis of the data is complex and consistently deliberated. The complexities of the data are due in large part to the inherently complicated characteristics of nanomaterials. Also, testing protocols and assays used for nanomaterials are diverse and lacking standardization. The Nanomaterial Registry has been developed to address such challenges as the need for standard methods, data formatting, and controlled vocabularies for data sharing. The Registry is an authoritative, web-based tool whose purpose is to simplify the community's level of effort in assessing nanomaterial data from environmental and biological interaction studies. Because the Registry is meant to be an authoritative resource, all data-driven content is systematically archived and reviewed by subject-matter experts. To support and advance nanomaterial research, a set of minimal information about nanomaterials (MIAN) has been developed and is foundational to the Registry data model. The MIAN has been used to create evaluation and similarity criteria for nanomaterials that are curated into the Registry. The Registry is a publicly available resource that is being built through collaborations with many stakeholder groups in the nanotechnology community, including industry, regulatory, government, and academia. Features of the Registry website (http://www.nanomaterialregistry.org) currently include search, browse, side-by-side comparison of nanomaterials, compliance ratings based on the quality and quantity of data, and the ability to search for similar nanomaterials within the Registry. This paper is a modification and extension of a proceedings paper for the Institute of Electrical and Electronics Engineers.

  1. The Nanomaterial Registry: facilitating the sharing and analysis of data in the diverse nanomaterial community

    PubMed Central

    Ostraat, Michele L; Mills, Karmann C; Guzan, Kimberly A; Murry, Damaris

    2013-01-01

    The amount of data being generated in the nanotechnology research space is significant, and the coordination, sharing, and downstream analysis of the data is complex and consistently deliberated. The complexities of the data are due in large part to the inherently complicated characteristics of nanomaterials. Also, testing protocols and assays used for nanomaterials are diverse and lacking standardization. The Nanomaterial Registry has been developed to address such challenges as the need for standard methods, data formatting, and controlled vocabularies for data sharing. The Registry is an authoritative, web-based tool whose purpose is to simplify the community’s level of effort in assessing nanomaterial data from environmental and biological interaction studies. Because the Registry is meant to be an authoritative resource, all data-driven content is systematically archived and reviewed by subject-matter experts. To support and advance nanomaterial research, a set of minimal information about nanomaterials (MIAN) has been developed and is foundational to the Registry data model. The MIAN has been used to create evaluation and similarity criteria for nanomaterials that are curated into the Registry. The Registry is a publicly available resource that is being built through collaborations with many stakeholder groups in the nanotechnology community, including industry, regulatory, government, and academia. Features of the Registry website (http://www.nanomaterialregistry.org) currently include search, browse, side-by-side comparison of nanomaterials, compliance ratings based on the quality and quantity of data, and the ability to search for similar nanomaterials within the Registry. This paper is a modification and extension of a proceedings paper for the Institute of Electrical and Electronics Engineers. PMID:24098075

  2. Contraction of rat thoracic aorta strips induced by phorbol 12-myristate 13-acetate

    SciTech Connect

    Itoh, H.; Lederis, K.

    1987-02-01

    Phorbol 12-myristate 13-acetate (PMA) induced a slow and progressive increase in tension of rat thoracic aorta strips in the presence of extracellular CaS . Complete relaxation could not be obtained in CaS -free buffer containing 1 mM ethyleneglycol-bis(US -aminoethylether)-N,N'-tetraacetic acid (EGTA) and 10 X M PMA. In the absence of extracellular CaS , PMA (10 X M) induced a small but sustained contraction which was not altered by the addition of another 2 mM EGTA and 3 x 10 V M verapamil. Papaverine (10 U M) relaxed the PMA-induced contraction to the base line, but phentolamine (10 V M), cyproheptadine (10 V M), atropine (10 V M) and tetrodotoxine (10 W M) did not change the contraction. CaS -depleted muscle strips, prepared by four repeated applications of 10 X M norepinephrine in CaS -free buffer, were contracted by 10 X M PMA, but at a lower maximum tension than nontreated strips. The action of PMA on rat aorta strips in CaS -free buffer did not require the presence of the adventitial layer or endothelial cells. These results suggest that PMA may induce activation of protein kinase C and smooth muscle contraction in the absence of extracellular CaS , without an increase in myoplasmic CaS .

  3. Rapid isolation and purification of phorbol esters from Jatropha curcas by high-speed countercurrent chromatography.

    PubMed

    Hua, Wan; Hu, Huiling; Chen, Fang; Tang, Lin; Peng, Tong; Wang, Zhanguo

    2015-03-18

    In this work, a high-speed countercurrent chromatography (HSCCC) method was established for the preparation of phorbol esters (PEs) from Jatropha curcas. n-Hexane-ethyl acetate-methanol-water (1.5:1.5:1.2:0.5, v/v) was selected as the optimum two-phase solvent system to separate and purify jatropha factor C1 (JC1) with a purity of 85.2%, as determined by HPLC, and to obtain a mixture containing four or five PEs. Subsequently, continuous semipreparative HPLC was applied to further purify JC1 (99.8% as determined by HPLC). In addition, UPLC-PDA and UPLC-MS were established and successfully used to evaluate the isolated JC1 and PE-rich crude extract. The purity of JC1 was only 87.8% by UPLC-UV. A peak (a compound highly similar to JC1) was indentified as the isomer of JC1 by comparing the characteristic UV absorption and MS spectra. Meanwhile, this strategy was also applied to analyze the PE-rich crude extract from J. curcas. It is interesting that there may be more than 15 PEs according to the same quasi-molecular ion peaks, highly similar sequence-specific fragment ions, and similar UV absorption spectrum. PMID:25686848

  4. T-cell response to phorbol ester PMA and calcium ionophore A23187 in Down's syndrome.

    PubMed

    Bertotto, A; Crupi, S; Arcangeli, C; Gerli, R; Scalise, F; Fabietti, G; Agea, E; Vaccaro, R

    1989-11-01

    The proliferative response of purified T cells to anti-CD2 monoclonal antibodies (T112 plus T113) was found to be markedly reduced in 12 subjects with Down's syndrome (DS). The addition of phorbol ester PMA, which activates Ca2+/phospholipid-dependent enzyme protein kinase C, or calcium ionophore A23187, which increases intracytosolic free Ca2+ concentration, enhanced, but did not normalize, the defective anti-CD2-mediated T-cell mitogenesis. In contrast, the proliferation of resting lymphocytes from trisomic patients was comparable to that of the control cells when PMA and A23187 were used as co-blastogenic reagents. Because PMA and A23187 together bypass the early activation pathways and promote T-cell growth through the direct induction of membrane interleukin 2 (IL-2) receptor expression and IL-2 synthesis and secretion, it could reasonably be hypothesized that the faulty DS T-cell activation induced by antigen or mitogen is due to a deranged transmembrane signal transduction, rather than a defect in the later intracellular events. PMID:2573952

  5. Potentiation of phorbol ester-induced coronary vasoconstriction in dogs following endothelium disruption

    SciTech Connect

    Roberts, R.B.; Ku, D.D.

    1986-03-05

    In the present study, the effect of phorbol ester, 12-0-tetradecanoylphorbol 13-acetate (TPA), activation of protein kinase C on coronary vascular reactivity was studied in isolated dog coronary arteries. Addition of TPA (10-100 nM) produced a slow, time- and dose-dependent contraction reaching a maximum at approx 2-3 hrs and was essentially irreversible upon washing. Disruption of the endothelium(EC) greatly accelerated the development as well as increase the magnitude of TPA contraction (50-100%). Prior treatment of vessels with phentolamine (1..mu..M), cyproheptadine (1..mu..H) and ibuprofen (1..mu..g/ml) did not alter the TPA contraction. Furthermore, in contrast to previously reported calcium-dependence of TPA contraction in other vessels, complete removal of extracellular calcium (Ca/sub 0/) or addition of 1..mu..M nimodipine after TPA(30nM) resulted in only 32 +/- 4% and 25 +/- 3% reversal of TPA contraction, respectively. Addition of amiloride (10..mu..M to 1mM), however, resulted in a dose-dependent reversal of TPA contraction. The results of the present study indicate that a similar activation of protein kinase C by TPA leads to potent coronary vasoconstriction, which is not completely dependent on Ca/sub 0/. More importantly, these results further support their hypothesis that EC also functions as an inhibitory barrier to prevent circulating vasoconstrictors from exerting their deleterious constrictory effects.

  6. The effect of phorbol myristate acetate on the metabolism and ultrastructure of human alveolar macrophages.

    PubMed Central

    Hoidal, J. R.; Repine, J. E.; Beall, G. D.; Rasp, F. L.; White, J. G.

    1978-01-01

    In the present investigation we examined the influence of the surface-active agent phorbol myristate acetate (PMA) and opsonized heat-killed bacteria (HKB) on oxygen consumption, superoxide release, and glucose oxidation of human alveolar macrophages (AM). Both PMA and HKB produced a surge in oxygen consumption, superoxide release, and oxidation of 1-14C-glucose and 6-14C-glucose by human AM. Examination of AM by electron microscopy following stimulation by these two agents demonstrated membrane ruffling, loss of microvilli, and increased vacuolization in PMA-treated cells and phagocytic vacuoles containing bacteria in HKB-treated cells. The vacuolization produced by PMA-treated AM was much less striking than the vacuolization produced in PMA-treated leukocytes. The similarity in the metabolic and some of the physical responses of AM stimulated by PMA and HKB suggest that PMA may be a useful agent for evaluating cell-membrane-related events of phagocytosis in AM. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figures 9 and 10 Figures 11 and 12 PMID:207188

  7. Rapid isolation and purification of phorbol esters from Jatropha curcas by high-speed countercurrent chromatography.

    PubMed

    Hua, Wan; Hu, Huiling; Chen, Fang; Tang, Lin; Peng, Tong; Wang, Zhanguo

    2015-03-18

    In this work, a high-speed countercurrent chromatography (HSCCC) method was established for the preparation of phorbol esters (PEs) from Jatropha curcas. n-Hexane-ethyl acetate-methanol-water (1.5:1.5:1.2:0.5, v/v) was selected as the optimum two-phase solvent system to separate and purify jatropha factor C1 (JC1) with a purity of 85.2%, as determined by HPLC, and to obtain a mixture containing four or five PEs. Subsequently, continuous semipreparative HPLC was applied to further purify JC1 (99.8% as determined by HPLC). In addition, UPLC-PDA and UPLC-MS were established and successfully used to evaluate the isolated JC1 and PE-rich crude extract. The purity of JC1 was only 87.8% by UPLC-UV. A peak (a compound highly similar to JC1) was indentified as the isomer of JC1 by comparing the characteristic UV absorption and MS spectra. Meanwhile, this strategy was also applied to analyze the PE-rich crude extract from J. curcas. It is interesting that there may be more than 15 PEs according to the same quasi-molecular ion peaks, highly similar sequence-specific fragment ions, and similar UV absorption spectrum.

  8. Study of protein modifications induced by phorbol ester tumor promoters in mouse skin

    SciTech Connect

    Nelson, K.G.

    1981-08-01

    The purpose of this study was to determine if the phorbol ester tumor promoter 12-0-tetradecanoylphorbol-13-acetate (TPA) induced any specific changes in mouse epidermal proteins using the high resolution technique of two-dimensional electrophoresis. To accomplish this goal of determining the specificity and possibly the stage in promotion with which these protein changes were associated, epidermal proteins were analyzed (1) after treatment of adult mouse epidermis with several weakly promoting hyperplasiogenic agents, (2) following treatment with TPA in combination with various inhibitors of tumor promotion, (3) in basal kerotinocytes isolated from adult epidermis following treatment with TPA or several weakly promoting agents, and (4) during an initiation-promotion experiment. Evidence was found which indicated that the potent tumor promoter TPA as well as the weakly promoting hyperplasiogenic agents, mezerein, ethylphenylpropiolate (EPP), and mechanical abrasion, induced similar modifications of epidermal proteins, particularly among the keratins. These keratin modifications progressed with time following treatment resulting in a keratin pattern which resembled that of newborn epidermis.

  9. Identification of a phorbol ester-repressible v-src-inducible gene

    SciTech Connect

    Simmons, D.L.; Levy, D.B.; Yannoni, Y.; Erikson, R.L. )

    1989-02-01

    Chicken embryo fibroblasts (CEF) infected with a temperature-sensitive Rous sarcoma virus (RSV) mutant, tsNY72-4, express a set of pp60{sup v-src}-induced RNAs soon after shift to the permissive temperature. By subtractive and differential screening, the authors have cloned 12 of these sequences, 2 of which were c-fos and krox-24. Serum induced all the v-src-inducible genes tested, suggesting that these genes serve roles in normal cell division and are not specific to transformation per se. Significantly, however, v-src produced prolonged, and in some cases kinetically complex, patterns of induction compared to serum. For most of the clones, phorbol 12-tetradecanoate 13-acetate (TPA) induced mRNAs with kinetics similar to that of serum. However, one clone (CEF-4) was expressed in a biphasic manner. Another (CEF-10) was repressed by TPA at 1 hr, after which this mRNA was permanently induced. The pattern of repression-induction of CEF-10 mRNA is the inverse of protein kinase C (PKC) activity in the cell, suggesting that PKC actively represses this gene. In vivo expression of CEF-10 mRNA is restricted predominantly to the lung. A full-length CEF-10 cDNA encodes a 41-kDa protein that has an amino-terminal signal peptide for secretion, contains a markedly high number of cysteine residues, and shows no sequence similarity to known proteins.

  10. Increased phorbol 12,13-dibutyrate (PDBu) receptor function associated with sickle red cell membrane ghosts

    SciTech Connect

    Ramachandran, M.; Nair, C.N.; Abraham, E.C.

    1987-05-01

    The biological receptor for tumor-promoting phorbol esters has been identified as the CaS /phospholipid dependent enzyme, protein kinase C. In the red cell, this enzyme is mainly cytosolic but becomes translocated to the membrane if the cellular CaS is allowed to rise. Since cellular CaS in sickle red cells is high, it was reasoned that this enzyme may become more membrane-bound. In fact, the authors noticed a four-fold increase in the binding of TH-PDBu by membrane ghosts isolated from sickle red cells compared to normal red cells (pmoles PDBu bound/mg protein; normal = 0.3 vs sickle cell = 1.4). Attempts to assay the enzyme directly as phospholipid-activated TSP incorporation into the acid-precipitable membrane proteins also indicated a two-fold increase in the radiolabelling of sickle cell membrane ghosts. Autophosphorylation of membrane proteins and analysis of the phosphorylation profile by SDS-PAGE and autoradiography revealed phosphorylation predominantly of bands 3, 4.1 and 4.9 which are known protein kinase C substrates for the red cell enzyme. The increased membrane-associated protein kinase C in sickle red cells may have a bearing on the altered membrane properties reported in this condition.

  11. Insulin and phorbol ester stimulate conductive Na/sup +/ transport through a common pathway

    SciTech Connect

    Civan, M.M.; Peterson-Yantorno, K.; O'Brien, T.G.

    1988-02-01

    Insulin stimulates Na/sup +/ transport across frog skin, toad urinary bladder, and the distal renal nephron. This stimulation reflects an increase in apical membrane Na/sup +/ permeability and a stimulation of the basolateral membrane Na,K-exchange pump. Considerable indirect evidence has suggested that the apical natriferic effect of insulin is mediated by activation of protein kinase C. However, no direct information has been available documenting that insulin and protein kinase C indeed share a common pathway in stimulating Na/sup +/ transport across frog skin. In the present work, the authors have studied the interaction of insulin and phorbol 12-myristate 13-acetate (PMA), a documented activator of protein kinase C. Preincubation of skins with 1,2-dioctanoylglycerol, another activator of protein kinase C, increases baseline Na/sup +/ transport and reduces the subsequent natriferic response to PMA. Preincubation with PMA markedly reduces the subsequent natriferic action of insulin. This effect does not appear to primarily reflect PMA-induced internalization of insulin receptors. The insulin receptors are localized on the basolateral surface of frog skin, but the application of PMA to this surface is much less effective than mucosal treatment in reducing the response to insulin. The current results provide documentation that insulin and protein kinase C share a common pathway in stimulating Na/sup +/ transport across frog skin. The data are consistent with the concept that the natriferic effect of insulin on frog skin is, at least in part, mediated by activation of protein kinase C.

  12. Overview of Risk Management for Engineered Nanomaterials

    PubMed Central

    Schulte, PA; Geraci, CL; Hodson, LL; Zumwalde, RD; Kuempel, ED; Murashov, V; Martinez, KF; Heidel, DS

    2015-01-01

    Occupational exposure to engineered nanomaterials (ENMs) is considered a new and challenging occurrence. Preliminary information from laboratory studies indicates that workers exposed to some kinds of ENMs could be at risk of adverse health effects. To protect the nanomaterial workforce, a precautionary risk management approach is warranted and given the newness of ENMs and emergence of nanotechnology, a naturalistic view of risk management is useful. Employers have the primary responsibility for providing a safe and healthy workplace. This is achieved by identifying and managing risks which include recognition of hazards, assessing exposures, characterizing actual risk, and implementing measures to control those risks. Following traditional risk management models for nanomaterials is challenging because of uncertainties about the nature of hazards, issues in exposure assessment, questions about appropriate control methods, and lack of occupational exposure limits (OELs) or nano-specific regulations. In the absence of OELs specific for nanomaterials, a precautionary approach has been recommended in many countries. The precautionary approach entails minimizing exposures by using engineering controls and personal protective equipment (PPE). Generally, risk management utilizes the hierarchy of controls. Ideally, risk management for nanomaterials should be part of an enterprise-wide risk management program or system and this should include both risk control and a medical surveillance program that assesses the frequency of adverse effects among groups of workers exposed to nanomaterials. In some cases, the medical surveillance could include medical screening of individual workers to detect early signs of work-related illnesses. All medical surveillance should be used to assess the effectiveness of risk management; however, medical surveillance should be considered as a second line of defense to ensure that implemented risk management practices are effective. PMID

  13. Overview of Risk Management for Engineered Nanomaterials

    NASA Astrophysics Data System (ADS)

    Schulte, P. A.; Geraci, C. L.; Hodson, L. L.; Zumwalde, R. D.; Kuempel, E. D.; Murashov, V.; Martinez, K. F.; Heidel, D. S.

    2013-04-01

    Occupational exposure to engineered nanomaterials (ENMs) is considered a new and challenging occurrence. Preliminary information from laboratory studies indicates that workers exposed to some kinds of ENMs could be at risk of adverse health effects. To protect the nanomaterial workforce, a precautionary risk management approach is warranted and given the newness of ENMs and emergence of nanotechnology, a naturalistic view of risk management is useful. Employers have the primary responsibility for providing a safe and healthy workplace. This is achieved by identifying and managing risks which include recognition of hazards, assessing exposures, characterizing actual risk, and implementing measures to control those risks. Following traditional risk management models for nanomaterials is challenging because of uncertainties about the nature of hazards, issues in exposure assessment, questions about appropriate control methods, and lack of occupational exposure limits (OELs) or nano-specific regulations. In the absence of OELs specific for nanomaterials, a precautionary approach has been recommended in many countries. The precautionary approach entails minimizing exposures by using engineering controls and personal protective equipment (PPE). Generally, risk management utilizes the hierarchy of controls. Ideally, risk management for nanomaterials should be part of an enterprise-wide risk management program or system and this should include both risk control and a medical surveillance program that assesses the frequency of adverse effects among groups of workers exposed to nanomaterials. In some cases, the medical surveillance could include medical screening of individual workers to detect early signs of work-related illnesses. All medical surveillance should be used to assess the effectiveness of risk management; however, medical surveillance should be considered as a second line of defense to ensure that implemented risk management practices are effective.

  14. Terahertz Dynamics in Carbon Nanomaterials

    NASA Astrophysics Data System (ADS)

    Kono, Junichiro

    2012-02-01

    This NSF Partnerships for International Research and Education (PIRE) project supports a unique interdisciplinary and international partnership investigating terahertz (THz) dynamics in nanostructures. The 0.1 to 10 THz frequency range of the electromagnetic spectrum is where electrical transport and optical transitions merge, offering exciting opportunities to study a variety of novel physical phenomena in condensed matter. By combining THz technology and nanotechnology, we can advance our understanding of THz physics while improving and developing THz devices. Specifically, this PIRE research explores THz dynamics of electrons in carbon nanomaterials, namely, nanotubes and graphene --- low-dimensional, sp^2-bonded carbon systems with unique finite-frequency properties. Japan and the U.S. are global leaders in both THz research and carbon research, and stimulating cooperation is critical to further advance THz science and to commercialize products developed in the lab. However, obstacles exist for international collaboration --- primarily linguistic and cultural barriers --- and this PIRE project aims to address these barriers through the integration of our research and education programs. Our strong educational portfolio endeavours to cultivate interest in nanotechnology amongst young U.S. undergraduate students and encourage them to pursue graduate study and academic research in the physical sciences, especially those from underrepresented groups. Our award-winning International Research Experience for Undergraduates Program, NanoJapan, provides structured research internships in Japanese university laboratories with Japanese mentors --- recognized as a model international education program for science and engineering students. The project builds the skill sets of nanoscience researchers and students by cultivating international and inter-cultural awareness, research expertise, and specific academic interests in nanotechnology. U.S. project partners include Rice

  15. Functional nanomaterials can optimize the efficacy of vaccines.

    PubMed

    Liu, Ye; Xu, Yingying; Tian, Yue; Chen, Chunying; Wang, Chen; Jiang, Xingyu

    2014-11-01

    Nanoscale materials can improve the efficacy of vaccines. Herein we review latest developments that use nanomaterials for vaccines. By highlighting the relationships between the nanoscale physicochemical characteristics and working mechanisms of nanomaterials, this paper shows the current status of the developments where researchers employ functional nanomaterials as vector and/or immunoregulators for vaccines. It also provides us some clues for improving the design and application of nanomaterials to optimize the efficacy of vaccines.

  16. Developing Korean Standard for Nanomaterial Exposure Assessment

    PubMed Central

    Lee, Ji Hyun; Lee, Jun Yeob

    2011-01-01

    Nanotechnology is now applied to many industries, resulting in wide range of nanomaterial-containing products, such as electronic components, cosmetic, medicines, vehicles, and home appliances. Nanoparticles can be released throughout the life cycle of nanoproducts, including the manufacture, consumer use, and disposal, thereby involving workers, consumers, and the environment in potential exposure. However, there is no current consensus on the best sampling method for characterizing manufactured-nanoparticle exposure. Therefore, this report aims to provide a standard method for assessing nanoparticle exposure, including the identification of nanoparticle emission, the assessment of worker exposure, and the evaluation of exposure mitigation actions in nanomaterial-handling workplaces or research institutes. PMID:24278552

  17. Bioresponsive peptide-inorganic hybrid nanomaterials.

    PubMed

    Aili, Daniel; Stevens, Molly M

    2010-09-01

    Bioanalytical techniques that enable simple, fast and reliable high sensitivity monitoring of biomolecular interactions are of immense importance for diagnostics and drug development. This tutorial review provides an overview of recent progress in the development of peptide-based hybrid nanomaterials that transduce molecular interactions by exploiting the optical and magnetic properties of nanoparticles. Peptides have emerged as an interesting alternative to conventional biomolecular receptors, such as antibodies, and are facilitating the design of responsive hybrid nanomaterials that are both robust and sensitive for biodiagnostic applications. PMID:20596582

  18. Simulating the fate and transport of nanomaterials in surface waters

    EPA Science Inventory

    The unique properties of nanomaterials have resulted in their increased production. However, it is unclear how nanomaterials will move and react once released to the environment One approach for addressing possible exposure of nanomaterials in surface waters is by using numerical...

  19. Antioxidant and Antiradical Activities of Manihot esculenta Crantz (Euphorbiaceae) Leaves and Other Selected Tropical Green Vegetables Investigated on Lipoperoxidation and Phorbol-12-myristate-13-acetate (PMA) Activated Monocytes

    PubMed Central

    Tsumbu, Cesar N.; Deby-Dupont, Ginette; Tits, Monique; Angenot, Luc; Franck, Thierry; Serteyn, Didier; Mouithys-Mickalad, Ange

    2011-01-01

    Abelmoschus esculentus (Malvaceae), Hibiscus acetosella (Malvaceae), Manihot esculenta Crantz (Euphorbiaceae) and Pteridium aquilinum (Dennstaedtiaceae) leaves are currently consumed as vegetables by migrants from sub-Saharan Africa living in Western Europe and by the people in the origin countries, where these plants are also used in the folk medicine. Manihot leaves are also eaten in Latin America and some Asian countries. This work investigated the capacity of aqueous extracts prepared from those vegetables to inhibit the peroxidation of a linoleic acid emulsion. Short chain, volatile C-compounds as markers of advanced lipid peroxidation were measured by gas chromatography by following the ethylene production. The generation of lipid hydroperoxides, was monitored by spectroscopy using N-N′-dimethyl-p-phenylene-diamine (DMPD). The formation of intermediate peroxyl, and other free radicals, at the initiation of the lipid peroxidation was investigated by electron spin resonance, using α-(4-pyridyl-1-oxide)-N-tert-butylnitrone as spin trap agent. The ability of the extracts to decrease the cellular production of reactive oxygen species (ROS) in “inflammation like” conditions was studied by fluorescence technique using 2′,7′-dichlorofluorescine-diacetate as fluorogenic probe, in a cell model of human monocytes (HL-60 cells) activated with phorbol ester. Overall the extracts displayed efficient concentration-dependent inhibitory effects. Their total polyphenol and flavonoid content was determined by classic colorimetric methods. An HPLC-UV/DAD analysis has clearly identified the presence of some polyphenolic compounds, which explains at least partially the inhibitions observed in our models. The role of these plants in the folk medicine by sub-Saharan peoples as well as in the prevention of oxidative stress and ROS related diseases requires further consideration. PMID:22254126

  20. Antioxidant and antiradical activities of Manihot esculenta Crantz (Euphorbiaceae) leaves and other selected tropical green vegetables investigated on lipoperoxidation and phorbol-12-myristate-13-acetate (PMA) activated monocytes.

    PubMed

    Tsumbu, Cesar N; Deby-Dupont, Ginette; Tits, Monique; Angenot, Luc; Franck, Thierry; Serteyn, Didier; Mouithys-Mickalad, Ange

    2011-09-01

    Abelmoschus esculentus (Malvaceae), Hibiscus acetosella (Malvaceae), Manihot esculenta Crantz (Euphorbiaceae) and Pteridium aquilinum (Dennstaedtiaceae) leaves are currently consumed as vegetables by migrants from sub-Saharan Africa living in Western Europe and by the people in the origin countries, where these plants are also used in the folk medicine. Manihot leaves are also eaten in Latin America and some Asian countries. This work investigated the capacity of aqueous extracts prepared from those vegetables to inhibit the peroxidation of a linoleic acid emulsion. Short chain, volatile C-compounds as markers of advanced lipid peroxidation were measured by gas chromatography by following the ethylene production. The generation of lipid hydroperoxides, was monitored by spectroscopy using N-N'-dimethyl-p-phenylene-diamine (DMPD). The formation of intermediate peroxyl, and other free radicals, at the initiation of the lipid peroxidation was investigated by electron spin resonance, using α-(4-pyridyl-1-oxide)-N-tert-butylnitrone as spin trap agent. The ability of the extracts to decrease the cellular production of reactive oxygen species (ROS) in "inflammation like" conditions was studied by fluorescence technique using 2',7'-dichlorofluorescine-diacetate as fluorogenic probe, in a cell model of human monocytes (HL-60 cells) activated with phorbol ester. Overall the extracts displayed efficient concentration-dependent inhibitory effects. Their total polyphenol and flavonoid content was determined by classic colorimetric methods. An HPLC-UV/DAD analysis has clearly identified the presence of some polyphenolic compounds, which explains at least partially the inhibitions observed in our models. The role of these plants in the folk medicine by sub-Saharan peoples as well as in the prevention of oxidative stress and ROS related diseases requires further consideration.

  1. Topical application of the adenosine A2A receptor agonist CGS-21680 prevents phorbol-induced epidermal hyperplasia and inflammation in mice.

    PubMed

    Arasa, Jorge; Martos, Patricio; Terencio, María Carmen; Valcuende-Cavero, Francisca; Montesinos, María Carmen

    2014-08-01

    The nucleoside adenosine is a known regulator of immunity and inflammation that mediates, at least in part, the anti-inflammatory effect of methotrexate, an immunosuppressive agent widely used to treat autoimmune inflammatory diseases. Adenosine A2A receptors play a key role in the inhibition of the inflammatory process besides promoting wound healing. Therefore, we aimed to determine the topical effect of a selective agonist, CGS-21680, on a murine model of skin hyperplasia with a marked inflammatory component. Pretreatment with either CGS-21680 (5 μg per site) or the reference agent dexamethasone (200 μg/site) prevented the epidermal hyperplasia and inflammatory response induced by topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA, 2 nmol/site) for three consecutive days. The histological analysis showed that both CGS-21680 and dexamethasone produced a marked reduction of inflammatory cell infiltrate, which correlated with diminished myeloperoxidase (MPO) activity in skin homogenates. Both treatments reduced the levels of the chemotactic mediators LTB4 and CXCL-1, and the inflammatory cytokine TNF-α, through the suppression of NFκB phosphorylation. The immunohistochemical analysis of the hyperproliferative markers cytokeratin 6 (CK6) and Ki67 revealed that while both agents inhibit the number of proliferating cells in the epidermis, CGS-21680 treatment promoted dermal fibroblasts proliferation. Consistently, increased collagen deposition in dermis was observed in tissue sections from agonist-treated mice. Our results showed that CGS 21680 efficiently prevents phorbol-induced epidermal hyperplasia and inflammation in mice without the deleterious atrophic effect of topical corticosteroids. PMID:24889129

  2. Antioxidant and antiradical activities of Manihot esculenta Crantz (Euphorbiaceae) leaves and other selected tropical green vegetables investigated on lipoperoxidation and phorbol-12-myristate-13-acetate (PMA) activated monocytes.

    PubMed

    Tsumbu, Cesar N; Deby-Dupont, Ginette; Tits, Monique; Angenot, Luc; Franck, Thierry; Serteyn, Didier; Mouithys-Mickalad, Ange

    2011-09-01

    Abelmoschus esculentus (Malvaceae), Hibiscus acetosella (Malvaceae), Manihot esculenta Crantz (Euphorbiaceae) and Pteridium aquilinum (Dennstaedtiaceae) leaves are currently consumed as vegetables by migrants from sub-Saharan Africa living in Western Europe and by the people in the origin countries, where these plants are also used in the folk medicine. Manihot leaves are also eaten in Latin America and some Asian countries. This work investigated the capacity of aqueous extracts prepared from those vegetables to inhibit the peroxidation of a linoleic acid emulsion. Short chain, volatile C-compounds as markers of advanced lipid peroxidation were measured by gas chromatography by following the ethylene production. The generation of lipid hydroperoxides, was monitored by spectroscopy using N-N'-dimethyl-p-phenylene-diamine (DMPD). The formation of intermediate peroxyl, and other free radicals, at the initiation of the lipid peroxidation was investigated by electron spin resonance, using α-(4-pyridyl-1-oxide)-N-tert-butylnitrone as spin trap agent. The ability of the extracts to decrease the cellular production of reactive oxygen species (ROS) in "inflammation like" conditions was studied by fluorescence technique using 2',7'-dichlorofluorescine-diacetate as fluorogenic probe, in a cell model of human monocytes (HL-60 cells) activated with phorbol ester. Overall the extracts displayed efficient concentration-dependent inhibitory effects. Their total polyphenol and flavonoid content was determined by classic colorimetric methods. An HPLC-UV/DAD analysis has clearly identified the presence of some polyphenolic compounds, which explains at least partially the inhibitions observed in our models. The role of these plants in the folk medicine by sub-Saharan peoples as well as in the prevention of oxidative stress and ROS related diseases requires further consideration. PMID:22254126

  3. Applications of nanomaterials as vaccine adjuvants

    PubMed Central

    Zhu, Motao; Wang, Rongfu; Nie, Guangjun

    2014-01-01

    Vaccine adjuvants are applied to amplify the recipient's specific immune responses against pathogen infection or malignancy. A new generation of adjuvants is being developed to meet the demands for more potent antigen-specific responses, specific types of immune responses, and a high margin of safety. Nanotechnology provides a multifunctional stage for the integration of desired adjuvant activities performed by the building blocks of tailor-designed nanoparticles. Using nanomaterials for antigen delivery can provide high bioavailability, sustained and controlled release profiles, and targeting and imaging properties resulting from manipulation of the nanomaterials’ physicochemical properties. Moreover, the inherent immune-regulating activity of particular nanomaterials can further promote and shape the cellular and humoral immune responses toward desired types. The combination of both the delivery function and immunomodulatory effect of nanomaterials as adjuvants is thought to largely benefit the immune outcomes of vaccination. In this review, we will address the current achievements of nanotechnology in the development of novel adjuvants. The potential mechanisms by which nanomaterials impact the immune responses to a vaccine and how physicochemical properties, including size, surface charge and surface modification, impact their resulting immunological outcomes will be discussed. This review aims to provide concentrated information to promote new insights for the development of novel vaccine adjuvants. PMID:25483497

  4. Anisotropic nanomaterials: structure, growth, assembly, and functions

    PubMed Central

    Sajanlal, Panikkanvalappil R.; Sreeprasad, Theruvakkattil S.; Samal, Akshaya K.; Pradeep, Thalappil

    2011-01-01

    Comprehensive knowledge over the shape of nanomaterials is a critical factor in designing devices with desired functions. Due to this reason, systematic efforts have been made to synthesize materials of diverse shape in the nanoscale regime. Anisotropic nanomaterials are a class of materials in which their properties are direction-dependent and more than one structural parameter is needed to describe them. Their unique and fine-tuned physical and chemical properties make them ideal candidates for devising new applications. In addition, the assembly of ordered one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) arrays of anisotropic nanoparticles brings novel properties into the resulting system, which would be entirely different from the properties of individual nanoparticles. This review presents an overview of current research in the area of anisotropic nanomaterials in general and noble metal nanoparticles in particular. We begin with an introduction to the advancements in this area followed by general aspects of the growth of anisotropic nanoparticles. Then we describe several important synthetic protocols for making anisotropic nanomaterials, followed by a summary of their assemblies, and conclude with major applications. PMID:22110867

  5. Tools for Assessing Ecological Nanomaterial Exposures

    EPA Science Inventory

    Manufactured nanomaterials (MNs) are commonly defined as being commercial products with at least one dimension in the size range of 1 nm to 100 nm that also possess unique properties as the result of their size. Anecdotal evidence suggests that at least 600 MN products a...

  6. DNA-incorporating nanomaterials in biotechnological applications

    SciTech Connect

    Stadler, A.; van der Lelie, D.; Chi, C.; Gang, O.

    2010-02-01

    The recently developed ability to controllably connect biological and inorganic objects on a molecular scale opens a new page in biomimetic methods with potential applications in biodetection, tissue engineering, targeted therapeutics and drug/gene delivery. Particularly in the biodetection arena, a rapid development of new platforms has largely been stimulated by a spectrum of novel nanomaterials with physical properties that offer efficient, sensitive and inexpensive molecular sensing. Recently, DNA-functionalized nano-objects have emerged as a new class of nanomaterials that can be controllably assembled in predesigned structures. Such DNA-based nanoscale structures might provide a new detection paradigm due to their regulated optical, electrical and magnetic responses, chemical heterogeneity and high local biomolecular concentration. The specific biorecognition DNA and its physical-chemical characteristics allows for an exploitation of DNA-functionalized nanomaterials for sensing of nucleic acids, while a broad tunability of DNA interactions permits extending their use for detection of proteins, small molecules and ions. We discuss the progress that was achieved in the last decade in the exploration of new detection methods based on DNA-incorporating nanomaterials as well as their applications to gene delivery. The comparison between various detection platforms, their sensitivity and selectivity, and specific applications are reviewed.

  7. Workplace exposure at nanomaterial production processes

    NASA Astrophysics Data System (ADS)

    Möhlmann, Carsten; Welter, Johannes; Klenke, Martin; Sander, Jürgen

    2009-05-01

    Typical nanomaterial production processes from daily practice had been performed in order to determine simultaneously the exposure to nanoparticles. They involve mixing of ZnO powder into a liquid, filling and emptying an oven with indium tin oxide (ITO), spraying a suspension of nanoparticles, flame spraying of silanes, and an outside location as comparison.

  8. Sustainable Synthesis of Nanomaterials Using Microwave irradiation

    EPA Science Inventory

    The presentation summarizes our recent activity in MW-assisted synthesis of nanomaterials under benign conditions. Shape-controlled aqueous synthesis of noble nanostructures via MW-assisted spontaneous reduction of noble metal salts using -D-glucose, sucrose, and maltose will be...

  9. The insurability of nanomaterial production risk

    NASA Astrophysics Data System (ADS)

    Mullins, Martin; Murphy, Finbarr; Baublyte, Lijana; McAlea, Eamonn M.; Tofail, Syed A. M.

    2013-04-01

    Without insurance the long-term sustainability of nanotechnology is questionable, but insurance companies are encumbered by their institutional memory of losses from the asbestos crisis and the absence of suitable actuarial models to measure the potential risks of nanotechnology. Here we propose a framework that supports the transfer of nanomaterial production risk to the insurance sector.

  10. Nanomaterials and nanofabrication for biomedical applications

    NASA Astrophysics Data System (ADS)

    Cheng, Chao-Min; Chia-Wen Wu, Kevin

    2013-08-01

    Traditional boundaries between materials science and engineering and life sciences are rapidly disintegrating as interdisciplinary research teams develop new materials-science-based tools for exploring fundamental issues in both medicine and biology. With recent technological advances in multiple research fields such as materials science, cell and molecular biology and micro-/nano-technology, much attention is shifting toward evaluating the functional advantages of nanomaterials and nanofabrication, at the cellular and molecular levels, for specific, biomedically relevant applications. The pursuit of this direction enhances the understanding of the mechanisms of, and therapeutic potentials for, some of the most lethal diseases, including cardiovascular diseases, organ fibrosis and cancers. This interdisciplinary approach has generated great interest among researchers working in a wide variety of communities including industry, universities and research laboratories. The purpose of this focus issue in Science and Technology of Advanced Materials is to bridge nanotechnology and biology with medicine, focusing more on the applications of nanomaterials and nanofabrication in biomedically relevant issues. This focus issue, we believe, will provide a more comprehensive understanding of (i) the preparation of nanomaterials and the underlying mechanisms of nanofabrication, and (ii) the linkage of nanomaterials and nanofabrication with biomedical applications. The multidisciplinary focus issue that we have attempted to organize is of interest to various research fields including biomaterials and tissue engineering, bioengineering, nanotechnology and nanomaterials, i.e. chemistry, physics and engineering. Nanomaterials and nanofabrication topics addressed in this focus issue include sensing and diagnosis (e.g. immunosensing and diagnostic devices for diseases), cellular and molecular biology (e.g. probing cellular behaviors and stem cell differentiation) and drug delivery

  11. Aptamer-conjugated nanomaterials for bioanalysis and biotechnology applications

    NASA Astrophysics Data System (ADS)

    Chen, Tao; Shukoor, Mohammed Ibrahim; Chen, Yan; Yuan, Quan; Zhu, Zhi; Zhao, Zilong; Gulbakan, Basri; Tan, Weihong

    2011-02-01

    In recent years, nanomaterials have captured the attention of scientists from a wide spectrum of domains. With their unique properties, nanomaterials offer great promise for numerous applications, ranging from catalysis to energy harvesting and information technology. Functionalized with the desired biomolecules, nanomaterials can also be utilized for many biomedical applications. This paper summarizes recent achievements in the use of aptamer-conjugated nanomaterials for bioanalysis and biotechnology applications. First, we discuss the features and properties of aptamers and then illustrate the use of aptamer-conjugated nanomaterials as sensing platforms and delivery vehicles, emphasizing how such integration can result in enhanced sensitivity and selectivity.

