scholarly journals EVALUATION OF A HYBRID BIOCOMPOSITE OF HA/HDPE REINFORCED WITH MULTI-WALLED CARBON NANOTUBES (MWCNTs) AS A BONE-SUBSTITUTE MATERIAL

2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Ali A. Al- Allaq ◽  
Jenan S. Kashan ◽  
Mohamed T. El-Wakad ◽  
Ahmed M. Soliman

In this investigation, multi-wall carbon nanotubes (MWCNT) with various percentages (0.6%, 1%, 1.4%, 2%) were combined into   ​and High-density polyethylene HDPE (60) wt. % and hydroxyapatite (40) wt. % to form biocomposite using hot-press techniques. The surface topography by AFM images illustrates differences in the roughness of the sample's surface with different adding percentages of MWCNT. The DSC technique exhibits the effect of adding MWCNT in different percentages with the degree of crystallinity, which its effect on mechanical properties for samples. The in vitro bioactivity was investigated by immersion the samples in Ringer's solution as simulated body fluid (SBF) at (0, 3, 6, 9, 12) days (after immersing). The FE-SEM and EDx image explained the apatite layers formation on the sample's surface after 3 days immersed in Ringer solution. Based on XRD Technique, after immersion days in the Ringer solution, the crystallographic structure of hydroxyapatite is formed, forming the monetite.  ​The enhancement of bioactivity has been shown during the incorporation of MWCNT into HA/HDPE composite. These results exhibited excellent indications of biocompatibility properties with the possibility of making promising biomaterials for making bone substitute applications.                                                                                                       

2003 ◽  
Vol 772 ◽  
Author(s):  
T. Seeger ◽  
G. de la Fuente ◽  
W.K. Maser ◽  
A.M. Benito ◽  
A. Righi ◽  
...  

AbstractCarbon nanotubes (CNT) are interesting candidates for the reinforcement in robust composites and for conducting fillers in polymers due to their fascinating electronic and mechanical properties. For the first time, we report the incorporation of multi walled carbon nanotubes (MWNTs) into silica-glass surfaces by means of partial surface-melting caused by a continuous wave Nd:YAG laser. MWNTs were detected being well incorporated in the silica-surface. The composites are characterized using scanning electron microscopy (SEM) and Raman-spectroscopy. A model for the composite-formation is proposed based on heatabsorption by MWNTs and a partial melting of the silica-surface.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 883 ◽  
Author(s):  
Sandeep Keshavan ◽  
Fernando Torres Andón ◽  
Audrey Gallud ◽  
Wei Chen ◽  
Knut Reinert ◽  
...  

Engineered nanomaterials are potentially very useful for a variety of applications, but studies are needed to ascertain whether these materials pose a risk to human health. Here, we studied three benchmark nanomaterials (Ag nanoparticles, TiO2 nanoparticles, and multi-walled carbon nanotubes, MWCNTs) procured from the nanomaterial repository at the Joint Research Centre of the European Commission. Having established a sub-lethal concentration of these materials using two human cell lines representative of the immune system and the lungs, respectively, we performed RNA sequencing of the macrophage-like cell line after exposure for 6, 12, and 24 h. Downstream analysis of the transcriptomics data revealed significant effects on chemokine signaling pathways. CCR2 was identified as the most significantly upregulated gene in MWCNT-exposed cells. Using multiplex assays to evaluate cytokine and chemokine secretion, we could show significant effects of MWCNTs on several chemokines, including CCL2, a ligand of CCR2. The results demonstrate the importance of evaluating sub-lethal concentrations of nanomaterials in relevant target cells.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.


2014 ◽  
Vol 70 (6) ◽  
pp. 964-971
Author(s):  
Xu Chen ◽  
Zhen-hu Xiong

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g · L−1, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and π–π stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater.


