NH2+ implantations induced superior hemocompatibility of carbon nanotubes

Exploring the mechanism of the antithrombotic effects of Pueraria lobata and Pueraria lobata var. thomsonii based on network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Pueraria lobata (Willd.) Ohwi and Pueraria lobata var. thomsonii (Benth.) Maesen are nutritious medicine food homology plants that are widely used in the food and health products industry and are excellent natural materials for the development of new health foods, with great potential for domestic and foreign markets. Clinically, P. lobata and P. thomsonii are used to treat coronary heart disease, atherosclerosis, cerebral infarction and other cardiovascular diseases, and antithrombotic actions may be their core effect in the treatment of thrombotic diseases. However, the underlying mechanisms of the antithrombotic properties of P. lobata and P. thomsonii have not been clarified.

METHODS

First, P. lobata and P. thomsonii were identified by high-performance liquid chromatography (HPLC). An arteriovenous bypass thrombosis rat model was established. Thrombus dry‒wet weight, platelet accumulation rate and the four coagulation indices, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (FIB), were detected in plasma to manifest the P. lobata and P. thomsonii antithrombotic function. Network pharmacology and molecular docking methods were used to obtain key targets and verify reliability. David 6.8 was used for GO and KEGG analyses to explore pathways and potential targets for P. lobata and P. thomsonii antithrombotic functions. Prostaglandin I2 (PGI2), thromboxane A2 (TXA2), cyclooxygenase 2 (COX-2), myeloperoxidase (MPO) and endothelial nitric oxide synthase (eNOS) were tested by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results indicated that P. lobata and P. thomsonii can reduce thrombus dry‒wet weight and platelet accumulation in rats and inhibit TT, APTT, FIB, and PT. A comprehensive network pharmacology approach successfully identified 9 active ingredients in P. lobata and P. thomsonii. The main active ingredients include polyphenols, amino acids and flavonoids. A total of 15 antithrombotic function targets were obtained, including 3 key targets (PTGS2, NOS3, MPO). Pathway analysis showed 10 significant related pathways and 29 biological processes. P. lobata and P. thomsonii inhibited platelet aggregation by upregulating PGI2 and downregulating TXA2, inhibited PTGS2 to reduce inflammation, and increased the level of eNOS to promote vasodilation. In addition, P. lobata and P. thomsonii alleviated oxidative stress by increasing SOD levels and significantly decreasing MDA contents.

CONCLUSION

The results of the study further clarify the antithrombotic mechanism of action of P. lobata and P. thomsonii, which provides a scientific basis for the development of new drugs for thrombogenic diseases and lays the foundation for the development of P. lobata and P. thomsonii herbal resources and P. lobata and P. thomsonii health products.

Enhanced anti-biofilm and biocompatibility of Zn and Mg substituted β-tricalcium phosphate/functionalized multiwalled carbon nanotube composites towards A. baumannii and Methicillin-Resistant Staphylococcus aureus, and MG-63 cells

In this work, Zn and Mg substituted β-tricalcium phosphate/functionalized multiwalled carbon nanotube (f-MWCNT) nanocomposites were prepared by the co-precipitation method. The structural, vibrational, morphological and biological properties of the prepared nanocomposites were studied. The structural study revealed that the increase of Zn concentration shifts the β-tricalcium phosphate planes towards higher angle. Morphological analysis confirmed the formation of hexagonal-shaped particles after substitution of Zn. The particle size of the nanoparticles decreased with the increase of Zn concentration. XPS analysis clearly showed the presence of Zn, Mg, P, Ca, O and C. The Zn (5%) rich nanocomposites have better antibiofilm activity compared to 2% of zinc substituted composite. Also, it has been proven that the prepared nanocomposites have the ability to enhance the bioactivity of commercial antibiotics by means of a decrease in drug resistance. Finally, this study acted as a pioneer to improve drug efficiency and reduced the biofilm formation of certain medically important bacteria. The in-vitro cell viability and anti-biofilm results of zinc (5%) rich nanocomposite confirmed that prepared nanocomposite has biocompatible and enhanced anti-biofilm property, which will be beneficial candidate for biomedical applications.

