جستجوی مقالات مرتبط با کلیدواژه « carbon nanotubes » در نشریات گروه « پزشکی »

Carbon nanotubes (CNTs) serve as molecular carriers for in vivo and in vitro delivery. Initial studies have suggested that nanotubes in drug delivery can enhance the therapeutic response to anti-cancer drugs. The present study intended to investigate the effect of CNTs carrying tamoxifen (TAM-CNTs) on the induction of apoptosis in the MDA-MB-231 cell line.

The cells were treated with various concentrations of TAM and TAM-CNTs. The IC50 for these compounds was determined using a MTT assay. The cells were then treated with a lower concentration of IC50. The BAX and BCL-2 genes expression were evaluated by Real-Time PCR and Western blot. Flow cytometry was employed for evaluating apoptosis induction by TAM and TAM-CNTs.

The IC50 value of TAM and TAM-CNTs in a 48-hour period was 66.19 mg/mL and 36.59 mg/mL, respectively. The results demonstrated that BAX in the cells treated with TAM and TAM-CNTs was upregulated 3.64 and 7.88 times, respectively (P <0.05). Conversely, BCL-2 was downregulated 3.98 and 5.31 times (P <0.05). Furthermore, Western blot experiments confirmed the expression of BAX and BCL-2 proteins based on their gene expression. Flow cytometry results indicated that the viability of MDA-MB-231 cells in the control group, TAM-treated, and TAM-CNTs-treated cells was 95.3%, 64.9%, and 13.75%, respectively. This suggests that TAM-CNTs significantly diminishes cell viability compared to TAM (P <0.001).

The findings revealed that TAM accompanied by CNTs exhibits a greater cytotoxic and apoptotic effect on MDA-MB-231 cells.

 Carbon nanotubes (CNTs) are a significant discovery in nanotechnology, with widespread applications in modern technology. However, there are concerns about their potential toxicity, particularly in skin cells. This study aimed to investigate the mechanisms by which CNTs induced cytotoxicity and apoptosis in mouse skin fibroblasts.

Experimental approach: 

The mice skin fibroblasts were isolated and exposed to two types of CNTs at various concentrations and then analyzed for changes in viability, reactive oxygen species (ROS) production, the levels of Bcl-2-associated X protein (Bax), and lactate production.

 The results demonstrated that CNTs reduced cell viability and increased ROS production in a dose-dependent manner. Additionally, the current study found that CNTs increased the protein levels of Bax, a pro-apoptotic protein, in mouse skin fibroblasts. Furthermore, it was observed a significant decrease in lactate production in cells exposed to CNTs.

Conclusion and implications:

 The findings concluded that CNTs have the potential to be toxic substances for skin fibroblasts, which serve as the body's first line of defense. This is evidenced by their ability to increase the production of ROS and the protein levels of Bax, as well as reduce lactic acid levels. As lactic acid has been reported to have beneficial effects on skin collagen production, further studies are needed to fully understand the impact of carbon nanotube exposure on human skin health.

Multi-walled carbon nanotubes (MWCNTs) are being utilized in various fields. With regard to their numerous applications, MWCNTinduced toxicity has not been extensively investigated. Thus, the present study sheds light on the protective effect of caffeic acid (CA) on mitochondrial toxicity in the kidney caused by MWCNTs in Wistar rats employing the MTT assay as well as reactive oxygen species (ROS) indices, based on measuring glutathione (GSH), mitochondrial membrane potential (MMP), malondialdehyde (MDA), and catalase (CAT) activity. According to the MTT assay, using MWCNTs could significantly diminish mitochondrial viability based on doses. Furthermore, the study findings suggested that MWCNTs could reduce GSH content and CAT activity and subsequently improve mitochondrial ROS formation and damage the mitochondrial membrane of the kidney. The findings also implied that CA could protect renal mitochondria against toxicity induced by MWCNTs by lowering oxidative stress.

