carbon-based nanomaterials Dotaz Zobrazit nápovědu
In the field of science, technology and medicine, carbon-based nanomaterials and nanoparticles (CNMs) are becoming attractive nanomaterials that are increasingly used. However, it is important to acknowledge the risk of nanotoxicity that comes with the widespread use of CNMs. CNMs can enter the body via inhalation, ingestion, intravenously or by any other route, spread through the bloodstream and penetrate tissues where (in both compartments) they interact with components of the immune system. Like invading pathogens, CNMs can be recognized by large numbers of receptors that are present on the surface of innate immune cells, notably monocytes and macrophages. Depending on the physicochemical properties of CNMs, i.e., shape, size, or adsorbed contamination, phagocytes try to engulf and process CNMs, which might induce pro/anti-inflammatory response or lead to modulation and disruption of basic immune activity. This review focuses on existing data on the immunotoxic potential of CNMs, particularly in professional phagocytes, as they play a central role in processing and eliminating foreign particles. The results of immunotoxic studies are also described in the context of the entry routes, impacts of contamination and means of possible elimination. Mechanisms of proinflammatory effect depending on endocytosis and intracellular distribution of CNMs are highlighted as well.
The supply of safe drinking and clean water is becoming increasingly challenging proposition throughout the world. The deployment of environmentally sustainable nanomaterials with unique advantages namely high efficiency and selectivity, earth-abundance, recyclability, low-cost of production processes, and stability, has been a priority although several important challenges and constraints still remained unresolved. Carbon nanomaterials namely activated carbon, multi-walled- and single-walled carbon nanotubes, have been developed and applied as adsorbents for wastewater treatment and purification; graphene and graphene oxide-based nanomaterials as well as carbon and graphene quantum dots-derived nanomaterials have shown significant promise for water and wastewater treatment and purification, especially, for industrial- and pharmaceutical-laden wastes. This review encompasses advanced carbonaceous nanomaterials and methodologies that are deployed for the elimination of contaminants and ionic metals in aqueous media, and as novel nanosorbents for wastewater, drinking and ground water treatment. Additionally, recent trends and challenges pertaining to the sustainable carbon and graphene quantum dots-derived nanomaterials and their appliances for treating and purifying wastewater are highlighted.
- MeSH
- čištění vody * MeSH
- nanostruktury * MeSH
- nanotrubičky uhlíkové * MeSH
- odpadní voda MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Precise detection of important pharmaceuticals with narrow therapeutic index (NTI) is very critical as there is a small window between their effective dose and the doses at which the adverse reactions are very likely to appear. Regarding the fact that various pharmacokinetics will be plausible while considering pharmacogenetic factors and also differences between generic and brand name drugs, accurate detection of NTI will be more important. Current routine analytical techniques suffer from many drawbacks while using novel biosensors can bring up many advantages including fast detection, accuracy, low cost with simple and repeatable measurements. Recently the well-known carbon Nano-allotropes including carbon nanotubes and graphenes have been widely used for development of different Nano-biosensors for a diverse list of analytes because of their great physiochemical features such as high tensile strength, ultra-light weight, unique electronic construction, high thermo-chemical stability, and an appropriate capacity for electron transfer. Because of these exceptional properties, scientists have developed an immense interest in these nanomaterials. In this case, there are important reports to show the effective Nano-carbon based biosensors in the detection of NTI drugs and the present review will critically summarize the available data in this field.
Non-spherical metal-based and carbon-based nanostructures have found applications in every facet of scientific endeavors, including engineering and biomedical fields. These nanostructures attract attention because of their biocompatibility and negligible cytotoxicity. Chemical and physical methods have been used for synthesizing earlier generations of metal-based and carbon-based nanostructures with variable architectures, including nanorods, nanowires, nanodots and nanosheets. However, these synthesis strategies utilize organic passivators which are toxic to the environment and the human body. Biogenic synthesis of nanoparticles is becoming increasing popular because of the necessity to develop eco-friendly and non-toxic strategies. Nanoparticles synthesized by natural compounds have immense potential in the biomedical arena. The present review focuses on plant-mediated synthesis of metal-based and carbon-based non-spherical nanoarchitectures and the role of green synthesis in improving their activities for biomedical applications.
