Hemostatic Effect of Aminated Multiwalled Carbon Nanotubes/Oxidized Regenerated Cellulose Nanocomposites

2019 ◽  
Vol 19 (11) ◽  
pp. 7410-7415 ◽  
Author(s):  
Baode Zhang ◽  
Ali Nabipour Chakoli ◽  
Jin Mei He ◽  
Yu Dong Huang ◽  
Andrey N. Aleshin
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Regenerated Cellulose ◽  
Oxidized Regenerated Cellulose ◽  
Multiwalled Carbon ◽  
Hemostatic Effect ◽  
Pristine Mwcnts ◽  
Ft Ir ◽  
Cellulose Nanocomposites

We have investigated the covalent conjugation of aminated multiwalled carbon nanotubes (MWCNTNH2)s with Oxidized Regenerated Cellulose (ORC) in order to enhance the hemostatic effect. The MWCNT-NH2s were prepared by functionalization of pristine MWCNTs (pMWCNTs) using amine groups. Neat ORC gauze and MWCNT-NH2s were reacted using glutamic acid as cross linking bridge. We investigated an amination of pMWCNTs as well as the dispersion of MWCNT-NH2s in the ORC gauze as matrix and their interfacial interactions by SEM and FT-IR. The results revealed that relatively strong interaction exists between aminated MWCNTs and the ORC macromolecules. The hydrophilicity test results in the significant increment of water uptake of MWCNT-NH2s/ORC composites with increasing the concentration of MWCNT-NH2s in composite. The in-vitro procoagulation test shows that the MWCNT-NH2s/ORC gauzes have significant procoagulant activity. The hemostatic evaluation of MWCNT-NH2s/ORC composites on rabbits shows that the aminated MWCNTs increase the rate of blood stopping and hence they decrease the blood loosing from injured sites. Hemostatic evaluation indicates that the MWCNT-NH2s/ORC gauze has a valuable hemostatic performance. The products of platelets release reaction, activated platelets glycoprotein and activated clotting enzymes were increased simultaneously. The mechanism of the hemostasis for MWCNT-NH2s/ORC gauze is discussed.

Enhanced oxidized regenerated cellulose with functionalized multiwalled carbon nanotubes for hemostasis applications

RSC Advances ◽  
2014 ◽  
Vol 4 (94) ◽  
pp. 52372-52378 ◽  
Author(s):  
Ali Nabipour Chakoli ◽  
Jinmei He ◽  
Weilu Cheng ◽  
Yudong Huang
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Water Uptake ◽  
Regenerated Cellulose ◽  
Oxidized Regenerated Cellulose ◽  
Multiwalled Carbon ◽  
Hemostatic Effect ◽  
Functionalized Multiwalled Carbon Nanotubes

The hemostatic effect of oxidized regenerated cellulose (ORC) was enhanced using aminated MWCNTs which covalently grafted to the surface of ORC. The aminated MWCNTs increases the water uptake and hemostatic effect of ORC gradually.

Enhanced Photoluminescence Effect of Poly(L-lactide) Biodegradable Polymer with Functionalized Carbon Nanotubes

2013 ◽  
Vol 829 ◽  
pp. 304-308 ◽  
Author(s):  
Maryam Amirian ◽  
Ali Nabipour Chakoli ◽  
Hossein Zamani Zeinali ◽  
Hossein Afarideh
Keyword(s):  
Carbon Nanotubes ◽  
Oxygen Vacancies ◽  
Blue Shift ◽  
Polymer Chains ◽  
Multiwalled Carbon ◽  
Enhanced Photoluminescence ◽  
Pristine Mwcnts ◽  
Ft Ir ◽  
Amine Groups

Functionalization of Multiwalled Carbon Nanotubes (MWCNTs) for biological applications was considered. For this purpose, the pristine MWCNTs (pMWCNTs) are covalently aminated using p-amino benzoic acid and phosphoric acid without shortening of pMWCNTs. The grafted amine groups on the sidewall of pMWCNTs are useful as initiator for grafting of polymer chains on the sidewall of aminated MWCNTs (MWCNT-NH2). The PLLA homopolymer chains grafted covalently from the sidewall of aminated MWCNTs successfully. The FT-IR spectra revealed that the amine groups and the PLLA chains grafted form the sidewall of pMWCNTs strongly. The fluoroscopy test results shows that the pMWCNTs and aminated MWCNTs have not any significant photoluminescence (PL) effect at 350 nm excitation. The MWCNT-g-PLLAs exhibit an extremely strong visible emission at 404 nm and 429 nm. These results may be ascribed to the contribution of oxygen vacancies and defects at the end chain of grafted PLLA chains on the sidewall of MWCNTs that created by Sn atoms of initiator during polymerization on the sidewall of MWCNTs. The oxygen vacancies usually act as radiative centers in the PL process. In addition, The MWCNT-g-PLLAs enhance the PL of neat PLLA. The PL of composites slightly diminishes with blue shift during in-vitro degradation. As mentioned above, the MWCNT-g-PLLAs are the functionalized MWCNTs that applicable in the field of medicine. Due to biocompatible and biodegradable molecular groups on the sidewall of MWCNTs, it is predictable that the MWCNT-g-PLLAs will pass all exams for its application in medicine.

scholarly journals Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Ball Milling ◽  
Multiwalled Carbon Nanotubes ◽  
Tribological Properties ◽  
Extreme Pressure ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Gear Oil ◽  
The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

Synthesis and Performance of Dopa-Modified Multiwalled Carbon Nanotubes

2012 ◽  
Vol 184-185 ◽  
pp. 1289-1293
Author(s):  
Lu Zhi Wang ◽  
Lin Yu ◽  
Xiao Ling Cheng ◽  
Jun He ◽  
Le Jia Lin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Multiwalled Nanotubes ◽  
Mixed Acid ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Performance