  12. Bactericidal capacity of phorbol myristate acetate-treated human polymorphonuclear leukocytes.

    PubMed Central

    Wang-Iverson, P; Pryzwansky, K B; Spitznagel, J K; Cooney, M H

    1978-01-01

    Thus far, the functional capacity of phorbol myristate acetate- (PMA)-treated human polymorphonuclear leukocytes has been undefined. PMA induced exocytosis of lactoferrin, the specific granule marker, but not of myeloperoxidase, the azurophil granule marker. This phenomenon was demonstrated both biochemically and with fluorescent antibody conjugates. PMA-treated neutrophils contained virtually no specific granules when viewed by electron microscopy. Separation of the granule classes by linear sucrose density gradient centrifugation revealed the loss, from PMA-treated neutrophils, of lactoferrin and the specific granule (D20(20) = 1.89) band usually resolved from normal neutrophils. Cells treated with PMA appeared to retain those functions normally associated with intraleukocytic microbicidal action. The hexose monophosphate shunt activated by phagocytic challenge was present in PMA-treated neutrophils. As demonstrated by electron microscopy, the azurophil granules of these cells appeared intact, and they retained the capacity for degranulation with translocation of myeloperoxidase to the site of phagocytized Escherichia coli. The PMA-treated neutrophils also remained capable of degrading the ingested microorganisms. PMA-treated neutrophils exhibited a decrease in phagocytic ability at all levels of bacterial challenge. In the presence of a high multiplicity of bacteria they demonstrated an impairment in killing. These same cells were able to kill low multiplicities of E. coli as well as control cells. It thus appeared that the loss of the specific granules, plus other undefined PMA-induced alterations, impaired neither the viability of these neutrophils nor their killing ability in the presence of a modest phagocytic challenge. Images PMID:730386

  13. Phorbol myristate acetate and catechol as skin cocarcinogens in SENCAR mice

    SciTech Connect

    Van Duuren, B.L.; Melchionne, S.; Seidman, I.

    1986-09-01

    The enhancement of the carcinogenicity of benzo(a) pyrene (B(a)P) and ..beta..-propiolactone (BPL) by the mouse skin cocarcinogens phorbol myristate acetate (PMA) and catechol were examined in female SENCAR mice, 30 per group. The carcinogen and cocarcinogen were applied simultaneously, three times weekly for 490-560 days. B(a)P and BPL were used at constant doses of 5 and 50 ..mu..g, respectively, in all experiments. PMA was used at three doses, 2.5, 1.0, and 0.5 ..mu..g per application, and catechol was used at one dose, 2 mg per application. Control groups included animals that received carcinogen only, cocarcinogen only, acetone only, and no treatment. The carcinogenicity of B(a)P and BPL were enhanced by the cocarcinogens, particularly in terms of tumor multiplicity. For both carcinogens, the most marked cocarcinogenic effects were observed at the lowest dose of PMA used (0.5 ..mu..g per application). This observation applied for days to first tumor, animals with tumors, tumor multiplicity, and incidence of malignant skin tumors. Catechol applied alone did not induce any tumors; with PMA alone there were significant incidences of benign and malignant tumors, e.g., at a dose of only 0.5 ..mu..g per application, 15 of 30 animals had 28 tumors, 5 of which were squamous carcinomas. In two-stage carcinogenesis experiments with 7,12-dimethylbenz(a)anthracene (DMBA) as initiator and PMA as promoter, SENCAR mice showed a greater susceptibility to tumor induction when compared to ICR/Ha mice used in earlier work. This susceptibility was most notable in terms of rate of tumor appearance and tumor multiplicity.

  14. Increased intestinal protein permeability in a model of lung injury induced by phorbol myristate acetate.

    PubMed

    St John, R C; Mizer, L A; Weisbrode, S E; Dorinsky, P M

    1991-11-01

    Multiple nonpulmonary organ failure is a frequent complication of the adult respiratory distress syndrome (ARDS), and contributes significantly to the high mortality rate associated with this disorder. Although previous studies suggest that systemic organ injury may be an integral component of ARDS, little is known about the specific functional alterations that occur in these target organs. The present study was designed, therefore, to test the hypothesis that endothelial damage, as assessed by microvascular permeability changes, develops in systemic organs in a model of acute lung injury. To test this postulate, the microvascular permeability for total protein was estimated using the steady-state relationship between the lymph (CL) to plasma (Cp) protein concentration ratio (i.e., CL/Cp) and lymph flow in autoperfused cat ileum preparations. Specifically, CL/Cp was measured in five cats, 2 h after acute lung injury was induced by intravenously administered phorbol myristate acetate (PMA), 15 micrograms/kg, and the results were compared with those of seven time-matched control animals. Prior to PMA infusion, the PaO2/FIO2 ratio was 451 +/- 28 in both groups and remained unchanged (486 +/- 26) in the control group. By contrast, the PaO2/FIO2 ratio fell to 275 +/- 95 after PMA infusion (p less than 0.05). In addition, whereas CL/Cp was 0.099 +/- 0.008 in the control animals, it increased to 0.36 +/- 0.06 in the PMA-injured animals (p less than 0.01). In summary, this study demonstrated that in this model of acute lung injury produced by PMA-induced activation of circulating inflammatory cells, both acute lung injury and systemic organ injury (i.e., morphologic and permeability alterations) occurred.

  15. Adsorbed Proteins Influence the Biological Activity and Molecular Targeting of Nanomaterials

    SciTech Connect

    Dutta, Debamitra; Sundaram, S. K.; Teeguarden, Justin G.; Riley, Brian J.; Fifield, Leonard S.; Jacobs, Jon M.; Addleman, Raymond S.; Kaysen, George A.; Moudgil, Brij M.; Weber, Thomas J.

    2007-11-01

    The possible combination of unique physicochemical properties operating at unique sites of action within cells and tissues has led to considerable uncertainty surrounding nanomaterial toxic potential. Here we have investigated the relative importance of proteins adsorbed onto nanomaterial surfaces in guiding uptake and toxicity to determine whether a priori identification of adsorbed proteins will contribute to nanomaterial toxicity assessment. Albumin was identified as the major protein adsorbed onto single walled carbon nanotubes (SWCNTs) following incubation with fetal bovine or human serum/plasma, but not when plasma from the Nagase Analbuminemic Rat (NAR) was used, and precoating SWCNTs with a non-ionic surfactant (Pluronic F127) inhibited albumin adsorption. Damaged or structurally altered albumin is rapidly cleared by scavenger receptors. In the RAW 264.7 macrophage-like model, we observed that SWCNTs inhibited the induction of cyclooxygenase-2 (Cox-2) by lipopolysaccharide (LPS; 1 ng/ml, 6 hr) and this anti-inflammatory response was inhibited by fucoidan (scavenger receptor antagonist) and by precoating SWCNTs with Pluronic F127. Fucoidan also reduced the uptake of fluorescent SWCNTs (Alexa647) in RAW 264.7 cells. Albumin-coated SWCNTs reduced LPS-mediated Cox-2 induction. SWCNTs did not appear to reduce binding of a fluorescent LPS (Alexa488) to RAW 264.7 cells. The profile of proteins adsorbed onto amorphous silica (50 – 1000 nm) was qualitatively different, relative to SWCNTs, and coating amorphous silica with Pluronic F127 dramatically reduced protein binding and toxicity. Collectively, these observations are consistent with an important role for adsorbed proteins in guiding nanomaterial disposition and toxicity.

  16. Biological responses to engineered nanomaterials: Needs for the next decade

    SciTech Connect

    Murphy, Catherine J.; Vartanian, Ariane M.; Geiger, Franz M.; Hamers, Robert J.; Pedersen, Joel A.; Cui, Qiang; Haynes, Christy L.; Carlson, Erin E.; Hernandez, Rigoberto; Klaper, Rebecca D.; Orr, Galya; Rosenzweig, Ze'ev

    2015-06-09

    In this study, the interaction of nanomaterials with biomolecules, cells, and organisms is an enormously vital area of current research, with applications in nanoenabled diagnostics, imaging agents, therapeutics, and contaminant removal technologies. Yet the potential for adverse biological and environmental impacts of nanomaterial exposure is considerable and needs to be addressed to ensure sustainable development of nanomaterials. In this Outlook four research needs for the next decade are outlined: (i) measurement of the chemical nature of nanomaterials in dynamic, complex aqueous environments; (ii) real-time measurements of nanomaterial-biological interactions with chemical specificity; (iii) delineation of molecular modes of action for nanomaterial effects on living systems as functions of nanomaterial properties; and (iv) an integrated systems approach that includes computation and simulation across orders of magnitude in time and space.

  17. Carbon Nanomaterials and DNA: from Molecular Recognition to Applications.

    PubMed

    Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2016-03-15

    highly sensitive detection of ppm levels of SWNTs in cells, and the other monitored i-motif DNA formation. Further studies indicated that SWNTs could inhibit telomerase activity in living cells and cause telomere dysfunction, providing new insight into the biological effects of SWNTs. Then, some applications that are based on the interactions between graphene and DNA are also summarized. Combined with other nanomaterials, such as metal and upconversion nanoparticles, several hybrid nanomaterials were successfully constructed, and a series of DNA logic gates were successfully developed. Afterwards, the newcomer of the carbon nanomaterials family, carbon quantum dots (CQDs), were found to be capable of modulating right-handed B-form DNA to left-handed Z-form DNA. These were further used to design FRET logic gates that were based on the CQD-derived DNA conformational transition. Taking into account the remaining challenges and promising aspects, CNM-based DNA nanotechnology and its biomedical applications will attract more attention and produce new breakthroughs in the near future.

  18. Carbon Nanomaterials and DNA: from Molecular Recognition to Applications.

    PubMed

    Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2016-03-15

    highly sensitive detection of ppm levels of SWNTs in cells, and the other monitored i-motif DNA formation. Further studies indicated that SWNTs could inhibit telomerase activity in living cells and cause telomere dysfunction, providing new insight into the biological effects of SWNTs. Then, some applications that are based on the interactions between graphene and DNA are also summarized. Combined with other nanomaterials, such as metal and upconversion nanoparticles, several hybrid nanomaterials were successfully constructed, and a series of DNA logic gates were successfully developed. Afterwards, the newcomer of the carbon nanomaterials family, carbon quantum dots (CQDs), were found to be capable of modulating right-handed B-form DNA to left-handed Z-form DNA. These were further used to design FRET logic gates that were based on the CQD-derived DNA conformational transition. Taking into account the remaining challenges and promising aspects, CNM-based DNA nanotechnology and its biomedical applications will attract more attention and produce new breakthroughs in the near future. PMID:26907723

  19. National Survey of Workplaces Handling and Manufacturing Nanomaterials, Exposure to and Health Effects of Nanomaterials, and Evaluation of Nanomaterial Safety Data Sheets.

    PubMed

    Kim, Jeongho; Yu, Il Je

    2016-01-01

    A national survey on workplace environment nanomaterial handling and manufacturing was conducted in 2014. Workplaces relevant to nanomaterials were in the order of TiO2 (91), SiO2 (88), carbon black (84), Ag (35), Al2O3 (35), ZnO (34), Pb (33), and CeO2 (31). The survey results indicated that the number of workplaces handling or manufacturing nanomaterials was 340 (0.27% of total 126,846) workplaces. The number of nanomaterials used and products was 546 (1.60 per company) and 583 (1.71 per company), respectively. For most workplaces, the results on exposure to hazardous particulate materials, including nanomaterials, were below current OELs, yet a few workplaces were above the action level. As regards the health status of workers, 9 workers were diagnosed with a suspected respiratory occupational disease, where 7 were recommended for regular follow-up health monitoring. 125 safety data sheets (SDSs) were collected from the nanomaterial-relevant workplaces and evaluated for their completeness and reliability. Only 4 CNT SDSs (3.2%) included the term nanomaterial, while most nanomaterial SDSs were not regularly updated and lacked hazard information. When taken together, the current analysis provides valuable national-level information on the exposure and health status of workers that can guide the next policy steps for nanomaterial management in the workplace.

  20. National Survey of Workplaces Handling and Manufacturing Nanomaterials, Exposure to and Health Effects of Nanomaterials, and Evaluation of Nanomaterial Safety Data Sheets

    PubMed Central

    2016-01-01

    A national survey on workplace environment nanomaterial handling and manufacturing was conducted in 2014. Workplaces relevant to nanomaterials were in the order of TiO2 (91), SiO2 (88), carbon black (84), Ag (35), Al2O3 (35), ZnO (34), Pb (33), and CeO2 (31). The survey results indicated that the number of workplaces handling or manufacturing nanomaterials was 340 (0.27% of total 126,846) workplaces. The number of nanomaterials used and products was 546 (1.60 per company) and 583 (1.71 per company), respectively. For most workplaces, the results on exposure to hazardous particulate materials, including nanomaterials, were below current OELs, yet a few workplaces were above the action level. As regards the health status of workers, 9 workers were diagnosed with a suspected respiratory occupational disease, where 7 were recommended for regular follow-up health monitoring. 125 safety data sheets (SDSs) were collected from the nanomaterial-relevant workplaces and evaluated for their completeness and reliability. Only 4 CNT SDSs (3.2%) included the term nanomaterial, while most nanomaterial SDSs were not regularly updated and lacked hazard information. When taken together, the current analysis provides valuable national-level information on the exposure and health status of workers that can guide the next policy steps for nanomaterial management in the workplace. PMID:27556041

  1. National Survey of Workplaces Handling and Manufacturing Nanomaterials, Exposure to and Health Effects of Nanomaterials, and Evaluation of Nanomaterial Safety Data Sheets.

    PubMed

    Kim, Jeongho; Yu, Il Je

    2016-01-01

    A national survey on workplace environment nanomaterial handling and manufacturing was conducted in 2014. Workplaces relevant to nanomaterials were in the order of TiO2 (91), SiO2 (88), carbon black (84), Ag (35), Al2O3 (35), ZnO (34), Pb (33), and CeO2 (31). The survey results indicated that the number of workplaces handling or manufacturing nanomaterials was 340 (0.27% of total 126,846) workplaces. The number of nanomaterials used and products was 546 (1.60 per company) and 583 (1.71 per company), respectively. For most workplaces, the results on exposure to hazardous particulate materials, including nanomaterials, were below current OELs, yet a few workplaces were above the action level. As regards the health status of workers, 9 workers were diagnosed with a suspected respiratory occupational disease, where 7 were recommended for regular follow-up health monitoring. 125 safety data sheets (SDSs) were collected from the nanomaterial-relevant workplaces and evaluated for their completeness and reliability. Only 4 CNT SDSs (3.2%) included the term nanomaterial, while most nanomaterial SDSs were not regularly updated and lacked hazard information. When taken together, the current analysis provides valuable national-level information on the exposure and health status of workers that can guide the next policy steps for nanomaterial management in the workplace. PMID:27556041

  2. Saccharin and Cyclamate Inhibit Binding of Epidermal Growth Factor

    NASA Astrophysics Data System (ADS)

    Lee, L. S.

    1981-02-01

    The binding of 125I-labeled mouse epidermal growth factor (EGF) to 18 cell lines, including HeLa (human carcinoma), MDCK (dog kidney cells), HTC (rat hepatoma), K22 (rat liver), HF (human foreskin), GM17 (human skin fibroblasts), XP (human xeroderma pigmentosum fibroblasts), and 3T3-L1 (mouse fibroblasts), was inhibited by saccharin and cyclamate. The human cells were more sensitive to inhibition by these sweeteners than mouse or rat cells. EGF at doses far above the physiological levels reversed the inhibition in rodent cells but not in HeLa cells. In HeLa cells, the doses of saccharin and cyclamate needed for 50% inhibition were 3.5 and 9.3 mg/ml, respectively. Glucose, 2-deoxyglucose, sucrose, and xylitol did not inhibit EGF binding. Previous studies have shown that phorbol esters, strongly potent tumor promoters, also inhibit EGF binding to tissue culture cells. To explain the EGF binding inhibition by such greatly dissimilar molecules as phorbol esters, saccharin, and cyclamate, it is suggested that they operate through the activation of a hormone response control unit.

  3. Multimedia Environmental Distribution of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Liu, Haoyang Haven

    Engineered nanomaterials (ENMs), which may be released to the environment due to human-related activities, can move across environmental phase boundaries and be found in most media. Given the rapid development and growing applications of nanotechnology, there is concern and thus the need to assess the potential environmental impact associated with ENMs. Accordingly, a modeling platform was developed to enable evaluation of the dynamic multimedia environmental distribution of ENMs (MendNano) and the range of potential exposure concentrations of ENMs. The MendNano was based on a dynamic multimedia compartmental modeling approach that was guided by detailed analysis of the agglomeration of ENMs, life-cycle analysis based estimates of their potential release to the environment, and incorporation of mechanistic sub-models of various intermedia transport processes. Model simulations for various environmental scenarios indicated that ENM accumulation in the sediment increased significantly with increased ENMs attachment to suspended solids in water. Atmospheric dry and wet depositions can be important pathways for ENMs input to the terrestrial environment in the absence of direct and distributed ENM release to soil. Increased ENM concentration in water due to atmospheric deposition (wet and dry) is expected as direct ENM release to water diminishes. However, for soluble ENMs dissolution can be the dominant pathway for suspended ENM removal from water even compared to advective transport. For example, simulations for Los Angeles showed that dry deposition, rain scavenging, and wind dilution can remove 90% of ENMs from the atmospheric airshed in ~100-230 days, ~2-6 hrs, and ~0.5-2 days, respectively. For the evaluated ENMs (metal, metal oxides, carbon nanotubes (CNT), nanoclays), mass accumulation in the multimedia environment was mostly in the soil and sediment. Additionally, simulation results for TiO2 in Los Angeles demonstrates that the ENM concentrations in air and

  4. Multimedia Environmental Distribution of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Liu, Haoyang Haven

    Engineered nanomaterials (ENMs), which may be released to the environment due to human-related activities, can move across environmental phase boundaries and be found in most media. Given the rapid development and growing applications of nanotechnology, there is concern and thus the need to assess the potential environmental impact associated with ENMs. Accordingly, a modeling platform was developed to enable evaluation of the dynamic multimedia environmental distribution of ENMs (MendNano) and the range of potential exposure concentrations of ENMs. The MendNano was based on a dynamic multimedia compartmental modeling approach that was guided by detailed analysis of the agglomeration of ENMs, life-cycle analysis based estimates of their potential release to the environment, and incorporation of mechanistic sub-models of various intermedia transport processes. Model simulations for various environmental scenarios indicated that ENM accumulation in the sediment increased significantly with increased ENMs attachment to suspended solids in water. Atmospheric dry and wet depositions can be important pathways for ENMs input to the terrestrial environment in the absence of direct and distributed ENM release to soil. Increased ENM concentration in water due to atmospheric deposition (wet and dry) is expected as direct ENM release to water diminishes. However, for soluble ENMs dissolution can be the dominant pathway for suspended ENM removal from water even compared to advective transport. For example, simulations for Los Angeles showed that dry deposition, rain scavenging, and wind dilution can remove 90% of ENMs from the atmospheric airshed in ~100-230 days, ~2-6 hrs, and ~0.5-2 days, respectively. For the evaluated ENMs (metal, metal oxides, carbon nanotubes (CNT), nanoclays), mass accumulation in the multimedia environment was mostly in the soil and sediment. Additionally, simulation results for TiO2 in Los Angeles demonstrates that the ENM concentrations in air and

  5. The Phorbol Ester Fraction from Jatropha curcas Seed Oil: Potential and Limits for Crop Protection against Insect Pests

    PubMed Central

    Ratnadass, Alain; Wink, Michael

    2012-01-01

    The physic nut shrub, Jatropha curcas (Euphorbiaceae), has been considered as a “miracle tree”, particularly as a source of alternate fuel. Various extracts of the plant have been reported to have insecticidal/acaricidal or molluscicidal/anthelminthic activities on vectors of medical or veterinary interest or on agricultural or non-agricultural pests. Among those extracts, the phorbol ester fraction from seed oil has been reported as a promising candidate for use as a plant-derived protectant of a variety of crops, from a range of pre-harvest and post-harvest insect pests. However, such extracts have not been widely used, despite the “boom” in the development of the crop in the tropics during recent years, and societal concerns about overuse of systemic chemical pesticides. There are many potential explanations to such a lack of use of Jatropha insecticidal extracts. On the one hand, the application of extracts potentially harmful to human health on stored food grain, might not be relevant. The problem of decomposition of phorbol esters and other compounds toxic to crop pests in the field needing further evaluation before such extracts can be widely used, may also be a partial explanation. High variability of phorbol ester content and hence of insecticidal activity among physic nut cultivars/ecotypes may be another. Phytotoxicity to crops may be further limitation. Apparent obstacles to a wider application of such extracts are the costs and problems involved with registration and legal approval. On the other hand, more studies should be conducted on molluscicidal activity on slugs and land snails which are major pests of crops, particularly in conservation agriculture systems. Further evaluation of toxicity to natural enemies of insect pests and studies on other beneficial insects such as pollinators are also needed. PMID:23203190

  6. New Insights on the Influence of Organic Co-Contaminants on the Aquatic Toxicology of Carbon Nanomaterials.

    PubMed

    Sanchís, Josep; Olmos, Mar; Vincent, Phil; Farré, Marinella; Barceló, Damià

    2016-01-19

    At present, there is a lack of understanding of the combined ecotoxicity of carbon-based nanomaterials and co-contaminants. In this paper, we report on the toxicity of three carbon nanomaterials (fullerene-soot, multiwall carbon nanotubes, and graphene). Two standardized toxicity bioassays, the immobilization of the invertebrate Daphnia magna and the bioluminescence inhibition of the marine bacteria Vibrio fischeri, have been used. Synergistic and antagonistic effects of binary mixtures composed of fullerene soot and organic co-contaminants as malathion, glyphosate, diuron, triclosan, and nonylphenol were assessed. The isobologram method was used to evaluate the concentrations producing an effect, in comparison to those effects expected by a simple additive approach. In this study, antagonism was the predominant effect. However, synergism was also observed as in the case of D. magna exposed to mixtures of malathion and fullerene soot. D. magna was shown to be the most sensitive assay when carbon nanomaterials were present. Toxicity to D. magna was as follows: fullerene soot > multiwall carbon nanotubes > graphene. These results were proportional to the size of aggregates, smaller aggregates being the most toxic. The vector function of nanomaterials aggregates and the unexpected release inside living organisms was proven for malathion. These results highlight new insights on the risks associated with the release of carbon nanomaterials into the environment. PMID:26694946

  7. Regulation of plasminogen activator in 3T3 cells: effect of phorbol myristate acetate on subcellular distribution and molecular weight

    PubMed Central

    1981-01-01

    The tumor promoter, phorbol myristate acetate (PMA), stimulates plasminogen activator production and extracellular release in confluent Swiss 3T3 cells. Coordinated with the increased extracellular release is a redistribution of the activity into plasma membrane-enriched fractions and a shift in the predominant molecular weight species from 75,000 to 49,000 daltons. The evidence suggests that PMA induces the formation of the 49,000 dalton species which is preferentially located in plasma membrane-enriched fractions. PMID:7197280

  8. Association of phorbol ester-induced hyperphosphorylation and reversible regulation of transferrin membrane receptors in HL60 cells.

    PubMed Central

    May, W S; Jacobs, S; Cuatrecasas, P

    1984-01-01

    Phorbol diesters are tumor-promoting agents that cause differentiation of HL60 human leukemic cells and concomitantly alter surface transferrin-receptor expression [Rovera, G., Ferreo, D., Pagliardi, G. L., Vartikar, J., Pessano, S., Bottero, L., Abraham, S. & Lebman, D. (1982) Ann. N.Y. Acad. Sci. 397, 211-220]. Transferrin-receptor regulation is shown here to result from a rapid and reversible internalization process that is temporally associated with reversible increased phosphorylation (hyperphosphorylation) of the transferrin receptor. Such a reversible mechanism involving regulation of these surface proteins could result in the rapid generation of an early signal for HL60 cellular differentiation. Images PMID:6326098

  9. WISP-2/CCN5 is involved as a novel signaling intermediate in phorbol ester-protein kinase Calpha-mediated breast tumor cell proliferation.

    PubMed

    Sengupta, Krishanu; Banerjee, Snigdha; Dhar, Kakali; Saxena, Neela K; Mehta, Smita; Campbell, Donald R; Banerjee, Sushanta K

    2006-09-01

    PMA and active phorbol esters stimulate the proliferation of various tumor cells, including ER-positive human breast tumor cell lines. However, the specific signaling pathways involved in the PMA-induced mitogenic effect on breast tumor cells have not been fully elucidated. In the present study, we explored the mechanisms associated with the mitogenic influence of PMA on breast tumor cells. Following an acute exposure (i.e., within 2 to 6 h) to PMA (50 nM), a mitogenic effect was observed on WISP-2/CCN5-positive breast tumor cell lines, including MCF-7, ZR-75-1 and SKBR-3 cells, and induction of WISP-2/CCN5 mRNA expression paralleled the observed mitogenic proliferation. This effect was undetected in WISP-2/CCN5 negative MDA-MB-231 breast tumor cells or human mammary epithelial cells with or without ER-alpha transfection. The mitogenic effect of PMA was perturbed by short hairpin RNA (shRNA)-mediated inhibition of WISP-2/CCN5 signaling in MCF-7 cells. Moreover, the upregulation of WISP-2/CCN5 by PMA is not ER dependent but is instead mediated through a complex PKCalpha-MAPK/ERK and SAPK/JNK signaling pathway, which leads to growth stimulation of MCF-7 breast tumor cells. These series of experiments provide the first evidence that WISP-2/CCN5 is a novel signaling molecule that critically participates in the mitogenic action of PMA on noninvasive, WISP-2/CCN5-positive breast tumor cells through PKCalpha-dependent, multiple molecular signal transduction pathways.

  10. Ionic, electrical, and secretory effects of protein kinase C activation in mouse pancreatic B-cells: studies with a phorbol ester

    SciTech Connect

    Bozem, M.; Nenquin, M.; Henquin, J.C.

    1987-09-01

    The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was used to study the effects of protein kinase C activation on stimulus-secretion coupling in mouse pancreatic B-cells. At a nonstimulatory concentration of glucose (3 mM), 100 nM TPA, but not 10 nM TPA, slightly and slowly increased insulin release and /sup 45/Ca/sup 2 +/ efflux and decreased /sup 86/Rb/sup +/ efflux, but did not affect the membrane potential of B-cells. At a threshold concentration of glucose (7 mM), 100 nM TPA markedly increased insulin release without triggering electrical activity in B-cells. At a stimulatory concentration of glucose (10 mM), TPA caused a dose-dependent irreversible increase in insulin release, /sup 45/Ca/sup 2 +/ efflux, and /sup 86/Rb/sup +/ efflux and slightly augmented islet cAMP levels. Omission of extracellular Ca/sup 2 +/ abolished the effects of 10 nM TPA and partially inhibited those of 100 nM TPA on insulin release and /sup 45/Ca/sup 2 +/ efflux. In contrast, their effect on /sup 86/Rb/sup +/ efflux was paradoxically augmented. Glucose-induced electrical activity in B-cells was only marginally affected by TPA; the duration of the slow waves with spikes was not modified, but a small shortening of the polarized intervals raised their frequency and slightly increased the overall activity. This increase was significant only with 10 nM TPA, whereas only 100 nM TPA brought about a minute increase in /sup 45/Ca/sup 2 +/ influx. These results thus show that TPA induces insulin release or potentiates glucose-induced insulin release without mimicking or amplifying the initial ionic and electrical signals triggered by glucose. They suggest that protein kinase C activation affects stimulus-secretion coupling by modulating intracellular and/or nonelectrogenic membrane events.

  11. Assessing the protection of the nanomaterial workforce.

    PubMed

    Schulte, Paul A; Iavicoli, Ivo; Rantanen, Jorma H; Dahmann, Dirk; Iavicoli, Sergio; Pipke, Rüdiger; Guseva Canu, Irina; Boccuni, Fabio; Ricci, Maximo; Polci, Maria Letizia; Sabbioni, Enrico; Pietroiusti, Antonio; Mantovani, Elvio

    2016-09-01

    Responsible development of any technology, including nanotechnology, requires protecting workers, the first people to be exposed to the products of the technology. In the case of nanotechnology, this is difficult to achieve because in spite of early evidence raising health and safety concerns, there are uncertainties about hazards and risks. The global response to these concerns has been the issuance by authoritative agencies of precautionary guidance to strictly control exposures to engineered nanomaterials (ENMs). This commentary summarizes discussions at the "Symposium on the Health Protection of Nanomaterial Workers" held in Rome (25 and 26 February 2015). There scientists and practitioners from 11 countries took stock of what is known about hazards and risks resulting from exposure to ENMs, confirmed that uncertainties still exist, and deliberated on what it would take to conduct a global assessment of how well workers are being protected from potentially harmful exposures.

  12. Characterization of Nanomaterials by Physical Methods

    NASA Astrophysics Data System (ADS)

    Rao, C. N. R.; Biswas, Kanishka

    2009-07-01

    Much progress in nanoscience and nanotechnology has been made in the past few years thanks to the increased availability of sophisticated physical methods to characterize nanomaterials. These techniques include electron microscopy and scanning probe microscopies, in addition to standard techniques such as X-ray and neutron diffraction, X-ray scattering, and various spectroscopies. Characterization of nanomaterials includes the determination not only of size and shape, but also of the atomic and electronic structures and other important properties. In this article we describe some of the important methods employed for characterization of nanostructures, describing a few case studies for illustrative purposes. These case studies include characterizations of Au, ReO3, and GaN nanocrystals; ZnO, Ni, and Co nanowires; inorganic and carbon nanotubes; and two-dimensional graphene.

  13. Carbon Nanomaterials as Reinforcements for Composites

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, S. L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Carbon nanomaterials including fellerenes, nanotubes (CNT) and nanofibers have been proposed for many applications. One of applications is to use the carbon nanomaterials as reinforcements for composites, especially for polymer matrices. Carbon nanotubes is a good reinforcement for lightweight composite applications due to its low mass density and high Young's modulus. Two obscures need to overcome for carbon nanotubes as reinforcements in composites, which are large quantity production and functioning the nanotubes. This presentation will discuss the carbon nanotube growth by chemical vapor deposition. In order to reduce the cost of producing carbon nanotubes as well as preventing the sliding problems, carbon nanotubes were also synthesized on carbon fibers. The synthesis process and characterization results of nanotubes and nanotubes/fibers will be discussed in the presentation.

  14. Engineering the heart: Evaluation of conductive nanomaterials for improving implant integration and cardiac function

    PubMed Central

    Zhou, Jin; Chen, Jun; Sun, Hongyu; Qiu, Xiaozhong; Mou, Yongchao; Liu, Zhiqiang; Zhao, Yuwei; Li, Xia; Han, Yao; Duan, Cuimi; Tang, Rongyu; Wang, Chunlan; Zhong, Wen; Liu, Jie; Luo, Ying; (Mengqiu) Xing, Malcolm; Wang, Changyong

    2014-01-01

    Recently, carbon nanotubes together with other types of conductive materials have been used to enhance the viability and function of cardiomyocytes in vitro. Here we demonstrated a paradigm to construct ECTs for cardiac repair using conductive nanomaterials. Single walled carbon nanotubes (SWNTs) were incorporated into gelatin hydrogel scaffolds to construct three-dimensional ECTs. We found that SWNTs could provide cellular microenvironment in vitro favorable for cardiac contraction and the expression of electrochemical associated proteins. Upon implantation into the infarct hearts in rats, ECTs structurally integrated with the host myocardium, with different types of cells observed to mutually invade into implants and host tissues. The functional measurements showed that SWNTs were essential to improve the performance of ECTs in inhibiting pathological deterioration of myocardium. This work suggested that conductive nanomaterials hold therapeutic potential in engineering cardiac tissues to repair myocardial infarction. PMID:24429673

  15. Engineering the heart: Evaluation of conductive nanomaterials for improving implant integration and cardiac function

    NASA Astrophysics Data System (ADS)

    Zhou, Jin; Chen, Jun; Sun, Hongyu; Qiu, Xiaozhong; Mou, Yongchao; Liu, Zhiqiang; Zhao, Yuwei; Li, Xia; Han, Yao; Duan, Cuimi; Tang, Rongyu; Wang, Chunlan; Zhong, Wen; Liu, Jie; Luo, Ying; (Mengqiu) Xing, Malcolm; Wang, Changyong

    2014-01-01

    Recently, carbon nanotubes together with other types of conductive materials have been used to enhance the viability and function of cardiomyocytes in vitro. Here we demonstrated a paradigm to construct ECTs for cardiac repair using conductive nanomaterials. Single walled carbon nanotubes (SWNTs) were incorporated into gelatin hydrogel scaffolds to construct three-dimensional ECTs. We found that SWNTs could provide cellular microenvironment in vitro favorable for cardiac contraction and the expression of electrochemical associated proteins. Upon implantation into the infarct hearts in rats, ECTs structurally integrated with the host myocardium, with different types of cells observed to mutually invade into implants and host tissues. The functional measurements showed that SWNTs were essential to improve the performance of ECTs in inhibiting pathological deterioration of myocardium. This work suggested that conductive nanomaterials hold therapeutic potential in engineering cardiac tissues to repair myocardial infarction.

  16. Macro-ions collapse leading to hybrid bio-nanomaterials.

    SciTech Connect

    Achyuthan, Komandoor E.

    2009-10-01

    I used supramolecular self-assembling cyanine and the polyamine spermine binding to Escherichia coli genomic DNA as a model for DNA collapse during high throughput screening. Polyamine binding to DNA converts the normally right handed B-DNA into left handed Z-DNA conformation. Polyamine binding to DNA was inhibited by the supramolecular self-assembling cyanine. Self-assembly of cyanine upon DNA scaffold was likewise competitively inhibited by spermine as signaled by fluorescence quench from DNA-cyanine ensemble. Sequence of DNA exposure to cyanine or spermine was critical in determining the magnitude of fluorescence quench. Methanol potentiated spermine inhibition by >10-fold. The IC{sub 50} for spermine inhibition was 0.35 {+-} 0.03 {micro}M and the association constant Ka was 2.86 x 10{sup -6}M. Reversibility of the DNA-polyamine interactions was evident from quench mitigation at higher concentrations of cyanine. System flexibility was demonstrated by similar spermine interactions with {lambda}DNA. The choices and rationale regarding the polyamine, the cyanine dye as well as the remarkable effects of methanol are discussed in detail. Cyanine might be a safer alternative to the mutagenic toxin ethidium bromide for investigating DNA-drug interactions. The combined actions of polyamines and alcohols mediate DNA collapse producing hybrid bio-nanomaterials with novel signaling properties that might be useful in biosensor applications. Finally, this work will be submitted to Analytical Sciences (Japan) for publication. This journal published our earlier, related work on cyanine supramolecular self-assembly upon a variety of nucleic acid scaffolds.

  17. Pharmacological potential of bioactive engineered nanomaterials.

    PubMed

    Caputo, Fanny; De Nicola, Milena; Ghibelli, Lina

    2014-11-01

    In this study we present an overview of the recent results of a novel approach to antioxidant and anticancer therapies, consisting in the administration of intrinsically active nano-structured particles. Their particulate (as opposed to molecular) nature allows designing multifunctional platforms via the binding of molecular determinants, including targeting molecules and chemotherapy drugs, thereby facilitating their localization at the desired site. The intrinsic activity of nanomaterials with pharmacological potential include peculiar trans-excitation reactions that render them able to transform radiofrequency, UV, visible or infrared radiations into cytocidal reactive oxygen species or heat, thereby inducing local cytotoxity in selected areas. The use of such devices has been shown to improve the efficacy of antitumor chemo- and radio-therapies, increasing the selectivity of the cytocidal effects, and reducing systemic side effects. In addition, catalytic nanomaterials such as cerium oxide nanoparticles can perform energy-free antioxidant cycles that scavenge the most noxious reactive oxygen species via SOD- and catalase-mimetic activities. A vast body of in vivo and in vitro studies has demonstrated that they reduce the damage induced by environmental stress and ameliorate an impressive series of clinically relevant oxidation-related pathologies. Similar effects are reported for carbon-based materials such as fullerenes. Overall, great improvements are expected by this novel approach. However, caution must be posed due to the poor knowledge of possible adverse body reactions against these novel devices, thoroughly analyzing the biocompatibility of these nanomaterials, especially concerning the biokinetics and the problems potentially caused by long term retention of non-biodegradable inorganic nanomaterials. PMID:25175739

  18. Biomedical Applications of Zinc Oxide Nanomaterials

    PubMed Central

    Zhang, Yin; Nayak, Tapas R.; Hong, Hao; Cai, Weibo

    2013-01-01

    Nanotechnology has witnessed tremendous advancement over the last several decades. Zinc oxide (ZnO), which can exhibit a wide variety of nanostructures, possesses unique semiconducting, optical, and piezoelectric properties hence has been investigated for a wide variety of applications. One of the most important features of ZnO nanomaterials is low toxicity and biodegradability. Zn2+ is an indispensable trace element for adults (~10 mg of Zn2+ per day is recommended) and it is involved in various aspects of metabolism. Chemically, the surface of ZnO is rich in -OH groups, which can be readily functionalized by various surface decorating molecules. In this review article, we summarized the current status of the use of ZnO nanomaterials for biomedical applications, such as biomedical imaging (which includes fluorescence, magnetic resonance, positron emission tomography, as well as dual-modality imaging), drug delivery, gene delivery, and biosensing of a wide array of molecules of interest. Research in biomedical applications of ZnO nanomaterials will continue to flourish over the next decade, and much research effort will be needed to develop biocompatible/biodegradable ZnO nanoplatforms for potential clinical translation. PMID:24206130

  19. Nanomaterials for biosensing applications: A Review

    NASA Astrophysics Data System (ADS)

    Holzinger, Michael; Le Goff, Alan; Cosnier, Serge

    2014-08-01

    A biosensor device is defined by its biological, or bioinspired receptor unit with unique specificities towards corresponding analytes. These analytes are often of biological origin like DNAs or proteins from the immune system (antibodies, antigens) of diseases or infections. Such analytes can also be simple molecules like glucose or pollutants when a biological receptor unit with particular specificity is available. One of many other challenges in biosensor development is the efficient signal capture of the biological recognition event (transduction). Such transducers translate the interaction of the analyte with the biological element into electrochemical, electrochemiluminescent, magnetic, gravimetric, or optical signals. In order to increase sensitivities and to lower detection limits down to even individual molecules, nanomaterials are promising candidates due to the possibility to immobilize an enhanced quantity of bioreceptor units at reduced volumes and even to act itself as transduction element. Among such nanomaterials, gold nanoparticles, semi-conductor quantum dots, polymer nanoparticles, carbon nanotubes, nanodiamonds, and graphene are intensively studied. Due to the vast evolution of this research field, this review summarizes in a non-exhaustive way the advantages of nanomaterials by focusing on nano-objects which provide further beneficial properties than “just” an enhanced surface area.