Development of Antithrombogenic ECM-Based Nanocomposite Heart Valve Leaflets

Thrombogenicity, which is commonly encountered in artificial heart valves after replacement surgeries, causes valvular failure. Even life-long anticoagulant drug use may not be sufficient to prevent thrombogenicity. In this study, it was aimed to develop a heart valve construct with antithrombogenic properties and suitable mechanical strength by combining multiwalled carbon nanotubes within a decellularized bovine pericardium. In this context, the decellularization process was performed by using the combination of freeze–thawing and sodium dodecyl sulfate (SDS). Evaluation of decellularization efficiency was determined by histology (Hematoxylin and Eosin, DAPI and Masson’s Trichrome) and biochemical (DNA, sGAG and collagen) analyses. After the decellularization process of the bovine pericardium, composite pericardial tissues were prepared by incorporating −COOH-modified multiwalled carbon nanotubes (MWCNTs). Characterization of MWCNT incorporation was performed by ATR-FTIR, TGA, and mechanical analysis, while SEM and AFM were used for morphological evaluations. Thrombogenicity assessments were studied by platelet adhesion test, Calcein-AM staining, kinetic blood clotting, hemolysis, and cytotoxicity analyses. As a result of this study, the composite pericardial material revealed improved mechanical and thermal stability and hemocompatibility in comparison to decellularized pericardium, without toxicity. Approximately 100% success is achieved in preventing platelet adhesion. In addition, kinetic blood-coagulation analysis demonstrated a low rate and slow coagulation kinetics, while the hemolysis index was below the permissible limit for biomaterials.

Nitrogen plasma modification boosts up the hemocompatibility of new PVDF-carbon nanohorns composite materials with potential cardiological and circulatory system implants application

To design new material for blood-related applications one needs to consider various factors such as cytotoxicity, platelet adhesion, or anti-thrombogenic properties. The aim of this work is the design of new, highly effective materials possessing high blood compatibility. To do this, the new composites based on the poly(vinylidene fluoride) (PVDF) support covered with a single-walled carbon nanohorns (CNHs) layer were prepared. The PVDF-CNHs composites were subsequently used for the first time in the hemocompatibility studies. To raise the hemocompatibility a new, never applied before for CNHs, plasma-surface modifications in air, nitrogen and ammonia were implemented. This relatively cheap, facile and easy method allows generating the new hybrid materials with high effectiveness and significant differences in surface properties (water contact angle, surface ζ-potential, and surface functional groups composition). Changing those properties made it possible to select the most promising samples for blood-related applications. This was done in a fully controlled way by applying Taguchi's "orthogonal array" procedure. It is shown for the first time that nitrogen plasma treatment of new surfaces is the best tool for hemocompatibility rise and leads to very low blood platelet adhesion, no cytotoxicity, and excellent performance in thromboelastometry and hemolysis tests. We propose a possible mechanism explaining this behavior. The optimisation results are coherent with biological characterisation and are supported with Hansen Solubility Parameters. New surfaces can find potential applications in cardiological and circulatory system implants as well as other blood-related biomaterials.

Anti-Alzheimer's potential of berberine using surface decorated multi-walled carbon nanotubes: A preclinical evidence

Carbon nanotubes (CNTs), a sub-family of fullerenes, are nanosized seamless cylinders of graphene sheets with enormous drug loading potential. The current studies entail the systematic development of berberine (BRB)-loaded multiwalled carbon nanotubes (MWCNTs) with polysorbate and phospholipid coating for effective management of Alzheimer's Disease (AD). For systematic optimization using design of experiment (DoE), a central composite design (FCCD) was employed and the optimized formulation was choosen using numerical desirability function. Optimized formulation exhibited particle size of 186nm, 68.6% drug adsorption and amount of drug released in 16h (Q_16h) of 96%. Degree of carboxylation was observed to be 36%. FTIR and FESEM studies confirmed the coating of polysorbate and phospholipid onto the MWCNTs side walls. Confocal studies ratified the uptake potential of BRB-loaded MWCNT formulations on SH-SY5Y cell lines. In vivo pharmacokinetic studies in rats showed significant improvement in the rate and extent of drug absorption in the plasma and brain tissues, both, vis-a-vis pure drug. Behavioral assessment employing Morris Maze test demonstrated the enhanced performance efficiency of the formed MWCNT complexes. Moreover, the phospholipid-coated and the polysorbate-coated MWCNTs exhibited remarkable recovery in memory performance from 18th to 20th day vis-a-vis other groups. Maintenance of normal biochemical levels in brain tissue demonstrated the potential of these coated MWCNTs in reducing β-amyloid induced AD. The studies, in a nutshell, demonstrate significant potential of polysorbate/phospholipid coated MWCNTs of BRB in holistic management of AD.

The enhanced anticoagulation for graphene induced by COOH(+) ion implantation

Graphene may have attractive properties for some biomedical applications, but its potential adverse biological effects, in particular, possible modulation when it comes in contact with blood, require further investigation. Little is known about the influence of exposure to COOH(+)-implanted graphene (COOH(+)/graphene) interacting with red blood cells and platelets. In this paper, COOH(+)/graphene was prepared by modified Hummers' method and implanted by COOH(+) ions. The structure and surface chemical and physical properties of COOH(+)/graphene were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurement. Systematic evaluation of anticoagulation, including in vitro platelet adhesion assays and hemolytic assays, proved that COOH(+)/graphene has significant anticoagulation. In addition, at the dose of 5 × 10(17) ions/cm(2), COOH(+)/graphene responded best on platelet adhesion, aggregation, and platelet activation.