The Dopamine-modified multiwalled carbon nanotubes (MWNT-Dopa) were synthesized by chemical reaction between dopamine (Dopa) and multiwalled carbon nanotubes which oxidazed by mixed-acid (MWNT-COOH). The structure of MWNT-Dopa were analyzed by Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric (TG), Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques and the dispersity of MWNT-Dopa were studied by Dispersion stability analyzer. The results show that dopamine has been grafted on multiwalled carbon nanotubes successfully, and a dopamine layer which wraps on the surface of multiwalled nanotubes make multiwalled nanotubes have outstanding dispersity in water.

scholarly journals Sulfonitric Treatment of Multiwalled Carbon Nanotubes and Their Dispersibility in Water

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2442 ◽  
Author(s):  
Hui Liu ◽  
Jianfeng Wang ◽  
Jiachen Wang ◽  
Suping Cui
Keyword(s):  
Carbon Nanotubes ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Oxidation Degree ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Scattering Measurements ◽  
Ft Ir

In this study, Multiwalled carbon nanotubes (MWCNTs) were oxidized by a mixture of sulfuric acid and nitric acid (V:V = 3:1) at 70 °C for 1, 2, and 4 h, respectively. The oxidized MWCNTs were characterized by N2 adsorption, Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), and Raman spectroscopy to determine the oxidation degree. The dispersion of the MWCNTs was investigated by UV-vis-NIR, SEM, and dynamic light scattering measurements. Results show that sulfonitric treatment increased the surface area and total pore volume and reduced the average pore diameter of MWCNTs. The treatment promoted the formation of oxidized species on the surface MWCNTs, as identified by FT-IR, TGA, and X-ray photoelectron spectroscopy measurements, and more oxygen-containing functional groups were generated when treatment time was extended. Moreover, a general relationship between oxidation degree and dispersibility of MWCNTs in water was established. UV-vis-NIR and dynamic light scattering measurements and SEM images revealed that MWCNTs with higher oxidation degree showed better dispersibility in water.

scholarly journals Nitrogen-Doped Multiwalled Carbon Nanotubes Inhibit Fat Deposition via Immunomodulatory Actions

2021 ◽  
Author(s):  
Haifang Li ◽  
Xue Xiao ◽  
Geng Hu ◽  
Dalin He ◽  
Wenqian Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Mammalian Cells ◽  
Fat Metabolism ◽  
Fat Deposition ◽  
The Body ◽  
Inflammatory Factors ◽  
Multiwalled Carbon ◽  
Nitrogen Doped

Abstract Multiwalled carbon nanotubes (MWCNTs) offer immense opportunities to deliver drug and biomolecules to targeted tissues. However, it’s unclear for us about their effects on fat metabolism. Here, we demonstrate that nitrogen-doped carboxylate-functionalized MWCNTs (N-MWCNTs) inhibit fat deposition both in vivo and in vitro primarily by suppressing adipogenesis. N-MWCNTs show good biocompatability in HEK293 mammalian cells. Intramuscular administration of N-MWCNTs does not affect the body weight gain and feed intake of mice, but reduces the fat mass. In in vitro-cultured adipocytes, N-MWCNTs suppress fat accumulation, accompanying with decreased and increased expression of adipogenic and lipolysis genes, respectively. Transcriptome analysis further certified the N-MWCNT alteration of fat metabolism-related genes. Interestingly, we observed the phagocytosis of N-MWCNTs by macrophage-like cells via TEM imaging. The mRNA sequencing data also showed remarkable variation of the genes involved in TLRs pathway, ultimately leading to down- or up-regulation of inflammatory factors, of which Tnfα, Il1, Il7, Il10, and Il12 are decreased, whereas Il6 and Il11 are increased. In conclusion, N-MWCNTs induce the production of inflammatory cytokines through immune responses, which trigger the reduction of fat deposition. These findings support the usage of N-MWCNTs as a promising delivery for anti-obesity agents.

scholarly journals Preparation, Characterization, andIn VitroandVivoAntitumor Activity of Oridonin-Conjugated Multiwalled Carbon Nanotubes Functionalized with Carboxylic Group

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Chuanjin Wang ◽  
Wei Li
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Tumor Therapy ◽  
Water Soluble ◽  
Carboxylic Group ◽  
Multiwalled Carbon ◽  
Compound C ◽  
Poorly Water Soluble

Carbon nanotubes have shown great potential in tumor therapy. Oridonin (ORI) is a poorly water-soluble diterpenoid compound (C20H28O6) used in the treatment of esophageal and hepatic carcinoma for decades. For the purpose of enhancing the antitumor potency and reducing cytotoxicity of ORI, multiwalled carbon nanotubes functionalized with carboxylic group (MWCNTs-COOH) were used as ORI carrier. ORI was noncovalently encapsulated into (or onto) the functionalized carbon nanotubes (MWCNTs-ORI). The obtained MWCNTs-ORI has been characterized. The ORI loading efficiency in MWCNTs-COOH carrier was studied to be about 82.6% (w/w).In vitrocytotoxicity assay on MWCNTs-ORI gave IC50of7.29±0.5 μg/mL and ORI-F gave IC50of14.5±1.4 μg/mL. The antitumor effect studiesin vivoshowed that MWCNTs-ORI improved antitumor activity of ORI in comparison with ORI-F. The tumor inhibition ratio for MWCNTs-ORI (1.68×10-2 g·Kg−1·d−1) was 86.4%, higher than that of ORI-F (1.68×10-2 g·Kg−1·d−1) which was 39.2%. This can greatly improve the pharmaceutical efficiency and reduce potential side effects.

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