  20. Synthesis of silica based porous nanomaterials

    NASA Astrophysics Data System (ADS)

    Mueller, Paul S.

    Silica is one of the most abundant elements on the planet, has flexible bonding properties and generally excellent stability. Because of these properties, silica has been a vital component in technologies ranging from ancient glassware to modern supercomputers. Silica is able to form a wide range of materials both alone and as a component of larger material frameworks. Porous silica based nanomaterials are rapidly growing in importance because of their many applications in a wide variety of fields. This thesis focuses on the synthesis of silica based porous nanomaterials: nanocrystalline zeolites, mesoporous silica nanoparticles, and iron oxide core/shell nanocomposites. The synthetic conditions of these materials were varied in order to maximize efficiency, minimize environmental impact, and produce high quality material with far reaching potential applications. The materials were characterized by physicochemical techniques including Transmission Electron Microscopy, Dynamic Light Scattering, Powder X-Ray Diffraction, Solid State NMR, and Nitrogen Adsorption Isotherms. The materials were evaluated and conditions were controlled to produce high yields of quality nanomaterials and hypothesize methods for further synthetic control. The products will be used in studies involving nanoparticle toxicity, environmental remediation, and drug delivery.

  1. Ras activation in response to phorbol ester proceeds independently of the EGFR via an unconventional nucleotide-exchange factor system in COS-7 cells.

    PubMed

    Rubio, Ignacio; Rennert, Knut; Wittig, Ute; Beer, Katrin; Dürst, Matthias; Stang, Stacey L; Stone, Jim; Wetzker, Reinhard

    2006-09-01

    Ras is a major mediator of PE (phorbol ester) effects in mammalian cells. Various mechanisms for PE activation of Ras have been reported [Downward, Graves, Warne, Rayter and Cantrell (1990) Nature (London) 346, 719-723; Shu, Wu, Mosteller and Broek (2002) Mol. Cell. Biol. 22, 7758-7768; Roose, Mollenauer, Gupta, Stone and Weiss (2005) Mol. Cell. Biol. 25, 4426-4441; Grosse, Roelle, Herrlich, Höhn and Gudermann (2000) J. Biol. Chem. 275, 12251-12260], including pathways that target GAPs (GTPase-activating proteins) for inactivation and those that result in activation of GEFs (guanine nucleotide-exchange factors) Sos (son of sevenless homologue) or RasGRP (RAS guanyl releasing protein). However, a biochemical link between PE and GAP inactivation is missing and GEF stimulation is hard to reconcile with the observation that dominant-negative S17N-Ras does not compromise Ras-dependent ERK (extracellular-signal-regulated kinase) activation by PE. We have addressed this controversy and carried out an in-depth biochemical study of PE-induced Ras activation in COS-7 cells. Using a cell-permeabilization approach to monitor nucleotide exchange on Ras, we demonstrate that PE-induced Ras-GTP accumulation results from GEF stimulation. Nucleotide exchange stimulation by PE is prevented by PKC (protein kinase C) inhibition but not by EGFR [EGF (epidermal growth factor) receptor] blockade, despite the fact that EGFR inhibition aborts basal and PE-induced Shc (Src homology and collagen homology) phosphorylation and Shc-Grb2 (growth-factor-receptor-bound protein 2) association. In fact, EGFR inhibition ablates basal nucleotide exchange on Ras in growth-arrested COS-7 cells. These data disclose the existence of two separate GEF systems that operate independently from each other to accomplish PE-dependent formation of Ras-GTP and to maintain resting Ras-GTP levels respectively. We document that COS-7 cells do not express RasGRP and present evidence that the PE-responsive GEF system

  2. Biological Responses to Engineered Nanomaterials: Needs for the Next Decade

    PubMed Central

    2015-01-01

    The interaction of nanomaterials with biomolecules, cells, and organisms is an enormously vital area of current research, with applications in nanoenabled diagnostics, imaging agents, therapeutics, and contaminant removal technologies. Yet the potential for adverse biological and environmental impacts of nanomaterial exposure is considerable and needs to be addressed to ensure sustainable development of nanomaterials. In this Outlook four research needs for the next decade are outlined: (i) measurement of the chemical nature of nanomaterials in dynamic, complex aqueous environments; (ii) real-time measurements of nanomaterial–biological interactions with chemical specificity; (iii) delineation of molecular modes of action for nanomaterial effects on living systems as functions of nanomaterial properties; and (iv) an integrated systems approach that includes computation and simulation across orders of magnitude in time and space. PMID:27162961

  3. Biological responses to engineered nanomaterials: Needs for the next decade

    DOE PAGES

    Murphy, Catherine J.; Vartanian, Ariane M.; Geiger, Franz M.; Hamers, Robert J.; Pedersen, Joel A.; Cui, Qiang; Haynes, Christy L.; Carlson, Erin E.; Hernandez, Rigoberto; Klaper, Rebecca D.; et al

    2015-06-09

    In this study, the interaction of nanomaterials with biomolecules, cells, and organisms is an enormously vital area of current research, with applications in nanoenabled diagnostics, imaging agents, therapeutics, and contaminant removal technologies. Yet the potential for adverse biological and environmental impacts of nanomaterial exposure is considerable and needs to be addressed to ensure sustainable development of nanomaterials. In this Outlook four research needs for the next decade are outlined: (i) measurement of the chemical nature of nanomaterials in dynamic, complex aqueous environments; (ii) real-time measurements of nanomaterial-biological interactions with chemical specificity; (iii) delineation of molecular modes of action for nanomaterialmore » effects on living systems as functions of nanomaterial properties; and (iv) an integrated systems approach that includes computation and simulation across orders of magnitude in time and space.« less

  4. Nano-bio effects: interaction of nanomaterials with cells

    NASA Astrophysics Data System (ADS)

    Cheng, Liang-Chien; Jiang, Xiumei; Wang, Jing; Chen, Chunying; Liu, Ru-Shi

    2013-04-01

    With the advancements in nanotechnology, studies on the synthesis, modification, application, and toxicology evaluation of nanomaterials are gaining increased attention. In particular, the applications of nanomaterials in biological systems are attracting considerable interest because of their unique, tunable, and versatile physicochemical properties. Artificially engineered nanomaterials can be well controlled for appropriate usage, and the tuned physicochemical properties directly influence the interactions between nanomaterials and cells. This review summarizes recently synthesized major nanomaterials that have potential biomedical applications. Focus is given on the interactions, including cellular uptake, intracellular trafficking, and toxic response, while changing the physicochemical properties of versatile materials. The importance of physicochemical properties such as the size, shape, and surface modifications of the nanomaterials in their biological effects is also highlighted in detail. The challenges of recent studies and future prospects are presented as well. This review benefits relatively new researchers in this area and gives them a systematic overview of nano-bio interaction, hopefully for further experimental design.

  5. Insulin and phorbol myristic acetate induce ornithine decarboxylase in Reuber H35 rat hepatoma cells by different mechanisms.

    PubMed

    Goodman, S A; Esau, B; Koontz, J W

    1988-11-01

    Reuber H35 rat hepatoma cells respond to insulin or to tumor promoting phorbol esters with an increase in ornithine decarboxylase enzyme activity. This occurs in a time- and dose-dependent manner with both types of agonist. We report here that the increase in ornithine decarboxylase activity with optimal concentrations of both agonists is additive. Furthermore, the initial increase is dependent on continued RNA and protein synthesis. We also find that both of these agonists cause an increase in mRNA coding for ornithine decarboxylase in a time- and dose-dependent manner which suggests that the increase in enzyme activity can be accounted for by the increase in transcript levels. The difference in the time course of induction by the agonists, the additivity of induction by the two agonists, the differential sensitivity of induction to cycloheximide and RNA synthesis inhibitors, and the observation that phorbol myristic acetate causes a further increase in ornithine decarboxylase activity and transcript levels in cells already maximally induced by insulin suggest that these two agonists act through separate mechanisms.

  6. Phorbol esters and A23187 regulate Na/sup +/=K/sup +/-pump activity in pancreatic acinar cells

    SciTech Connect

    Hootman, S.R.; Brown, M.E.; Williams, J.A.

    1987-04-01

    To clarify the subcellular mechanisms that mediate stimulation of Na/sup +/-K/sup +/-pump activity in pancreatic acinar cells by cholinergic agonists, the authors examined the effects of the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) and the Ca/sup 2 +/ ionophore A23187 on (/sup 3/H)ouabain binding to dispersed guinea pig pancreatic acinar cells under conditions in which binding reflects the average rate of pump cycling. The phorbol ester more than doubled Na/sup +/-K/sup +/-pump activity as did the diacylglycerol analogue, 1-oleoyl-2-acetolyl-sn-3-glycerol. A23187 increased pump activity by a maximum of 31% at 0.3 ..mu..M but was progressively inhibitory at higher concentrations. The stimulatory effects of TPA and A23187 were additive, although either secretagogue elicited a less than additive response when added together with a maximally effective concentration of the cholinergic agonist, carbachol. Removal of extracellular Ca/sup 2 +/ had little effect on the pump response to TPA and did not reduce the maximal effect of A23187 but abolished the inhibitory effect seen at high ionophore concentrations in Ca/sup 2 +/-containing medium. These results indicate that both Ca/sup 2 +/ and protein kinase c are involved in regulating Na/sup +/-K/sup +/-pump activity in the pancreatic acinar cell.

  7. Management of nanomaterials safety in research environment

    PubMed Central

    2010-01-01

    Despite numerous discussions, workshops, reviews and reports about responsible development of nanotechnology, information describing health and environmental risk of engineered nanoparticles or nanomaterials is severely lacking and thus insufficient for completing rigorous risk assessment on their use. However, since preliminary scientific evaluations indicate that there are reasonable suspicions that activities involving nanomaterials might have damaging effects on human health; the precautionary principle must be applied. Public and private institutions as well as industries have the duty to adopt preventive and protective measures proportionate to the risk intensity and the desired level of protection. In this work, we present a practical, 'user-friendly' procedure for a university-wide safety and health management of nanomaterials, developed as a multi-stakeholder effort (government, accident insurance, researchers and experts for occupational safety and health). The process starts using a schematic decision tree that allows classifying the nano laboratory into three hazard classes similar to a control banding approach (from Nano 3 - highest hazard to Nano1 - lowest hazard). Classifying laboratories into risk classes would require considering actual or potential exposure to the nanomaterial as well as statistical data on health effects of exposure. Due to the fact that these data (as well as exposure limits for each individual material) are not available, risk classes could not be determined. For each hazard level we then provide a list of required risk mitigation measures (technical, organizational and personal). The target 'users' of this safety and health methodology are researchers and safety officers. They can rapidly access the precautionary hazard class of their activities and the corresponding adequate safety and health measures. We succeed in convincing scientist dealing with nano-activities that adequate safety measures and management are promoting

  8. Nanomaterials in the application of tumor vaccines: advantages and disadvantages

    PubMed Central

    Li, XD; Gao, JY; Yang, Y; Fang, HY; Han, YJ; Wang, XM; Ge, W

    2013-01-01

    Tumor vaccines are a novel approach to the treatment of malignancy, and are attracting the attention of the medical profession. Nanomaterials have significant advantages in the preparation of a tumor vaccine, including their ability to penetrate and target cancer tissue and their antigenic properties. In this review, we focus on several nanomaterials, ie, carbon nanotubes, nanoemulsions, nanosized aluminum, and nanochitosan. Applications for these nanomaterials in nanovaccines and their biological characteristics, as well as their potential toxicity, are discussed. PMID:23776336

  9. Size effects of latex nanomaterials on lung inflammation in mice

    SciTech Connect

    Inoue, Ken-ichiro Takano, Hirohisa; Yanagisawa, Rie; Koike, Eiko; Shimada, Akinori

    2009-01-01

    Effects of nano-sized materials (nanomaterials) on sensitive population have not been well elucidated. This study examined the effects of pulmonary exposure to (latex) nanomaterials on lung inflammation related to lipopolysaccharide (LPS) or allergen in mice, especially in terms of their size-dependency. In protocol 1, ICR male mice were divided into 8 experimental groups that intratracheally received a single exposure to vehicle, latex nanomaterials (250 {mu}g/animal) with three sizes (25, 50, and 100 nm), LPS (75 {mu}g/animal), or LPS plus latex nanomaterials. In protocol 2, ICR male mice were divided into 8 experimental groups that intratracheally received repeated exposure to vehicle, latex nanomaterials (100 {mu}g/animal), allergen (ovalbumin: OVA; 1 {mu}g/animal), or allergen plus latex nanomaterials. In protocol 1, latex nanomaterials with all sizes exacerbated lung inflammation elicited by LPS, showing an overall trend of amplified lung expressions of proinflammatory cytokines. Furthermore, LPS plus nanomaterials, especially with size less than 50 nm, significantly elevated circulatory levels of fibrinogen, macrophage chemoattractant protein-1, and keratinocyte-derived chemoattractant, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. In protocol 2, latex nanomaterials with all sizes did not significantly enhance the pathophysiology of allergic asthma, characterized by eosinophilic lung inflammation and Igs production, although latex nanomaterials with less than 50 nm significantly induced/enhanced neutrophilic lung inflammation. These results suggest that latex nanomaterials differentially affect two types of (innate and adaptive immunity-dominant) lung inflammation.

  10. Exploring the possibilities and limitations of a nanomaterials genome.

    PubMed

    Qian, Chenxi; Siler, Todd; Ozin, Geoffrey A

    2015-01-01

    What are we going to do with the cornucopia of nanomaterials appearing in the open and patent literature, every day? Imagine the benefits of an intelligent and convenient means of categorizing, organizing, sifting, sorting, connecting, and utilizing this information in scientifically and technologically innovative ways by building a Nanomaterials Genome founded upon an all-purpose Periodic Table of Nanomaterials. In this Concept article, inspired by work on the Human Genome project, which began in 1989 together with motivation from the recent emergence of the Materials Genome project initiated in 2011 and the Nanoinformatics Roadmap 2020 instigated in 2010, we envision the development of a Nanomaterials Genome (NMG) database with the most advanced data-mining tools that leverage inference engines to help connect and interpret patterns of nanomaterials information. It will be equipped with state-of-the-art visualization techniques that rapidly organize and picture, categorize and interrelate the inherited behavior of complex nanomatter from the information programmed in its constituent nanomaterials building blocks. A Nanomaterials Genome Initiative (NMGI) of the type imagined herein has the potential to serve the global nanoscience community with an opportunity to speed up the development continuum of nanomaterials through the innovation process steps of discovery, structure determination and property optimization, functionality elucidation, system design and integration, certification and manufacturing to deployment in technologies that apply these versatile nanomaterials in environmentally responsible ways. The possibilities and limitations of this concept are critically evaluated in this article. PMID:25244158

  11. Health and safety implications of occupational exposure to engineered nanomaterials.

    PubMed

    Stebounova, Larissa V; Morgan, Hallie; Grassian, Vicki H; Brenner, Sara

    2012-01-01

    The rapid growth and commercialization of nanotechnology are currently outpacing health and safety recommendations for engineered nanomaterials. As the production and use of nanomaterials increase, so does the possibility that there will be exposure of workers and the public to these materials. This review provides a summary of current research and regulatory efforts related to occupational exposure and medical surveillance for the nanotechnology workforce, focusing on the most prevalent industrial nanomaterials currently moving through the research, development, and manufacturing pipelines. Their applications and usage precedes a discussion of occupational health and safety efforts, including exposure assessment, occupational health surveillance, and regulatory considerations for these nanomaterials.

  12. Exploring the possibilities and limitations of a nanomaterials genome.

    PubMed

    Qian, Chenxi; Siler, Todd; Ozin, Geoffrey A

    2015-01-01

    What are we going to do with the cornucopia of nanomaterials appearing in the open and patent literature, every day? Imagine the benefits of an intelligent and convenient means of categorizing, organizing, sifting, sorting, connecting, and utilizing this information in scientifically and technologically innovative ways by building a Nanomaterials Genome founded upon an all-purpose Periodic Table of Nanomaterials. In this Concept article, inspired by work on the Human Genome project, which began in 1989 together with motivation from the recent emergence of the Materials Genome project initiated in 2011 and the Nanoinformatics Roadmap 2020 instigated in 2010, we envision the development of a Nanomaterials Genome (NMG) database with the most advanced data-mining tools that leverage inference engines to help connect and interpret patterns of nanomaterials information. It will be equipped with state-of-the-art visualization techniques that rapidly organize and picture, categorize and interrelate the inherited behavior of complex nanomatter from the information programmed in its constituent nanomaterials building blocks. A Nanomaterials Genome Initiative (NMGI) of the type imagined herein has the potential to serve the global nanoscience community with an opportunity to speed up the development continuum of nanomaterials through the innovation process steps of discovery, structure determination and property optimization, functionality elucidation, system design and integration, certification and manufacturing to deployment in technologies that apply these versatile nanomaterials in environmentally responsible ways. The possibilities and limitations of this concept are critically evaluated in this article.

  13. Toxicity and Environmental Risks of Nanomaterials: Challenges and Future Needs

    PubMed Central

    Ray, Paresh Chandra; Yu, Hongtao; Fu, Peter P.

    2010-01-01

    Nanotechnology has gained a great deal of public interest due to the needs and applications of nanomaterials in many areas of human endeavors including industry, agriculture, business, medicine and public health. Environmental exposure to nanomaterials is inevitable as nanomaterials become part of our daily life, and as a result, nanotoxicity research is gaining attention. This review presents a summary of recent research efforts on fate, behavior and toxicity of different classes of nanomaterials in the environment. A critical evaluation of challenges and future needs for the safe environmental nanotechnology has been discussed. PMID:19204862

  14. Tailoring thermal interfaces with nanomaterials

    NASA Astrophysics Data System (ADS)

    Seshadri, Indira

    Thermal interfaces are key to ensure the reliable performance of many semiconductor, energy and electronic systems. High thermal conductivity (k), low elastic modulus (E) interface materials are required to dissipate heat and relieve thermo-mechanical stresses. The aim of this thesis is to develop compliant, high k nanocomposite materials for thermal interface applications utilizing nanostructured networks. Realizing high k nanocomposites is a challenge because of difficulties in incorporating high fractions of uniformly dispersed nanofillers and countering low filler-matrix interfacial conductance, while retaining a low elastic modulus. In this thesis, it is demonstrated that these issues are obviated by using < 5 volume % sub-10-nm cold welded gold nanowire fillers to obtain an unprecedented 30-fold increase in polydimethylsiloxane thermal conductivity that is 6-fold higher than previously reported nanocomposites at low nanofiller loadings and exceeds theoretical predictions. The nanowire diameter and aspect ratio are key to obtain cold-welded networks that enhance k at low filler fractions, while fostering low E. Along with high k, tailoring high thermal contact conductance G c is crucial for many applications. This thesis reveals a critical correlation between the rheological behavior of a high k gold-nanowire-filled polydimethylsiloxane nanocomposite and its thermal contact conductance with copper. At a critical filler fraction, an abrupt increase in the nanocomposite k is accompanied by a liquid-solid transition and a multifold decrease in Gc. These concurrent changes are attributed to nanowire percolation network formation and pre-cure polymer gelation that inhibits the formation of conformal void-free interfaces. These findings will be important for designing processing sequences to realize heterointerfaces with nanowire filled high k nanocomposite materials. Another important finding of this thesis is that nanowire networks can result in mechanical

  15. Therapeutic application of anti-angiogenic nanomaterials in cancers

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sudip; Patra, Chitta Ranjan

    2016-06-01

    Angiogenesis, the formation of new blood vessels from pre-existing vasculature, plays a vital role in physiological and pathological processes (embryonic development, wound healing, tumor growth and metastasis). The overall balance of angiogenesis inside the human body is maintained by pro- and anti-angiogenic signals. The processes by which drugs inhibit angiogenesis as well as tumor growth are called the anti-angiogenesis technique, a most promising cancer treatment strategy. Over the last couple of decades, scientists have been developing angiogenesis inhibitors for the treatment of cancers. However, conventional anti-angiogenic therapy has several limitations including drug resistance that can create problems for a successful therapeutic strategy. Therefore, a new comprehensive treatment strategy using antiangiogenic agents for the treatment of cancer is urgently needed. Recently researchers have been developing and designing several nanoparticles that show anti-angiogenic properties. These nanomedicines could be useful as an alternative strategy for the treatment of various cancers using anti-angiogenic therapy. In this review article, we critically focus on the potential application of anti-angiogenic nanomaterial and nanoparticle based drug/siRNA/peptide delivery systems in cancer therapeutics. We also discuss the basic and clinical perspectives of anti-angiogenesis therapy, highlighting its importance in tumor angiogenesis, current status and future prospects and challenges.Angiogenesis, the formation of new blood vessels from pre-existing vasculature, plays a vital role in physiological and pathological processes (embryonic development, wound healing, tumor growth and metastasis). The overall balance of angiogenesis inside the human body is maintained by pro- and anti-angiogenic signals. The processes by which drugs inhibit angiogenesis as well as tumor growth are called the anti-angiogenesis technique, a most promising cancer treatment strategy. Over the

  16. Tailoring thermal interfaces with nanomaterials

    NASA Astrophysics Data System (ADS)

    Seshadri, Indira

    Thermal interfaces are key to ensure the reliable performance of many semiconductor, energy and electronic systems. High thermal conductivity (k), low elastic modulus (E) interface materials are required to dissipate heat and relieve thermo-mechanical stresses. The aim of this thesis is to develop compliant, high k nanocomposite materials for thermal interface applications utilizing nanostructured networks. Realizing high k nanocomposites is a challenge because of difficulties in incorporating high fractions of uniformly dispersed nanofillers and countering low filler-matrix interfacial conductance, while retaining a low elastic modulus. In this thesis, it is demonstrated that these issues are obviated by using < 5 volume % sub-10-nm cold welded gold nanowire fillers to obtain an unprecedented 30-fold increase in polydimethylsiloxane thermal conductivity that is 6-fold higher than previously reported nanocomposites at low nanofiller loadings and exceeds theoretical predictions. The nanowire diameter and aspect ratio are key to obtain cold-welded networks that enhance k at low filler fractions, while fostering low E. Along with high k, tailoring high thermal contact conductance G c is crucial for many applications. This thesis reveals a critical correlation between the rheological behavior of a high k gold-nanowire-filled polydimethylsiloxane nanocomposite and its thermal contact conductance with copper. At a critical filler fraction, an abrupt increase in the nanocomposite k is accompanied by a liquid-solid transition and a multifold decrease in Gc. These concurrent changes are attributed to nanowire percolation network formation and pre-cure polymer gelation that inhibits the formation of conformal void-free interfaces. These findings will be important for designing processing sequences to realize heterointerfaces with nanowire filled high k nanocomposite materials. Another important finding of this thesis is that nanowire networks can result in mechanical

  17. Active Oxygen Metabolites and Thromboxane in Phorbol Myristate Acetate Toxicity to the Isolated, Perfused Rat Lung.

    NASA Astrophysics Data System (ADS)

    Carpenter, Laurie Jean

    When administered intravenously or intratracheally to rats, rabbits and sheep, phorbol myristate acetate (PMA) produces changes in lung morphology and function are similar to those seen in humans with the adult respiratory distress syndrome (ARDS). Therefore, it is thought that information about the mechanism of ARDS development can be gained from experiments using PMA-treated animals. Currently, the mechanisms by which PMA causes pneumotoxicity are unknown. Results from other studies in rabbits and in isolated, perfused rabbit lungs suggest that PMA-induced lung injury is mediated by active oxygen species from neutrophils (PMN), whereas studies in sheep and rats suggest that PMN are not required for the toxic response. The role of PMN, active oxygen metabolites and thromboxane (TxA_2) in PMA-induced injury to isolated, perfused rat lungs (IPLs) was examined in this thesis. To determine whether PMN were required for PMA to produce toxicity to the IPL, lungs were perfused for 30 min with buffer containing various concentrations of PMA (in the presence or absence of PMN). When concentrations >=q57 ng/ml were added to medium devoid of added PMN, perfusion pressure and lung weight increased. When a concentration of PMA (14-28 ng/ml) that did not by itself cause lungs to accumulate fluid was added to the perfusion medium containing PMN (1 x 10 ^8), perfusion pressure increased, and lungs accumulated fluid. These results indicate that high concentrations of PMA produce lung injury which is independent of PMN, whereas injury induced by lower concentrations is PMN-dependent. To examine whether active oxygen species were involved in mediating lung injury induced by PMA and PMN, lungs were coperfused with the oxygen radical scavengers SOD and/or catalase. Coperfusion with either or both of these enzymes totally protected lungs against injury caused by PMN and PMA. These results suggest that active oxygen species (the hydroxyl radical in particular), mediate lung injury in

  18. The stimulation of rat astrocytes with phorbol-12-myristate-13-acetate increases the proenkephalin mRNA: involvement of proto-oncogenes.

    PubMed

    Won, J S; Song, D K; Kim, Y H; Huh, S O; Suh, H W

    1998-03-01

    The effect of phorbol-12-myristate-13-acetate (PMA) on the regulation of proenkephalin (proENK) mRNA level, ENKCRE-2 or AP-1 DNA binding activity, and the mRNA and protein levels of proto-oncogenes (c-fos, fra-1, and c-jun) in primary cultured rat astrocytes were studied. The proENK mRNA level was elevated at 4 h after the treatment of PMA (2.5 microM) without altering the intracellular proENK protein level, and this increase was attenuated by pre-treatment with cycloheximide (CHX; 15 microM), a protein synthesis inhibitor. Both AP-1 and ENKCRE-2 DNA binding activities were markedly increased at 1-4 h by PMA treatment and these PMA-induced responses were inhibited by pre-treatment with CHX, showing that the increase of proENK mRNA level was well correlated with the AP-1 and ENKCRE-2 DNA binding activities. In contrast, although the phospho-CREBP level was also increased by PMA at 0.5-1 h, the pre-treatment with CHX further increased the PMA-induced phospho-CREBP level. In addition, PMA caused the induction of c-fos, c-jun and fra-1 mRNA level and, especially, PMA-induced increase of fra-1 mRNA level was further enhanced by CHX treatment at 4 h. Furthermore, western immunoblot assay showed that PMA caused induction of c-Fos, Fra-1, and c-Jun protein levels. PMA-induced increases of proto-oncoproteins levels were also inhibited by CHX treatment. The results suggest that newly synthesized AP-1 proteins, such as c-Fos, Fra-1, and c-Jun may play important roles in the regulation of PMA-induced proENK gene expression in cultured rat astrocytes. Phospho-CREB protein appears not to be involved in the regulation of PMA-induced proENK gene expression.

  19. Conformation of the C1 phorbol-ester-binding domain participates in the activating conformational change of protein kinase C.

    PubMed Central

    Ho, C; Slater, S J; Stagliano, B A; Stubbs, C D

    1999-01-01

    The fluorescent phorbol ester 12-N-methylanthraniloylphorbol 13-acetate [sapintoxin D (SAPD)] was used as both the activator and the probe for the activating conformational change of the C1 domain of recombinant protein kinase C (PKC)alpha. Fluorescence emission spectra and steady-state anisotropy measurements of SAPD in fully active membrane-associated PKC show that there is a relatively hydrophobic environment and restricted motional freedom characterizing the phorbol-ester-binding site. SAPD also interacts with the membrane lipids so that it was necessary to resort to time-resolved anisotropy measurements to resolve the signals corresponding to PKC-bound SAPD from that associated with buffer and lipid. In the presence of membrane lipids (unilamellar vesicles of phosphatidylcholine and phosphatidylserine, 4:1 molar ratio) and Ca(2+), at a concentration sufficient to activate the enzyme fully, a long correlation time characteristic of highly restricted motion was observed for PKC-associated SAPD. The fraction of SAPD molecules displaying this restricted motion, in comparison with the total SAPD including that in lipids and in buffer, increased with increasing concentrations of Ca(2+) and paralleled the appearance of enzyme activity, whereas the rotational correlation time remained constant. This could be rationalized as an increase in the number of active PKC conformers in the total population of PKC molecules. It therefore seems that there is a distinct conformation of the C1 activator-binding domain associated with the active form of PKC. The addition of SAPD and dioleoyl-sn-glycerol together produced an activity higher than that achievable by either activator alone both at concentrations that alone induced maximal activity for the respective activator; this higher activity was associated with a further restriction in SAPD motion. Increasing the cholesterol concentration, the phosphatidylethanolamine concentration, the sn-2 unsaturation in phosphatidylcholine

  20. Germanium-Based Nanomaterials for Rechargeable Batteries.

    PubMed

    Wu, Songping; Han, Cuiping; Iocozzia, James; Lu, Mingjia; Ge, Rongyun; Xu, Rui; Lin, Zhiqun

    2016-07-01

    Germanium-based nanomaterials have emerged as important candidates for next-generation energy-storage devices owing to their unique chemical and physical properties. In this Review, we provide a review of the current state-of-the-art in germanium-based materials design, synthesis, processing, and application in battery technology. The most recent advances in the area of Ge-based nanocomposite electrode materials and electrolytes for solid-state batteries are summarized. The limitations of Ge-based materials for energy-storage applications are discussed, and potential research directions are also presented with an emphasis on commercial products and theoretical investigations.

  1. Terahertz science and technology of carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Hartmann, R. R.; Kono, J.; Portnoi, M. E.

    2014-08-01

    The diverse applications of terahertz (THz) radiation and its importance to fundamental science makes finding ways to generate, manipulate and detect THz radiation one of the key areas of modern applied physics. One approach is to utilize carbon nanomaterials, in particular, single-wall carbon nanotubes and graphene. Their novel optical and electronic properties offer much promise to the field of THz science and technology. This article describes the past, current, and future of THz science and technology of carbon nanotubes and graphene. We will review fundamental studies such as THz dynamic conductivity, THz nonlinearities and ultrafast carrier dynamics as well as THz applications such as THz sources, detectors, modulators, antennas and polarizers.

  2. Nanomaterials: amyloids reflect their brighter side

    PubMed Central

    Mankar, Shruti; Anoop, A.; Sen, Shamik; Maji, Samir K.

    2011-01-01

    Amyloid fibrils belong to the group of ordered nanostructures that are self-assembled from a wide range of polypeptides/proteins. Amyloids are highly rigid structures possessing a high mechanical strength. Although amyloids have been implicated in the pathogenesis of several human diseases, growing evidence indicates that amyloids may also perform native functions in host organisms. Discovery of such amyloids, referred to as functional amyloids, highlight their possible use in designing novel nanostructure materials. This review summarizes recent advances in the application of amyloids for the development of nanomaterials and prospective applications of such materials in nanotechnology and biomedicine. PMID:22110868

  3. Nanomaterials Meet Li-ion Batteries.

    PubMed

    Kwon, Nam Hee; Brog, Jean-Pierre; Maharajan, Sivarajakumar; Crochet, Aurélien; Fromm, Katharina M

    2015-01-01

    Li-ion batteries are used in many applications in everyday life: cell phones, laser pointers, laptops, cordless drillers or saws, bikes and even cars. Yet, there is room for improvement in order to make the batteries smaller and last longer. The Fromm group contributes to this research focusing mainly on nanoscale lithium ion cathode materials. This contribution gives an overview over our current activities in the field of batteries. After an introduction on the nano-materials of LiCoO(2) and LiMnPO(4), the studies of our cathode composition and preparation will be presented.

  4. Polymer-mediated formation of polyoxomolybdate nanomaterials

    NASA Astrophysics Data System (ADS)

    Wan, Quan

    A polymer-mediated synthetic pathway to a polyoxomolybdate nanomaterial is investigated in this work. Block copolymers or homopolymers containing poly(ethylene oxide) (PEO) are mixed with a MoO2(OH)(OOH) aqueous solution to form a golden gel or viscous solution. As revealed by synchrotron X-ray scattering measurements, electron microscopy, and other characterization techniques, the final dark blue polyoxomolybdate product is a highly ordered simple cubic network similar to certain zeolite structure but with a much larger lattice constant of ˜5.2 nm. The average size of the cube-like single crystals is close to 1 mum. Based on its relatively low density (˜2.2 g/cm3), the nanomaterial can be highly porous if the amount of the residual polymer can be substantially reduced. The valence of molybdenum is ˜5.7 based on cerimetric titration, representing the mixed-valence nature of the polyoxomolybdate structure. The self-assembled structures (if any) of the polymer gel do not have any correlation with the final polyoxomolybdate nanostructure, excluding the possible role of polymers being a structure-directing template. On the other hand, the PEO polymer stabilizes the precursor molybdenum compound through coordination between its ether oxygen atoms and molybdenum atoms, and reduces the molybdenum (VI) precursor compound with its hydroxyl group being a reducing agent. The rare simple cubic ordering necessitates the existence of special affinities among the polyoxomolybdate nanosphere units resulted from the reduction reaction. Our mechanism study shows that the acidified condition is necessary for the synthesis of the mixed-valence polyoxomolybdate clusters, while H2O2 content modulates the rate of the reduction reaction. The polymer degradation is evidenced by the observation of a huge viscosity change, and is likely through a hydrolysis process catalyzed by molybdenum compounds. Cube-like polyoxomolybdate nanocrystals with size of ˜40 nm are obtained by means of

  5. Antineoplastic Activity Comparison of Bovine Serum Albumin--Conjugated Sulfides Semiconductor Nanomaterials.

    PubMed

    Wang, Hua-Jie; Huang, Jing-Chun; Wu, Sha-Sha; Wang, Cai-Feng; Yu, Xue-Hong; Cao, Ying

    2015-04-01

    Although tumor is one of the most frequently occurring diseases and a leading cause of death, nanotechnology, one of the frontier sciences, is exhibiting its great potential to tumor treatments. The aim of this study was to design a facile and environmentally-friendly method to prepare bovine serum albumin-conjugated heavy metal sulfides nano-materials, including Ag2S, PbS and CdS. Here, bovine serum albumin was introduced in order to direct the synthesis of nano-materials by using its template effect and supply more sites for further modification in future. The crystal structure and morphology were analyzed by XRD and TEM, respectively. Additionally, the antineoplastic activity of nano-materials was compared by cell viability analysis, optical and electron microscopy observation after exposure of the human hepatoma cell line. The results showed that the inhibition effect of heavy metal sulfides on tumor cells was in the order of nano-PbS > bulk CdS > nano-Ag2S > nano-CdS > bulk PbS > bulk Ag2S. It could be concluded that heavy metal sulfides had significantly negative impact on human hepatoma cells growth but it could not be obviously generalized that nano-particles were always more effective to kill tumor cells than bulk materials. The size and surface reactivity might be the important factors causing the difference.

  6. Innate Immune Responses to Engineered Nanomaterials During Allergic Airway Inflammation

    NASA Astrophysics Data System (ADS)

    Shipkowski, Kelly Anne

    The field of nanotechnology is continually advancing, and increasing amounts of consumer goods are being produced using engineered nanomaterials (ENMs). The health risks of occupational and/or consumer exposure to ENMs are not completely understood, although significant research indicates that pulmonary exposure to nanomaterials induces toxic effects in the lungs of exposed animals. Multi-walled carbon nanotubes (MWCNTs) are a specific category of ENMs and consist of sheets of graphene rolled into cylinders that are multiple layers thick in order to strengthen their rigidity. MWCNTs have a fiber-like shape, similar to that of asbestos, which allows for a high aspect ratio and makes them difficult to clear from the lung. Studies with rodent models have demonstrated that pulmonary exposure to ENMs, in particular MWCNTs, results in acute lung inflammation and the subsequent development of chronic fibrosis, suggesting a potential human health risk to individuals involved in the manufacturing of products utilizing these nanomaterials. Induction of IL-1beta secretion via activation of the inflammasome is a prime mechanism of MWCNT-induced inflammation. The inflammasome is a multi-protein scaffold found in a variety of cell types that forms in response to a variety of immune signals, including particulates. Sensitization with allergens, such as house dust mite (HDM), increases levels of the T helper 2 (Th2) cytokines IL-4 and IL-13 in mice and in humans, and there is particular cause for concern in cases of MWCNT exposure in individuals with pre-existing allergic airway disease, such as asthma. MWCNT exposure exacerbates airway inflammation and fibrosis in animal models of pre-existing allergic asthma, suggesting that individuals suffering from asthma are more susceptible to the toxic pulmonary effects of MWCNT exposure. Asthma is an exceptionally prominent human disease, and therefore the goal of this research was to better understand how pre-existing allergic airway

  7. The effect of lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) on whole blood oxidative response as assessed by luminol-amplified chemiluminescence in dairy cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The differences between lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) on whole blood oxidative response using luminol-amplified chemiluminescence (CL) are currently unknown in cattle. Luminol-dependent CL measures the amount of reactive oxygen species released from leukocytes a...

  8. Development of a Nanomaterials One-Week Intersession Course

    ERIC Educational Resources Information Center

    Walters, Keith A.; Bullen, Heather A.

    2008-01-01

    A novel one-week intersession lecture-lab hybrid course on nanomaterials is presented. The course provided a combination of background theory and hands-on laboratory experiments to educate students about nanomaterials and nanotechnology. The design of the course, subject matter, and laboratory experiments are discussed. Topics and level were…

  9. Effects of Copper Nanomaterials on Marine Benthic Communities

    EPA Science Inventory

    Copper nanomaterials (CuNMs) are used as an anti-bacterial and anti-fouling agent in numerous commercial and industrial products, including water purifiers, fungicides, wood and touch surfaces. The widespread popularity of copper nanomaterials in consumer products increases the r...

  10. [Importance of researches on chronic effects by manufactured nanomaterials].

    PubMed

    Hirose, Akihiko; Takagi, Atsuya; Nishimura, Tetsuji; Tsuda, Hiroyuki; Sakamoto, Yoshimitsu; Ogata, Akio; Nakae, Dai; Hino, Okio; Kanno, Jun

    2011-02-01

    Manufactured nanomaterials are the most important substances for the nanotechnology. The nanomaterials possess different physico-chemical properties from bulk materials. The new properties may lead to biologically beneficial effects and/or adverse effects. However, there are no standardized evaluation methods at present. Some domestic research projects and international OECD programs are ongoing, in order to share the health impact information of nanomaterials or to standardize the evaluation methods. From 2005, our institutes have been conducting the research on the establishment of health risk assessment methodology of manufactured nanomaterials. In the course of the research project, we revealed that the nanomaterials were competent to cause chronic effects, by analyzing the intraperitoneal administration studies and carcinogenic promotion studies. These studies suggested that even aggregated nanomaterials were crumbled into nanosized particles inside the body during the long-term, and the particles were transferred to other organs. Also investigations of the toxicokinetic properties of nanomaterials after exposure are important to predict the chronically targeted tissues. The long lasting particles/fibers in the particular tissues may cause chronic adverse effects. Therefore, focusing on the toxicological characterization of chronic effects was considered to be most appropriate approach for establishing the risk assessment methods of nanomaterials.