- MeSH
- biokompatibilní materiály chemie metabolismus MeSH
- kovy chemie MeSH
- lidé MeSH
- nanostruktury chemie MeSH
- nanotechnologie metody MeSH
- uhlík chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Today, researchers have focused on the application of environmentally-benign and sustainable micro- and nanosystems for drug delivery and cancer therapy. Compared to conventional chemotherapeutics, advanced micro- and nanosystems designed by applying abundant, natural, and renewable feedstocks have shown biodegradability, biocompatibility, and low toxicity advantages. However, important aspects of toxicological assessments, clinical translational studies, and suitable functionalization/modification still need to be addressed. Herein, the benefits and challenges of green nanomedicine in cancer nanotherapy and targeted drug delivery are cogitated using nanomaterials designed by exploiting natural and renewable resources. The application of nanomaterials accessed from renewable natural resources, comprising metallic nanomaterials, carbon-based nanomaterials, metal-organic frameworks, natural-derived nanomaterials, etc. for targeted anticancer drug delivery and cancer nanotherapy are deliberated, with emphasis on important limitations/challenges and future perspectives.
- MeSH
- lidé MeSH
- nádory * farmakoterapie MeSH
- nanomedicína MeSH
- nanostruktury * terapeutické užití MeSH
- přírodní zdroje MeSH
- systémy cílené aplikace léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are well recognized for playing a dual role, since they can be either deleterious or beneficial to biological systems. An imbalance between ROS production and elimination is termed oxidative stress, a critical factor and common denominator of many chronic diseases such as cancer, cardiovascular diseases, metabolic diseases, neurological disorders (Alzheimer's and Parkinson's diseases), and other disorders. To counteract the harmful effects of ROS, organisms have evolved a complex, three-line antioxidant defense system. The first-line defense mechanism is the most efficient and involves antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This line of defense plays an irreplaceable role in the dismutation of superoxide radicals (O2•-) and hydrogen peroxide (H2O2). The removal of superoxide radicals by SOD prevents the formation of the much more damaging peroxynitrite ONOO- (O2•- + NO• → ONOO-) and maintains the physiologically relevant level of nitric oxide (NO•), an important molecule in neurotransmission, inflammation, and vasodilation. The second-line antioxidant defense pathway involves exogenous diet-derived small-molecule antioxidants. The third-line antioxidant defense is ensured by the repair or removal of oxidized proteins and other biomolecules by a variety of enzyme systems. This review briefly discusses the endogenous (mitochondria, NADPH, xanthine oxidase (XO), Fenton reaction) and exogenous (e.g., smoking, radiation, drugs, pollution) sources of ROS (superoxide radical, hydrogen peroxide, hydroxyl radical, peroxyl radical, hypochlorous acid, peroxynitrite). Attention has been given to the first-line antioxidant defense system provided by SOD, CAT, and GPx. The chemical and molecular mechanisms of antioxidant enzymes, enzyme-related diseases (cancer, cardiovascular, lung, metabolic, and neurological diseases), and the role of enzymes (e.g., GPx4) in cellular processes such as ferroptosis are discussed. Potential therapeutic applications of enzyme mimics and recent progress in metal-based (copper, iron, cobalt, molybdenum, cerium) and nonmetal (carbon)-based nanomaterials with enzyme-like activities (nanozymes) are also discussed. Moreover, attention has been given to the mechanisms of action of low-molecular-weight antioxidants (vitamin C (ascorbate), vitamin E (alpha-tocopherol), carotenoids (e.g., β-carotene, lycopene, lutein), flavonoids (e.g., quercetin, anthocyanins, epicatechin), and glutathione (GSH)), the activation of transcription factors such as Nrf2, and the protection against chronic diseases. Given that there is a discrepancy between preclinical and clinical studies, approaches that may result in greater pharmacological and clinical success of low-molecular-weight antioxidant therapies are also subject to discussion.
- MeSH
- anthokyaniny metabolismus farmakologie MeSH
- antioxidancia * farmakologie metabolismus MeSH
- chronická nemoc MeSH
- kyselina peroxydusitá farmakologie MeSH
- lidé MeSH
- nádory * MeSH
- oxid dusnatý MeSH
- oxidační stres MeSH
- peroxid vodíku MeSH
- reaktivní formy kyslíku metabolismus MeSH
- superoxiddismutasa metabolismus MeSH
- superoxidy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND: The widespread application of engineered nanomaterials (ENMs) and the increasing likelihood of general and occupational exposure raised concerns on their possible human health impact. ENMs, in fact, may induce alterations in different organ systems, and particularly in the respiratory tract. This makes it important to identify possible biomarkers of early lung effect in exposed workers. In this regard, the possibility to use the fractional exhaled levels of nitric oxide (FENO) in biological monitoring has attracted considerable interest. OBJECTIVE: To comprehensively assess the role of FENO as a possible biomarker of lung effect in ENM exposed workers. METHODS: A systematic search was performed on Pubmed, Scopus, and ISI Web of Knowledge databases according to the PRISMA guidelines. RESULTS: Seven studies investigated FENO in workers exposed to different kinds of metal- (i.e. silver and gold), metal oxide- (titanium and silica dioxide), and carbon-based ENMs (carbon nanotubes). In general, no significant alterations were detected between exposed workers and controls. CONCLUSION: Definite conclusion on the function of FENO in occupational biological monitoring cannot be extrapolated due to the limited number of available studies and the small size of investigated populations. Additionally, the lack of environmental monitoring data and the fragmented knowledge on ENM modes of action prevent to establish dose-response relationships. Future research appears necessary to deeply define the possibility to employ FENO as an early biomarker of lung effects taking in consideration possible occupational exposure issues, i.e. differently characterized ENMs and work tasks, as well as individual influencing factors, i.e. smoking and atopy.