Nano-theranostics (NTs) are versatile nanomaterials, explored in the current scenario of cancer therapy. A nano-theranostic material alone can diagnose and generate a therapeutic effect. Various materials have been explored for their NT action like gold and carbon-based material. The photon-based cancer theranostics has grabbed the attention of researchers due to their localized and trigger activated effect. NTs have shown a promising result in pre-clinical and clinical studies. The current review illustrates the meticulous efforts conducted by researchers across the globe to innovate and explore the photon-based cancer NT platforms of gold and carbon with their application in cancer therapy.

The development of carbon-based nanomaterials has extensively facilitated new discoveries in various fields. Carbon nanotube-based nanocomposites (CNT-based nanocomposites) have lately recognized as promising biomaterials for a wide range of biomedical applications due to their unique electronic, mechanical, and biological properties. Nanocomposite materials such as silver nanoparticles (AgNPs), polymers, biomolecules, enzymes, and peptides have been reported in many studies, possess a broad range of antibacterial activity when incorporated with carbon nanotubes (CNTs). It is crucial to understand the mechanism which governs the antimicrobial activity of these CNT-based nanocomposite materials, including the decoupling individual and synergistic effects on the cells. In this review, the interaction behavior between microorganisms and different types of CNT-based nanocomposites is summarized to understand the respective antimicrobial performance in different conditions. Besides, the current development stage of CNT-based nanocomposite materials, the technical challenges faced, and the exceptional prospect of implementing potential antimicrobial CNT-based nanocomposite materials are also discussed.

Prostate cancer (PCa) is one of the leading diseases in men all over the world caused due to over-expression of prostate-specific membrane antigen (PSMA). Currently, the detection and targeting of PCa is one of the major challenges in the prostate gland. Therefore, Bruton tyrosine kinase inhibitor molecules like ibrutinib (Ibr) loaded with nanomaterials like multiwalled carbon nanotubes (MWCNTs), which has good physico-chemical properties may be the best regimen to treat PCa. In this strategy, the chemically modified MWCNTs have excellent ‘Biosensing’ properties makes it easy for detecting PCa without fluorescent agent and thus targets particular site of PCa. In the present study, Ibr/MWCNTs conjugated with T30 oligonucleotide may selectively target and inhibit PSMA thereby reduce the over-expression in PCa. Hence, the proposed formulation design can extensively reduce the dosage regimen without any toxic effect. Additionally, the present hypothesis also revealed the binding mode of Ibr in the catalytic pocket of PSMA by in silico method. Therefore, we presume that if this hypothesis proves correct, it becomes an additional novel tool and one of the conceivable therapeutic options in treating PCa.

Acinetobacter baumannii is critical for healthcare-associated infections with significant regional differences in the resistance rate, but its risk factors and infection trends have not been well studied. Carbon nanotubes are substantially cylindrical molecules made entirely of carbon atoms and can use as nanocarriers. Multi-wall carbon nanotubes, through their unique properties, hold great promise in the fight against multidrug-resistant bacterial infections. In this research, antimicrobial effects study and the ability to overcome antibiotic resistance evaluation of nanofluid containing functionalized carbon nanotubes on A. baumannii were done.

Multi-wall carbon nanotubes provided from the United States Research and the nanofluid prepared after carbon nanotube functionalization. Microplate, Alamar Blue Cell viability assay, carried out after incubation of A. baumannii affected with the nanofluid (100µg/ml) for 24h.

Antimicrobial effect of functionalized carbon nanotubes nanofluid was found on the A. baumannii in a dose-specific concentration manner.

This study showed that functionalized carbon nanotubes nanofluid could have antimicrobial effects on A. baumannii by overcoming bacterial antibiotic resistance. Although to get more accurate results, to prevent nosocomial infections, more specific cellular and molecular studies are necessary.