  11. Effects of Engineered Nanomaterials on Plants Growth: An Overview

    PubMed Central

    Bagheri, Samira; Muhd Julkapli, Nurhidayatullaili; Juraimi, Abdul Shukor; Hashemi, Farahnaz Sadat Golestan

    2014-01-01

    Rapid development and wide applications of nanotechnology brought about a significant increment on the number of engineered nanomaterials (ENs) inevitably entering our living system. Plants comprise of a very important living component of the terrestrial ecosystem. Studies on the influence of engineered nanomaterials (carbon and metal/metal oxides based) on plant growth indicated that in the excess content, engineered nanomaterials influences seed germination. It assessed the shoot-to-root ratio and the growth of the seedlings. From the toxicological studies to date, certain types of engineered nanomaterials can be toxic once they are not bound to a substrate or if they are freely circulating in living systems. It is assumed that the different types of engineered nanomaterials affect the different routes, behavior, and the capability of the plants. Furthermore, different, or even opposing conclusions, have been drawn from most studies on the interactions between engineered nanomaterials with plants. Therefore, this paper comprehensively reviews the studies on the different types of engineered nanomaterials and their interactions with different plant species, including the phytotoxicity, uptakes, and translocation of engineered nanomaterials by the plant at the whole plant and cellular level. PMID:25202734

  12. Effects of engineered nanomaterials on plants growth: an overview.

    PubMed

    Aslani, Farzad; Bagheri, Samira; Muhd Julkapli, Nurhidayatullaili; Juraimi, Abdul Shukor; Hashemi, Farahnaz Sadat Golestan; Baghdadi, Ali

    2014-01-01

    Rapid development and wide applications of nanotechnology brought about a significant increment on the number of engineered nanomaterials (ENs) inevitably entering our living system. Plants comprise of a very important living component of the terrestrial ecosystem. Studies on the influence of engineered nanomaterials (carbon and metal/metal oxides based) on plant growth indicated that in the excess content, engineered nanomaterials influences seed germination. It assessed the shoot-to-root ratio and the growth of the seedlings. From the toxicological studies to date, certain types of engineered nanomaterials can be toxic once they are not bound to a substrate or if they are freely circulating in living systems. It is assumed that the different types of engineered nanomaterials affect the different routes, behavior, and the capability of the plants. Furthermore, different, or even opposing conclusions, have been drawn from most studies on the interactions between engineered nanomaterials with plants. Therefore, this paper comprehensively reviews the studies on the different types of engineered nanomaterials and their interactions with different plant species, including the phytotoxicity, uptakes, and translocation of engineered nanomaterials by the plant at the whole plant and cellular level. PMID:25202734

  13. Recent Development of Nano-Materials Used in DNA Biosensors

    PubMed Central

    Xu, Kai; Huang, Junran; Ye, Zunzhong; Ying, Yibin; Li, Yanbin

    2009-01-01

    As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR) in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future. PMID:22346713

  14. Renal scarring is enhanced by phorbol myristate acetate following infection with bacteria with mannose-sensitive pili.

    PubMed

    Matsumoto, T; Haraoka, M; Mizunoe, Y; Kubo, S; Takahashi, K; Tanaka, M; Kumazawa, J

    1993-01-01

    Renal scarring is considered to develop in the later stages of chronic pyelonephritis. In our experimental model of pyelonephritis, bacteria with mannose-sensitive (MS) pili on their surface promoted renal scarring following inoculation into the renal parenchyma. The administration of cyclophosphamide to induce leukopenia and of superoxide dismutase to inactivate superoxide released from polymorphonuclear leukocytes (PMN) at the infection site suppressed any renal scarring following the infection. Conversely, the administration of phorbol myristate acetate at an early stage of infection significantly enhanced the renal scarring. These findings suggest that the PMNs which infiltrate the infection site and the superoxide they release play an important role in any renal scarring following infection with MS-piliated bacteria.

  15. Toxicity, Uptake, and Translocation of Engineered Nanomaterials in Vascular plants.

    PubMed

    Miralles, Pola; Church, Tamara L; Harris, Andrew T

    2012-09-01

    To exploit the promised benefits of engineered nanomaterials, it is necessary to improve our knowledge of their bioavailability and toxicity. The interactions between engineered nanomaterials and vascular plants are of particular concern, as plants closely interact with soil, water, and the atmosphere, and constitute one of the main routes of exposure for higher species, i.e. accumulation through the food chain. A review of the current literature shows contradictory evidence on the phytotoxicity of engineered nanomaterials. The mechanisms by which engineered nanomaterials penetrate plants are not well understood, and further research on their interactions with vascular plants is required to enable the field of phytotoxicology to keep pace with that of nanotechnology, the rapid evolution of which constantly produces new materials and applications that accelerate the environmental release of nanomaterials.

  16. Design of nanomaterial based systems for novel vaccine development.

    PubMed

    Yang, Liu; Li, Wen; Kirberger, Michael; Liao, Wenzhen; Ren, Jiaoyan

    2016-05-26

    With lower cell toxicity and higher specificity, novel vaccines have been greatly developed and applied to emerging infectious and chronic diseases. However, due to problems associated with low immunogenicity and complicated processing steps, the development of novel vaccines has been limited. With the rapid development of bio-technologies and material sciences, nanomaterials are playing essential roles in novel vaccine design. Incorporation of nanomaterials is expected to improve delivery efficiency, to increase immunogenicity, and to reduce the administration dosage. The purpose of this review is to discuss the employment of nanomaterials, including polymeric nanoparticles, liposomes, virus-like particles, peptide amphiphiles micelles, peptide nanofibers and microneedle arrays, in vaccine design. Compared to traditional methods, vaccines made from nanomaterials display many appealing benefits, including precise stimulation of immune responses, effective targeting to certain tissue or cells, and desirable biocompatibility. Current research suggests that nanomaterials may improve our approach to the design and delivery of novel vaccines.

  17. Editorial: Functional nanomaterials for energy applications

    SciTech Connect

    Devan, Rupesh S.; Ma, Yuan -Ron; Kim, Jin -Hyeok; Bhattacharya, Raghu N.; Ghosh, Kartik C.

    2015-02-16

    In order to leap forward from the energy crisis issues and improve lifestyle, we all are looking positively toward nanomaterials or nanostructures. Thus, the exploration of new features of both typical and novel materials at the nanoscale level is playing important role in the development of innovative and improved energy technologies that have the capability of conserve/convert energy at large extend. By tailoring the surface morphology of materials in its nanoforms, the functional properties can be significantly adapted and specifically combined to produce highly potent multifunctional materials for conversion, storage, and consumption of energy in various forms. The papers selected for this special issue represent a good panel for addressing various energy applications including solar cell, fuel cells, nanofluid twisters, and gas sensors. Of course, the selected topic and the papers are not an exhaustive representation of the utilization of functional nanomaterials for energy applications. Nevertheless, they represent the rich and many-facet knowledge, which we have the pleasure of sharing with the readers.

  18. Design of Nanomaterial Synthesis by Aerosol Processes

    PubMed Central

    Buesser, Beat; Pratsinis, Sotiris E.

    2013-01-01

    Aerosol synthesis of materials is a vibrant field of particle technology and chemical reaction engineering. Examples include the manufacture of carbon blacks, fumed SiO2, pigmentary TiO2, ZnO vulcanizing catalysts, filamentary Ni, and optical fibers, materials that impact transportation, construction, pharmaceuticals, energy, and communications. Parallel to this, development of novel, scalable aerosol processes has enabled synthesis of new functional nanomaterials (e.g., catalysts, biomaterials, electroceramics) and devices (e.g., gas sensors). This review provides an access point for engineers to the multiscale design of aerosol reactors for the synthesis of nanomaterials using continuum, mesoscale, molecular dynamics, and quantum mechanics models spanning 10 and 15 orders of magnitude in length and time, respectively. Key design features are the rapid chemistry; the high particle concentrations but low volume fractions; the attainment of a self-preserving particle size distribution by coagulation; the ratio of the characteristic times of coagulation and sintering, which controls the extent of particle aggregation; and the narrowing of the aggregate primary particle size distribution by sintering. PMID:22468598

  19. Uncertainty in Life Cycle Assessment of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Seager, T. P.; Linkov, I.

    Despite concerns regarding environmental fate and toxicology, engineered nanostructured material manufacturing is expanding at an increasingly rapid pace. In particular, the unique properties of single walled carbon nanotubes (SWCNT) have made them attractive in many areas, including high-tech power applications such as experimental batteries, fuel cells or electrical wiring. The intensity of research interest in SWCNT has raised questions regarding the life cycle environmental impact of nanotechnologies, including assessment of: worker and consumer safety, greenhouse gas emissions, toxicological risks associated with production or product emissions and the disposition of nanoproducts at end of life. However, development of appropriate nanotechnology assessment tools has lagged progress in the nanotechnologies themselves. In particular, current approaches to life cycle assessment (LCA) — originally developed for application in mature manufacturing industries such as automobiles and chemicals — suffer from several shortcomings that make applicability to nanotechnologies problematic. Among these are uncertainties related to the variability of material properties, toxicity and risk, technology performance in the use phase, nanomaterial degradation and change during the product life cycle and the impact assessment stage of LCA. This chapter expounds upon the unique challenges presented by nanomaterials in general, specifies sources of uncertainty and variability in LCA of SWCNT for use in electric and hybrid vehicle batteries and makes recommendations for modeling and decision-making using LCA in a multi-criteria decision analysis framework under conditions of high uncertainty.1

  20. NEIMiner: nanomaterial environmental impact data miner

    PubMed Central

    Tang, Kaizhi; Liu, Xiong; Harper, Stacey L; Steevens, Jeffery A; Xu, Roger

    2013-01-01

    As more engineered nanomaterials (eNM) are developed for a wide range of applications, it is crucial to minimize any unintended environmental impacts resulting from the application of eNM. To realize this vision, industry and policymakers must base risk management decisions on sound scientific information about the environmental fate of eNM, their availability to receptor organisms (eg, uptake), and any resultant biological effects (eg, toxicity). To address this critical need, we developed a model-driven, data mining system called NEIMiner, to study nanomaterial environmental impact (NEI). NEIMiner consists of four components: NEI modeling framework, data integration, data management and access, and model building. The NEI modeling framework defines the scope of NEI modeling and the strategy of integrating NEI models to form a layered, comprehensive predictability. The data integration layer brings together heterogeneous data sources related to NEI via automatic web services and web scraping technologies. The data management and access layer reuses and extends a popular content management system (CMS), Drupal, and consists of modules that model the complex data structure for NEI-related bibliography and characterization data. The model building layer provides an advanced analysis capability for NEI data. Together, these components provide significant value to the process of aggregating and analyzing large-scale distributed NEI data. A prototype of the NEIMiner system is available at http://neiminer.i-a-i.com/. PMID:24098076

  1. Human Health Risks of Engineered Nanomaterials

    NASA Astrophysics Data System (ADS)

    Elder, A.; Lynch, I.; Grieger, K.; Chan-Remillard, S.; Gatti, A.; Gnewuch, H.; Kenawy, E.; Korenstein, R.; Kuhlbusch, T.; Linker, F.; Matias, S.; Monteiro-Riviere, N.; Pinto, V. R. S.; Rudnitsky, R.; Savolainen, K.; Shvedova, A.

    There are currently hundreds of available consumer products that contain nanoscale materials. Human exposure is, therefore, likely to occur in occupational and environmental settings. Mounting evidence suggests that some nanomaterials exert toxicity in cultured cells or following in vivo exposures, but this is dependent on the physicochemical characteristics of the materials and the dose. This Working Group report summarizes the discussions of an expert scientific panel regarding the gaps in knowledge that impede effective human health risk assessment for nanomaterials, particularly those that are suspended in a gas or liquid and, thus, deposit on skin or in the respiratory tract. In addition to extensive descriptions of material properties, the Group identified as critical research areas: external and internal dose characterization, mechanisms of response, identification of sensitive subpopulations, and the development of screening strategies and technology to support these investigations. Important concepts in defining health risk are reviewed, as are the specific kinds of studies that will quickly reduce the uncertainties in the risk assessment process.

  2. [PHYSIOLOGY AND PHARMACOLOGICAL PROPERTIES OF NANOMATERIALS].

    PubMed

    Chekman, I S

    2015-01-01

    Literature data and results of our department studies on theoretical and practical basics of nanoscience were summarized in the article. Much attention is paid to research in the field of physical, chemical, biological, medical, physiological, pharmacological, and toxicological properties of nanomaterials with the aim of their wider implementation into practice lately. The discovery of new quantum/wave properties of nanoparticles is of particular importance. The author of the article advances an idea: wave properties of nanomaterials play greater role with a decrease in particle size. The preponderance of wave properties compared with corpuscular ones in nanostructures determines a great change in their physical. chemical properties and an increase in physical, mechanical biological, physiological, pharmacological, and toxicologica activity. The idea advanced in the article hasn't been verified by theoretical or experimental studies for now. Joined efforts of scientists of different scientific fields are needed. A confirmation of hypothesis by specific findings will be of great importance for physiology, medicine, pharmacology and promote an implementation of new efficacious preparations into clinical practice. New fundamental discoveries could be made only by multidisciplinary approach.

  3. Nanomaterials for Hydrogen Storage Applications: A Review

    DOE PAGES

    Niemann, Michael U.; Srinivasan, Sesha S.; Phani, Ayala R.; Kumar, Ashok; Goswami, D. Yogi; Stefanakos, Elias K.

    2008-01-01

    Nmore » anomaterials have attracted great interest in recent years because of the unusual mechanical, electrical, electronic, optical, magnetic and surface properties. The high surface/volume ratio of these materials has significant implications with respect to energy storage. Both the high surface area and the opportunity for nanomaterial consolidation are key attributes of this new class of materials for hydrogen storage devices.anostructured systems including carbon nanotubes, nano-magnesium based hydrides, complex hydride/carbon nanocomposites, boron nitride nanotubes, TiS 2 / MoS 2 nanotubes, alanates, polymer nanocomposites, and metal organic frameworks are considered to be potential candidates for storing large quantities of hydrogen. Recent investigations have shown that nanoscale materials may offer advantages if certain physical and chemical effects related to the nanoscale can be used efficiently. The present review focuses the application of nanostructured materials for storing atomic or molecular hydrogen. The synergistic effects of nanocrystalinity and nanocatalyst doping on the metal or complex hydrides for improving the thermodynamics and hydrogen reaction kinetics are discussed. In addition, various carbonaceous nanomaterials and novel sorbent systems (e.g. carbon nanotubes, fullerenes, nanofibers, polyaniline nanospheres and metal organic frameworks etc.) and their hydrogen storage characteristics are outlined.« less

  4. Nanomanufacturing metrology for cellulosic nanomaterials: an update

    NASA Astrophysics Data System (ADS)

    Postek, Michael T.

    2014-08-01

    The development of the metrology and standards for advanced manufacturing of cellulosic nanomaterials (or basically, wood-based nanotechnology) is imperative to the success of this rising economic sector. Wood-based nanotechnology is a revolutionary technology that will create new jobs and strengthen America's forest-based economy through industrial development and expansion. It allows this, previously perceived, low-tech industry to leap-frog directly into high-tech products and processes and thus improves its current economic slump. Recent global investments in nanotechnology programs have led to a deeper appreciation of the high performance nature of cellulose nanomaterials. Cellulose, manufactured to the smallest possible-size ( 2 nm x 100 nm), is a high-value material that enables products to be lighter and stronger; have less embodied energy; utilize no catalysts in the manufacturing, are biologically compatible and, come from a readily renewable resource. In addition to the potential for a dramatic impact on the national economy - estimated to be as much as $250 billion worldwide by 2020 - cellulose-based nanotechnology creates a pathway for expanded and new markets utilizing these renewable materials. The installed capacity associated with the US pulp and paper industry represents an opportunity, with investment, to rapidly move to large scale production of nano-based materials. However, effective imaging, characterization and fundamental measurement science for process control and characterization are lacking at the present time. This talk will discuss some of these needed measurements and potential solutions.

  5. NEIMiner: nanomaterial environmental impact data miner.

    PubMed

    Tang, Kaizhi; Liu, Xiong; Harper, Stacey L; Steevens, Jeffery A; Xu, Roger

    2013-01-01

    As more engineered nanomaterials (eNM) are developed for a wide range of applications, it is crucial to minimize any unintended environmental impacts resulting from the application of eNM. To realize this vision, industry and policymakers must base risk management decisions on sound scientific information about the environmental fate of eNM, their availability to receptor organisms (eg, uptake), and any resultant biological effects (eg, toxicity). To address this critical need, we developed a model-driven, data mining system called NEIMiner, to study nanomaterial environmental impact (NEI). NEIMiner consists of four components: NEI modeling framework, data integration, data management and access, and model building. The NEI modeling framework defines the scope of NEI modeling and the strategy of integrating NEI models to form a layered, comprehensive predictability. The data integration layer brings together heterogeneous data sources related to NEI via automatic web services and web scraping technologies. The data management and access layer reuses and extends a popular content management system (CMS), Drupal, and consists of modules that model the complex data structure for NEI-related bibliography and characterization data. The model building layer provides an advanced analysis capability for NEI data. Together, these components provide significant value to the process of aggregating and analyzing large-scale distributed NEI data. A prototype of the NEIMiner system is available at http://neiminer.i-a-i.com/.

  6. Zinc Oxide Nanomaterials for Biomedical Fluorescence Detection

    PubMed Central

    Hahm, Jong-in

    2014-01-01

    One-dimensional zinc oxide nanomaterials have been recently developed into novel, extremely effective, optical signal-enhancing bioplatforms. Their usefulness has been demonstrated in various biomedical fluorescence assays. Fluorescence is extensively used in biology and medicine as a sensitive and noninvasive detection method for tracking and analyzing biological molecules. Achieving high sensitivity via improving signal-to-noise ratio is of paramount importance in fluorescence-based, trace-level detection. Recent advances in the development of optically superior one-dimensional materials have contributed to this important biomedical area of detection. This review article will discuss major research developments that have so far been made in this emerging and exciting topical field. The discussion will cover a broad range of subjects including synthesis of zinc oxide nanorods (ZnO NRs), various properties differentiating them as suitable optical biodetection platforms, their demonstrated applicability in DNA and protein detection, and the nanomaterial characteristics relevant for biomolecular fluorescence enhancement. This review will then summarize the current status of ZnO NR-based biodetection and further elaborate future utility of ZnO NR platforms for advanced biomedical assays, based on their proven advantages. Lastly, present challenges experienced in this topical area will be identified and focal subject areas for future research will be suggested as well. PMID:24730276

  7. Catalytic applications of bio-inspired nanomaterials

    NASA Astrophysics Data System (ADS)

    Pacardo, Dennis Kien Balaong

    The biomimetic synthesis of Pd nanoparticles was presented using the Pd4 peptide, TSNAVHPTLRHL, isolated from combinatorial phage display library. Using this approach, nearly monodisperse and spherical Pd nanoparticles were generated with an average diameter of 1.9 +/- 0.4 nm. The peptide-based nanocatalyst were employed in the Stille coupling reaction under energy-efficient and environmentally friendly reaction conditions of aqueous solvent, room temperature and very low catalyst loading. To this end, the Pd nanocatalyst generated high turnover frequency (TOF) value and quantitative yields using ≥ 0.005 mol% Pd as well as catalytic activities with different aryl halides containing electron-withdrawing and electron-donating groups. The Pd4-capped Pd nanoparticles followed the atom-leaching mechanism and were found to be selective with respect to substrate identity. On the other hand, the naturally-occurring R5 peptide (SSKKSGSYSGSKGSKRRIL) was employed in the synthesis of biotemplated Pd nanomaterials which showed morphological changes as a function of Pd:peptide ratio. TOF analysis for hydrogenation of olefinic alcohols showed similar catalytic activity regardless of nanomorphology. Determination of catalytic properties of these bio-inspired nanomaterials are important as they serve as model system for alternative green catalyst with applications in industrially important transformations.

  8. Editorial: Functional nanomaterials for energy applications

    DOE PAGES

    Devan, Rupesh S.; Ma, Yuan -Ron; Kim, Jin -Hyeok; Bhattacharya, Raghu N.; Ghosh, Kartik C.

    2015-02-16

    In order to leap forward from the energy crisis issues and improve lifestyle, we all are looking positively toward nanomaterials or nanostructures. Thus, the exploration of new features of both typical and novel materials at the nanoscale level is playing important role in the development of innovative and improved energy technologies that have the capability of conserve/convert energy at large extend. By tailoring the surface morphology of materials in its nanoforms, the functional properties can be significantly adapted and specifically combined to produce highly potent multifunctional materials for conversion, storage, and consumption of energy in various forms. The papers selectedmore » for this special issue represent a good panel for addressing various energy applications including solar cell, fuel cells, nanofluid twisters, and gas sensors. Of course, the selected topic and the papers are not an exhaustive representation of the utilization of functional nanomaterials for energy applications. Nevertheless, they represent the rich and many-facet knowledge, which we have the pleasure of sharing with the readers.« less

  9. Effect of wortmannin and phorbol ester on Paramecium fluid-phase uptake in the presence of transferrin.

    PubMed

    Wiejak, J; Surmacz, L; Wyroba, E

    2001-01-01

    The kinetics of the uptake of the fluid phase marker Lucifer Yellow (LY), and its alteration by wortmannin, an inhibitor of phosphatidylinositol-3 kinase (PI-3K), and the PKC modulators: GF 109203 X, an inhibitor, and phorbol ester, an activator was studied in eukaryotic model Paramecium aurelia. Spectrophotometric quantification of LY accumulation was performed in the presence or absence of transferrin, a marker of receptor-mediated endocytosis. Internalization of LY showed a curvilinear kinetics: the high initial rate of LY uptake (575 ng LY/mg protein/hr) decreased almost 5-fold within 15 min, reaching plateau at 126 ng/mg protein/hr. Transferrin induced a small increase (7.5%) in the fluid phase uptake rate (after 5 min) followed by a small decrease at longer incubation times. Lucifer Yellow and transferrin (visualized by streptavidin-FITC) were localized in Paramecium by 3-D reconstruction by confocal microscopy. LY showed a scattered, diffuse fluorescence typical of fluid phase uptake whereas transferrin accumulated in membrane-surrounded endosomes. Wortmannin did not affect LY accumulation but decreased it when transferrin was present in the incubation medium. This suggests an effect on the transferrin uptake pathway, presumably on the stage of internalization in "mixing" endosomes to which transferrin and LY were targeted. Phorbol ester diminished LY accumulation by 22% and this effect persisted up to 25 min of incubation. PKC inhibitor did not affect LY uptake. However, in the presence of transferrin, the LY uptake increased within the first 15 minutes followed by a rapid 20% decrease in comparison to the control. Such an effect of PKC modulators suggests that PMA action on fluid phase uptake is not directly mediated by PKC.

  10. Predictive modeling of nanomaterial exposure effects in biological systems

    PubMed Central

    Liu, Xiong; Tang, Kaizhi; Harper, Stacey; Harper, Bryan; Steevens, Jeffery A; Xu, Roger

    2013-01-01

    Background Predictive modeling of the biological effects of nanomaterials is critical for industry and policymakers to assess the potential hazards resulting from the application of engineered nanomaterials. Methods We generated an experimental dataset on the toxic effects experienced by embryonic zebrafish due to exposure to nanomaterials. Several nanomaterials were studied, such as metal nanoparticles, dendrimer, metal oxide, and polymeric materials. The embryonic zebrafish metric (EZ Metric) was used as a screening-level measurement representative of adverse effects. Using the dataset, we developed a data mining approach to model the toxic endpoints and the overall biological impact of nanomaterials. Data mining techniques, such as numerical prediction, can assist analysts in developing risk assessment models for nanomaterials. Results We found several important attributes that contribute to the 24 hours post-fertilization (hpf) mortality, such as dosage concentration, shell composition, and surface charge. These findings concur with previous studies on nanomaterial toxicity using embryonic zebrafish. We conducted case studies on modeling the overall effect/impact of nanomaterials and the specific toxic endpoints such as mortality, delayed development, and morphological malformations. The results show that we can achieve high prediction accuracy for certain biological effects, such as 24 hpf mortality, 120 hpf mortality, and 120 hpf heart malformation. The results also show that the weighting scheme for individual biological effects has a significant influence on modeling the overall impact of nanomaterials. Sample prediction models can be found at http://neiminer.i-a-i.com/nei_models. Conclusion The EZ Metric-based data mining approach has been shown to have predictive power. The results provide valuable insights into the modeling and understanding of nanomaterial exposure effects. PMID:24098077

  11. Reinforcement of cement-based matrices with graphite nanomaterials

    NASA Astrophysics Data System (ADS)

    Sadiq, Muhammad Maqbool

    Cement-based materials offer a desirable balance of compressive strength, moisture resistance, durability, economy and energy-efficiency; their tensile strength, fracture energy and durability in aggressive environments, however, could benefit from further improvements. An option for realizing some of these improvements involves introduction of discrete fibers into concrete. When compared with today's micro-scale (steel, polypropylene, glass, etc.) fibers, graphite nanomaterials (carbon nanotube, nanofiber and graphite nanoplatelet) offer superior geometric, mechanical and physical characteristics. Graphite nanomaterials would realize their reinforcement potential as far as they are thoroughly dispersed within cement-based matrices, and effectively bond to cement hydrates. The research reported herein developed non-covalent and covalent surface modification techniques to improve the dispersion and interfacial interactions of graphite nanomaterials in cement-based matrices with a dense and well graded micro-structure. The most successful approach involved polymer wrapping of nanomaterials for increasing the density of hydrophilic groups on the nanomaterial surface without causing any damage to the their structure. The nanomaterials were characterized using various spectrometry techniques, and SEM (Scanning Electron Microscopy). The graphite nanomaterials were dispersed via selected sonication procedures in the mixing water of the cement-based matrix; conventional mixing and sample preparation techniques were then employed to prepare the cement-based nanocomposite samples, which were subjected to steam curing. Comprehensive engineering and durability characteristics of cement-based nanocomposites were determined and their chemical composition, microstructure and failure mechanisms were also assessed through various spectrometry, thermogravimetry, electron microscopy and elemental analyses. Both functionalized and non-functionalized nanomaterials as well as different

  12. Comparative assessment of nanomaterial definitions and safety evaluation considerations.

    PubMed

    Boverhof, Darrell R; Bramante, Christina M; Butala, John H; Clancy, Shaun F; Lafranconi, Mark; West, Jay; Gordon, Steve C

    2015-10-01

    Nanomaterials continue to bring promising advances to science and technology. In concert have come calls for increased regulatory oversight to ensure their appropriate identification and evaluation, which has led to extensive discussions about nanomaterial definitions. Numerous nanomaterial definitions have been proposed by government, industry, and standards organizations. We conducted a comprehensive comparative assessment of existing nanomaterial definitions put forward by governments to highlight their similarities and differences. We found that the size limits used in different definitions were inconsistent, as were considerations of other elements, including agglomerates and aggregates, distributional thresholds, novel properties, and solubility. Other important differences included consideration of number size distributions versus weight distributions and natural versus intentionally-manufactured materials. Overall, the definitions we compared were not in alignment, which may lead to inconsistent identification and evaluation of nanomaterials and could have adverse impacts on commerce and public perceptions of nanotechnology. We recommend a set of considerations that future discussions of nanomaterial definitions should consider for describing materials and assessing their potential for health and environmental impacts using risk-based approaches within existing assessment frameworks. Our intent is to initiate a dialogue aimed at achieving greater clarity in identifying those nanomaterials that may require additional evaluation, not to propose a formal definition.

  13. Biomedical applications and potential health risks of nanomaterials: molecular mechanisms.

    PubMed

    Lanone, Sophie; Boczkowski, Jorge

    2006-09-01

    Nanotechnologies, defined as techniques aimed to conceive, characterize and produce material at the nanometer scale, represent a fully expanding domain, and one can predict without risk that production and utilization of nanomaterials will increase exponentially in the coming years. Applications of nanotechnologies are numerous, in constant development, and their potential use in the medical field as diagnosis and therapeutics tools is very attractive. The size particularity of these nanomaterials gives them novel properties, allowing them to adopt new comportments because of the laws of quantum physics that exist at this scale. However, worries are expressed regarding the exact properties that make these nanomaterials attractive, and questions are raised regarding their potential toxicity, their long-term secondary effects or their biodegradability, particularly when thinking of their use in the (nano)medical field. These questions are justified by the knowledge of the toxic effects of atmospheric pollution micrometric particles on health, and the fear to get an amplification of these effects because of the size of the materials blamed. In this paper, we first expose the sensed medical applications of nanomaterials, and the physicochemical and molecular determinants potentially responsible for nanomaterials biological effects. Finally, we present a synthesis of the actual knowledge regarding toxicological effects of nanomaterials. It is clear that, in regard to the almost empty field of what is known on the subject, there's an urge to better understand biological effects of nanomaterials, which will allow their safe use, in particular in the nanomedicine field.

  14. Knowledge gaps between nanotoxicological research and nanomaterial safety.

    PubMed

    Hu, Xiangang; Li, Dandan; Gao, Yue; Mu, Li; Zhou, Qixing

    2016-09-01

    With the wide research and application of nanomaterials in various fields, the safety of nanomaterials attracts much attention. An increasing number of reports in the literature have shown the adverse effects of nanomaterials, representing the quick development of nanotoxicology. However, many studies in nanotoxicology have not reflected the real nanomaterial safety, and the knowledge gaps between nanotoxicological research and nanomaterial safety remain large. Considering the remarkable influence of biological or environmental matrices (e.g., biological corona) on nanotoxicity, the situation of performing nanotoxicological experiments should be relevant to the environment and humans. Given the possibility of long-term and low-concentration exposure of nanomaterials, the reversibility of and adaptation to nanotoxicity, and the transgenerational effects should not be ignored. Different from common pollutants, the specific analysis methodology for nanotoxicology need development and exploration furthermore. High-throughput assay integrating with omics was highlighted in the present review to globally investigate nanotoxicity. In addition, the biological responses beyond individual levels, special mechanisms and control of nanotoxicity deserve more attention. The progress of nanotoxicology has been reviewed by previous articles. This review focuses on the blind spots in nanotoxicological research and provides insight into what we should do in future work to support the healthy development of nanotechnology and the evaluation of real nanomaterial safety.

  15. [Nanomaterials in cosmetics--present situation and future].

    PubMed

    Masunaga, Takuji

    2014-01-01

    Cosmetics are consumer products intended to contribute to increasing quality of life and designed for long-term daily use. Due to such features of cosmetics, they are required to ensure quality and safety at a high level, as well as to perform well, in response to consumers' demands. Recently, the technology associated with nanomaterials has progressed rapidly and has been applied to various products, including cosmetics. For example, nano-sized titanium dioxide has been formulated in sunscreen products in pursuit of improving its performance. As some researchers and media have expressed concerns about the safety of nanomaterials, a vague feeling of anxiety has been raised in society. In response to this concern, the Japan Cosmetic Industry Association (JCIA) has begun original research related to the safety assurance of nanomaterials formulated in cosmetics, to allow consumers to use cosmetics without such concerns. This paper describes the activities of the JCIA regarding safety research on nanomaterials, including a survey of the actual usage of nanomaterials in cosmetics, analysis of the existence of nanomaterials on the skin, and assessment of skin carcinogenicity of nano-sized titanium dioxide. It also describes the international status of safety assurance and regulation regarding nanomaterials in cosmetics.

  16. Carbon Nanomaterials Interfacing with Neurons: An In vivo Perspective

    PubMed Central

    Baldrighi, Michele; Trusel, Massimo; Tonini, Raffaella; Giordani, Silvia

    2016-01-01

    Developing new tools that outperform current state of the art technologies for imaging, drug delivery or electrical sensing in neuronal tissues is one of the great challenges in neurosciences. Investigations into the potential use of carbon nanomaterials for such applications started about two decades ago. Since then, numerous in vitro studies have examined interactions between these nanomaterials and neurons, either by evaluating their compatibility, as vectors for drug delivery, or for their potential use in electric activity sensing and manipulation. The results obtained indicate that carbon nanomaterials may be suitable for medical therapies. However, a relatively small number of in vivo studies have been carried out to date. In order to facilitate the transformation of carbon nanomaterial into practical neurobiomedical applications, it is essential to identify and highlight in the existing literature the strengths and weakness that different carbon nanomaterials have displayed when probed in vivo. Unfortunately the current literature is sometimes sparse and confusing. To offer a clearer picture of the in vivo studies on carbon nanomaterials in the central nervous system, we provide a systematic and critical review. Hereby we identify properties and behavior of carbon nanomaterials in vivo inside the neural tissues, and we examine key achievements and potentially problematic toxicological issues. PMID:27375413

  17. Nano-QSPR Modelling of Carbon-Based Nanomaterials Properties.

    PubMed

    Salahinejad, Maryam

    2015-01-01

    Evaluation of chemical and physical properties of nanomaterials is of critical importance in a broad variety of nanotechnology researches. There is an increasing interest in computational methods capable of predicting properties of new and modified nanomaterials in the absence of time-consuming and costly experimental studies. Quantitative Structure- Property Relationship (QSPR) approaches are progressive tools in modelling and prediction of many physicochemical properties of nanomaterials, which are also known as nano-QSPR. This review provides insight into the concepts, challenges and applications of QSPR modelling of carbon-based nanomaterials. First, we try to provide a general overview of QSPR implications, by focusing on the difficulties and limitations on each step of the QSPR modelling of nanomaterials. Then follows with the most significant achievements of QSPR methods in modelling of carbon-based nanomaterials properties and their recent applications to generate predictive models. This review specifically addresses the QSPR modelling of physicochemical properties of carbon-based nanomaterials including fullerenes, single-walled carbon nanotube (SWNT), multi-walled carbon nanotube (MWNT) and graphene.

  18. Redefining risk research priorities for nanomaterials

    PubMed Central

    Baun, Anders; Owen, Richard

    2009-01-01

    Chemical-based risk assessment underpins the current approach to responsible development of nanomaterials (NM). It is now recognised, however, that this process may take decades, leaving decision makers with little support in the near term. Despite this, current and near future research efforts are largely directed at establishing (eco)toxicological and exposure data for NM, and comparatively little research has been undertaken on tools or approaches that may facilitate near-term decisions, some of which we briefly outline in this analysis. We propose a reprioritisation of NM risk research efforts to redress this imbalance, including the development of more adaptive risk governance frameworks, alternative/complementary tools to risk assessment, and health and environment surveillance. PMID:21170127

  19. Nanomaterial-based x-ray sources.

    PubMed

    Cole, Matthew T; Parmee, R J; Milne, William I

    2016-02-26

    Following the recent global excitement and investment in the emerging, and rapidly growing, classes of one and two-dimensional nanomaterials, we here present a perspective on one of the viable applications of such materials: field electron emission based x-ray sources. These devices, which have a notable history in medicine, security, industry and research, to date have almost exclusively incorporated thermionic electron sources. Since the middle of the last century, field emission based cathodes were demonstrated, but it is only recently that they have become practicable. We outline some of the technological achievements of the past two decades, and describe a number of the seminal contributions. We explore the foremost market hurdles hindering their roll-out and broader industrial adoption and summarise the recent progress in miniaturised, pulsed and multi-source devices.

  20. Nanomaterial-based x-ray sources

    NASA Astrophysics Data System (ADS)

    Cole, Matthew T.; Parmee, R. J.; Milne, William I.

    2016-02-01

    Following the recent global excitement and investment in the emerging, and rapidly growing, classes of one and two-dimensional nanomaterials, we here present a perspective on one of the viable applications of such materials: field electron emission based x-ray sources. These devices, which have a notable history in medicine, security, industry and research, to date have almost exclusively incorporated thermionic electron sources. Since the middle of the last century, field emission based cathodes were demonstrated, but it is only recently that they have become practicable. We outline some of the technological achievements of the past two decades, and describe a number of the seminal contributions. We explore the foremost market hurdles hindering their roll-out and broader industrial adoption and summarise the recent progress in miniaturised, pulsed and multi-source devices.

  1. Nanomaterials for renewable energy production and storage.

    PubMed

    Chen, Xiaobo; Li, Can; Grätzel, Michaël; Kostecki, Robert; Mao, Samuel S

    2012-12-01

    Over the past decades, there have been many projections on the future depletion of the fossil fuel reserves on earth as well as the rapid increase in green-house gas emissions. There is clearly an urgent need for the development of renewable energy technologies. On a different frontier, growth and manipulation of materials on the nanometer scale have progressed at a fast pace. Selected recent and significant advances in the development of nanomaterials for renewable energy applications are reviewed here, and special emphases are given to the studies of solar-driven photocatalytic hydrogen production, electricity generation with dye-sensitized solar cells, solid-state hydrogen storage, and electric energy storage with lithium ion rechargeable batteries.

  2. Nanomaterial-based x-ray sources.

    PubMed

    Cole, Matthew T; Parmee, R J; Milne, William I

    2016-02-26

    Following the recent global excitement and investment in the emerging, and rapidly growing, classes of one and two-dimensional nanomaterials, we here present a perspective on one of the viable applications of such materials: field electron emission based x-ray sources. These devices, which have a notable history in medicine, security, industry and research, to date have almost exclusively incorporated thermionic electron sources. Since the middle of the last century, field emission based cathodes were demonstrated, but it is only recently that they have become practicable. We outline some of the technological achievements of the past two decades, and describe a number of the seminal contributions. We explore the foremost market hurdles hindering their roll-out and broader industrial adoption and summarise the recent progress in miniaturised, pulsed and multi-source devices. PMID:26807781

  3. Nanomaterials based biosensors for cancer biomarker detection

    NASA Astrophysics Data System (ADS)

    Malhotra, Bansi D.; Kumar, Saurabh; Mouli Pandey, Chandra

    2016-04-01

    Biosensors have enormous potential to contribute to the evolution of new molecular diagnostic techniques for patients suffering with cancerous diseases. A major obstacle preventing faster development of biosensors pertains to the fact that cancer is a highly complex set of diseases. The oncologists currently rely on a few biomarkers and histological characterization of tumors. Some of the signatures include epigenetic and genetic markers, protein profiles, changes in gene expression, and post-translational modifications of proteins. These molecular signatures offer new opportunities for development of biosensors for cancer detection. In this context, conducting paper has recently been found to play an important role towards the fabrication of a biosensor for cancer biomarker detection. In this paper we will focus on results of some of the recent studies obtained in our laboratories relating to fabrication and application of nanomaterial modified paper based biosensors for cancer biomarker detection.