2018 ◽  
Vol 33 (5) ◽  
pp. 543-557 ◽  
Author(s):  
Jianfei Cao ◽  
Yue Lu ◽  
Hechun Chen ◽  
Lifang Zhang ◽  
Chengdong Xiong

Poly(etheretherketone) exhibits good biocompatibility, excellent mechanical properties, and bone-like stiffness. However, the natural bio-inertness of pure poly(etheretherketone) hinders its applications in biomedical field, especially when direct bone-implant osteo-integration is desired. For developing an alternative biomaterial for load-bearing orthopedic application, combination of bioactive fillers with poly(etheretherketone) matrix is a feasible approach. In this study, a bioactive multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite was prepared through a compounding and injection-molding process for the first time. Bioactive calcium polyphosphate was added to polymer matrix to enhance the bioactivity of the composite, and incorporation of multi-walled carbon nanotubes to composite was aimed to improve both the mechanical property and biocompatibility. Furthermore, the microstructures, surface hydrophilicity, and mechanical property of multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite, as well as the cellular responses of MC3T3-E1 osteoblast cells to this material were investigated. The mechanical testing revealed that mechanical performance of the resulting ternary composite was significantly enhanced by adding the multi-walled carbon nanotubes and the mechanical values obtained were close to or higher than those of human cortical bone. More importantly, cell culture tests showed that initial cell adhesion, cell viability, and osteogenic differentiation of MC3T3-E1 cells were significantly promoted on the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite. Accordingly, the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite may be used as a promising bone repair material in dental and orthopedic applications.


Nanoscale ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 11013-11020 ◽  
Author(s):  
E. González-Lavado ◽  
N. Iturrioz-Rodríguez ◽  
E. Padín-González ◽  
J. González ◽  
L. García-Hevia ◽  
...  

Mild oxidation treatments improve the in vitro and in vivo macrophage biodegradation of carbon nanotubes that trigger remarkable anti-tumoral effects in malignant melanoma solid tumors produced in mice.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 230 ◽  
Author(s):  
Jie Xu ◽  
Xueyan Hu ◽  
Siyu Jiang ◽  
Yiwei Wang ◽  
Roxanne Parungao ◽  
...  

In this study, composite scaffolds with different multi-walled carbon nanotubes (MWCNTs) content were prepared by freeze-drying. These scaffolds were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), porosity, hydrophilicity, mechanical strength, and degradation. The MWCNTs scaffolds were structurally sound and had porous structures that offered ample space for adherence, proliferation, and differentiation of MC3T3-E1 cells, and also supported the transport of nutrients and metabolic waste. CS/Gel/nHAp/0.3%MWCNTs scaffolds provided the best outcomes in terms of scaffold porosity, hydrophilicity, and degradation rate. However, CS/Gel/nHAp/0.6%MWCNTs scaffolds were found to support the optimal growth, homogenous distribution, and biological activity of MC3T3-E1 cells. The excellent properties of CS/Gel/nHAp/0.6%MWCNTs scaffolds for the adhesion, proliferation, and osteogenesis differentiation of MC3T3-E1 cells in vitro highlights the potential applications of this scaffold in bone tissue regeneration.


2015 ◽  
Vol 19 (04) ◽  
pp. 622-630 ◽  
Author(s):  
Saeed Rayati ◽  
Zahra Sheybanifard

In the present work, oxidation of alkenes with hydrogen peroxide in the presence of meso-tetrakis(4-hydroxyphenyl)porphyrinatoiron(III) chloride supported onto surface of functionalized multi-wall carbon nanotubes (FMWCNT), [ Fe ( THPP ) Cl@MWCNT ], is reported. The simple heterogeneous catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and also thermal analysis. The amount of the catalyst loaded on the nanotubes was determined by atomic absorption spectroscopy. This heterogeneous catalyst proved to be an efficient and green catalyst and was successfully able to activate hydrogen peroxide without any additive toward the oxidation of alkenes in ethanol as a green solvent. Performance of the catalyst in oxidation of various alkenes was inspected under reflux, ultrasonic irradiation and mechanical stirring. Moreover, the catalyst can be reused several times under similar conditions.


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