scholarly journals The effects of nano-sized carbon fillers on the physico-chemical, mechanical, and biological properties of polyester nanocomposites

Author(s):  
Zygmunt Staniszewski ◽  
Peter Sobolewski ◽  
Agnieszka Piegat ◽  
Miroslawa El Fray

<p>Nanocomposites based on poly(ethylene terephthalate-ethylene dilinoleate) (PET-DLA) copolymers of different hard to soft segment ratios (40:60 and 60:40) and three different carbon nanofillers of different aspect ratios (dimensions), as 0D carbon black, 1D multiwalled carbon nanotubes, and 2D graphene, have been prepared <i>in situ</i>during two-stage polymerization. FTIR and NMR spectroscopy was used to characterize the chemical structures of the obtained nanocomposites. Scanning electron microscopy (SEM) indicated very good dispersions of all carbon nanofillers in both polymer matrices. DSC results revealed that the addition of nano-sized fillers eliminated cold crystallization of materials containing 40% hard segments in polymer matrix. We found that the high aspect ratio, 1D nano-filler (multiwalled carbon nanotubes) strongly nucleated crystallization of materials containing 60% of hard segments. This nanofiller also yielded the greatest improvement in the Young’s modulus as assessed by tensile tests, both at 24 ºC and 37 ºC. On the other hand, for nanocomposites containing 2D nanofiller (graphene) we observed reduced bacterial adhesion. Finally, <i>in vitro </i>cytocompatibility tests with L929 murine fibroblasts demonstrated cell growth on all materials except nanocomposites containing carbon nanotubes, where the lowest fibroblast viability was observed.</p>

2018 ◽  
Author(s):  
Zygmunt Staniszewski ◽  
Peter Sobolewski ◽  
Agnieszka Piegat ◽  
Miroslawa El Fray

<div><div><div><p>Nanocomposites based on poly(ethylene terephthalate-ethylene dilinoleate) (PET-DLA) copolymers of different hard to soft segment ratios (40:60 and 60:40) and three different carbon nanofillers of different aspect ratios (dimensions), as 0D carbon black, 1D multiwalled carbon nanotubes, and 2D graphene, have been prepared in situ during two-stage polymerization. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the chemical structures of the obtained nanocomposites. Scanning electron microscopy (SEM) indicated very good dispersions of all carbon nanofillers in both polymer matrices. Differential scanning calorimetry (DSC) results revealed that the addition of nano-sized fillers eliminated cold crystallization of materials containing 40% hard segments in polymer matrix. We found that the high aspect ratio, 1D nano-filler (multiwalled carbon nanotubes) strongly nucleated crystallization of materials containing 60% of hard segments. This nanofiller also yielded the greatest improvement in the Young’s modulus as assessed by tensile tests, both at 24 oC and 37 oC. We did not observe reduced bacterial adhesion to nanocomposites, likely due to increased roughness. Importantly, in vitro cytocompatibility tests with L929 murine fibroblasts demonstrated cell viability and growth on all materials except those containing carbon nanotubes. Finally, both high aspect ratio nanofillers markedly improved the barrier properties of obtained nanocomposites. New materials were successfully used for manufacturing of prototype of heart assist device, with pneumatic membrane made of graphene nanocomposite.</p></div></div></div>


2018 ◽  
Author(s):  
Zygmunt Staniszewski ◽  
Peter Sobolewski ◽  
Agnieszka Piegat ◽  
Miroslawa El Fray

<div><div><div><p>Nanocomposites based on poly(ethylene terephthalate-ethylene dilinoleate) (PET-DLA) copolymers of different hard to soft segment ratios (40:60 and 60:40) and three different carbon nanofillers of different aspect ratios (dimensions), as 0D carbon black, 1D multiwalled carbon nanotubes, and 2D graphene, have been prepared in situ during two-stage polymerization. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the chemical structures of the obtained nanocomposites. Scanning electron microscopy (SEM) indicated very good dispersions of all carbon nanofillers in both polymer matrices. Differential scanning calorimetry (DSC) results revealed that the addition of nano-sized fillers eliminated cold crystallization of materials containing 40% hard segments in polymer matrix. We found that the high aspect ratio, 1D nano-filler (multiwalled carbon nanotubes) strongly nucleated crystallization of materials containing 60% of hard segments. This nanofiller also yielded the greatest improvement in the Young’s modulus as assessed by tensile tests, both at 24 oC and 37 oC. We did not observe reduced bacterial adhesion to nanocomposites, likely due to increased roughness. Importantly, in vitro cytocompatibility tests with L929 murine fibroblasts demonstrated cell viability and growth on all materials except those containing carbon nanotubes. Finally, both high aspect ratio nanofillers markedly improved the barrier properties of obtained nanocomposites. New materials were successfully used for manufacturing of prototype of heart assist device, with pneumatic membrane made of graphene nanocomposite.</p></div></div></div>


2019 ◽  
Vol 19 (11) ◽  
pp. 7410-7415 ◽  
Author(s):  
Baode Zhang ◽  
Ali Nabipour Chakoli ◽  
Jin Mei He ◽  
Yu Dong Huang ◽  
Andrey N. Aleshin

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.


2021 ◽  
Author(s):  
Haifang Li ◽  
Xue Xiao ◽  
Geng Hu ◽  
Dalin He ◽  
Wenqian Zhang ◽  
...  

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.


2019 ◽  
Vol 35 (5) ◽  
pp. 267-280 ◽  
Author(s):  
Sanaz Soleymani Eil Bakhtiari ◽  
Saeed Karbasi ◽  
Sayed Ali Hassanzadeh Tabrizi ◽  
Reza Ebrahimi-Kahrizsangi ◽  
Hossein Salehi

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Chuanjin Wang ◽  
Wei Li

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.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2588
Author(s):  
Nader Tanideh ◽  
Negar Azarpira ◽  
Najmeh Sarafraz ◽  
Shahrokh Zare ◽  
Aida Rowshanghiyas ◽  
...  

Appropriate selection of suitable materials and methods is essential for scaffolds fabrication in tissue engineering. The major challenge is to mimic the structure and functions of the extracellular matrix (ECM) of the native tissues. In this study, an optimized 3D structure containing poly(3-hydroxybutyrate) (P3HB), multiwalled carbon nanotubes (MCNTs) and curcumin (CUR) was created by electrospinning a novel biomimetic scaffold. CUR, a natural anti-inflammatory compound, has been selected as a bioactive component to increase the biocompatibility and reduce the potential inflammatory reaction of electrospun scaffolds. The presence of CUR in electrospun scaffolds was confirmed by 1H NMR and Fourier-transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) revealed highly interconnected porosity of the obtained 3D structures. Addition of up to 20 wt% CUR has enhanced mechanical properties of the scaffolds. CUR has also promoted in vitro bioactivity and hydrolytic degradation of the electrospun nanofibers. The developed P3HB-MCNT composite scaffolds containing 20 wt% of CUR revealed excellent in vitro cytocompatibility using mesenchymal stem cells and in vivo biocompatibility in rat animal model study. Importantly, the reduced inflammatory reaction in the rat model after 8 weeks of implantation has also been observed for scaffolds modified with CUR. Overall, newly developed P3HB-MCNTs-CUR electrospun scaffolds have demonstrated their high potential for tissue engineering applications.


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