  4. Carbon and fullerene nanomaterials in plant system

    PubMed Central

    2014-01-01

    Both the functionalized and non functionalized carbon nanomaterials influence fruit and crop production in edible plants and vegetables. The fullerene, C60 and carbon nanotubes have been shown to increase the water retaining capacity, biomass and fruit yield in plants up to ~118% which is a remarkable achievement of nanotechnology in recent years. The fullerene treated bitter melon seeds also increase the phytomedicine contents such as cucurbitacin-B (74%), lycopene (82%), charantin (20%) and insulin (91%). Since as little as 50 μg mL−1 of carbon nanotubes increase the tomato production by about 200%, they may be exploited to enhance the agriculture production in future. It has been observed that, in certain cases, non functionalized multi-wall carbon nanotubes are toxic to both plants and animals but the toxicity can be drastically reduced if they are functionalized. PMID:24766786

  5. Inorganic Nanomaterials as Carriers for Drug Delivery.

    PubMed

    Chen, Shizhu; Hao, Xiaohong; Liang, Xingjie; Zhang, Qun; Zhang, Cuimiao; Zhou, Guoqiang; Shen, Shigang; Jia, Guang; Zhang, Jinchao

    2016-01-01

    For safe and effective therapy, drugs must be delivered efficiently and with minimal systemic side effects. Nanostructured drug carriers enable the delivery of small-molecule drugs as well as nucleic acids and proteins. Inorganic nanomaterials are ideal for drug delivery platforms due to their unique physicochemical properties, such as facile preparation, good storage stability and biocompatibility. Many inorganic nanostructure-based drug delivery platforms have been prepared. Although there are still many obstacles to overcome, significant advances have been made in recent years. This review focuses on the status and development of inorganic nanostructures, including silica, quantum dots, gold, carbon-based and magnetic iron oxide-based nanostructures, as carriers for chemical and biological drugs. We specifically highlight the extensive use of these inorganic drug carriers for cancer therapy. Finally, we discuss the most important areas in the field that urgently require further study. PMID:27301169

  6. Supramolecular self-assemblies as functional nanomaterials

    NASA Astrophysics Data System (ADS)

    Busseron, Eric; Ruff, Yves; Moulin, Emilie; Giuseppone, Nicolas

    2013-07-01

    In this review, we survey the diversity of structures and functions which are encountered in advanced self-assembled nanomaterials. We highlight their flourishing implementations in three active domains of applications: biomedical sciences, information technologies, and environmental sciences. Our main objective is to provide the reader with a concise and straightforward entry to this broad field by selecting the most recent and important research articles, supported by some more comprehensive reviews to introduce each topic. Overall, this compilation illustrates how, based on the rules of supramolecular chemistry, the bottom-up approach to design functional objects at the nanoscale is currently producing highly sophisticated materials oriented towards a growing number of applications with high societal impact.

  7. Terahertz science and technology of carbon nanomaterials.

    PubMed

    Hartmann, R R; Kono, J; Portnoi, M E

    2014-08-15

    The diverse applications of terahertz (THz) radiation and its importance to fundamental science makes finding ways to generate, manipulate and detect THz radiation one of the key areas of modern applied physics. One approach is to utilize carbon nanomaterials, in particular, single-wall carbon nanotubes and graphene. Their novel optical and electronic properties offer much promise to the field of THz science and technology. This article describes the past, current, and future of THz science and technology of carbon nanotubes and graphene. We will review fundamental studies such as THz dynamic conductivity, THz nonlinearities and ultrafast carrier dynamics as well as THz applications such as THz sources, detectors, modulators, antennas and polarizers. PMID:25051014

  8. Silicon nanomaterials platform for bioimaging, biosensing, and cancer therapy.

    PubMed

    Peng, Fei; Su, Yuanyuan; Zhong, Yiling; Fan, Chunhai; Lee, Shuit-Tong; He, Yao

    2014-02-18

    Silicon nanomaterials are an important class of nanomaterials with great potential for technologies including energy, catalysis, and biotechnology, because of their many unique properties, including biocompatibility, abundance, and unique electronic, optical, and mechanical properties, among others. Silicon nanomaterials are known to have little or no toxicity due to favorable biocompatibility of silicon, which is an important precondition for biological and biomedical applications. In addition, huge surface-to-volume ratios of silicon nanomaterials are responsible for their unique optical, mechanical, or electronic properties, which offer exciting opportunities for design of high-performance silicon-based functional nanoprobes, nanosensors, and nanoagents for biological analysis and detection and disease treatment. Moreover, silicon is the second most abundant element (after oxygen) on earth, providing plentiful and inexpensive resources for large-scale and low-cost preparation of silicon nanomaterials for practical applications. Because of these attractive traits, and in parallel with a growing interest in their design and synthesis, silicon nanomaterials are extensively investigated for wide-ranging applications, including energy, catalysis, optoelectronics, and biology. Among them, bioapplications of silicon nanomaterials are of particular interest. In the past decade, scientists have made an extensive effort to construct a silicon nanomaterials platform for various biological and biomedical applications, such as biosensors, bioimaging, and cancer treatment, as new and powerful tools for disease diagnosis and therapy. Nonetheless, there are few review articles covering these important and promising achievements to promote the awareness of development of silicon nanobiotechnology. In this Account, we summarize recent representative works to highlight the recent developments of silicon functional nanomaterials for a new, powerful platform for biological and

  9. Engineered nanomaterials for biophotonics applications: improving sensing, imaging, and therapeutics.

    PubMed

    West, Jennifer L; Halas, Naomi J

    2003-01-01

    Advances in chemistry and physics are providing an expanding array of nanostructured materials with unique and powerful optical properties. These nanomaterials provide a new set of tools that are available to biomedical engineers, biologists, and medical scientists who seek new tools as biosensors and probes of biological fluids, cells, and tissue chemistry and function. Nanomaterials are also being used to develop optically controlled devices for applications such as modulated drug delivery as well as optical therapeutics. This review discusses applications that have been successfully demonstrated using nanomaterials including semiconductor nanocrystals, gold nanoparticles, gold nanoshells, and silver plasmon resonant particles. PMID:14527314

  10. Bio-inspired supramolecular self-assembly towards soft nanomaterials

    PubMed Central

    LIN, Yiyang; MAO, Chuanbin

    2011-01-01

    Supramolecular self-assembly has proven to be a reliable approach towards versatile nanomaterials based on multiple weak intermolecular forces. In this review, the development of bio-inspired supramolecular self-assembly into soft materials and their applications are summarized. Molecular systems used in bio-inspired “bottom-up self-assembly” involve small organic molecules, peptides or proteins, nucleic acids, and viruses. Self-assembled soft nanomaterials have been exploited in various applications such as inorganic nanomaterial synthesis, drug or gene delivery, tissue engineering, and so on. PMID:21980594

  11. Nanomaterials for fresh-keeping and sterilization in food preservation.

    PubMed

    Liu, Dongfang; Gu, Ning

    2009-06-01

    Food sterilizing and antistaling technologies are very important to the public's health and safety and have been attracting more and more attentions. In the past several years, new development chance was created by the introduction of nanomaterials to this critical field. Nanomaterials possess lots of outstanding properties, such as unique quantum size effect, large surface area and catalytic properties, which jointly facilitate high effective fresh-keeping, and thus were considered as promising materials in food sterilization and antistale. This review article focuses on the patented applications of nanomaterials as food biocidal agents, bacteriostatic agents, catalysts and carriers for antistaling agents.

  12. Application of nanomaterials in environmental analysis and monitoring.

    PubMed

    Liang, Minmin; Guo, Liang-Hong

    2009-04-01

    Recent advances in the development and application of nanomaterials in analytical chemistry for environmental analysis and monitoring are reviewed, with focus on sensors, separation and extraction techniques, including the use of nanomaterials as transducer elements for electrochemical sensors, as nanolabels for optical sensors, as stationary phases for liquid chromatography and gas chromatography, as pseudostationary phases or buffer additives in capillary electrophoresis, capillary electrochromatography, and microchip electrophoresis, as well as extraction materials for enrichment prior to chromatographic analysis. Examples of different nanomaterials-based analytical techniques for the detection of major families of environmental pollutants, i.e., organic contaminants, heavy metals and air pollutants, are presented.

  13. Adenosine (ADO) prevents phorbol myristate acetate (PMA) injury in rabbit lungs: Role of leukotrienes (LT)

    SciTech Connect

    Zanaboni, P.; Bradley, J.; Webster, R.; Baudendistel. L.; Dahms, T. )

    1991-03-11

    Pretreatment with ADO prevents the PMA-induced increase in the fluid filtration coefficient (K{sub f}) in isolated perfused rabbit lungs. ADO can block the synthesis of LTs. This study determined whether the protective effect of ADO in PMA induced injury was due to decreased LT production. Isolated rabbit lungs were perfused with a 1:1 mixture of blood and 6% albumin in Krebs-Henseleit buffer. K{sub f} was measured after hemodynamic and weight stabilization and then 30 min after PMA. Perfusate samples were collected after each K{sub f} measurement for determination of LTC{sub 4} and LTD{sub 4} by RIA. The specific role of LT was studied by pretreating with MK-886, a LT synthesis inhibitor. In the vehicle pretreatment group, PMA caused a significant increase in K{sub f} and LTC{sub 4} + LTD{sub 4}. ADO inhibited both the increase in K{sub f} and in LTC{sub 4} + LTD{sub 4}. Pretreatment with MK-886 blocked the PMA-induced increase in LT but did not inhibit the K{sub f} increase. ADO alters the production of LTC{sub 4} + LTD{sub 4} following PMA; but it is probably not the mechanism by which ADO prevents the increase in microvascular permeability.

  14. Atractylodin Inhibits Interleukin-6 by Blocking NPM-ALK Activation and MAPKs in HMC-1.

    PubMed

    Chae, Hee-Sung; Kim, Young-Mi; Chin, Young-Won

    2016-09-02

    Atractylodin is one of the major constituents of the rhizome of Atractylodes lancea, which is widely used in Korean traditional medicine as a remedy for the treatment of gastritis and gastric ulcers. Despite of a major constituent of widely used botanical to treat inflammatory responses little is known about anti-inflammatory effect of atractylodin in the human mast cell (HMC-1). Hence, we evaluated the effect of atractylodin on the release of IL-6, the involvement of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) and mitogen-activated protein kinases (MAPKs) in phorbol-12-myristate-13-acetate and A23187-induced HMC-1. In addition, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), phospholipase C (PLC) gamma 1, and AKT phosphorylation relevant to NPM-ALK signal pathway were assessed. IL-6 levels in the HMC-1 stimulated by phorbol-12-myristate-13-acetate and A23187 were apparently decreased by the treatment of atractylodin. Concurrently, atractylodin not only inhibited the phosphorylation of NPM-ALK, but also suppressed the phosphorylation of JAK2, STAT3, PLC gamma 1, and AKT. Furthermore, the activated mitogen-activated protein kinases (MAPKs) by phorbol-12-myristate-13-acetate and A23187 were inhibited by atractylodin. These results suggested that atractylodin might have a potential regulatory effect on inflammatory mediator expression through blockade of both the phosphorylation of MAPKs and the NPM-ALK signaling pathway.

  15. Atractylodin Inhibits Interleukin-6 by Blocking NPM-ALK Activation and MAPKs in HMC-1.

    PubMed

    Chae, Hee-Sung; Kim, Young-Mi; Chin, Young-Won

    2016-01-01

    Atractylodin is one of the major constituents of the rhizome of Atractylodes lancea, which is widely used in Korean traditional medicine as a remedy for the treatment of gastritis and gastric ulcers. Despite of a major constituent of widely used botanical to treat inflammatory responses little is known about anti-inflammatory effect of atractylodin in the human mast cell (HMC-1). Hence, we evaluated the effect of atractylodin on the release of IL-6, the involvement of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) and mitogen-activated protein kinases (MAPKs) in phorbol-12-myristate-13-acetate and A23187-induced HMC-1. In addition, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), phospholipase C (PLC) gamma 1, and AKT phosphorylation relevant to NPM-ALK signal pathway were assessed. IL-6 levels in the HMC-1 stimulated by phorbol-12-myristate-13-acetate and A23187 were apparently decreased by the treatment of atractylodin. Concurrently, atractylodin not only inhibited the phosphorylation of NPM-ALK, but also suppressed the phosphorylation of JAK2, STAT3, PLC gamma 1, and AKT. Furthermore, the activated mitogen-activated protein kinases (MAPKs) by phorbol-12-myristate-13-acetate and A23187 were inhibited by atractylodin. These results suggested that atractylodin might have a potential regulatory effect on inflammatory mediator expression through blockade of both the phosphorylation of MAPKs and the NPM-ALK signaling pathway. PMID:27598116

  16. Interferon-γ enhances phorbol myristate acetate-induced cell attachment and tumor necrosis factor production via the NF-κB pathway in THP-1 human monocytic cells.

    PubMed

    Kurihara, Yuichi; Furue, Masutaka

    2013-06-01

    During inflammation, activated macrophages express adhesion molecules and produce cytokines that interact with other hematopoietic and stromal cells. THP-1 non-adherent human monocytic cells differentiate into plastic-adherent macrophages via αVβ3 integrin, by ERK activation in the presence of phorbol myristate acetate (PMA). This has proven to be a valuable model for investigating functional monocyte/macrophage diversity. Interferon-γ (IFN-γ) is a Th1-cytokine that is crucial in macrophage activation. In this study, we investigated the effects of IFN-γ on adhesion and the secretion of tumor necrosis factor (TNF) by PMA-stimulated THP-1 cells. IFN-γ is incapable of inducing cell attachment and TNF production; however, it cumulatively upregulated PMA-induced basal adhesion and TNF production. IFN-γ increased αV integrin, ICAM-1 and VCAM-1 expression and among these PMA-induced cell surface adhesion molecules, the blocking antibody for αV integrin suppressed adhesion and TNF production. Furthermore, IFN-γ enhanced PMA-induced NF-κB phosphorylation and not ERK phosphorylation. Accordingly, the NF-κB pathway inhibitor (BAY 11-7082) inhibited the enhancing effect of IFN-γ on adhesion and TNF production. By contrast, the MEK inhibitor (U0126) almost completely eliminated PMA-induced basal adhesion and TNF production. In conclusion, IFN-γ regulates macrophage activation by mediating the NF-κB signaling pathway. PMID:23589028

  17. Interferon-γ enhances phorbol myristate acetate-induced cell attachment and tumor necrosis factor production via the NF-κB pathway in THP-1 human monocytic cells.

    PubMed

    Kurihara, Yuichi; Furue, Masutaka

    2013-06-01

    During inflammation, activated macrophages express adhesion molecules and produce cytokines that interact with other hematopoietic and stromal cells. THP-1 non-adherent human monocytic cells differentiate into plastic-adherent macrophages via αVβ3 integrin, by ERK activation in the presence of phorbol myristate acetate (PMA). This has proven to be a valuable model for investigating functional monocyte/macrophage diversity. Interferon-γ (IFN-γ) is a Th1-cytokine that is crucial in macrophage activation. In this study, we investigated the effects of IFN-γ on adhesion and the secretion of tumor necrosis factor (TNF) by PMA-stimulated THP-1 cells. IFN-γ is incapable of inducing cell attachment and TNF production; however, it cumulatively upregulated PMA-induced basal adhesion and TNF production. IFN-γ increased αV integrin, ICAM-1 and VCAM-1 expression and among these PMA-induced cell surface adhesion molecules, the blocking antibody for αV integrin suppressed adhesion and TNF production. Furthermore, IFN-γ enhanced PMA-induced NF-κB phosphorylation and not ERK phosphorylation. Accordingly, the NF-κB pathway inhibitor (BAY 11-7082) inhibited the enhancing effect of IFN-γ on adhesion and TNF production. By contrast, the MEK inhibitor (U0126) almost completely eliminated PMA-induced basal adhesion and TNF production. In conclusion, IFN-γ regulates macrophage activation by mediating the NF-κB signaling pathway.

  18. Purification and characterization of a calcium-unresponsive, phorbol ester/phospholipid-activated protein kinase from porcine spleen.

    PubMed

    Leibersperger, H; Gschwendt, M; Marks, F

    1990-09-25

    A calcium-unresponsive, phorbol ester/phospholipid-activated protein kinase was purified to apparent homogeneity from a Triton X-100 extract of an EGTA/EDTA-preextracted particulate fraction of porcine spleen by chromatography on S-Sepharose Fast Flow, phenyl-Sepharose Fast Flow, protamine-agarose, and Superdex 200. The enzyme had a Mr of 76,000, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (p76-kinase). A similar value (78,000) was obtained by gel filtration. The purified p76-kinase proved to be much more stable than the enzyme in crude preparations. Storage in a buffer containing 50 mM mercaptoethanol and 20% glycerol at -20 degrees C for at least 4 months caused less than 20% loss in enzyme activity. The enzyme exhibited a pH optimum of 8.3. The affinity of the novel enzyme for substrates and cofactors differed to some extent from that of conventional alpha, beta, gamma protein kinase C (PKC). p76-kinase did not respond to calcium, had a lower requirement for magnesium, and a higher affinity for histone III-S than PKC. Both the p76-kinase-catalyzed phosphorylation of histone III-S and the autophosphorylation of the enzyme could be activated by the phorbol ester TPA (or diacylglycerol) plus phosphatidyl serine, but not by calcium plus phosphatidyl serine. The stoichiometry of autophosphorylation suggested that fully phosphorylated p76-kinase contained two phosphoserine residues and one phosphothreonine residue. Like PKC, p76-kinase bound TPA with high affinity (KD = 9.6 nM). In the absence of TPA, various unsaturated fatty acids, particularly arachidonic acid, were more potent as activators of the enzyme than phosphatidyl serine. The p76-kinase was recognized by an antiserum raised against a delta PKC-specific peptide, but not by an alpha, beta, gamma PKC-specific antiserum. The previously described p82-kinase of mouse epidermis and spleen exhibiting the same properties as the p76-kinase did also react with the p76-kinase

  19. Dislocation-driven synthesis and bioinspired assembly of functional nanomaterials

    NASA Astrophysics Data System (ADS)

    Morin, Stephen A.

    Nanomaterial-based technologies demand the ability to precisely and simultaneously control the synthesis and assembly of inorganic materials at the nanoscale. Motivated by this challenge, my research has focused on the fundamental nucleation and growth processes of functional nanomaterials and the variables we can manipulate to control them for rational synthesis and assembly. In particular, by combining fundamental concepts of crystal growth theory with crystal growth principles derived from natural biomineralization processes this work has yielded new nanomaterial synthesis and assembly strategies. Specifically, this dissertation describes the solution-based growth of nanowires (NWs), nanotubes (NTs), and nanoplates that is driven by screw dislocations and offers new methods for the bottom-up fabrication of hybrid nanostructures, which together enable the formation of tailored functional nanomaterials for a variety of useful applications in diverse areas such as renewable energy and nanoelectronics.

  20. Structural heterogeneities of self-assembled peptide nanomaterials

    NASA Astrophysics Data System (ADS)

    Anthony, Neil R.; Bisignano, Anthony J.; Mehta, Anil K.; Lynn, David G.; Berland, Keith M.

    2012-03-01

    We use Fluorescence Lifetime Imaging Microscopy (FLIM) and Second Harmonic Imaging Microscopy (SHIM) to investigate the fundamental molecular mechanisms responsible for nucleation and growth of amyloidogenic-derived nanomaterials. The nanomaterials are assembled from of Amyloid-β(16-22), specifically Ac-KLVFFAE-NH2, the nucleating core of the Alzheimer's Amyloid-β protein. We describe how FLIM and SHIM can be used to follow different nucleation pathways and to quantify structural heterogeneities within these complex nanomaterials. New evidence suggests that different structures emerge from distinct nucleation pathways and these insights inform our understanding of the peptide self-assembly mechanisms. We discuss these insights in the context of a top down understanding of amyloidogenic diseases, the bottom up control of functional nanomaterials and the discovery of realtime structural indicators for nanofabrication strategies.

  1. Surface engineering of graphene-based nanomaterials for biomedical applications.

    PubMed

    Shi, Sixiang; Chen, Feng; Ehlerding, Emily B; Cai, Weibo

    2014-09-17

    Graphene-based nanomaterials have attracted tremendous interest over the past decade due to their unique electronic, optical, mechanical, and chemical properties. However, the biomedical applications of these intriguing nanomaterials are still limited due to their suboptimal solubility/biocompatibility, potential toxicity, and difficulties in achieving active tumor targeting, just to name a few. In this Topical Review, we will discuss in detail the important role of surface engineering (i.e., bioconjugation) in improving the in vitro/in vivo stability and enriching the functionality of graphene-based nanomaterials, which can enable single/multimodality imaging (e.g., optical imaging, positron emission tomography, magnetic resonance imaging) and therapy (e.g., photothermal therapy, photodynamic therapy, and drug/gene delivery) of cancer. Current challenges and future research directions are also discussed and we believe that graphene-based nanomaterials are attractive nanoplatforms for a broad array of future biomedical applications.

  2. A Decision Support Framework for Evaluation of Engineered Nanomaterials

    EPA Science Inventory

    Engineered nanomaterials (ENM) are currently being developed and applied at rates that far exceed our ability to evaluate their potential for environmental or human health risks. The gap between material development and capacity for assessment grows wider every day. Transforma...

  3. ASSESSING THE EFFECTS OF PULMONARY EXPOSURE TO NANOMATERIALS

    EPA Science Inventory

    Nanotechnology is a dynamic and enabling technology capable of producing a wide diversity of nano-scale (<100 nm) materials displaying unique physicochemical properties for a variety of applications. Nanomaterials may also display unique toxicological properties and routes of exp...

  4. Nanomaterial-based functional scaffolds for amperometric sensing of bioanalytes.

    PubMed

    Dey, Ramendra Sundar; Bera, Raj Kumar; Raj, C R

    2013-04-01

    Functional nanomaterials have emerged as promising candidates in the development of an amperometric sensing platform for the detection and quantification of bioanalytes. The remarkable characteristics of nanomaterials based on metal and metal oxide nanoparticles, carbon nanotubes, and graphene ensure enhanced performance of the sensors in terms of sensitivity, selectivity, detection limit, response time, and multiplexing capability. The electrocatalytic properties of these functional materials can be combined with the biocatalytic activity of redox enzymes to develop integrated biosensing platforms. Highly sensitive and stable miniaturized amperometric sensors have been developed by integrating the nanomaterials and biocatalyst with the transducers. This review provides an update on recent progress in the development of amperometric sensors/biosensors using functional nanomaterials for the sensing of clinically important metabolites such as glucose, cholesterol, lactate, and glutamate, immunosensing of cancer biomarkers, and genosensing.

  5. Characterization of Carbon Onion Nanomaterials for Environmental Remediation

    EPA Science Inventory

    The unique properties of carbonaceous nanomaterials, including small particle size, high surface area, and manipulatable surface chemistry, provide high potential for their application to environmental remediation. While research has devoted to develop nanotechnology for environm...

  6. The retina as a potential site of nanomaterial phototoxicity

    EPA Science Inventory

    Manufactured nanomaterials are designed for their unique properties, one of which is to be photoreactive. Photocatalysts are desirable in many applications including self-cleaning surfaces, sterilization and decontamination of polluted media, and photovoltaic devices. Photo-catal...

  7. Two-dimensional soft nanomaterials: a fascinating world of materials.

    PubMed

    Zhuang, Xiaodong; Mai, Yiyong; Wu, Dongqing; Zhang, Fan; Feng, Xinliang

    2015-01-21

    The discovery of graphene has triggered great interest in two-dimensional (2D) nanomaterials for scientists in chemistry, physics, materials science, and related areas. In the family of newly developed 2D nanostructured materials, 2D soft nanomaterials, including graphene, Bx Cy Nz nanosheets, 2D polymers, covalent organic frameworks (COFs), and 2D supramolecular organic nanostructures, possess great advantages in light-weight, structural control and flexibility, diversity of fabrication approaches, and so on. These merits offer 2D soft nanomaterials a wide range of potential applications, such as in optoelectronics, membranes, energy storage and conversion, catalysis, sensing, biotechnology, etc. This review article provides an overview of the development of 2D soft nanomaterials, with special highlights on the basic concepts, molecular design principles, and primary synthesis approaches in the context.

  8. Effects of nanomaterial physicochemical properties on in vivo toxicity

    PubMed Central

    Aillon, Kristin L.; Xie, Yumei; El-Gendy, Nashwa; Berkland, Cory J.; Forrest, M. Laird

    2009-01-01

    It is well recognized that physical and chemical properties of materials can alter dramatically at nanoscopic scale, and the growing use of nanotechnologies requires careful assessment of unexpected toxicities and biological interactions. However, most in vivo toxicity concerns focus primarily on pulmonary, oral, and dermal exposure to ultrafine particles. As nanomaterials expand as therapeutics and as diagnostic tools, parenteral administration of engineered nanomaterials should also be recognized as a critical aspect for toxicity consideration. Due to the complex nature of nanomaterials, conflicting studies have led to different views of their safety. Here, the physicochemical properties of four representative nanomaterials (dendrimers, carbon nanotubes, quantum dots, and gold nanoparticles) as it relates to their toxicity after systemic exposure is discussed. PMID:19386275

  9. Investigating the Toxicity and Environmental Fate of Graphene Nanomaterials

    EPA Science Inventory

    The Hersam Laboratory at Northwestern University works with the Center for Environmental Implications of Nanotechnology and the United States Environmental Protection Agency to study the toxicity and environmental fate of emergent nanomaterials, specifically carbon-based nanomate...

  10. Surface Engineering of Graphene-Based Nanomaterials for Biomedical Applications

    PubMed Central

    2015-01-01

    Graphene-based nanomaterials have attracted tremendous interest over the past decade due to their unique electronic, optical, mechanical, and chemical properties. However, the biomedical applications of these intriguing nanomaterials are still limited due to their suboptimal solubility/biocompatibility, potential toxicity, and difficulties in achieving active tumor targeting, just to name a few. In this Topical Review, we will discuss in detail the important role of surface engineering (i.e., bioconjugation) in improving the in vitro/in vivo stability and enriching the functionality of graphene-based nanomaterials, which can enable single/multimodality imaging (e.g., optical imaging, positron emission tomography, magnetic resonance imaging) and therapy (e.g., photothermal therapy, photodynamic therapy, and drug/gene delivery) of cancer. Current challenges and future research directions are also discussed and we believe that graphene-based nanomaterials are attractive nanoplatforms for a broad array of future biomedical applications. PMID:25117569

  11. Oxidant-dependent metabolic activation of polycyclic aromatic hydrocarbons by phorbol ester-stimulated human polymorphonuclear leukocytes: possible link between inflammation and cancer

    SciTech Connect

    Trush, M.A.; Seed, J.L.; Kensler, T.W.

    1985-08-01

    Oxidants, such as those generated by metabolically activated phagocytes in inflammation, have been implicated in the metabolic activation of carcinogens, and in this study the authors demonstrate that the interaction of (+/-)-trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene (BP 7,8-dihydrodiol) with phorbol ester-stimulated polymorphonuclear leukocytes (PMNs) results in the generation of both a chemiluminescent intermediate and one that covalently binds to DNA. Concordant with the formation of a carcinogen-DNA adduct, the admixture of BP 7,8-dihydrodiol and phorbol ester-stimulated PMNs elicited mutagenesis in Salmonella typhimurium strain TA100. These results demonstrate that oxidants generated by metabolically stimulated PMNs can activate penultimate polycyclic aromatic hydrocarbons to a genotoxic metabolite and further defines a role for inflammation in carcinogenesis.

  12. Oscillations in cytosolic free Ca2+ induced by ADP and ATP in single rat hepatocytes display differential sensitivity to application of phorbol ester.

    PubMed Central

    Dixon, C J; Cobbold, P H; Green, A K

    1995-01-01

    We have previously described differences in the oscillatory responses of cytosolic free Ca2+ concentration ([Ca2+]i) in hepatocytes to ADP and ATP, which we have interpreted as evidence that these two nucleotides are acting at distinct receptors. We show here that ADP- and ATP-induced oscillations are differentially sensitive to application of the phorbol ester 4 beta-phorbol 12,13-dibutyrate (PDB). ADP-induced [Ca2+]i oscillations are abolished by low concentrations of PDB (5-10 nM), whereas ATP-induced oscillations of long duration are refractory to PDB, even at greatly elevated concentrations (100 nM). The data illustrate a further difference in the actions of ADP and ATP, strengthening the argument that these agonists are not acting at the same receptor on rat hepatocytes. PMID:7619050

  13. Perspectives on the design of safer nanomaterials and manufacturing processes

    PubMed Central

    Geraci, Charles; Heidel, Donna; Sayes, Christie; Hodson, Laura; Schulte, Paul; Eastlake, Adrienne; Brenner, Sara

    2015-01-01

    A concerted effort is being made to insert Prevention through Design principles into discussions of sustainability, occupational safety and health, and green chemistry related to nanotechnology. Prevention through Design is a set of principles that includes solutions to design out potential hazards in nanomanufacturing including the design of nanomaterials, and strategies to eliminate exposures and minimize risks that may be related to the manufacturing processes and equipment at various stages of the lifecycle of an engineered nanomaterial. PMID:26435688

  14. A functional assay-based strategy for nanomaterial risk forecasting.

    PubMed

    Hendren, Christine Ogilvie; Lowry, Gregory V; Unrine, Jason M; Wiesner, Mark R

    2015-12-01

    The study of nanomaterial impacts on environment, health and safety (nanoEHS) has been largely predicated on the assumption that exposure and hazard can be predicted from physical-chemical properties of nanomaterials. This approach is rooted in the view that nanoöbjects essentially resemble chemicals with additional particle-based attributes that must be included among their intrinsic physical-chemical descriptors. With the exception of the trivial case of nanomaterials made from toxic or highly reactive materials, this approach has yielded few actionable guidelines for predicting nanomaterial risk. This article addresses inherent problems in structuring a nanoEHS research strategy based on the goal of predicting outcomes directly from nanomaterial properties, and proposes a framework for organizing data and designing integrated experiments based on functional assays (FAs). FAs are intermediary, semi-empirical measures of processes or functions within a specified system that bridge the gap between nanomaterial properties and potential outcomes in complex systems. The three components of a functional assay are standardized protocols for parameter determination and reporting, a theoretical context for parameter application and reference systems. We propose the identification and adoption of reference systems where FAs may be applied to provide parameter estimates for environmental fate and effects models, as well as benchmarks for comparing the results of FAs and experiments conducted in more complex and varied systems. Surface affinity and dissolution rate are identified as two critical FAs for characterizing nanomaterial behavior in a variety of important systems. The use of these FAs to predict bioaccumulation and toxicity for initial and aged nanomaterials is illustrated for the case of silver nanoparticles and Caenorhabditis elegans.

  15. A functional assay-based strategy for nanomaterial risk forecasting.

    PubMed

    Hendren, Christine Ogilvie; Lowry, Gregory V; Unrine, Jason M; Wiesner, Mark R

    2015-12-01

    The study of nanomaterial impacts on environment, health and safety (nanoEHS) has been largely predicated on the assumption that exposure and hazard can be predicted from physical-chemical properties of nanomaterials. This approach is rooted in the view that nanoöbjects essentially resemble chemicals with additional particle-based attributes that must be included among their intrinsic physical-chemical descriptors. With the exception of the trivial case of nanomaterials made from toxic or highly reactive materials, this approach has yielded few actionable guidelines for predicting nanomaterial risk. This article addresses inherent problems in structuring a nanoEHS research strategy based on the goal of predicting outcomes directly from nanomaterial properties, and proposes a framework for organizing data and designing integrated experiments based on functional assays (FAs). FAs are intermediary, semi-empirical measures of processes or functions within a specified system that bridge the gap between nanomaterial properties and potential outcomes in complex systems. The three components of a functional assay are standardized protocols for parameter determination and reporting, a theoretical context for parameter application and reference systems. We propose the identification and adoption of reference systems where FAs may be applied to provide parameter estimates for environmental fate and effects models, as well as benchmarks for comparing the results of FAs and experiments conducted in more complex and varied systems. Surface affinity and dissolution rate are identified as two critical FAs for characterizing nanomaterial behavior in a variety of important systems. The use of these FAs to predict bioaccumulation and toxicity for initial and aged nanomaterials is illustrated for the case of silver nanoparticles and Caenorhabditis elegans. PMID:26188653

  16. Recent trends in nanomaterials immobilised enzymes for biofuel production.

    PubMed

    Verma, Madan L; Puri, Munish; Barrow, Colin J

    2016-01-01

    Application of nanomaterials as novel supporting materials for enzyme immobilisation has generated incredible interest in the biotechnology community. These robust nanostructured forms, such as nanoparticles, nanofibres, nanotubes, nanoporous, nanosheets, and nanocomposites, possess a high surface area to volume ratios that can cause a high enzyme loading and facilitate reaction kinetics, thus improving biocatalytic efficiency for industrial applications. In this article, we discuss research opportunities of nanoscale materials in enzyme biotechnology and highlight recent developments in biofuel production using advanced material supports for enzyme immobilisation and stabilisation. Synthesis and functionalisation of nanomaterial forms using different methods are highlighted. Various simple and effective strategies designed to result in a stable, as well as functional protein-nanomaterial conjugates are also discussed. Analytical techniques confirming enzyme loading on nanomaterials and assessing post-immobilisation changes are discussed. The current status of versatile nanomaterial support for biofuel production employing cellulases and lipases is described in details. This report concludes with a discussion on the likely outcome that nanomaterials will become an integral part of sustainable bioenergy production.

  17. Nanomaterials in consumer's goods: the problems of risk assessment

    NASA Astrophysics Data System (ADS)

    Gmoshinski, I. V.; Khotimchenko, S. A.

    2015-11-01

    Nanotechnology and engineered nanomaterials are currently used in wide variety of cosmetic products, while their use in food industry, packaging materials, household chemicals etc. still includes a limited number of items and does not show a significant upward trend. However, the problem of priority nanomaterials associated risks is relevant due to their high production volumes and an constantly growing burden on the environment and population. In accordance with the frequency of use in mass-produced consumer goods, leading priority nanomaterials are silver nanoparticles (NPs) and (by a wide margin) NPs of gold, platinum, and titanium dioxide. Frequency of nanosized silica introduction into food products as a food additive, at the moment, seems to be underestimated, since the use of this nanomaterial is not declared by manufacturers of products and objective control of its content is difficult. Analysis of literature data on toxicological properties of nanomaterials shows that currently accumulated amount of information is sufficient to establish the safe doses of nanosized silver, gold and titanium dioxide. Data have been provided in a series of studies concerning the effect of oral intake of nanosized silica on the condition of laboratory animals, including on the performance of the immune system. The article examines the existing approaches to the assessment of population exposure to priority nanomaterials, characteristics of existing problems and risk management.

  18. Interactions of nanomaterials and biological systems: implications to personalized nanomedicine☆

    PubMed Central

    Zhang, Xue-Qing; Xu, Xiaoyang; Bertrand, Nicolas; Pridgen, Eric; Swami, Archana; Farokhzad, Omid C.

    2012-01-01

    The application of nanotechnology to personalized medicine provides an unprecedented opportunity to improve the treatment of many diseases. Nanomaterials offer several advantages as therapeutic and diagnostic tools due to design flexibility, small sizes, large surface-to-volume ratio, and ease of surface modification with multivalent ligands to increase avidity for target molecules. Nanomaterials can be engineered to interact with specific biological components, allowing them to benefit from the insights provided by personalized medicine techniques. To tailor these interactions, a comprehensive knowledge of how nanomaterials interact with biological systems is critical. Herein, we discuss how the interactions of nanomaterials with biological systems can guide their design for diagnostic, imaging and drug delivery purposes. A general overview of nanomaterials under investigation is provided with an emphasis on systems that have reached clinical trials. Finally, considerations for the development of personalized nanomedicines are summarized such as the potential toxicity, scientific and technical challenges in fabricating them, and regulatory and ethical issues raised by the utilization of nanomaterials. PMID:22917779

  19. Recent progress in nanomaterials for gene delivery applications.

    PubMed

    Keles, Erhan; Song, Yang; Du, Dan; Dong, Wen-Ji; Lin, Yuehe

    2016-08-16

    Nanotechnology-based gene delivery is the division of nanomedicine concerned with the synthesis, characterization, and functionalization of nanomaterials to be used in targeted-gene delivery applications. Nanomaterial-based gene delivery systems hold great promise for curing fatal inherited and acquired diseases, including neurological disorders, cancer, cardiovascular diseases, and acquired immunodeficiency syndrome (AIDS). However, their use in clinical applications is still controversial. To date, the Food and Drug Administration (FDA) has not approved any gene delivery system because of the unknown long-term toxicity and the low gene transfection efficiency of nanomaterials in vivo. Compared to viral vectors, nonviral gene delivery vectors are characterized by a low preexisting immunogenicity, which is important for preventing a severe immune response. In addition, nonviral vectors provide higher loading capacity and ease of fabrication. For these reasons, this review article focuses on applications of nonviral gene delivery systems, including those based on lipids, polymers, graphene, and other inorganic nanoparticles, and discusses recent advances in nanomaterials for gene therapy. Methods of synthesizing these nanomaterials are briefly described from a materials science perspective. Also, challenges, critical issues, and concerns about the in vivo applications of nanomaterial-based gene delivery systems are discussed. It should be noted that this article is not a comprehensive review of the literature. PMID:27480033

  20. European Regulation Affecting Nanomaterials - Review of Limitations and Future Recommendations

    PubMed Central

    Hansen, Steffen Foss; Baun, Anders

    2012-01-01

    After learning about the potential risks associated with various specific nanomaterials, concerns have been raised about adequacy of existing regulation in Europe and what should be done to address any potential regulatory gaps related to nanomaterials. Understanding the limitations of the current regulation in regard to nanomaterials is a starting point in a democratic and transparent process towards adapting existing laws and facilitating an informed discussion about which kind of regulatory options best address the identified limitations. In the following we will introduce key pieces of European legislation affecting nanomaterials, analyze their limitations, and provide a number of recommendations on how these can be overcome. We find that, although nanomaterials are in principle covered by the scope of many of the existing legislative frameworks, it is often unclear, if current regulations are actually applicable when it comes to specific nanomaterials and their diverse applications. Main limitations seem to be: that requirements to do safety evaluations are triggered by production volumes by tonnage not tailored to the nanoscale, the profound lack of (eco)toxicological data, and that thresholds values and occupational exposure limits cannot be established with existing methodologies. PMID:22942870

  1. Presence in, and release of, nanomaterials from consumer products.

    PubMed

    Yang, Yu; Westerhoff, Paul

    2014-01-01

    Widespread use of engineered nanomaterials (ENMs) in consumer products has led to concerns about their potential impact on humans and the environment. In order to fully assess the impacts and release of ENMs from consumer products, this chapter provides an overview of the types of consumer products that contain nanomaterials, the potential release mechanisms of these ENMs from consumer products, and the associated human exposure. Information from two large datasets on consumer goods associated with ENMs, namely, the U.S.-based Project for Emerging Nanotechnologies from the Woodrow Wilson International Center, and the European-based National Institute for Public Health and the Environment of Netherlands, have been summarized. These databases reveal that silver, titanium, carbon-based ENMs are the major nanomaterials associated with consumer products. The presence and potential release of silver, titanium, carbon-based, and other nanomaterials from consumer goods available in published literature are also summarized, as well as the potential human exposure scenarios of inhalation, ingestion, dermal, and combination of all means. The prospecting of nanomaterial in water and biosolids provides further evidence of ENM occurrence, which could be linked to the use of nanomaterials containing consumer goods. Finally, this overview provides guidelines on toxicity studies, which calls for further efforts to analyze the biological effects of ENMs on human beings and their exposure pathways in consumer products.