Pulmonary and hemostatic toxicity of multi-walled carbon nanotubes and zinc oxide nanoparticles after pulmonary exposure in Bmal1 knockout mice

BACKGROUND

Pulmonary exposure to nanoparticles (NPs) may affect, in addition to pulmonary toxicity, the cardiovascular system such as procoagulant effects, vascular dysfunction and progression of atherosclerosis. However, only few studies have investigated hemostatic effects after pulmonary exposure.

METHODS

We used Bmal1 (brain and muscle ARNT-like protein-1) knockout (Bmal1(-/-)) mice which have a disturbed circadian rhythm and procoagulant phenotype, to study the pulmonary and hemostatic toxicity of multi-walled carbon nanotubes (MWCNTs) and zinc oxide (ZnO) NPs after subacute pulmonary exposure. Bmal1(-/-) and wild-type (Bmal1(+/+)) mice were exposed via oropharyngeal aspiration, once a week, during 5 consecutive weeks, to a cumulative dose of 32 or 128 μg MWCNTs or 32 or 64 μg ZnO NPs.

RESULTS

MWCNTs caused a pronounced inflammatory response in the lung with increased cell counts in the broncho-alveolar lavage and increased secretion of interleukin-1β and cytokine-induced neutrophil chemo-attractant (KC), oxidative stress (increased ratio of oxidized versus reduced glutathione and decreased total glutathione) as well as anemic and procoagulant effects as evidenced by a decreased prothrombin time with increased fibrinogen concentrations and coagulation factor (F)VII. In contrast, the ZnO NPs seemed to suppress the inflammatory (decreased neutrophils in Bmal1(-/-) mice) and oxidative response (increased total glutathione in Bmal1(-/-) mice), but were also procoagulant with a significant increase of FVIII. The procoagulant effects, as well as the significant correlations between the pulmonary endpoints (inflammation and oxidative stress) and hemostasis parameters were more pronounced in Bmal1(-/-) mice than in Bmal1(+/+) mice.

CONCLUSIONS

The Bmal1(-/-) mouse is a sensitive animal model to study the procoagulant effects of engineered NPs. The MWCNTs and ZnO NPs showed different pulmonary toxicity but both NPs induced procoagulant effects, suggesting different mechanisms of affecting hemostasis. However, the correlation analysis suggests a causal association between the observed pulmonary and procoagulant effects.

Effect of nitrogen atomic percentage on N+-bombarded MWCNTs in cytocompatibility and hemocompatibility

N+-bombarded multi-walled carbon nanotubes (N+-bombarded MWCNTs), with different nitrogen atomic percentages, were achieved by different N ion beam currents using ion beam-assisted deposition (IBAD) on MWCNTs synthesized by chemical vapor deposition (CVD). Characterizations of N+-bombarded MWCNTs were evaluated by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Raman spectroscopy, and contact angle. For comparison, the in vitro cytocompatibility of the N+-bombarded MWCNTs with different N atomic percentages was assessed by cellular adhesion investigation using human endothelial cells (EAHY926) and mouse fibroblast cells (L929), respectively. The results showed that the presence of nitrogen in MWCNTs accelerated cell growth and proliferation of cell culture. The higher nitrogen content of N+-bombarded MWCNTs, the better cytocompatibility. In addition, N+-bombarded MWCNTs with higher N atomic percentage displayed lower platelet adhesion rate. No hemolysis can be observed on the surfaces. These results proved that higher N atomic percentage led N+-bombarded MWCNTs to better hemocompatibility.

Hemotoxicity of carbon nanotubes

Carbon nanotubes may enter into the bloodstream and interact with blood components indirectly via translocation following unintended exposure or directly after an intended administration for biomedical purposes. Once introduced into systemic circulation, nanotubes will encounter various proteins, biomolecules or cells which have specific roles in the homeostasis of the circulatory system. It is therefore essential to determine whether those interactions will lead to adverse effects or not. Advances in the understanding of how carbon nanotubes interact with blood proteins, the complement system, red blood cells and the hemostatic system are reviewed in this article. While many studies on carbon nanotube health risk assessment and their biomedical applications have appeared in the last few years, reports on the hemocompatibility of these nanomaterials remain surprisingly limited. Yet, defining the hemotoxicological profile is a mandatory step toward the development of clinically-relevant medications or contrast agents based on carbon nanotubes.