- MeSH
- biologické markery MeSH
- dechové testy MeSH
- lidé MeSH
- nanostruktury * toxicita MeSH
- nanotrubičky uhlíkové MeSH
- oxid dusnatý MeSH
- pracoviště MeSH
- vydechnutí MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Edukační publikace se zabývá v první části luminiscenčními metodami: luminiscencí lanthanidů rozloženou v čase, luminiscencí lanthanidů zesílenou enzymem, homogenní imunoanalýzou s pohlcením luminiscence, chemiluminiscencí, elektrochemiluminiscencí (kompetitivní i sendvičové uspořádání a metoda přímé interakce) a možnostmi simultánních imunoanalýz s elektrochemiluminiscenční detekcí. Druhá část je věnována imunoanalýzám s elektrochemickou detekcí, zejména anodickou rozpouštěcí voltametrií a square-wave voltametrií. Jako značky se používají různé nanomateriály: zlato, stříbro, polovodiče (CdS, PbS, ZnS, CuS), uhlíkové nanotrubičky (plněné enzymem), apoferitin (plněný ferokyanidem nebo ionty Cd 2+ nebo Pb 2+ ), liposomy (plněné ferokyanidem), křemenné částice (s kovalentně vázaným polyguaninem, nebo plněné peroxidázou a thioninem), mikrokrystaly ferrocenu a jiné.
The first part of the educational article deals with luminescence methods as follows: lanthanide-based time-resolved luminescence, enzyme-amplified lanthanide luminescence, homogeneous immunoassays with luminescence quenching, chemiluminescence, electrochemiluminescence (competitive assay, sandwich-type assay, and direct interaction) and simultaneous immunoassays options with electrochemical luminescence detection. The second part covers immunoassays with electrochemical detection, particularly anodic stripping voltammetry and square-wave voltammetry. Many kinds of nanomaterials are used as labels, e.g. gold, silver, semiconductors (CdS, PbS, ZnS, CuS), carbon nanotubes (enzyme-loaded), apoferritin (hexacyanoferrate loaded, in some cases Cd 2+ or Pb 2+ ions are used), liposomes (hexacyanoferrate loaded), silica particles (by covalently binding polyguanine or with peroxidase & thionine loaded), ferrocene microcrystals, etc. Keywords: Lanthanide-based luminescence, chemiluminescence, electrochemiluminescence, electrochemical immunoassays, nanomaterials.
The carbon nanomaterials and congeners, e.g., graphene or graphene oxide (GO), dispose of numerous unique properties, which are not necessarily intrinsic but might be related to a content of impurities. The oxidation step of GO synthesis introduces a considerable amount of metallic species. Therefore, large-scale purification is an actual scientific challenge. Here we describe new purification technique (salt‑washing), which is based on three consecutive steps: (a) aggregation of GO sheets with NaCl (b) washing of the aggregates and (c) removing of the salt to afford purified GO (swGO). The considerably improved purity of swGO was demonstrated by ICP and EPR spectroscopy. The microscopic methods (TEM with SEAD, AFM) proved that the salt-washing does not affect the morphology or concentration of defects, showing the aggregation of GO with NaCl is fully reversible. The eligibility of swGO for biomedical applications was tested using fibroblastic cell cultures. The determined IC50 values clearly show a strong correlation between the purity of samples and cytotoxicity. Although the purification decreases cytotoxicity of GO, the IC50 values are still low proving that cytotoxic effect is not only impurities-related but also an intrinsic property. These findings may represent a serious limitation for usage of GO in biomedical applications.
- MeSH
- chlorid sodný toxicita MeSH
- grafit * toxicita MeSH
- nanostruktury * MeSH
- oxidace-redukce MeSH
- Publikační typ
- časopisecké články MeSH