  2. Recent progress in nanomaterials for gene delivery applications.

    PubMed

    Keles, Erhan; Song, Yang; Du, Dan; Dong, Wen-Ji; Lin, Yuehe

    2016-08-16

    Nanotechnology-based gene delivery is the division of nanomedicine concerned with the synthesis, characterization, and functionalization of nanomaterials to be used in targeted-gene delivery applications. Nanomaterial-based gene delivery systems hold great promise for curing fatal inherited and acquired diseases, including neurological disorders, cancer, cardiovascular diseases, and acquired immunodeficiency syndrome (AIDS). However, their use in clinical applications is still controversial. To date, the Food and Drug Administration (FDA) has not approved any gene delivery system because of the unknown long-term toxicity and the low gene transfection efficiency of nanomaterials in vivo. Compared to viral vectors, nonviral gene delivery vectors are characterized by a low preexisting immunogenicity, which is important for preventing a severe immune response. In addition, nonviral vectors provide higher loading capacity and ease of fabrication. For these reasons, this review article focuses on applications of nonviral gene delivery systems, including those based on lipids, polymers, graphene, and other inorganic nanoparticles, and discusses recent advances in nanomaterials for gene therapy. Methods of synthesizing these nanomaterials are briefly described from a materials science perspective. Also, challenges, critical issues, and concerns about the in vivo applications of nanomaterial-based gene delivery systems are discussed. It should be noted that this article is not a comprehensive review of the literature.

  3. Nanomaterials and Autophagy: New Insights in Cancer Treatment

    PubMed Central

    Panzarini, Elisa; Inguscio, Valentina; Tenuzzo, Bernardetta Anna; Carata, Elisabetta; Dini, Luciana

    2013-01-01

    Autophagy represents a cell’s response to stress. It is an evolutionarily conserved process with diversified roles. Indeed, it controls intracellular homeostasis by degradation and/or recycling intracellular metabolic material, supplies energy, provides nutrients, eliminates cytotoxic materials and damaged proteins and organelles. Moreover, autophagy is involved in several diseases. Recent evidences support a relationship between several classes of nanomaterials and autophagy perturbation, both induction and blockade, in many biological models. In fact, the autophagic mechanism represents a common cellular response to nanomaterials. On the other hand, the dynamic nature of autophagy in cancer biology is an intriguing approach for cancer therapeutics, since during tumour development and therapy, autophagy has been reported to trigger both an early cell survival and a late cell death. The use of nanomaterials in cancer treatment to deliver chemotherapeutic drugs and target tumours is well known. Recently, autophagy modulation mediated by nanomaterials has become an appealing notion in nanomedicine therapeutics, since it can be exploited as adjuvant in chemotherapy or in the development of cancer vaccines or as a potential anti-cancer agent. Herein, we summarize the effects of nanomaterials on autophagic processes in cancer, also considering the therapeutic outcome of synergism between nanomaterials and autophagy to improve existing cancer therapies. PMID:24216709

  4. Presence in, and release of, nanomaterials from consumer products.

    PubMed

    Yang, Yu; Westerhoff, Paul

    2014-01-01

    Widespread use of engineered nanomaterials (ENMs) in consumer products has led to concerns about their potential impact on humans and the environment. In order to fully assess the impacts and release of ENMs from consumer products, this chapter provides an overview of the types of consumer products that contain nanomaterials, the potential release mechanisms of these ENMs from consumer products, and the associated human exposure. Information from two large datasets on consumer goods associated with ENMs, namely, the U.S.-based Project for Emerging Nanotechnologies from the Woodrow Wilson International Center, and the European-based National Institute for Public Health and the Environment of Netherlands, have been summarized. These databases reveal that silver, titanium, carbon-based ENMs are the major nanomaterials associated with consumer products. The presence and potential release of silver, titanium, carbon-based, and other nanomaterials from consumer goods available in published literature are also summarized, as well as the potential human exposure scenarios of inhalation, ingestion, dermal, and combination of all means. The prospecting of nanomaterial in water and biosolids provides further evidence of ENM occurrence, which could be linked to the use of nanomaterials containing consumer goods. Finally, this overview provides guidelines on toxicity studies, which calls for further efforts to analyze the biological effects of ENMs on human beings and their exposure pathways in consumer products. PMID:24683024

  5. [International trend of guidance for nanomaterial risk assessment].

    PubMed

    Hirose, Akihiko

    2013-01-01

    In the past few years, several kinds of opinions or recommendations on the nanomaterial safety assessment have been published from international or national bodies. Among the reports, the first practical guidance of risk assessment from the regulatory body was published from the European Food Safety Authorities in May 2011, which included the determination of exposure scenario and toxicity testing strategy. In October 2011, European Commission (EC) adopted the definition of "nanomaterial" for regulation. And more recently, Scientific Committee on Consumer Safety of EC released guidance for assessment of nanomaterials in cosmetics in June 2012. A series of activities in EU marks an important step towards realistic safety assessment of nanomaterials. On the other hand, the US FDA announced a draft guidance for industry in June 2011, and then published draft guidance documents for both "Cosmetic Products" and "Food Ingredients and Food Contact Substances" in April 2012. These draft documents do not restrictedly define the physical properties of nanomaterials, but when manufacturing changes alter the dimensions, properties, or effects of an FDA-regulated product, the products are treated as new products. Such international movements indicate that most of nanomaterials with any new properties would be assessed or regulated as new products by most of national authorities in near future, although the approaches are still case by case basis. We will introduce such current international activities and consideration points for regulatory risk assessment.

  6. Chemical vapor deposition of carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Hussain, Ashfaq

    Developments in the field of nanotechnology are causing a revolution in the world of materials science and engineering. Carbon nanomaterial thin films like nanocrystalline diamond films and carbon nanotubes are among the most prominent materials at the forefront of the nanotechnology revolution. Chief methods for synthesizing these materials have involved chemical vapor deposition (CVD) growth by catalysis from substrates. So far, these methods of synthesis have presented problems of cost and scalability because they have either employed multi-step, extensive substrate surface preparation procedures or used expensive CVD methods to achieve the desired growth. This research work presents the successful results of achieving the synthesis of nanocrystalline diamond thin films and high quality carbon nanotubes by a method which is both low cost and scalable. Specifically, this research program has employed the low cost and scalable method of hot filament chemical vapor deposition (HFCVD) in combination with very simple substrate surface preparation procedures and the CVD variables method of shaping carbon nanostructures to achieve the desired growth of carbon nanomaterial thin films. The CVD variables method, uniquely refined as a carbon nanotube shaping tool in this research work, consists of variation of CVD parameters like precursor gas composition, pressure, and temperature to change nanostructure morphology. The precursor gas mixture used contained variable proportions of the gases methane, hydrogen, and argon. Using this methodology, synthesis of nanocrystalline diamond was achieved on polished silicon substrates at a CVD precursor gas mixture composition in which argon to hydrogen ratio played a decisive role. By the same approach, optimum conditions for growth of carbon nanotubes on Fe-Ni and ferric sulfate coated silicon substrates were determined, leading to the growth of high purity carbon nanotubes of random and vertical orientation. The structures of

  7. Inhibition of growth of established human glioma cell lines by modulators of the protein kinase-C system

    SciTech Connect

    Couldwell, W.T.; Antel, J.P.; Apuzzo, M.L.; Yong, V.W. )

    1990-10-01

    The protein kinase-C (PKC) second messenger system contributes to regulation of cell growth and differentiation. This study was undertaken to examine the effects of modulators of the PKC enzyme system on the state of differentiation and proliferation rates of human gliomas in vitro. The administration of the PKC-activating phorbol esters 4-beta-phorbol-12,13-dibutyrate (PDB) and phorbol-12-myristate-13-acetate (PMA) resulted in a dose-related inhibition of growth of human glioma cell lines in vitro as measured by 3H-thymidine uptake. The synthetic nonphorbol PKC activator (SC-9) produced an even more pronounced decrease of 3H-thymidine uptake. Diacylglycerol, an endogenous activator of the system, applied externally, transiently decreased the proliferation, in concordance with its short-lived existence in vivo. Conversely, the administration of 4-alpha-phorbol-12,13-didecanoate (alpha-PDD), a phorbol ester that binds but does not activate the enzyme, had no effect on the proliferation rate. At the dosages that maximally decreased proliferation, there was no evidence of direct glioma cell lysis induced by these agents as measured by a chromium-release assay. Immunocytochemical analysis and cytofluorometric measurement of glial fibrillary acidic protein (GFAP) staining in the treated cultures revealed an increase in GFAP staining over control cultures. In contrast to the response of glioma cells, nonmalignant human adult astrocytes treated with the PKC activators responded by increasing their proliferation rate. The authors postulate that the diametrically opposed effects of PKC activators on nonmalignant astrocytes versus glioma growth may be due to a high intrinsic PKC activity in glioma cells, with resultant down-regulation of enzyme activity following the administration of the pharmacological activators.

  8. Enhancement of human polymorphonuclear leukocyte adherence to plastic and endothelium by phorbol myristate acetate. Comparison with human C5a.

    PubMed Central

    Webster, R. O.; Wysolmerski, R. B.; Lagunoff, D.

    1986-01-01

    The adherence of circulating neutrophils to vascular endothelium represents a necessary step in the chemotactic emigration of neutrophils to extravascular inflammatory sites. Studies of neutrophil adherence induced by phorbol myristate acetate (PMA) were undertaken to determine the ability of a nonchemotactic neutrophil stimulus to provoke increased adherence. The authors found that the adherence of human neutrophils to plastic surfaces or confluent monolayers of endothelial cells is enhanced in a concentration-dependent fashion by exposure of neutrophils to PMA. The effect of PMA concentration (0.1-5.0 ng/ml) on increased neutrophil adherence parallels that observed for superoxide anion generation and release of lysosomal enzymes from specific granules. Whereas complement C5a-treated neutrophils exhibited a fourfold to fivefold increase in adherence to endothelial cells, PMA-treated neutrophils showed a 10-fold to 20-fold increase. The ability of PMA to cause increased neutrophil adherence to endothelium appeared to be directed primarily at the neutrophil. Pretreatment of neutrophils with PMA was as effective as coincubation in causing increased adherence to plastic surfaces or confluent cultured endothelial cells, but pretreatment of endothelial cells with PMA failed to promote neutrophil adherence. Alteration of neutrophil cytoskeletal structures by cytochalasin B treatment did not prevent subsequent PMA-stimulated neutrophil adherence. These results demonstrate that increased neutrophil adherence to surfaces can be induced by a nonchemotactic stimulus and that neutrophil adherence is independent of organized microfilaments. Images Figure 4 Figure 6 PMID:3789092

  9. beta. -Endorphin and related peptides suppress phorbol myristate acetate-induced respiratory burst in human polymorphonuclear leukocytes

    SciTech Connect

    Diamant, M.; Henricks, P.A.J.; Nijkamp, F.P.; de Wied, D. )

    1989-01-01

    In the present study, the immunomodulatory effect of {beta}-endorphin ({beta}-E) and shorter pro-opiomelancortin (POMC) fragments was evaluated by assessing their influence on respiratory burst in human polymorphonuclear leukocytes (PMN). The effect of the peptides on phorbol myristate acetate (PMA)-stimulated production of reactive oxygen metabolites was measured in a lucigenin-enhanced chemiluminescence (CL) assay. Both POMC peptides with opiate-like activity and their non-opioid derivatives were tested. With the exception of {alpha}-E, PMA-stimulated respiratory burst was suppressed by all POMC fragments tested. A U-shaped dose-response relation was observed. Doses lower than 10{sup {minus}17}M and higher than 10{sup {minus}8}M were without effect. {beta}-E and dT{beta}E both suppressed PMA-induced oxidative burst in human PMN at physiological concentrations. {gamma}-E and dT{gamma}E proved to be less potent inhibitors, reaching maximal effect at higher concentrations. DE{gamma}E exerted an even less pronounced but still significant suppressive effect at the concentration of 10{sup {minus}10}M. None of the endorphins tested was shown to affect resting oxidative metabolism in the PMN. The modulatory effects of the opioid peptides could not be blocked by the opioid antagonist naloxone.

  10. Treatment of mouse melanoma cells with phorbol 12-myristate 13-acetate counteracts mannosylerythritol lipid-induced growth arrest and apoptosis.

    PubMed

    Zhao, X; Geltinger, C; Kishikawa, S; Ohshima, K; Murata, T; Nomura, N; Nakahara, T; Yokoyama, K K

    2000-07-01

    Mannosylerythritol lipid (MEL), an extracellularglycolipid from yeast, induces the differentiation ofHL-60 promyelocytic leukemia cells towardsgranulocytes. We show here that MEL is also a potentinhibitor of the proliferation of mouse melanoma B16cells. Flow-cytometric analysis of the cell cycle ofMEL-treated B16 cells revealed the accumulation ofcells in the sub-G(0)/G(1) phase, which is a hallmark ofcells undergoing apoptosis. Treatment of B16 cellsfor 24 h with phorbol 12-myristate 13-acetate (PMA),an activator of protein kinase C (PKC), did notinterfere with the growth and survival of the cells,but it effectively counteracted the MEL-induced growtharrest and apoptosis. The activity of PKC was reducedin B16 cells treated with MEL at a concentration atwhich MEL induced apoptosis. However, incubation withPMA in addition to MEL reversed this reduction in theactivity of PKC. These results suggest thatconverging signaling pathways are triggeredindependently by MEL and PMA and that the signalsmight both be mediated by PKC. PMID:19002819

  11. Phorbol 12,13-dibutyrate and 1-oleyl-2-acetyldiacylglycerol stimulate inositol trisphosphate dephosphorylation in human platelets

    SciTech Connect

    Molina y Vedia, L.M.; Lapetina, E.G.

    1986-08-15

    Inositol trisphosphate (IP3) is formed in response to specific agonists that cause activation of phospholipase C and degradation of phosphatidylinositol bisphosphate. IP3 is a second messenger that releases Ca/sup 2 +/ from the dense tubular system to the cytosol in stimulated platelets. Our present information indicates that (/sup 3/H)IP3 is dephosphorylated to (/sup 3/H)inositol bisphosphate (IP2) and (/sup 3/H)inositol monophosphate (IP) by human platelets treated with 0.05-0.10% Triton X-100. This dephosphorylation of (/sup 3/H)IP3 to (/sup 3/H)IP2 and (/sup 3/H)IP is also observed when platelets are permeabilized by electrical stimulation or by 20 micrograms/ml saponin. These detergents or electropermeabilization allow IP3 to access cytosolic IP3 phosphatase. Pretreatment of intact platelets with phorbol dibutyrate and 1-oleyl-2-acetyldiacylglycerol for 30 s, at concentrations that maximally activate protein kinase C, stimulates the conversion of IP3 to IP2 and IP. This suggests a role for protein kinase C in the regulation of IP3 degradation.

  12. Innate Immune Responses to Engineered Nanomaterials During Allergic Airway Inflammation

    NASA Astrophysics Data System (ADS)

    Shipkowski, Kelly Anne

    The field of nanotechnology is continually advancing, and increasing amounts of consumer goods are being produced using engineered nanomaterials (ENMs). The health risks of occupational and/or consumer exposure to ENMs are not completely understood, although significant research indicates that pulmonary exposure to nanomaterials induces toxic effects in the lungs of exposed animals. Multi-walled carbon nanotubes (MWCNTs) are a specific category of ENMs and consist of sheets of graphene rolled into cylinders that are multiple layers thick in order to strengthen their rigidity. MWCNTs have a fiber-like shape, similar to that of asbestos, which allows for a high aspect ratio and makes them difficult to clear from the lung. Studies with rodent models have demonstrated that pulmonary exposure to ENMs, in particular MWCNTs, results in acute lung inflammation and the subsequent development of chronic fibrosis, suggesting a potential human health risk to individuals involved in the manufacturing of products utilizing these nanomaterials. Induction of IL-1beta secretion via activation of the inflammasome is a prime mechanism of MWCNT-induced inflammation. The inflammasome is a multi-protein scaffold found in a variety of cell types that forms in response to a variety of immune signals, including particulates. Sensitization with allergens, such as house dust mite (HDM), increases levels of the T helper 2 (Th2) cytokines IL-4 and IL-13 in mice and in humans, and there is particular cause for concern in cases of MWCNT exposure in individuals with pre-existing allergic airway disease, such as asthma. MWCNT exposure exacerbates airway inflammation and fibrosis in animal models of pre-existing allergic asthma, suggesting that individuals suffering from asthma are more susceptible to the toxic pulmonary effects of MWCNT exposure. Asthma is an exceptionally prominent human disease, and therefore the goal of this research was to better understand how pre-existing allergic airway

  13. [Inhibition of neutrophil adhesion by pectic galacturonans].

    PubMed

    Popov, S V; Ovodova, R G; Popova, G Iu; Nikitina, I R; Ovodov, Iu S

    2007-01-01

    The inhibition of the adhesion of neutrophils to fibronectin by the fragments of the main galacturonan chain of the following pectins was demonstrated: comaruman from the marsh cinquefoil Comarum polustre, bergenan from the Siberian tea Bergenia crassifolia, lemnan from the duckweed Lemna minor, zosteran from the seagrass Zostera marina, and citrus pectin. The parent pectins, except for comaruman, did not affect the cell adhesion. Galacturonans prepared from the starting pectins by acidic hydrolysis were shown to reduce the neutrophil adhesion stimulated by phorbol 12-myristate 13-acetate (1.625 microM) and dithiothreitol (0.5 mM) at a concentration of 50-200 microg/ml. The presence of carbohydrate chains with molecular masses higher than 300, from 100 to 300, and from 50 to 100 kDa in the galacturonan fractions was proved by membrane ultrafiltration. PMID:17375675

  14. Inhibitory effect of dihydroartemisinin against phorbol ester-induced cyclooxygenase-2 expression in macrophages.

    PubMed

    Kim, Hyung Gyun; Yang, Ji Hye; Han, Eun Hee; Choi, Jae Ho; Khanal, Tilak; Jeong, Myung Ho; Jeong, Tae Cheon; Jeong, Hye Gwang

    2013-06-01

    Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has recently been shown to possess antitumor activity in various cancer cells. However, the effect of anti-inflammatory potentials of DHA in murine macrophage RAW 264.7 cells has not been studied. The present study investigated the effect of COX-2 and molecular mechanisms by DHA in PMA stimulated RAW 264.7 cells. DHA dose-dependently decreased PMA-induced COX-2 expression and PGE2 production, as well as COX-2 promoter-driven luciferase activity. Additionally, DHA decreased luciferase activity of COX-2 regulation-related transcription factors including NF-κB, AP-1, C/EBP and CREB. DHA also remarkably reduced PMA-induced p65, C/EBPβ, c-jun and CREB nuclear translocation. Furthermore, DHA evidently inhibited PMA-induced phosphorylation of AKT and the MAP Kinases, such as ERK, JNK and p38. Taken together, our data indicated that DHA effectively attenuates COX-2 production via down-regulation of AKT and MAPK pathway, revealing partial molecular basis for the anti-inflammatory properties of DHA. PMID:23429041

  15. Carbon nanomaterials-based electrochemical aptasensors.

    PubMed

    Wang, Zonghua; Yu, Jianbo; Gui, Rijun; Jin, Hui; Xia, Yanzhi

    2016-05-15

    Carbon nanomaterials (CNMs) have attracted increasing attention due to their unique electrical, optical, thermal, mechanical and chemical properties. CNMs are extensively applied in electronic, optoelectronic, photovoltaic and sensing devices fields, especially in bioassay technology. These excellent properties significantly depend on not only the functional atomic structures of CNMs, but also the interactions with other materials, such as gold nanoparticles, SiO2, chitosan, etc. This review systematically summarizes applications of CNMs in electrochemical aptasensors (ECASs). Firstly, definition and development of ECASs are introduced. Secondly, different ways of ECASs about working principles, classification and construction of CNMs are illustrated. Thirdly, the applications of different CNMs used in ECASs are discussed. In this review, different types of CNMs are involved such as carbon nanotubes, graphene, graphene oxide, etc. Besides, the newly emerging CNMs and CNMs-based composites are also discoursed. Finally, we demonstrate the future prospects of CNMs-based ECASs, and some suggestions about the near future development of CNMs-based ECASs are highlighted. PMID:26703992

  16. Carbon nanomaterials: Biologically active fullerene derivatives.

    PubMed

    Bogdanović, Gordana; Djordjević, Aleksandar

    2016-01-01

    Since their discovery, fullerenes, carbon nanotubes, and graphene attract significant attention of researches in various scientific fields including biomedicine. Nano-scale size and a possibility for diverse surface modifications allow carbon nanoallotropes to become an indispensable nanostructured material in nanotechnologies, including nanomedicine. Manipulation of surface chemistry has created diverse populations of water-soluble derivatives of fullerenes, which exhibit different behaviors. Both non-derivatized and derivatized fullerenes show various biological activities. Cellular processes that underline their toxicity are oxidative, genotoxic, and cytotoxic responses.The antioxidant/cytoprotective properties of fullerenes and derivatives have been considered in the prevention of organ oxidative damage and treatment. The same unique physiochemical properties of nanomaterials may also be associated with potential health hazards. Non-biodegradability and toxicity of carbon nanoparticles still remain a great concern in the area of biomedical application. In this review, we report on basic physical and chemical properties of carbon nano-clusters--fullerenes, nanotubes, and grapheme--their specificities, activities, and potential application in biological systems. Special emphasis is given to our most important results obtained in vitro and in vivo using polyhydroxylated fullerene derivative C₆₀(OH)₂₄.

  17. Carbon nanomaterials-based electrochemical aptasensors.

    PubMed

    Wang, Zonghua; Yu, Jianbo; Gui, Rijun; Jin, Hui; Xia, Yanzhi

    2016-05-15

    Carbon nanomaterials (CNMs) have attracted increasing attention due to their unique electrical, optical, thermal, mechanical and chemical properties. CNMs are extensively applied in electronic, optoelectronic, photovoltaic and sensing devices fields, especially in bioassay technology. These excellent properties significantly depend on not only the functional atomic structures of CNMs, but also the interactions with other materials, such as gold nanoparticles, SiO2, chitosan, etc. This review systematically summarizes applications of CNMs in electrochemical aptasensors (ECASs). Firstly, definition and development of ECASs are introduced. Secondly, different ways of ECASs about working principles, classification and construction of CNMs are illustrated. Thirdly, the applications of different CNMs used in ECASs are discussed. In this review, different types of CNMs are involved such as carbon nanotubes, graphene, graphene oxide, etc. Besides, the newly emerging CNMs and CNMs-based composites are also discoursed. Finally, we demonstrate the future prospects of CNMs-based ECASs, and some suggestions about the near future development of CNMs-based ECASs are highlighted.

  18. Carbon nanomaterials: Biologically active fullerene derivatives.

    PubMed

    Bogdanović, Gordana; Djordjević, Aleksandar

    2016-01-01

    Since their discovery, fullerenes, carbon nanotubes, and graphene attract significant attention of researches in various scientific fields including biomedicine. Nano-scale size and a possibility for diverse surface modifications allow carbon nanoallotropes to become an indispensable nanostructured material in nanotechnologies, including nanomedicine. Manipulation of surface chemistry has created diverse populations of water-soluble derivatives of fullerenes, which exhibit different behaviors. Both non-derivatized and derivatized fullerenes show various biological activities. Cellular processes that underline their toxicity are oxidative, genotoxic, and cytotoxic responses.The antioxidant/cytoprotective properties of fullerenes and derivatives have been considered in the prevention of organ oxidative damage and treatment. The same unique physiochemical properties of nanomaterials may also be associated with potential health hazards. Non-biodegradability and toxicity of carbon nanoparticles still remain a great concern in the area of biomedical application. In this review, we report on basic physical and chemical properties of carbon nano-clusters--fullerenes, nanotubes, and grapheme--their specificities, activities, and potential application in biological systems. Special emphasis is given to our most important results obtained in vitro and in vivo using polyhydroxylated fullerene derivative C₆₀(OH)₂₄. PMID:27483572

  19. Nanomaterials driven energy, environmental and biomedical research

    NASA Astrophysics Data System (ADS)

    Sharma, Prakash C.; Srinivasan, Sesha S.; Wilson, Jeremiah F.

    2014-03-01

    We have developed state-of-the-art nanomaterials such as nanofibers, nanotubes, nanoparticles, nanocatalysts and nanostructures for clean energy, environmental and biomedical research. Energy can neither be created nor be destroyed, but it can be converted from one form to another. Based on this principle, chemical energy such as hydrogen has been produced from water electrolysis at a much lower voltage using RuO2 nanoparticles on the Si wafer substrate. Once the hydrogen is produced from the clean sources such as solar energy and water, it has to be stored by physisorption or chemisorption processes on to the solid state systems. For the successful physical adsorption of hydrogen molecule, we have developed novel polyaniline nanostructures via chemical templating and electrospinning routes. Chemical or complex hydrides involving nano MgH2 and transition metal nanocatalysts have been synthesized to tailor both the thermodynamics and kinetics of hydrogen (chemi) sorption respectively. Utilization of solar energy (UV-Vis) and a coupling of novel semiconductor oxide nanoparticles have been recently demonstrated with enhancement in photo-oxidation and/or photo-reduction processes for the water/air detoxification and sustainable liquid fuel production respectively. Magnetic nanoparticles such as ZnFe2O4 have been synthesized and optimized for biomedical applications such as targeted drug delivery and tumor diagnostic sensing (MRI).

  20. Stimuli-Responsive Nanomaterials for Biomedical Applications

    PubMed Central

    2015-01-01

    Nature employs a variety of tactics to precisely time and execute the processes and mechanics of life, relying on sequential sense and response cascades to transduce signaling events over multiple length and time scales. Many of these tactics, such as the activation of a zymogen, involve the direct manipulation of a material by a stimulus. Similarly, effective therapeutics and diagnostics require the selective and efficient homing of material to specific tissues and biomolecular targets with appropriate temporal resolution. These systems must also avoid undesirable or toxic side effects and evade unwanted removal by endogenous clearing mechanisms. Nanoscale delivery vehicles have been developed to package materials with the hope of delivering them to select locations with rates of accumulation and clearance governed by an interplay between the carrier and its cargo. Many modern approaches to drug delivery have taken inspiration from natural activatable materials like zymogens, membrane proteins, and metabolites, whereby stimuli initiate transformations that are required for cargo release, prodrug activation, or selective transport. This Perspective describes key advances in the field of stimuli-responsive nanomaterials while highlighting some of the many challenges faced and opportunities for development. Major hurdles include the increasing need for powerful new tools and strategies for characterizing the dynamics, morphology, and behavior of advanced delivery systems in situ and the perennial problem of identifying truly specific and useful physical or molecular biomarkers that allow a material to autonomously distinguish diseased from normal tissue. PMID:25474531

  1. Nanomaterials to Combat NO(x) Pollution.

    PubMed

    Balbuena, J; Cruz-Yusta, M; Sánchez, L

    2015-09-01

    The presence of NO9x) gases (NO+NO2) in the atmosphere is a major concern of society because of their associated adverse and harmful effects. In order to remove the NO(x) gases from the air, photocatalysis arises as an innovative and promising technique. Through the use of photochemical oxidation processes the NO and NO2 gases are oxidised to NO3- form and thus removed from the air. In recent years new nanomaterials are being developed by researchers with the aim to enhance their photocatalytic activity to combat the NO(x) pollution. The main focus is devoted to preparing new TiO2 based compounds with the highest specific surface area (SSA), different morphology and chemical modifications. In order to increase the SSA, different substrates were used to disperse the TiO2 nanoparticles: organic and carbon fibres, mesoporous materials, clays composites and nanoporous microparticles. In the other hand, high photocatalytic performances were obtained with nanotubes, self-orderer nano-tubular films and nanoparticles with the lowest size. Conversely, when TiO2 is doped with ions the oxide exhibited a better photocatalytic performance under visible light, which is related to the creation of intermediate energy states between the conduction band and the valence band. Alternatively, visible light photocatalysts different from titanium oxide have been studied, which exhibit a good De-NO(x) efficiency working under λ > 400 nm visible light irradiation. PMID:26716191

  2. Nanomaterials to Combat NO(x) Pollution.

    PubMed

    Balbuena, J; Cruz-Yusta, M; Sánchez, L

    2015-09-01

    The presence of NO9x) gases (NO+NO2) in the atmosphere is a major concern of society because of their associated adverse and harmful effects. In order to remove the NO(x) gases from the air, photocatalysis arises as an innovative and promising technique. Through the use of photochemical oxidation processes the NO and NO2 gases are oxidised to NO3- form and thus removed from the air. In recent years new nanomaterials are being developed by researchers with the aim to enhance their photocatalytic activity to combat the NO(x) pollution. The main focus is devoted to preparing new TiO2 based compounds with the highest specific surface area (SSA), different morphology and chemical modifications. In order to increase the SSA, different substrates were used to disperse the TiO2 nanoparticles: organic and carbon fibres, mesoporous materials, clays composites and nanoporous microparticles. In the other hand, high photocatalytic performances were obtained with nanotubes, self-orderer nano-tubular films and nanoparticles with the lowest size. Conversely, when TiO2 is doped with ions the oxide exhibited a better photocatalytic performance under visible light, which is related to the creation of intermediate energy states between the conduction band and the valence band. Alternatively, visible light photocatalysts different from titanium oxide have been studied, which exhibit a good De-NO(x) efficiency working under λ > 400 nm visible light irradiation.

  3. Engineering noble metal nanomaterials for environmental applications

    NASA Astrophysics Data System (ADS)

    Li, Jingguo; Zhao, Tingting; Chen, Tiankai; Liu, Yanbiao; Ong, Choon Nam; Xie, Jianping

    2015-04-01

    Besides being valuable assets in our daily lives, noble metals (namely, gold, silver, and platinum) also feature many intriguing physical and chemical properties when their sizes are reduced to the nano- or even subnano-scale; such assets may significantly increase the values of the noble metals as functional materials for tackling important societal issues related to human health and the environment. Among which, designing/engineering of noble metal nanomaterials (NMNs) to address challenging issues in the environment has attracted recent interest in the community. In general, the use of NMNs for environmental applications is highly dependent on the physical and chemical properties of NMNs. Such properties can be readily controlled by tailoring the attributes of NMNs, including their size, shape, composition, and surface. In this feature article, we discuss recent progress in the rational design and engineering of NMNs with particular focus on their applications in the field of environmental sensing and catalysis. The development of functional NMNs for environmental applications is highly interdisciplinary, which requires concerted efforts from the communities of materials science, chemistry, engineering, and environmental science.

  4. Fabrication and Design of Optical Nanomaterials

    NASA Astrophysics Data System (ADS)

    Huntington, Mark D.

    Over the past several decades, advances in nanometer scale fabrication has sparked interes in applications that take advantage of materials that are structured at these small length scales. Specifically, metallic optical nanomaterials have emerged as a new way to control light at length scales that are smaller than the wavelength of light and have optical properties that are distinctly different from their macroscale counterparts. Although there have been may advances in nanofabrication, the performance and widespread use of optical nanomaterials is still limited by fabrication and design challenges. This dissertation describes advances in the fabrication, characterization, and design of optical nanomaterials. First we demonstrate how a portable and compact photolithography system can be made using a light source composed of UV LEDs. Our solid-state photolithography (SSP) system brings the capabilities of one of the most important yet workhorse tools of micro- and nanotechnology--the mask aligner--to the benchtop. The two main highlights of chapter 2 include: (i) portable, low-cost photolithography and (ii) high quality patterning. We replace the mask aligner with a system composed of UV LEDs and a diffuser that can be built for as little as $30. The design of the SSP system alleviates the need for dedicated power supplies, vacuum lines and cooling systems, which makes it a true benchtop photolithography system. We further show that sub-wavelength features can be fabricated across 4-in wafers and that these patterns are of high quality such that they can be easily transferred into functional materials. Chapter 3 describes a parallel method to create nanometer scale textures over large areas with unprecedented control over wrinkle wavelength. The main points of this chapter include: (i) a new material system for nanowrinkles, (ii) wrinkles with tunable wavelengths, and (iii) a method for measuring the skin thickness. First, we show that RIE treatment of PS with

  5. Molecular dynamics simulations of gold nanomaterials

    NASA Astrophysics Data System (ADS)

    Wang, Yanting

    We have carried out Molecular Dynamics simulations to study the thermal stability and melting behavior of gold nanoclusters and gold nanorods. The surface is found to play a very important role in both gold nanomaterials. Upon cooling from the liquid, we find that gold nanoclusters with 600-3000 atoms crystallize into a Mackay icosahedron. Upon heating, the {111} facets on the surface of the Mackay icosahedral gold nanoclusters soften but do not premelt below the bulk melting temperature. We attribute this surface softening to the increasing mobility of vertex and edge atoms with temperature, which leads to inter-layer and intra-layer diffusion, and a shrinkage of the average facet size. Upon heating, our simulated gold nanorods undergo a shape transformation preceding the melting transition. The shape transformation is induced by a minimization of the surface free energy, and is accompanied by a complete reconstruction of the internal structure driven by the surface change. During the transformation, the atoms on the end caps of the rod move to the sides of the rods, leading the rods to be shorter and wider. After the transformation, the surface of the stable intermediate state rod is mostly covered by the more stable {111} facets, other than the less stable {110} and {100} facets covering the sides of the initial constructed rod.

  6. Tailoring of polymer-nanomaterial interactions

    NASA Astrophysics Data System (ADS)

    Ojha, Lawanya Raj

    Polymeric nanocomposites are multi-component materials consisting of nanometer-scale filler materials embedded within a polymer matrix. The properties of nanocomposites are determined not only by the bulk properties of each of the components, as in the case with conventional macrocomposites, but also by complex interactions between the polymer and nanofillers. This work focused on the interactions of polymers with two different kinds of nanomaterials: (a) single-walled carbon nanotubes (SWNTs) and (b) polyhedral oligomeric silsesquioxanes (POSS). We demonstrate a novel method of dispersion of SWNTs in aqueous suspension by wrapping them with a crosslinkable polymer. Wrapping SWNTs with a poly(N-vinylpyrrolidone-co-allylamine) (PVP-PAAm) polymer gives stable dispersion of SWNTs in water. Crosslinking the PVP-PAAm with gluteraldehyde before removing the polymer/SWNTs complex from its initial water environment stabilizes the dispersion even against changing the solvent system. The presence of individual nanotubes before and after crosslinking of polymer was confirmed by photoluminescence spectroscopy. We also demonstrate the enhancement of thermomechanical properties of epoxy resin with the addition of POSS. We synthesized epoxy/POSS nanocomposites by the addition of very low weight fraction of POSS into epoxy resins by simple mechanical mixing. The glass transition temperature increased by 10 °C, gas permeability decreased by 70%, and fracture toughness of the epoxy resin improved by almost 40 % with the addition of 1 wt.% POSS. However, loadings above 1% by weight resulted in the agglomeration of POSS, degrading the properties of the materials.

  7. Relating nanomaterial properties and microbial toxicity

    NASA Astrophysics Data System (ADS)

    Suresh, Anil K.; Pelletier, Dale A.; Doktycz, Mitchel J.

    2012-12-01

    Metal and metal oxide nanoparticles are among the most commonly used nanomaterials and their potential for adversely affecting environmental systems raises concern. Complex microbial consortia underlie environmental processes, and the potential toxicity of nanoparticles to microbial systems, and the consequent impacts on trophic balances, is particularly worrisome. The diverse array of metal and metal oxides, the different sizes and shapes that can be prepared and the variety of possible surface coatings complicate assessments of toxicity. Further muddling biocidal interpretations are the diversity of microbes and their intrinsic tolerances to stresses. Here, we review a range of studies focused on nanoparticle-microbial interactions in an effort to correlate the physical-chemical properties of engineered metal and metal oxide nanoparticles to their biological response. General conclusions regarding the parent material of the nanoparticle and the nanoparticle's size and shape on potential toxicity can be made. However, the surface coating of the material, which can be altered significantly by environmental conditions, can ameliorate or promote microbial toxicity. Understanding nanoparticle transformations and how the nanoparticle surface can be designed to control toxicity represents a key area for further study. Additionally, the vast array of microbial species and the structuring of these species within communities complicate extrapolations of nanoparticle toxicity in real world settings. Ultimately, to interpret the effect and eventual fate of engineered materials in the environment, an understanding of the relationship between nanoparticle properties and responses at the molecular, cellular and community levels will be essential.

  8. Carbon Nanomaterials in Agriculture: A Critical Review

    PubMed Central

    Mukherjee, Arnab; Majumdar, Sanghamitra; Servin, Alia D.; Pagano, Luca; Dhankher, Om Parkash; White, Jason C.

    2016-01-01

    There has been great interest in the use of carbon nano-materials (CNMs) in agriculture. However, the existing literature reveals mixed effects from CNM exposure on plants, ranging from enhanced crop yield to acute cytotoxicity and genetic alteration. These seemingly inconsistent research-outcomes, taken with the current technological limitations for in situ CNM detection, present significant hurdles to the wide scale use of CNMs in agriculture. The objective of this review is to evaluate the current literature, including studies with both positive and negative effects of different CNMs (e.g., carbon nano-tubes, fullerenes, carbon nanoparticles, and carbon nano-horns, among others) on terrestrial plants and associated soil-dwelling microbes. The effects of CNMs on the uptake of various co-contaminants will also be discussed. Last, we highlight critical knowledge gaps, including the need for more soil-based investigations under environmentally relevant conditions. In addition, efforts need to be focused on better understanding of the underlying mechanism of CNM-plant interactions. PMID:26941751

  9. Novel Metal Nanomaterials and Their Catalytic Applications.

    PubMed

    Wang, Jiaqing; Gu, Hongwei

    2015-01-01

    In the rapidly developing areas of nanotechnology, nano-scale materials as heterogeneous catalysts in the synthesis of organic molecules have gotten more and more attention. In this review, we will summarize the synthesis of several new types of noble metal nanostructures (FePt@Cu nanowires, Pt@Fe₂O₃ nanowires and bimetallic Pt@Ir nanocomplexes; Pt-Au heterostructures, Au-Pt bimetallic nanocomplexes and Pt/Pd bimetallic nanodendrites; Au nanowires, CuO@Ag nanowires and a series of Pd nanocatalysts) and their new catalytic applications in our group, to establish heterogeneous catalytic system in "green" environments. Further study shows that these materials have a higher catalytic activity and selectivity than previously reported nanocrystal catalysts in organic reactions, or show a superior electro-catalytic activity for the oxidation of methanol. The whole process might have a great impact to resolve the energy crisis and the environmental crisis that were caused by traditional chemical engineering. Furthermore, we hope that this article will provide a reference point for the noble metal nanomaterials' development that leads to new opportunities in nanocatalysis. PMID:26393550

  10. Carbon Nanomaterials Alter Global Gene Expression Profiles.

    PubMed

    Woodman, Sara; Short, John C W; McDermott, Hyoeun; Linan, Alexander; Bartlett, Katelyn; Gadila, Shiva Kumar Goud; Schmelzle, Katie; Wanekaya, Adam; Kim, Kyoungtae

    2016-05-01

    Carbon nanomaterials (CNMs), which include carbon nanotubes (CNTs) and their derivatives, have diverse technological and biomedical applications. The potential toxicity of CNMs to cells and tissues has become an important emerging question in nanotechnology. To assess the toxicity of CNTs and fullerenol C60(OH)24, we in the present work used the budding yeast Saccharomyces cerevisiae, one of the simplest eukaryotic organisms that share fundamental aspects of eukaryotic cell biology. We found that treatment with CNMs, regardless of their physical shape, negatively affected the growth rates, end-point cell densities and doubling times of CNM-exposed yeast cells when compared to unexposed cells. To investigate potential mechanisms behind the CNMs-induced growth defects, we performed RNA-Seq dependent transcriptional analysis and constructed global gene expression profiles of fullerenol C60(OH)24- and CNT-treated cells. When compared to non-treated control cells, CNM-treated cells displayed differential expression of genes whose functions are implicated in membrane transporters and stress response, although differentially expressed genes were not consistent between CNT- and fullerenol C60(OH)24-treated groups, leading to our conclusion that CNMs could serve as environmental toxic factors to eukaryotic cells. PMID:27483901

  11. Nanomaterials driven energy, environmental and biomedical research

    SciTech Connect

    Sharma, Prakash C.; Srinivasan, Sesha S.; Wilson, Jeremiah F.

    2014-03-31

    We have developed state-of-the-art nanomaterials such as nanofibers, nanotubes, nanoparticles, nanocatalysts and nanostructures for clean energy, environmental and biomedical research. Energy can neither be created nor be destroyed, but it can be converted from one form to another. Based on this principle, chemical energy such as hydrogen has been produced from water electrolysis at a much lower voltage using RuO{sub 2} nanoparticles on the Si wafer substrate. Once the hydrogen is produced from the clean sources such as solar energy and water, it has to be stored by physisorption or chemisorption processes on to the solid state systems. For the successful physical adsorption of hydrogen molecule, we have developed novel polyaniline nanostructures via chemical templating and electrospinning routes. Chemical or complex hydrides involving nano MgH{sub 2} and transition metal nanocatalysts have been synthesized to tailor both the thermodynamics and kinetics of hydrogen (chemi) sorption respectively. Utilization of solar energy (UV-Vis) and a coupling of novel semiconductor oxide nanoparticles have been recently demonstrated with enhancement in photo-oxidation and/or photo-reduction processes for the water/air detoxification and sustainable liquid fuel production respectively. Magnetic nanoparticles such as ZnFe{sub 2}O{sub 4} have been synthesized and optimized for biomedical applications such as targeted drug delivery and tumor diagnostic sensing (MRI)

  12. Exploring release and recovery of nanomaterials from commercial polymeric nanocomposites

    NASA Astrophysics Data System (ADS)

    Busquets-Fité, Martí; Fernandez, Elisabet; Janer, Gemma; Vilar, Gemma; Vázquez-Campos, Socorro; Zanasca, R.; Citterio, C.; Mercante, L.; Puntes, Víctor

    2013-04-01

    Much concern has been raised about the risks associated with the broad use of polymers containing nanomaterials. Much is known about degradation and aging of polymers and nanomaterials independently, but very few studies have been done in order to understand degradation of polymeric nanocomposites containing nanomaterials and the fate of these nanomaterials, which may occur in suffering many processes such as migration, release and physicochemical modifications. Throughout the UE funded FP7 project NANOPOLYTOX, studies on the migration, release and alteration of mechanical properties of commercial nanocomposites due to ageing and weathering have been performed along with studies on the feasibility of recovery and recycling of the nanomaterials. The project includes the use as model nanocomposites of Polyamide-6 (PA), Polypropylene (PP) and Ethyl Vinyl Acetate (EVA) as polymeric matrix filled with a 3% in mass of a set of selected broadly used nanomaterials; from inorganic metal oxides nanoparticles (SiO2, TiO2 and ZnO) to multi-walled carbon nanotubes (MWCNT) and Nanoclays. These model nanocomposites were then treated under accelerated ageing conditions in climatic chamber. To determine the degree of degradation of the whole nanocomposite and possible processes of migration, release and modification of the nanofillers, nanocomposites were characterized by different techniques. Additionally, recovery of the nanomaterials fro m the polymeric matrix was addressed, being successfully achieved for PA and PP based nanocomposites. In the case of PA, dissolution of the polymeric matrix using formic acid and further centrifugation steps was the chosen approach, while for PP based nanocomposites calcination was performed.

  13. Engineered Nanomaterials, Sexy New Technology and Potential Hazards

    SciTech Connect

    Beaulieu, R A

    2009-05-04

    Engineered nanomaterials enhance exciting new applications that can greatly benefit society in areas of cancer treatments, solar energy, energy storage, and water purification. While nanotechnology shows incredible promise in these and other areas by exploiting nanomaterials unique properties, these same properties can potentially cause adverse health effects to workers who may be exposed during work. Dispersed nanoparticles in air can cause adverse health effects to animals not merely due to their chemical properties but due to their size, structure, shape, surface chemistry, solubility, carcinogenicity, reproductive toxicity, mutagenicity, dermal toxicity, and parent material toxicity. Nanoparticles have a greater likelihood of lung deposition and blood absorption than larger particles due to their size. Nanomaterials can also pose physical hazards due to their unusually high reactivity, which makes them useful as catalysts, but has the potential to cause fires and explosions. Characterization of the hazards (and potential for exposures) associated with nanomaterial development and incorporation in other products is an essential step in the development of nanotechnologies. Developing controls for these hazards are equally important. Engineered controls should be integrated into nanomaterial manufacturing process design according to 10CFR851, DOE Policy 456.1, and DOE Notice 456.1 as safety-related hardware or administrative controls for worker safety. Nanomaterial hazards in a nuclear facility must also meet control requirements per DOE standards 3009, 1189, and 1186. Integration of safe designs into manufacturing processes for new applications concurrent with the developing technology is essential for worker safety. This paper presents a discussion of nanotechnology, nanomaterial properties/hazards and controls.

  14. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    PubMed

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering.

  15. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    PubMed

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering. PMID:25090251

  16. Challenges for In vitro to in Vivo Extrapolation of Nanomaterial Dosimetry for Human Risk Assessment

    SciTech Connect

    Smith, Jordan N.

    2013-11-01

    The proliferation in types and uses of nanomaterials in consumer products has led to rapid application of conventional in vitro approaches for hazard identification. Unfortunately, assumptions pertaining to experimental design and interpretation for studies with chemicals are not generally appropriate for nanomaterials. The fate of nanomaterials in cell culture media, cellular dose to nanomaterials, cellular dose to nanomaterial byproducts, and intracellular fate of nanomaterials at the target site of toxicity all must be considered in order to accurately extrapolate in vitro results to reliable predictions of human risk.

  17. Inhibition of astroglial cell proliferation by alcohols: interference with the protein kinase C-phospholipase D signaling pathway.

    PubMed

    Kötter, K; Jin, S; Klein, J

    2000-12-01

    Ethanol inhibits astroglial cell proliferation, an effect that may contribute to the development of alcoholic embryopathy in humans. In the present study, we investigated inhibitory effects of ethanol and butanol isomers (1-, 2- and t-butanol) on astroglial cell proliferation induced by the strongly mitogenic phorbol ester, 4beta-phorbol-12alpha,13beta-dibutyrate (PDB). 4beta-Phorbol-12alpha,13beta-dibutyrate (PDB) induced a 10-fold increase of [3H] thymidine incorporation in cortical astrocytes prepared from newborn rats (EC50: 70 nM) which was blocked by Ro 31-8220, a cell-permeable protein kinase C (PKC) inhibitor. Ethanol blocked PDB-induced astroglial proliferation in a concentration-dependent manner; significant effects were already seen at 0.1% (v/v). Concomitantly, ethanol caused the formation of phosphatidylethanol (PEth) by phospholipase D (PLD) and reduced PLD-mediated formation of phosphatidic acid (PA). The butanols also inhibited the mitogenic action of phorbol ester; the inhibitory potency of the butanols was 1-butanol > 2-butanol > t-butanol. The same range of potencies was observed for the inhibitory activity of the butanols towards protein kinase C activity measured in vitro. At 0.3% concentration, 1-butanol potently suppressed the PDB-induced formation of phosphatidic acid while 2- and t-butanol were less active. Taken together, our results suggest that ethanol and 1-butanol exert a specific inhibitory effect on PKC-dependent astroglial cell proliferation by synergistically inhibiting PKC activity and the PLD signaling pathway.

  18. The Nanomaterial Data Curation Initiative: A Collaborative Approach to Assessing, Evaluating, and Advancing the State of the Field

    EPA Science Inventory

    The Nanomaterial Data Curation Initiative (NDCI) explores the critical aspect of data curation within the development of informatics approaches to understanding nanomaterial behavior. Data repositories and tools for integrating and interrogating complex nanomaterial datasets are...

  19. Relating nanomaterial properties and microbial toxicity

    SciTech Connect

    Suresh, Anil K; Pelletier, Dale A; Doktycz, Mitchel John

    2013-01-01

    Nanomaterials are meeting diverse needs in consumer and industrial products. Metal and metal oxide nanoparticles are among the most commonly used materials and their potential for adversely affecting environmental systems raises concern. Complex microbial consortia underlie environmental processes, and the potential toxicity of nanoparticles to microbial systems, and the consequent impacts on trophic balances, is particularly worrisome. The diverse array of metal and metal oxides, the different sizes and shapes that can be prepared and the variety of possible surface coatings complicate toxicity assessments. Further complicating toxicity interpretations are the diversity of microbial systems and their metabolic capabilities. Here, we review various studies focused on nanoparticle-microbial interactions in an effort to correlate the physical-chemical properties of engineered metal and metal oxide nanoparticles to their biological response. Gaining a predictive understanding of nanoparticle toxicity, based on the physical-chemical properties of the material, will be key to the design and responsible use of nanotechnologies. General conclusions regarding the parent material of the nanoparticle and nanoparticle s size and shape on potential toxicity can be made. However, the surface coating of the material, which can be altered significantly by environmental conditions, can ameliorate or promote microbial toxicity. Understanding nanoparticle transformations and how the nanoparticle surface can be designed to control toxicity represents a key area for further study. Additionally, the vast array of microbial species and their intrinsic metabolic capabilities complicates extrapolations of nanoparticle toxicity. A molecular-based understanding of the various microbial responses to nanoparticle-induced stress is needed. Ultimately, to interpret the effect and eventual fate of engineered materials in the environment, an understanding of the relationship between nanoparticle

  20. Effects of nanomaterials on marine invertebrates.

    PubMed

    Canesi, Laura; Corsi, Ilaria

    2016-09-15

    The development of nanotechnology will inevitably lead to the release of consistent amounts of nanomaterials (NMs) and nanoparticles (NPs) into marine ecosystems. Ecotoxicological studies have been carried out to identify potential biological targets of NPs, and suitable models for predicting their impact on the health of the marine environment. Recent studies in invertebrates mainly focused on NP accumulation and sub-lethal effects, rather than acute toxicity. Among marine invertebrates, bivalves represent by large the most studied group, with polychaetes and echinoderms also emerging as significant targets of NPs. However, major scientific gaps still need to be filled. In this work, factors affecting the fate of NPs in the marine environment, and their consequent uptake/accumulation/toxicity in marine invertebrates will be summarized. The results show that in different model species, NP accumulation mainly occurs in digestive tract and gills. Data on sub-lethal effects and modes of action of different types of NPs (mainly metal oxides and metal based NPs) in marine invertebrates will be reviewed, in particular on immune function, oxidative stress and embryo development. Moreover, the possibility that such effects may be influenced by NP interactions with biomolecules in both external and internal environment will be introduced. In natural environmental media, NP interactions with polysaccharides, proteins and colloids may affect their agglomeration/aggregation and consequent bioavailability. Moreover, once within the organism, NPs are known to interact with plasma proteins, forming a protein corona that can affect particle uptake and toxicity in target cells in a physiological environment. These interactions, leading to the formation of eco-bio-coronas, may be crucial in determining particle behavior and effects also in marine biota. In order to classify NPs into groups and predict the implications of their release into the marine environment, information on

  1. Effects of nanomaterials on marine invertebrates.

    PubMed

    Canesi, Laura; Corsi, Ilaria

    2016-09-15

    The development of nanotechnology will inevitably lead to the release of consistent amounts of nanomaterials (NMs) and nanoparticles (NPs) into marine ecosystems. Ecotoxicological studies have been carried out to identify potential biological targets of NPs, and suitable models for predicting their impact on the health of the marine environment. Recent studies in invertebrates mainly focused on NP accumulation and sub-lethal effects, rather than acute toxicity. Among marine invertebrates, bivalves represent by large the most studied group, with polychaetes and echinoderms also emerging as significant targets of NPs. However, major scientific gaps still need to be filled. In this work, factors affecting the fate of NPs in the marine environment, and their consequent uptake/accumulation/toxicity in marine invertebrates will be summarized. The results show that in different model species, NP accumulation mainly occurs in digestive tract and gills. Data on sub-lethal effects and modes of action of different types of NPs (mainly metal oxides and metal based NPs) in marine invertebrates will be reviewed, in particular on immune function, oxidative stress and embryo development. Moreover, the possibility that such effects may be influenced by NP interactions with biomolecules in both external and internal environment will be introduced. In natural environmental media, NP interactions with polysaccharides, proteins and colloids may affect their agglomeration/aggregation and consequent bioavailability. Moreover, once within the organism, NPs are known to interact with plasma proteins, forming a protein corona that can affect particle uptake and toxicity in target cells in a physiological environment. These interactions, leading to the formation of eco-bio-coronas, may be crucial in determining particle behavior and effects also in marine biota. In order to classify NPs into groups and predict the implications of their release into the marine environment, information on

  2. Engineered nanomaterials: exposures, hazards, and risk prevention

    PubMed Central

    2011-01-01

    Nanotechnology presents the possibility of revolutionizing many aspects of our lives. People in many settings (academic, small and large industrial, and the general public in industrialized nations) are either developing or using engineered nanomaterials (ENMs) or ENM-containing products. However, our understanding of the occupational, health and safety aspects of ENMs is still in its formative stage. A survey of the literature indicates the available information is incomplete, many of the early findings have not been independently verified, and some may have been over-interpreted. This review describes ENMs briefly, their application, the ENM workforce, the major routes of human exposure, some examples of uptake and adverse effects, what little has been reported on occupational exposure assessment, and approaches to minimize exposure and health hazards. These latter approaches include engineering controls such as fume hoods and personal protective equipment. Results showing the effectiveness - or lack thereof - of some of these controls are also included. This review is presented in the context of the Risk Assessment/Risk Management framework, as a paradigm to systematically work through issues regarding human health hazards of ENMs. Examples are discussed of current knowledge of nanoscale materials for each component of the Risk Assessment/Risk Management framework. Given the notable lack of information, current recommendations to minimize exposure and hazards are largely based on common sense, knowledge by analogy to ultrafine material toxicity, and general health and safety recommendations. This review may serve as an overview for health and safety personnel, management, and ENM workers to establish and maintain a safe work environment. Small start-up companies and research institutions with limited personnel or expertise in nanotechnology health and safety issues may find this review particularly useful. PMID:21418643

  3. Characterization of Carbon Onion Nanomaterials for Environmental Remediation

    NASA Astrophysics Data System (ADS)

    Li, Y.; Su, C.; Bailes, A.; Lu, Y.

    2009-12-01

    The unique properties of carbonaceous nanomaterials, including small particle size, high surface area, and manipulatable surface chemistry, provide high potential for their applications to environmental remediation. While research has been devoted to develop nanotechnology for environmental applications using carbonaceous nanomaterials, e.g. carbon nanotubes and C60 fullerenes, the practical applications are limited due to their high cost of production of about 50-100/g. We introduce a relatively new carbonaceous nanomaterial, i.e. carbon onion nanomaterials, which could be produced in a cost-effective way of about 1/g, by oxygen-depleted combustion of hydrocarbon gases. Carbon onion nanomaterials consist of spherical fullerene cores surrounded by onion-like nested spherical graphite layers, with diameters of around 20 nm. In this work, we characterized the properties of carbon onion nanomaterials to investigate their potential applications in environmental remediation. Dry carbon onion powders were first characterized using transmission electron microcopy (TEM), X-ray diffraction (XRD), and gas sorption Surface Area Analyzer. Sorption capacity of carbon onion nanomaterials for heavy metals, including Zn(II), Ni(II), Pb(II), Cd(II), and Cu(II), was explored using different pH conditions and surface modification approaches. We found that carbon onion nanomaterials can effectively adsorb heavy metal contaminants at high pH or when surface functionalized with carboxylate groups. Stable aqueous suspension of carbon onion aggregates was produced by exchange of toluene organic solvent. The properties of carbon onion aggregates in aqueous suspension, including particle size, zeta potential, and concentration, were determined using a Zetasizer Nano ZS analyzer, Scanning Electron Microscope (SEM) / Energy-Dispersive X-Ray (EDX), and UV-VIS Scanning Spectrophotometer. Carbon onion nanomaterials were found to be very well dispersed in aqueous phase, forming stable aggregates

  4. Fabrication of functional nanomaterials using flame assisted spray pyrolysis

    SciTech Connect

    Purwanto, Agus

    2014-02-24

    Flame assisted spray pyrolysis (FASP) is a class of synthesis method for nanomaterials fabrication. The ability to control nanomaterials characteristics and easy to be-scaled up are the main features of FASP. The crystallinity and particles size of the prepared nanomaterials can be easily controlled by variation of fuel flow rate. The precursor concentration, carrier gas flow rate, and carrier gas can be also used to control the prepared nanomaterials. Energy related nanomaterials preparation uses as the example case in FASP application. These material are yttrium aluminum garnet (YAG:Ce) and tungsten oxide (WO{sub 3}). It needs strategies to produce these materials into nano-sized order. YAG:Ce nanoparticles only can be synthesized by FASP using the urea addition. The decomposition of urea under high temperature of flame promotes the breakage of YAG:Ce particles into nanoparticles. In the preparation of WO{sub 3}, the high temperature flame can be used to gasify WO{sub 3} solid material. As a result, WO{sub 3} nanoparticles can be prepared easily. Generally, to produce nanoparticles via FASP method, the boiling point of the material is important to determine the strategy which will be used.

  5. Deformable devices with integrated functional nanomaterials for wearable electronics

    NASA Astrophysics Data System (ADS)

    Kim, Jaemin; Lee, Jongsu; Son, Donghee; Choi, Moon Kee; Kim, Dae-Hyeong

    2016-03-01

    As the market and related industry for wearable electronics dramatically expands, there are continuous and strong demands for flexible and stretchable devices to be seamlessly integrated with soft and curvilinear human skin or clothes. However, the mechanical mismatch between the rigid conventional electronics and the soft human body causes many problems. Therefore, various prospective nanomaterials that possess a much lower flexural rigidity than their bulk counterparts have rapidly established themselves as promising electronic materials replacing rigid silicon and/or compound semiconductors in next-generation wearable devices. Many hybrid structures of multiple nanomaterials have been also developed to pursue both high performance and multifunctionality. Here, we provide an overview of state-of-the-art wearable devices based on one- or two-dimensional nanomaterials (e.g., carbon nanotubes, graphene, single-crystal silicon and oxide nanomembranes, organic nanomaterials and their hybrids) in combination with zero-dimensional functional nanomaterials (e.g., metal/oxide nanoparticles and quantum dots). Starting from an introduction of materials strategies, we describe device designs and the roles of individual ones in integrated systems. Detailed application examples of wearable sensors/actuators, memories, energy devices, and displays are also presented.

  6. Carbon nanomaterials for electronics, optoelectronics, photovoltaics, and sensing.

    PubMed

    Jariwala, Deep; Sangwan, Vinod K; Lauhon, Lincoln J; Marks, Tobin J; Hersam, Mark C

    2013-04-01

    In the last three decades, zero-dimensional, one-dimensional, and two-dimensional carbon nanomaterials (i.e., fullerenes, carbon nanotubes, and graphene, respectively) have attracted significant attention from the scientific community due to their unique electronic, optical, thermal, mechanical, and chemical properties. While early work showed that these properties could enable high performance in selected applications, issues surrounding structural inhomogeneity and imprecise assembly have impeded robust and reliable implementation of carbon nanomaterials in widespread technologies. However, with recent advances in synthesis, sorting, and assembly techniques, carbon nanomaterials are experiencing renewed interest as the basis of numerous scalable technologies. Here, we present an extensive review of carbon nanomaterials in electronic, optoelectronic, photovoltaic, and sensing devices with a particular focus on the latest examples based on the highest purity samples. Specific attention is devoted to each class of carbon nanomaterial, thereby allowing comparative analysis of the suitability of fullerenes, carbon nanotubes, and graphene for each application area. In this manner, this article will provide guidance to future application developers and also articulate the remaining research challenges confronting this field.

  7. Phorbol ester stimulates ethanolamine release from the metastatic basal prostate cancer cell line PC3 but not from prostate epithelial cell lines LNCaP and P4E6

    PubMed Central

    Schmitt, J; Noble, A; Otsuka, M; Berry, P; Maitland, N J; Rumsby, M G

    2014-01-01

    Background: Malignancy alters cellular complex lipid metabolism and membrane lipid composition and turnover. Here, we investigated whether tumorigenesis in cancer-derived prostate epithelial cell lines influences protein kinase C-linked turnover of ethanolamine phosphoglycerides (EtnPGs) and alters the pattern of ethanolamine (Etn) metabolites released to the medium. Methods: Prostate epithelial cell lines P4E6, LNCaP and PC3 were models of prostate cancer (PCa). PNT2C2 and PNT1A were models of benign prostate epithelia. Cellular EtnPGs were labelled with [1-3H]-Etn hydrochloride. PKC was activated with phorbol ester (TPA) and inhibited with Ro31-8220 and GF109203X. D609 was used to inhibit PLD (phospholipase D). [3H]-labelled Etn metabolites were resolved by ion-exchange chromatography. Sodium oleate and mastoparan were tested as activators of PLD2. Phospholipase D activity was measured by a transphosphatidylation reaction. Cells were treated with ionomycin to raise intracellular Ca2+ levels. Results: Unstimulated cell lines release mainly Etn and glycerylphosphorylEtn (GPEtn) to the medium. Phorbol ester treatment over 3h increased Etn metabolite release from the metastatic PC3 cell line and the benign cell lines PNT2C2 and PNT1A but not from the tumour-derived cell lines P4E6 and LNCaP; this effect was blocked by Ro31-8220 and GF109203X as well as by D609, which inhibited PLD in a transphosphatidylation reaction. Only metastatic PC3 cells specifically upregulated Etn release in response to TPA treatment. Oleate and mastoparan increased GPEtn release from all cell lines at the expense of Etn. Ionomycin stimulated GPEtn release from benign PNT2C2 cells but not from cancer-derived cell lines P4E6 or PC3. Ethanolamine did not stimulate the proliferation of LNCaP or PC3 cell lines but decreased the uptake of choline (Cho). Conclusions: Only the metastatic basal PC3 cell line specifically increased the release of Etn on TPA treatment most probably by PKC activation of

  8. Modulation of phorbol ester-elicited events in mouse epidermis by dietary n-3 and n-6 fatty acids.

    PubMed

    Belury, M A; Leyton, J; Patrick, K E; Cumberland, A G; Locniskar, M; Fischer, S M

    1991-09-01

    Because arachidonic acid-derived eicosanoids are potent modulators of hyperproliferation and inflammation during skin tumor promotion with the phorbol ester, 12-0-tetradecanoylphorbol-13-acetate (TPA) (17, 18), it was hypothesized that dietary modification of epidermal fatty acids might modulate TPA-induced biochemical events in mouse skin. Semipurified diets containing 10% total fat composed of corn oil (CO) or a combination of CO and menhaden oil (MO) or coconut oil (CT) were fed to SENCAR mice for 4 weeks. Fatty acid composition of epidermal phospholipids generally reflected fatty acid composition of dietary oils fed to the mice. Since fatty acid-derived eicosanoids are thought to be essential in tumorigenesis, we compared the effects of dietary fats on prostaglandin E (PGE) production in epidermis treated with a single dose of TPA. TPA-induced PGE production in mouse epidermis from mice fed the MO diet was significantly reduced compared to PGE production in epidermal homogenates from mice fed the CO or CT diets. Type of dietary fats did not appear to modulate TPA-induced vascular permeability, however hyperplasia was slightly elevated in skins of mice fed MO. The subcellular distribution of protein kinase C, the plasma membrane receptor for TPA predominantly located in the cytosol (80%), was altered in epidermis from mice fed the MO diet compared to preparations from mice fed CO or CT diets which exhibited normal protein kinase C distribution. Our results suggest that n-3 rich dietary lipids modulate TPA-elicited events in mouse skin to a greater extent than diets containing higher proportions of saturated or n-6 fatty acids.

  9. Phorbol 12,13-Dibutyrate-Induced, Protein Kinase C-Mediated Contraction of Rabbit Bladder Smooth Muscle

    PubMed Central

    Wang, Tanchun; Kendig, Derek M.; Trappanese, Danielle M.; Smolock, Elaine M.; Moreland, Robert S.

    2012-01-01

    Contraction of bladder smooth muscle is predominantly initiated by M3 muscarinic receptor-mediated activation of the Gq/11-phospholipase C β-protein kinase C (PKC) and the G12/13-RhoGEF-Rho kinase (ROCK) pathways. However, these pathways and their downstream effectors are not well understood in bladder smooth muscle. We used phorbol 12,13-dibutyrate (PDBu), and 1,2-dioctanoyl-sn-glycerol (DOG), activators of PKC, in this investigation. We were interested in dissecting the role(s) of PKC and to clarify the signaling pathways in bladder smooth muscle contraction, especially the potential cross-talk with ROCK and their downstream effectors in regulating myosin light chain phosphatase activity and force. To achieve this goal, the study was performed in the presence or absence of the PKC inhibitor bisindolylmaleimide-1 (Bis) or the ROCK inhibitor H-1152. Phosphorylation levels of Thr38-CPI-17 and Thr696/Thr850 myosin phosphatase target subunit (MYPT1) were measured during PDBu or DOG stimulation using site specific antibodies. PDBu-induced contraction in bladder smooth muscle involved both activation of PKC and PKC-dependent activation of ROCK. CPI-17 as a major downstream effector, is phosphorylated by PKC and ROCK during PDBu and DOG stimulation. Our results suggest that Thr696 and Thr850-MYPT1 phosphorylation are not involved in the regulation of a PDBu-induced contraction. The results also demonstrate that bladder smooth muscle contains a constitutively active isoform of ROCK that may play an important role in the regulation of bladder smooth muscle basal tone. Together with the results from our previous study, we developed a working model to describe the complex signaling pathways that regulate contraction of bladder smooth muscle. PMID:22232602

  10. Activation of resting T cells: distinct roles of intact accessory cells, phorbol myristate acetate and interleukin 1

    SciTech Connect

    Davis, L.; Lipsky, P.E.

    1986-03-05

    The accessory cell (AC) signals involved in the activation of resting guinea pig T lymphocytes stimulated with mitogen (PHA), or the calcium ionophore, ionomycin (Ion) were examined. Activation of T cells was assessed by cell cycle analysis after acridine orange staining and /sup 3/H-thymidine incorporation. PHA-stimulated T cells depleted of all AC were unable to respond in the presence of phorbol myristate acetate (PMA), and/or interleukin 1 (IL 1). With suboptimal numbers of AC, PMA greatly augmented the number of T cells activated by PHA to enter and progress through the cell cycle, but only when present during the first few hours of culture. By contrast, IL 1 had little effect on the number of cells entering the cell cycle, although it enhanced S phase entry of the activated cells. IL 1 augmented DNA synthesis when added initially or later in culture. In contrast to the effects noted with PHA, PMA promoted activation and DNA synthesis of the majority of Ion stimulated cells in the complete absence of AC. IL 1 alone could not support Ion induced T cell activation although it enhanced T cell DNA synthesis in cultures stimulated by PMA and Ion. These studies indicate that intact AC, IL 1 and PMA-like signals play distinct roles in the progression of T cells through the initial cell cycle. Stimulation by Ion requires only PMA whereas PHA responses require intact AC and can be amplified by PMA. The major effect of IL 1 is to promote S phase entry of activated T cells.

  11. 1,25-dihydroxycholecalciferol-induced differentiation of myelomonocytic leukemic cells unresponsive to colony stimulating factors and phorbol esters

    SciTech Connect

    Bettens, F.; Schlick, E.; Farrar, W.; Ruscetti, F.

    1986-12-01

    The murine myelomonocytic leukemia cell line WEHI-3B D/sup +/, which differentiates in response to granulocyte colony stimulating factor (G-CSF), can also be induced to differentiate into monocyte-macrophages by phorbol myristate acetate (PMA) treatment, whereas the WEHI-3B D/sup -/ subline, which is unresponsive to G-CSF and PMA, can be induced to differentiate to granulocytes as well as monocytes by 1,25-dihydroxycholecalciferol (1,25-(OH)/sub 2/ D3), the biologically active metabolite of vitamin D3. A newly developed variant of the WEHI-3B D/sup +/ line, named WEHI-3B D/sup +/G, which was responsive to G-CSF but not to PMA, was also differentiated to granulocytes by 1,25-(OH)/sub 2/ D3. Although vitamin D3 has been reported to induce macrophage differentiation in responsive tumor cells, this is the first demonstration that 1,25-(OH)/sub 2/ D3 can induce granulocyte differentiation. In both differentiation pathways, cessation of cellular proliferation accompanies changes in morphologic and cytochemical properties of the cells. This suggests that leukemic cell lines unresponsive to differentiation agents acting at the cell surface retain their ability to differentiate in response to agents that do not act via the plasma membrane such as 1,25-(OH)/sub 2/ D3, which has cytosolic/nuclear receptors. These results suggest that low doses of 1,25-(OH)/sub 2/ D3 may be useful in combination with hemopoietic growth factors (CSFs) as therapeutic agent to induce leukemic cell differentiation in vivo.

  12. Inhibition by forskolin of insulin-stimulated glucose transport in L6 muscle cells.

    PubMed Central

    Klip, A; Ramlal, T; Douen, A G; Bilan, P J; Skorecki, K L

    1988-01-01

    The cardioactive diterpene forskolin is a known activator of adenylate cyclase, but recently a specific interaction of this compound with the glucose transporter has been identified that results in the inhibition of glucose transport in several human and rat cell types. We have compared the sensitivity of basal and insulin-stimulated hexose transport to inhibition by forskolin in skeletal muscle cells of the L6 line. Forskolin completely inhibited both basal and insulin-stimulated hexose transport when present during the transport assay. The inhibition of basal transport was completely reversible upon removal of the diterpene. In contrast, insulin-stimulated hexose transport did not recover, and basal transport levels were attained instead. This effect of inhibiting (or reversing) the insulin-stimulated fraction of transport is a novel effect of the diterpene. Forskolin treatment also inhibited the stimulated fraction of transport when the stimulus was by 4 beta-phorbol 12,13-dibutyrate, reversing back to basal levels. Half-maximal inhibition of the above-basal insulin-stimulated transport was achieved with 35-50 microM-forskolin, and maximal inhibition with 100 microM. Forskolin did not inhibit 125I-insulin binding under conditions where it caused significant inhibition of insulin-stimulated hexose transport. Forskolin significantly elevated the cyclic AMP levels in the cells; however its inhibitory effect on the above basal, insulin-stimulated fraction of hexose transport was not mediated by cyclic AMP since: (i) 8-bromo cyclic AMP and cholera toxin did not mimic this effect of the diterpene, (ii) significant decreases in cyclic AMP levels caused by 2',3'-dideoxyadenosine in the presence of forskolin did not prevent inhibition of insulin-stimulated hexose transport, (iii) isobutylmethylxanthine did not potentiate forskolin effects on glucose transport but did potentiate the elevation in cyclic AMP, and (iv) 1,9-dideoxyforskolin, which does not activate adenylate

  13. Nucleic Acid Conjugated Nanomaterials for Enhanced Molecular Recognition

    PubMed Central

    Wang, Hao; Yang, Ronghua; Yang, Liu; Tan, Weihong

    2009-01-01

    Nucleic acids, whether designed or selected in vitro, play important roles in biosensing, medical diagnostics and therapy. Specifically, the conjugation of functional nucleic acid-based probe molecules and nanomaterials has resulted in an unprecedented improvement in the field of molecular recognition. With their unique physical and chemical properties, nanomaterials facilitate the sensing process and amplify the signal of recognition events. Thus, the coupling of nucleic acids with various nanomaterials opens up a promising future for molecular recognition. The literature offers a broad spectrum of recent advances in biosensing by employing different nano-platforms with designed nucleic acids, especially gold nanoparticles, carbon nanotubes, silica nanoparticles and quantum dots. The advantages of these novel combinations are discussed from the perspective of molecular recognition in chemistry, biology and medicine, along with the problems confronting future applications. PMID:19658387

  14. Multidimensional nanomaterials for the control of stem cell fate

    NASA Astrophysics Data System (ADS)

    Chueng, Sy-Tsong Dean; Yang, Letao; Zhang, Yixiao; Lee, Ki-Bum

    2016-09-01

    Current stem cell therapy suffers low efficiency in giving rise to differentiated cell lineages, which can replace the original damaged cells. Nanomaterials, on the other hand, provide unique physical size, surface chemistry, conductivity, and topographical microenvironment to regulate stem cell differentiation through multidimensional approaches to facilitate gene delivery, cell-cell, and cell-ECM interactions. In this review, nanomaterials are demonstrated to work both alone and synergistically to guide selective stem cell differentiation. From three different nanotechnology families, three approaches are shown: (1) soluble microenvironmental factors; (2) insoluble physical microenvironment; and (3) nano-topographical features. As regenerative medicine is heavily invested in effective stem cell therapy, this review is inspired to generate discussions in the potential clinical applications of multi-dimensional nanomaterials.

  15. Nanomaterial-Enabled Dry Electrodes for Electrophysiological Sensing: A Review

    NASA Astrophysics Data System (ADS)

    Yao, Shanshan; Zhu, Yong

    2016-04-01

    Long-term, continuous, and unsupervised tracking of physiological data is becoming increasingly attractive for health/wellness monitoring and ailment treatment. Nanomaterials have recently attracted extensive attention as building blocks for flexible/stretchable conductors and are thus promising candidates for electrophysiological electrodes. Here we provide a review on nanomaterial-enabled dry electrodes for electrophysiological sensing, focusing on electrocardiography (ECG). The dry electrodes can be classified into contact surface electrodes, contact-penetrating electrodes, and noncontact capacitive electrodes. Different types of electrodes including their corresponding equivalent electrode-skin interface models and the sources of the noise are first introduced, followed by a review on recent developments of dry ECG electrodes based on various nanomaterials, including metallic nanowires, metallic nanoparticles, carbon nanotubes, and graphene. Their fabrication processes and performances in terms of electrode-skin impedance, signal-to-noise ratio, resistance to motion artifacts, skin compatibility, and long-term stability are discussed.

  16. The redox-active nanomaterial toolbox for cancer therapy.

    PubMed

    Ibañez, Irene L; Notcovich, Cintia; Catalano, Paolo N; Bellino, Martín G; Durán, Hebe

    2015-04-01

    Advances in nanomaterials science contributed in recent years to develop new devices and systems in the micro and nanoscale for improving the diagnosis and treatment of cancer. Substantial evidences associate cancer cells and tumor microenvironment with reactive oxygen species (ROS), while conventional cancer treatments and particularly radiotherapy, are often mediated by ROS increase. However, the poor selectivity and the toxicity of these therapies encourage researchers to focus efforts in order to enhance delivery and to decrease side effects. Thus, the development of redox-active nanomaterials is an interesting approach to improve selectivity and outcome of cancer treatments. Herein, we describe an overview of recent advances in redox nanomaterials in the context of current and emerging strategies for cancer therapy based on ROS modulation.

  17. Redox electrodes comprised of polymer-modified carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Roberts, Mark; Emmett, Robert; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao; Clemson Physics Team; Clemson Chemical Engineering Team

    2013-03-01

    A shift in how we generate and use electricity requires new energy storage materials and systems compatible with hybrid electric transportation and the integration of renewable energy sources. Supercapacitors provide a solution to these needs by combining the high power, rapid switching, and exceptional cycle life of a capacitor with the high energy density of a battery. Our research brings together nanotechnology and materials chemistry to address the limitations of electrode materials. Paper electrodes fabricated with various forms of carbon nanomaterials, such as nanotubes, are modified with redox-polymers to increase the electrode's energy density while maintaining rapid discharge rates. In these systems, the carbon nanomaterials provide the high surface area, electrical conductivity, nanoscale and porosity, while the redox polymers provide a mechanism for charge storage through Faradaic charge transfer. The design of redox polymers and their incorporation into nanomaterial electrodes will be discussed with a focus on enabling high power and high energy density electrodes.

  18. The redox-active nanomaterial toolbox for cancer therapy.

    PubMed

    Ibañez, Irene L; Notcovich, Cintia; Catalano, Paolo N; Bellino, Martín G; Durán, Hebe

    2015-04-01

    Advances in nanomaterials science contributed in recent years to develop new devices and systems in the micro and nanoscale for improving the diagnosis and treatment of cancer. Substantial evidences associate cancer cells and tumor microenvironment with reactive oxygen species (ROS), while conventional cancer treatments and particularly radiotherapy, are often mediated by ROS increase. However, the poor selectivity and the toxicity of these therapies encourage researchers to focus efforts in order to enhance delivery and to decrease side effects. Thus, the development of redox-active nanomaterials is an interesting approach to improve selectivity and outcome of cancer treatments. Herein, we describe an overview of recent advances in redox nanomaterials in the context of current and emerging strategies for cancer therapy based on ROS modulation. PMID:25597786

  19. Current Trends in Nanomaterial-Based Amperometric Biosensors

    PubMed Central

    Hayat, Akhtar; Catanante, Gaëlle; Marty, Jean Louis

    2014-01-01

    The last decade has witnessed an intensive research effort in the field of electrochemical sensors, with a particular focus on the design of amperometric biosensors for diverse analytical applications. In this context, nanomaterial integration in the construction of amperometric biosensors may constitute one of the most exciting approaches. The attractive properties of nanomaterials have paved the way for the design of a wide variety of biosensors based on various electrochemical detection methods to enhance the analytical characteristics. However, most of these nanostructured materials are not explored in the design of amperometric biosensors. This review aims to provide insight into the diverse properties of nanomaterials that can be possibly explored in the construction of amperometric biosensors. PMID:25494347

  20. Nanomaterial-enabled Rapid Detection of Water Contaminants.

    PubMed

    Mao, Shun; Chang, Jingbo; Zhou, Guihua; Chen, Junhong

    2015-10-28

    Water contaminants, e.g., inorganic chemicals and microorganisms, are critical metrics for water quality monitoring and have significant impacts on human health and plants/organisms living in water. The scope and focus of this review is nanomaterial-based optical, electronic, and electrochemical sensors for rapid detection of water contaminants, e.g., heavy metals, anions, and bacteria. These contaminants are commonly found in different water systems. The importance of water quality monitoring and control demands significant advancement in the detection of contaminants in water because current sensing technologies for water contaminants have limitations. The advantages of nanomaterial-based sensing technologies are highlighted and recent progress on nanomaterial-based sensors for rapid water contaminant detection is discussed. An outlook for future research into this rapidly growing field is also provided.

  1. Advances in biodegradable nanomaterials for photothermal therapy of cancer

    PubMed Central

    He, Chao-Feng; Wang, Shun-Hao; Yu, Ying-Jie; Shen, He-Yun; Zhao, Yan; Gao, Hui-Ling; Wang, Hai; Li, Lin-Lin; Liu, Hui-Yu

    2016-01-01

    Photothermal cancer therapy is an alternative to chemotherapy, radiotherapy, and surgery. With the development of nanophotothermal agents, this therapy holds immense potential in clinical translation. However, the toxicity issues derived from the fact that nanomaterials are trapped and retained in the reticuloendothelial systems limit their biomedical application. Developing biodegradable photothermal agents is the most practical route to address these concerns. In addition to the physicochemical properties of nanomaterials, various internal and external stimuli play key roles on nanomaterials uptake, transport, and clearance. In this review, we summarized novel nanoplatforms for photothermal therapy; these nanoplatforms can elicit stimuli-triggered degradation. We focused on the recent innovative designs endowed with biodegradable photothermal agents under different stimuli, including enzyme, pH, and near-infrared (NIR) laser. PMID:27807498

  2. Hybrid nanomaterial and its applications: IR sensing and energy harvesting

    NASA Astrophysics Data System (ADS)

    Tseng, Yi-Hsuan

    In this dissertation, a hybrid nanomaterial, single-wall carbon nanotubes-copper sulfide nanoparticles (SWNTs-CuS NPs), was synthesized and its properties were analyzed. Due to its unique optical and thermal properties, the hybrid nanomaterial exhibited great potential for infrared (IR) sensing and energy harvesting. The hybrid nanomaterial was synthesized with the non-covalent bond technique to functionalize the surface of the SWNTs and bind the CuS nanoparticles on the surface of the SWNTs. For testing and analyzing the hybrid nanomaterial, SWNTs-CuS nanoparticles were formed as a thin film structure using the vacuum filtration method. Two conductive wires were bound on the ends of the thin film to build a thin film device for measurements and analyses. Measurements found that the hybrid nanomaterial had a significantly increased light absorption (up to 80%) compared to the pure SWNTs. Moreover, the hybrid nanomaterial thin film devices exhibited a clear optical and thermal switching effect, which could be further enhanced up to ten times with asymmetric illumination of light and thermal radiation on the thin film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials was demonstrated, indicating a new route for achieving thermoelectricity. In addition, CuS nanoparticles have great optical absorption especially in the near-infrared region. Therefore, the hybrid nanomaterial thin films also have the potential for IR sensing applications. The first application to be covered in this dissertation is the IR sensing application. IR thin film sensors based on the SWNTs-CuS nanoparticles hybrid nanomaterials were fabricated. The IR response in the photocurrent of the hybrid thin film sensor was significantly enhanced, increasing the photocurrent by 300% when the IR light illuminates the thin film device asymmetrically. The detection limit could be as low as 48mW mm-2. The dramatically enhanced

  3. AN ASSESSMENT OF THE FATE OF METAL OXIDE NANOMATERIALS IN POROUS MEDIA

    EPA Science Inventory

    Developing procedures for assessing the potential environmental fate and transport of nanomaterials is an active endeavor of the environmental technical research community. Insufficient information exists for estimating the likelihood of nanomaterial deposition on natural surface...

  4. 77 FR 39236 - Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... AGENCY Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether... Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether Flame-Retardant Coatings... ``Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether...

  5. 77 FR 24722 - Draft Guidance for Industry: Safety of Nanomaterials in Cosmetic Products; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... Cosmetic Products; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The... ``Guidance for Industry: Safety of Nanomaterials in Cosmetic Products.'' The draft guidance, when finalized, will represent FDA's current thinking on the safety assessment of nanomaterials in cosmetic...

  6. Time-Course Determination of Cellular Stress Responses Elicited by Engineered Nanomaterials

    EPA Science Inventory

    Engineered nanomaterials are being incorporated continuously into consumer products, resulting in increased human exposures. The study of engineered nanomaterials has focused largely on oxidative stress and inflammation endpoints without further investigating potential pathways. ...

  7. [Degradation and transformation of engineering carbon nanomaterials in the environment: A review].

    PubMed

    Yue, Fang-Ning; Luo, Shui-Ming; Zhang, Cheng-Dong

    2013-02-01

    With the large amount production and application of engineering carbon nanomaterials, their potential ecological risk has attracted extensive attention. The degradation and transformation of the carbon nanomaterials in the environment directly affect the fates and eco-toxicity of the nanomaterials in the environment, and the research of the degradation and transformation processes of the nanomaterials in the environment is the key link for the determination of the environmental capacity of the nanomaterials and for the evaluation of the nanomaterials life cycle in the environment. This paper briefly introduced the chemical transformation, microbial degradation, and photodegradation of the major engineering carbon nanomaterials (carbon nanotubes and fullerene) in the environment, and summarized the environmental and structural factors affecting the degradation of the nanomaterials and the related intrinsic mechanisms. The shortcomings of the related researches and the directions of the future research were also put forward.

  8. Sensors As Tools for Quantitation, Nanotoxicity and Nanomonitoring Assessment of Engineered Nanomaterials

    EPA Science Inventory

    The discovery of fullerenes in 1985 has ushered in an explosive growth in the applications of engineered nanomaterials and consumer products. Nanotechnology and engineered nanomaterials (ENMs) are being incorporated into a range of commercial products such as consumer electronic...

  9. Meeting in New Orleans: An Assessment of the Fate of Metal Oxide Nanomaterials in Porous Media

    EPA Science Inventory

    This work assesses potential aqueous environmental metal oxide nanomaterial self-aggregation through the application of recent developments in surface complexation theory with historical DLVO procedures. Findings include: 1) nanomaterials with a Hamaker constant as large as 1E-1...

  10. Sunlight-induced Transformations of Graphene-based Nanomaterials in Aquatic Environments

    EPA Science Inventory

    Graphene-based nanomaterials and other related carbon nanomaterials (CNMs) can be released from products during their life cycles. Upon entry into aquatic environments, they are potentially transformed by photochemical reactions, oxidation reactions and biological processes, all ...

  11. EDITORIAL: Excelling under strain: band engineering in nanomaterials Excelling under strain: band engineering in nanomaterials

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2013-08-01

    A little stress or strain has been known to improve the performance of athletes, actors and of course nanomaterials alike. In fact strain in silicon is now a major engineering tool for improving the performance of devices, and is ubiquitously used in device design and fabrication. Strain engineering alters a material's band structure, a model of electron behaviour that describes how as atoms come together in a solid, their discrete electron orbitals overlap to ultimately give rise to bands of allowed energy levels. In a strained crystal lattice of silicon or silicon germanium the distance between atoms in the lattice is greater than usual and the bands of allowed energy levels change. This July marks 100 years since Bohr submitted his paper 'On the constitution of atoms and molecules' [1] where he describes the structure of the atom in terms of discrete allowed energy levels. The paper was a seminal contribution to the development of quantum mechanics and laid the initial theoretical precepts for band gap engineering in devices. In this issue Nrauda and a collaboration of researchers in Europe and Australia study the growth of defect-free SiGe islands on pre-patterned silicon [2]. They analyse the strain in the islands and determine at what point lattice dislocations set in with a view to informing implementation of strain engineering in devices. The effects of strain on band structure in silicon and germanium were already studied and reported in the 1950s [3, 4]. Since then the increasing focus on nanoscale materials and the hunger for control of electronic properties has prompted further study of strain effects. The increased surface area to volume ratio in nanostructures changes the strain behaviour with respect to bulk materials, and this can also be exploited for handling and fine tuning strain to manipulate material properties. It is perhaps no surprise that graphene, one of the most high-profile materials in current nanotechnology research, has attracted

  12. Dual concentration-dependent effects of phorbol 12, 13-dibutyrate on spontaneous and acetylcholine-induced electrical responses recorded from isolated circular smooth muscle of the guinea-pig stomach antrum.

    PubMed

    Nakamura, Eri; Suzuki, Hikaru

    2004-12-01

    Intracellular recordings of electrical activity were made from circular smooth muscle cells in small segments of tissue isolated from the guinea-pig stomach antrum. Every cell that was impaled exhibited a rhythmic generation of slow potentials. Experiments were carried out to test the effects of three different concentrations (1, 10 and 100 nM) of phorbol 12, 13-dibutyrate (PDBu) on these slow potentials and on the responses produced by acetylcholine (ACh), in the presence of nifedipine and N(omega)-nitro-L-arginine (nitroarginine), known inhibitors of L-type Ca-channels and nitric oxide synthase, respectively. The resting membrane potential was -62 +/- 7 mV, while the frequency and amplitude of the slow potentials were 1.6 +/- 0.1 cycle per min (cpm) and 33 +/- 1 mV, respectively. Application of 1 nM PDBu increased the frequency of slow potentials, with no significant change in the membrane potential and amplitude of slow potentials. At a concentration of 100 nM, PDBu depolarized the membrane by about 6 mV, and either decreased the amplitude and frequency of the slow potentials or abolished them. The amplitude and frequency of the slow potentials were not significantly changed in the presence of 10 nM PDBu. In the presence of chelerythrine (1-2 microM), a known inhibitor of protein kinase C (PKC), the increase in frequency of slow potentials by 1 nM PDBu and depolarization produced by 100 nM PDBu were not elicited. The increase in frequency of slow potentials by 100 nM ACh was inhibited by PDBu, in a concentration-dependent manner, and ACh-responses were abolished in the presence of 100 nM PDBu. These results indicate that PDBu has dual actions on the spontaneous activity of antral circular muscle, with low concentrations increasing and high concentrations inhibiting the frequency of the slow potentials. The former may be produced by activation of protein kinase C (PKC). As the ACh-induced excitation of slow potentials is inhibited by PDBu, a possible causal

  13. Flows of engineered nanomaterials through the recycling process in Switzerland

    SciTech Connect

    Caballero-Guzman, Alejandro; Sun, Tianyin; Nowack, Bernd

    2015-02-15

    Highlights: • Recycling is one of the likely end-of-life fates of nanoproducts. • We assessed the material flows of four nanomaterials in the Swiss recycling system. • After recycling, most nanomaterials will flow to landfills or incineration plants. • Recycled construction waste, plastics and textiles may contain nanomaterials. - Abstract: The use of engineered nanomaterials (ENMs) in diverse applications has increased during the last years and this will likely continue in the near future. As the number of applications increase, more and more waste with nanomaterials will be generated. A portion of this waste will enter the recycling system, for example, in electronic products, textiles and construction materials. The fate of these materials during and after the waste management and recycling operations is poorly understood. The aim of this work is to model the flows of nano-TiO{sub 2}, nano-ZnO, nano-Ag and CNT in the recycling system in Switzerland. The basis for this study is published information on the ENMs flows on the Swiss system. We developed a method to assess their flow after recycling. To incorporate the uncertainties inherent to the limited information available, we applied a probabilistic material flow analysis approach. The results show that the recycling processes does not result in significant further propagation of nanomaterials into new products. Instead, the largest proportion will flow as waste that can subsequently be properly handled in incineration plants or landfills. Smaller fractions of ENMs will be eliminated or end up in materials that are sent abroad to undergo further recovery processes. Only a reduced amount of ENMs will flow back to the productive process of the economy in a limited number of sectors. Overall, the results suggest that risk assessment during recycling should focus on occupational exposure, release of ENMs in landfills and incineration plants, and toxicity assessment in a small number of recycled inputs.

  14. Quantification of carbon nanomaterials in vivo.

    PubMed

    Wang, Haifang; Yang, Sheng-Tao; Cao, Aoneng; Liu, Yuanfang

    2013-03-19

    A diverse array of carbon nanomaterials (NMs), including fullerene, carbon nanotubes (CNTs), graphene, nanodiamonds, and carbon nanoparticles, have been discovered and widely applied in a variety of industries. Carbon NMs have been detected in the environment and have a strong possibility of entering the human body. The safety of carbon NMs has thus become a serious concern in academia and society. To achieve strict biosafety assessments, researchers need to fully understand the effects and fates of NMs in the human body, including information about absorption, distribution, metabolism, excretion, and toxicity (ADME/T). To acquire the ADME data, researchers must quantify NMs, but carbon NMs are very difficult to quantify in vivo. The carbon background in a typical biological system is high, particularly compared with the much lower concentration of carbon NMs. Moreover, carbon NMs lack a specific detection signal. Therefore, isotopic labeling, with its high sensitivity and specificity, is the first choice to quantify carbon NMs in vivo. Previously, researchers have used many isotopes, including ¹³C, ¹⁴C, ¹²⁵I, ¹³¹I, ³H, ⁶⁴Cu, ¹¹¹In, ⁸⁶Y, 99mTc, and ⁶⁷Ga, to label carbon NMs. We used these isotopic labeling methods to study the ADME of carbon NMs via different exposure pathways in animal models. Except for the metabolism of carbon NMs, which has seldom been investigated, significant amounts of data have been reported on the in vivo absorption, distribution, excretion, and toxicity of carbon NMs, which have revealed characteristic behaviors of carbon NMs, such as reticuloendothelial system (RES) capture. However, the complexity of the biological systems and diverse preparation and functionalization of the same carbon NMs have led to inconsistent results across different studies. Therefore, the data obtained so far have not provided a compatible and systematic profile of biosafety. Further efforts are needed to address these problems. In

  15. Ultrafast and nonlinear optics in carbon nanomaterials.

    PubMed

    Kono, Junichiro

    2013-02-01

    Carbon-based nanomaterials—single-wall carbon nanotubes (SWCNTs) and graphene, in particular—have emerged in the last decade as novel low-dimensional systems with extraordinary properties. Because they are direct-bandgap systems, SWCNTs are one of the leading candidates to unify electronic and optical functions in nanoscale circuitry; their diameter-dependent bandgaps can be utilized for multi-wavelength devices. Graphene's ultrahigh carrier mobilities are promising for high-frequency electronic devices, while, at the same time, it is predicted to have ideal properties for terahertz generation and detection due to its unique zero-gap, zero-mass band structure. There have been a large number of basic optical studies on these materials, but most of them were performed in the weak-excitation, quasi-equilibrium regime. In order to probe and assess their performance characteristics as optoelectronic materials under device-operating conditions, it is crucial to strongly drive them and examine their optical properties in highly non-equilibrium situations and with ultrashot time resolution. In this section, the reader will find the latest results in this rapidly growing field of research. We have assembled contributions from some of the leading experts in ultrafast and nonlinear optical spectroscopy of carbon-based nanomaterials. Specific topics featured include: thermalization, cooling, and recombination dynamics of photo-generated carriers; stimulated emission, gain, and amplification; ultrafast photoluminescence; coherent phonon dynamics; exciton–phonon and exciton–plasmon interactions; exciton–exciton annihilation and Auger processes; spontaneous and stimulated emission of terahertz radiation; four-wave mixing and harmonic generation; ultrafast photocurrents; the AC Stark and Franz–Keldysh effects; and non-perturbative light–mater coupling. We would like to express our sincere thanks to those who contributed their latest results to this special section

  16. Application of carbon nanomaterial as a microwave absorber.

    PubMed

    Sharon, Maheshwar; Pradhan, Debabrata; Zacharia, Renju; Puri, Vijaya

    2005-12-01

    Microwave absorption (8 GHz to 12 GHz) studies have been made with carbon nanomaterials for the first time. Carbon nanomaterials are synthesized by the pyrolysis of camphor. It is observed that film of carbon prepared under certain synthetic condition, can absorb microwave of either some specific wavelengths e.g., 9.5 GHz and 11.5 GHz or full range from 8-12 GHz to the extent of 20 dB depending upon their preparation condition. Carbon nanobeads seems to absorb the microwave in the range of 8-12 GHz.

  17. Optical characterization of ZnO nanomaterial with praseodymium ions

    NASA Astrophysics Data System (ADS)

    Sharma, Y. K.; Pal, Sudha; Goyal, Priyanka; Bind, Umesh Chandra

    2016-05-01

    ZnO nanomaterial with praseodymium ions was prepared by chemical synthesis method. The ZnO nanomaterial was characterized by XRD, SEM and TEM. Their absorption in UV-VIS/NIR regions was measured at room temperature. The experimental oscillator strengths were calculated from the areas under the absorption bands. Eight absorption bands have been observed. From these spectral data various energy interaction parameters like Slater-Condon, Lande, Racah, Nephelauxetic ratio and bonding parameters have been computed. Judd-Ofelt analysis has been carried out using the absorption spectra to evaluate the radiative properties for luminescent levels of the praseodymium ion and discussed. The observed nano particle size is 2nm.

  18. Carbon-based nanomaterials: multifunctional materials for biomedical engineering.

    PubMed

    Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

    2013-04-23

    Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), and extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications.

  19. Study of mechanical properties of nanomaterials under high pressure

    NASA Astrophysics Data System (ADS)

    Sharma, Jyoti; Kaur, Namrat; Srivastava, A. K.

    2015-08-01

    In the present work, the study of physical properties and behaviour of nanomaterials i.e. n-γ- Al2O3and n-Si3C4 under high pressure is done. For this purpose Murnaghan equation of state is used. The applicability of Murnaghan equation of state is fully tested by calculating mechanical properties of nano materials i.e. volume compression (V/Vo), bulk modulus (KT) and relative isothermal compression coefficient (α(P)/α0) at different pressures. The present calculated values of compression curve for the cited nanomaterials come out to be in reasonable good agreement with the available experimental data.

  20. Potential space applications of nanomaterials and standartization issues

    NASA Astrophysics Data System (ADS)

    Voronina, Ekaterina; Novikov, Lev

    Nanomaterials surpass traditional materials for space applications in many aspects due to their unique properties associated with nanoscale size of their constituents. This superiority in mechanical, thermal, electrical and optical properties will evidently inspire a wide range of applications in the next generation spacecraft intended for the long-term (~15-20 years) operation in near-Earth orbits and the automatic and manned interplanetary missions as well as in the construction of inhabited bases on the Moon. Nanocomposites with nanoclays, carbon nanotubes and various nanoparticles as fillers are one of the most promising materials for space applications. They may be used as light-weighted and strong structural materials as well as functional and smart materials of general and specific applications, e.g. thermal stabilization, radiation shielding, electrostatic charge mitigation, protection of atomic oxygen influence and space debris impact, etc. Currently, ISO activity on developing standards concerning different issues of nanomaterials manufacturing and applications is high enough. In this presentation, a brief review of existing standards and standards under development in this field is given. Most such standards are related to nanoparticles and nanotube production and characterization, thus the next important step in this activity is the creation of standards on nanomaterial properties and their behavior in different environmental conditions, including extreme environments. The near-Earth’s space is described as an extreme environment for materials due to high vacuum, space radiation, hot and cold plasma, micrometeoroids and space debris, temperature differences, etc. Existing experimental and theoretical data demonstrate that nanomaterials response to various space environment effects may differ substantially from the one of conventional bulk spacecraft materials. Therefore, it is necessary to determine the space environment components, critical for

  1. Enzyme-responsive nanomaterials for controlled drug delivery

    NASA Astrophysics Data System (ADS)

    Hu, Quanyin; Katti, Prateek S.; Gu, Zhen

    2014-10-01

    Enzymes underpin physiological function and exhibit dysregulation in many disease-associated microenvironments and aberrant cell processes. Exploiting altered enzyme activity and expression for diagnostics, drug targeting, and drug release is tremendously promising. When combined with booming research in nanobiotechnology, enzyme-responsive nanomaterials used for controlled drug release have achieved significant development and have been studied as an important class of drug delivery strategies in nanomedicine. In this review, we describe enzymes such as proteases, phospholipases and oxidoreductases that serve as delivery triggers. Subsequently, we explore recently developed enzyme-responsive nanomaterials with versatile applications for extracellular and intracellular drug delivery. We conclude by discussing future opportunities and challenges in this area.

  2. Enzyme-Responsive Nanomaterials for Controlled Drug Delivery

    PubMed Central

    Hu, Quanyin; Katti, Prateek S.; Gu, Zhen

    2015-01-01

    Enzymes underpin physiological function and exhibit dysregulation in many disease-associated microenvironments and aberrant cell processes. Exploiting altered enzyme activity and expression for diagnostics, drug targeting, and drug release is tremendously promising. When combined with booming research in nanobiotechnology, enzyme-responsive nanomaterials for controlled drug release have achieved significant development and been studied as an important class of drug delivery devices in nanomedicine. In this review, we describe enzymes such as proteases, phospholipase and oxidoreductases that serve as delivery triggers. Subsequently, we explore recently developed enzyme-responsive nanomaterials with versatile applications for extracellular and intracellular drug delivery. We conclude by discussing future opportunities and challenges in this area. PMID:25251024

  3. Sameness: The regulatory crux with nanomaterial identity and grouping schemes for hazard assessment.

    PubMed

    Walser, Tobias; Studer, Christoph

    2015-08-01

    Regulators and industry need clear rules for identification and grouping of nanomaterials for a streamlined quantitative hazard evaluation. Therefore, we provide convincing reasons for (i) why to introduce pragmatic definition of identities for nanomaterials, (ii) how to combine them into entities, and ultimately (iii) how the entities might be evaluated with testing strategies based on clouds of similar nanomaterials.

  4. Nanomaterials in Space: is the Future Granted?

    NASA Astrophysics Data System (ADS)

    Mircea, Chipara

    result, the energy deposited by the incident particle may be spreaded over several features, resulting in a cooperative irradiation effect. Analogous effects including significant departures from linearity were noticed in the degradation of polymers [3]. b). Radiation induced defects in nanomaterials. The effects of ionizing radiation on nanometer sized crystalline structures may be dramatic. This behavior is extremely simple taking into account that the incident particle may displace the target's nuclei, by producing lattice defects. For a macroscopic crystal consisting of a huge number of nuclei, such defects have usually a reduced weight and accordingly the structure of the target is not significantly affected. At nanometer scale, the number of nuclei is fairly low 102 to 106 and the relative weight of these processes in dramatically enhanced. It is possible to speculate that in space, the future nanomaterial is not a nanocrystal but rather a nano amorphous structure. In metamaterials or nanocomposites the nanometer sized interface is affected by several contributions as the displacement of the atoms from one side of the interface into the other side of the interface, the enhancement of the diffusion process within the interface due to the energy released as heat in the nanointerface by the incident particle, and even the appearance of new interfaces represented by cooperative nanometer sized defects, induced by the impinging particle. Such effects have been already reported in the case of irradiated copolymers and block copolymers [3]. c). Competition between several degradation processes. The space environment is not only a cocktail of ionizing particles. Several factors as temperature, thermal cycling, pressure, presence of atomic oxygen, UV-Vis or IR radiation compete with the ionizing radiation. A proper understanding of their effect as well as a detailed analysis of possible couplings between such processes is important. develop and test a new theory for the

  5. Understanding the biological and environmental implications of nanomaterials

    NASA Astrophysics Data System (ADS)

    Lin, Sijie

    The last two decades have witnessed the discovery, development, and large-scale manufacturing of novel nanomaterials. While nanomaterials bring in exciting and extraordinary properties in all areas of materials, electronics, mechanics, and medicine, they also could generate potential adverse effects in biological systems and in the environment. The currently limited application of nanomaterials in biological and ecological systems results from the insufficient and often controversial data on describing the complex behaviors of nanomaterials in living systems. The purpose of this dissertation intends to fill such a knowledge void with methodologies from the disciplines of biophysics, biology, and materials science and engineering. Chapter 1 of this dissertation provides a comprehensive review on the structures and properties of carbon nanomaterials (CBNMs), metal oxides, and quantum dots (QDs). This chapter also details the state-of-the-art on the biological applications, ecological applications, and toxicity of nanomaterials. With Chapter 1 serving as a background, Chapters 2-5 present my PhD research, an inquiry on the fate of nanomaterials in biological and ecological systems, on the whole organism and cellular levels. Specifically, CBNMs are introduced to rice plant seedlings and the uptake, translocation and generational transfer of fullerene C70 in the plant compartments are imaged and characterized. The interactions between CBNMs and rice plants on the whole organism level are initiated by the binding between CBNMs and natural organic matter (NOM), driven by the transpiration of water from the roots to the leaves of the plants and mediated by both the physiochemical properties of the CBNMs and plant physiology. In Chapter 3, semiconducting nanocrystals quantum dots (QDs) are introduced to green algae Chlamydomonas to probe the interactions of nanomaterials with ecological systems on the cellular level. The adsorption of QDs onto the algal cell wall is

  6. ASB16165, a phosphodiesterase 7A inhibitor, reduces cutaneous TNF-alpha level and ameliorates skin edema in phorbol ester 12-O-tetradecanoylphorbol-13-acetate-induced skin inflammation model in mice.

    PubMed

    Kadoshima-Yamaoka, Kumiko; Goto, Megumi; Murakawa, Masao; Yoshioka, Ryosuke; Tanaka, Yoshitaka; Inoue, Hidekazu; Murafuji, Hidenobu; Kanki, Satomi; Hayashi, Yasuhiro; Nagahira, Kazuhiro; Ogata, Atsuto; Nakatsuka, Takashi; Fukuda, Yoshiaki

    2009-06-24

    Possible role of phosphodiesterase 7A (PDE7A) in skin inflammation was examined using ASB16165, a specific inhibitor for PDE7A. Epicutaneous application of phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) to mouse ear resulted in induction of skin edema, and topical treatment with ASB16165 inhibited the induction of skin edema in a dose-dependent manner. The TPA challenge also increased the level of TNF-alpha at the application site, and the ASB16165 treatment reduced the TNF-alpha level in the skin. In addition, ASB16165 suppressed the production of TNF-alpha by human keratinocytes stimulated in vitro with TPA and calcium ionophore. Forskolin, an activator of adenylyl cyclase, as well as dibutyryl cAMP also showed inhibitory effect on the TNF-alpha production in the cells, suggesting involvement of cAMP in TNF-alpha generation. These results demonstrate that PDE7A might regulate TNF-alpha production in keratinocytes in a cAMP-dependent fashion. As immunostaining analysis revealed that PDE7A is expressed in the epidermis and TNF-alpha is known to contribute to the TPA-induced edema, it is possible that the inhibitory effect of ASB16165 on skin edema in mouse TPA-induced dermatitis model is mediated by suppression of TNF-alpha production. This is the first report suggesting the association of PDE7A with the function of keratinocytes. ASB16165 will be useful as an agent for skin inflammation in which TNF-alpha plays a pathogenic role (e.g. psoriasis).

  7. Cytosolic retention of phosphorylated extracellular signal-regulated kinase and a Rho-associated kinase-mediated signal impair expression of p21(Cip1/Waf1) in phorbol 12-myristate-13- acetate-induced apoptotic cells.

    PubMed

    Lai, Jin-Mei; Wu, Sulin; Huang, Duen-Yi; Chang, Zee-Fen

    2002-11-01

    In response to treatment with phorbol-12-myristate-13-acetate (PMA), the half-population of erythromyeloblast D2 cells, a cytokine-independent variant of TF-1 cells, displayed adhesion and differentiated into a monocyte/macrophage-like morphology, while the other half-population remained in suspension and underwent apoptosis. Expression of the cell cycle inhibitor p21(Cip1/Waf1) was induced after PMA treatment in the adherent cells but not in the proapoptotic cells. We investigated the mechanism responsible for the impairment of p21(Cip1/Waf1) induction in PMA-induced proapoptotic cells. We demonstrated that in PMA-induced adherent cells, upregulation of p21(Cip1/Waf1) requires the activation and nuclear translocation of phosphorylated extracellular signal-regulated kinase (phospho-ERK). Although ERK was phosphorylated to comparable levels in PMA-induced proapoptotic and adherent cells, nuclear distribution of phospho-ERK was seen only in the adherent, not in the proapoptotic cells. We also found that only PMA-induced proapoptotic cells contained the phosphorylated form of myosin light chain, which is dependent on Rho-associated kinase (ROCK) activation, and that expression of a dominant-active form of ROCK suppressed activation of the p21(Cip1/Waf1) promoter during PMA induction. Finally, we demonstrated that inhibition of ROCK restores nuclear distribution of phospho-ERK and activation of p21(Cip1/Waf1) expression. Based on these findings, we propose that a ROCK-mediated signal is involved in interfering with the process of ERK-mediated p21(Cip1/Waf1) induction in PMA-induced proapoptotic TF-1 and D2 cells.

  8. Toxicants inhibiting anaerobic digestion: a review.

    PubMed

    Chen, Jian Lin; Ortiz, Raphael; Steele, Terry W J; Stuckey, David C

    2014-12-01

    Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion. PMID:25457225

  9. Toxicants inhibiting anaerobic digestion: a review.

    PubMed

    Chen, Jian Lin; Ortiz, Raphael; Steele, Terry W J; Stuckey, David C

    2014-12-01

    Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion.

  10. Investigations into polymer and carbon nanomaterial separations

    NASA Astrophysics Data System (ADS)

    Owens, Cherie Nicole

    utilize as novel UTLC substrates. Additionally, aligned electrospun UTLC (AE-UTLC) substrates were developed to compare to the randomly oriented electrospun (E-UTLC) devices. The PHB plates were compared to commercially available substrates for the separation of biological samples: nucleotides and steroids. The electrospun substrates show lower band broadening and higher reproducibility in a smaller development distance than commercially available TLC plates, conserving both resources and time. The AE-UTLC plates provided further enhancement of reproducibility and development time compared to E-UTLC plates. Thus, the P3HB E-UTLC phases are an excellent sustainable option for TLC as they are biodegradable and perform better than commercial phases. A third topic of interest is the study of ordered carbon nanomaterials. The typical amorphous carbon used as a stationary phase in Hypercarb ® is known to consist of basal- and edge-plane oriented sites. This heterogeneity of the stationary phase can lead to peak broadening that may be improved by using homogeneous carbon throughout. Amorphous, basal-plane, and edge-plane carbons were produced in-house through membrane template synthesis. Amorphous, basal-plane, and edge-plane carbons were then used separately as chromatographic phases in capillary electrochomatography (CEC). Differences in chromatographic performance between these species were assessed by modeling retention data for test solutes to determine Linear Solvation Energy Relationships (LSER). The LSER study for the three carbon phases indicates that the main difference is in the polarizability, and hydrogen bonding character of the surface leading to unique solute interactions. These results highlight the possible usefulness of using these phases independently.

  11. Layered bismuth oxyhalide nanomaterials for highly efficient tumor photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Xu, Yu; Shi, Zhenzhi; Zhang, Ling'e.; Brown, Eric Michael Bratsolias; Wu, Aiguo

    2016-06-01

    Layered bismuth oxyhalide nanomaterials have received much more interest as promising photocatalysts because of their unique layered structures and high photocatalytic performance, which can be used as potential inorganic photosensitizers in tumor photodynamic therapy (PDT). In recent years, photocatalytic materials have been widely used in PDT and photothermal therapy (PTT) as inorganic photosensitizers. This investigation focuses on applying layered bismuth oxyhalide nanomaterials toward cancer PDT, an application that has never been reported so far. The results of our study indicate that the efficiency of UV-triggered PDT was highest when using BiOCl nanoplates followed by BiOCl nanosheets, and then TiO2. Of particular interest is the fact that layered BiOCl nanomaterials showed excellent PDT effects under low nanomaterial dose (20 μg mL-1) and low UV dose (2.2 mW cm-2 for 10 min) conditions, while TiO2 showed almost no therapeutic effect under the same parameters. BiOCl nanoplates and nanosheets have shown excellent performance and an extensive range of applications in PDT.

  12. A Scalable Platform for Functional Nanomaterials via Bubble-Bursting.

    PubMed

    Feng, Jie; Nunes, Janine K; Shin, Sangwoo; Yan, Jing; Kong, Yong Lin; Prud'homme, Robert K; Arnaudov, Luben N; Stoyanov, Simeon D; Stone, Howard A

    2016-06-01

    A continuous and scalable bubbling system to generate functional nanodroplets dispersed in a continuous phase is proposed. Scaling up of this system can be achieved by simply tuning the bubbling parameters. This new and versatile system is capable of encapsulating various functional nanomaterials to form functional nanoemulsions and nanoparticles in one step. PMID:27007617

  13. Toxicity Evaluation of New Engineered Nanomaterials in Zebrafish

    PubMed Central

    Brundo, Maria V.; Pecoraro, Roberta; Marino, Fabio; Salvaggio, Antonio; Tibullo, Daniele; Saccone, Salvatore; Bramanti, Vincenzo; Buccheri, Maria A.; Impellizzeri, Giuliana; Scuderi, Viviana; Zimbone, Massimo; Privitera, Vittorio

    2016-01-01

    The effect of the nanoparticles on the marine organisms, depends on their size, chemical composition, surface structure, solubility and shape. In order to take advantage from their activity, preserving the surrounding environment from a possible pollution, we are trying to trap the nanoparticles into new nanomaterials. The nanomaterials tested were synthesized proposing a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system to avoid the release of nanoparticles. The system was synthesized by wrapping Au nanoparticles with a thin layer of TiO2. The non-toxicity of the nano-system was established by testing the effect of the material on zebrafish larvae. Danio rerio o zebrafish was considered an excellent model for the environmental biomonitoring of aquatic environments and the Zebrafish Embryo Toxicity Test (ZFET) is considered an alternative method of animal test. For this reason zebrafish larvae were exposed to different concentrations of nanoparticles of TiO2 and Au and new nanomaterials. As biomarkers of exposure, we evaluated the expression of metallothioneins by immunohistochemistry analysis and western blotting analysis also. The results obtained by toxicity test showed that neither mortality as well as sublethal effects were induced by the different nanomaterials and nanoparticles tested. Only zebrafish larvae exposed to free Au nanoparticles showed a different response to anti-MT antibody. In fact, the immunolocalization analysis highlighted an increase of the metallothioneins synthesis. PMID:27148069

  14. 78 FR 36784 - Survey of Nanomaterial Risk Management Practices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ...: The National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control... HUMAN SERVICES Centers for Disease Control and Prevention (CDC) Survey of Nanomaterial Risk Management Practices AGENCY: National Institute for Occupational Safety and Health (NIOSH) of the Centers for...

  15. Issues in Assessing Environmental Exposures to Manufactured Nanomaterials

    EPA Science Inventory

    Manufactured nanomaterials (MNs) are commonly considered to be commercial products possessing at least one dimension in the size range of 10−9 m to 10−7 m. As particles in this size range represent the smaller fraction of colloidal particles characterized by dimensions of 10−9 m ...

  16. Interaction of engineered nanomaterials with hydrophobic organic pollutants.

    EPA Science Inventory

    As nanomaterials become an increasing part of everyday consumer products, it is imperative to monitor their potential release during production, use and disposal, and to assess their impact on the health of humans and the ecosystem. This necessitates research to better understand...

  17. Novel Sensor for the Identification and Quantitation of Engineered Nanomaterials

    EPA Science Inventory

    According to the US-National Nanotechnology initiative (NNI), nanomaterials encompass a wide variety of materials that have at least one dimension in the 1-to 100-nm range. One major aspect of the NNI is the need to develop useful approaches to identify and categorize nanomateria...

  18. Lanthanide-doped hollow nanomaterials as theranostic agents.

    PubMed

    Kang, Xiaojiao; Li, Chunxia; Cheng, Ziyong; Ma, Ping'an; Hou, Zhiyao; Lin, Jun

    2014-01-01

    The field of theranostics has sprung up to achieve personalized medicine. The theranostics fuses diagnostic and therapeutic functions, empowering early diagnosis, targeted drug delivery, and real-time monitoring of treatment effect into one step. One particularly attractive class of nanomaterials for theranostic application is lanthanide-doped hollow nanomaterials (LDHNs). Because of the existence of lanthanide ions, LDHNs show outstanding fluorescent and paramagnetic properties, enabling them to be used as multimodal bioimaging agents. Synchronously, the huge interior cavities of LDHNs are able to be applied as efficacious tools for storage and delivery of therapeutic agents. The LDHNs can be divided into two types based on difference of component: single-phase lanthanide-doped hollow nanomaterials and lanthanide-doped hollow nanocomposites. We describe the synthesis of first kind of nanomaterials by use of hard template, soft template, template-free, and self-sacrificing template method. For lanthanide-doped hollow nanocomposites, we divide the preparation strategies into three kinds (one-step, two-step, and multistep method) according to the synthetic procedures. Furthermore, we also illustrate the potential bioapplications of these LDHNs, including biodetection, imaging (fluorescent imaging and magnetic resonance imaging), drug/gene delivery, and other therapeutic applications.

  19. An Evaluation of Ecotoxicity Test Guidelines: Their Adequacy for Nanomaterials

    EPA Science Inventory

    Advances in nanotechnology are resulting in the production of new nanomaterials at a rapid pace. Driving the dramatic development of new materials and products is the prospect of stronger and lighter materials, better and more efficient energy systems, potential tremendous benefi...

  20. Toxicity Evaluation of New Engineered Nanomaterials in Zebrafish.

    PubMed

    Brundo, Maria V; Pecoraro, Roberta; Marino, Fabio; Salvaggio, Antonio; Tibullo, Daniele; Saccone, Salvatore; Bramanti, Vincenzo; Buccheri, Maria A; Impellizzeri, Giuliana; Scuderi, Viviana; Zimbone, Massimo; Privitera, Vittorio

    2016-01-01

    The effect of the nanoparticles on the marine organisms, depends on their size, chemical composition, surface structure, solubility and shape. In order to take advantage from their activity, preserving the surrounding environment from a possible pollution, we are trying to trap the nanoparticles into new nanomaterials. The nanomaterials tested were synthesized proposing a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system to avoid the release of nanoparticles. The system was synthesized by wrapping Au nanoparticles with a thin layer of TiO2. The non-toxicity of the nano-system was established by testing the effect of the material on zebrafish larvae. Danio rerio o zebrafish was considered an excellent model for the environmental biomonitoring of aquatic environments and the Zebrafish Embryo Toxicity Test (ZFET) is considered an alternative method of animal test. For this reason zebrafish larvae were exposed to different concentrations of nanoparticles of TiO2 and Au and new nanomaterials. As biomarkers of exposure, we evaluated the expression of metallothioneins by immunohistochemistry analysis and western blotting analysis also. The results obtained by toxicity test showed that neither mortality as well as sublethal effects were induced by the different nanomaterials and nanoparticles tested. Only zebrafish larvae exposed to free Au nanoparticles showed a different response to anti-MT antibody. In fact, the immunolocalization analysis highlighted an increase of the metallothioneins synthesis. PMID:27148069