Although bone tissue has the unique characteristic of self-repair in fractures, bone grafting is needed in somesituations. The synthetic substances that are used in such situations should bond to the porous bones, be biocompatibleand biodegradable, and do not stimulate the immune responses. Biomaterial engineering is the science of finding anddesigning novel products. In principle, the most suitable biodegradable matrix should have adequate compressive strengthof more than two megapascals. At this degradation rate, the matrix can eventually be replaced by the newly formed bone,and the osteoprogenitor cells migrate into the scaffold. This study aimed to evaluate the fabrication of a scaffold made ofpolymer-ceramic nanomaterials with controlled porosity resembling that of spongy bone tissue. A compound of resin polymer, single-walled carbon nanotube (SWCNT) as reinforcement, and hydroxyapatite(HA) were dissolved using an ultrasonic and magnetic stirrer. A bio-nano-composite scaffold model was designed in theSolidWorks software and built using the digital light processing (DLP) method. Polymer-HA scaffolds with the solvent systemwere prepared with similar porosity to that of human bones. HA-polymer scaffolds had a random irregular microstructure with homogenizing porous architecture. The SWCNTimproved the mechanical properties of the sample from 25 MPa to 36 MPa besides having a proper porosity value near55%, which can enhance the transformation and absorption of protein in human bone. The combined bio-nanocomposite had a suitable porous structure with acceptable strength that allowed it tobe used as a bone substitute in orthopedic surgery.

Acinetobacter baumannii is recognized as an important pathogen responsible for serious infections causing episodes of hospital infection. Carbon nanotubes (CNTs) have recently emerged as superior materials against antibiotic-resistant bacteria. In this study, a new chemical compound was designed in order to combat A. baumannii infections. Subsequently, the effect of this novel carbon nanotube coated with an antibacterial compound on Extensively Drug-Resistant (XDR), Multidrug-Resistant (MDR) and Pan-Drug-Resistance (PDR) strains of A. baumannii was investigated.

A total of 122 clinical isolates of A. baumannii were cultured from burn patients and their susceptibility to antibiotics were checked using disk diffusion method and Minimum inhibitory concentration. Antimicrobial effects of the coated carbon nanotube were evaluated on XDR, MDR and PDR isolates of A. baumannii. Cell viability was determined using tetrazolium reduction assay (MTT) on human fibroblast cell line (HDFa). Wound healing processes were assessed by quantitative polymerase chain reaction.

Of the 50 A. baumannii isolates, 38 (76%) were found to be MDR and 12 (24%) were XDR. No PDR strains were detected. Results indicated that the carbon nanotube combined with mercury had antibacterial effect against different A. baumannii species and it also was able to increase the expression of epidermal growth factor, platelet-derived growth factor and vascular endothelial growth factor A mRNA levels which are involved in wound healing.

The engineered carbon nanotube compound can potentially be used for treatment of burn related infections. This can potentially give clinicians a new tool for treating A. baumannii infections.

To evaluate the penetration of carbon nanotubes (CNTs) throughout retinoblastoma in a transgenic mice model.

CNTs functionalized with fluorescein isothiocyanate and targeting ligands biotin (CTN-FITC-Bio, 0.5mg/ml), or folic acid (CNT-FITC-FA, 0.5mg/ml) were injected into the vitreous of one eye of LHBETATAG transgenic mice. Other eye did not receive any injection and was used as control. Three mice were sacrificed at days 1, 2, and 3. Eyes were enucleated and stained with 4,6-diamidino-2-phenylindole. The sections were imaged by fluorescent microscope. The images were transformed into grey-scale in MATLAB for intensity analysis. Background intensity was normalized by marking squares outside the eyeball and using the mean intensity of these squares. Fluorescent intensity (FI) for each image was measured by calculating the intensity of a same-sized square within retinoblastoma.

Nine eyes of nine mice were included in each CNT-FITC-Bio and CNT-FITC-FA groups. The mean FI in CNT-FITCBio was 52.08 ± 6.33, 53.62 ± 9.00, and 65.54 ± 5.14 in days 1, 2, and 3, respectively. The mean FI in CNT-FITC-FA was 50.28 ± 7.37, 59.21 ± 6.43, and 58.38 ± 2.32 on days 1, 2, and 3, respectively. FI was significantly higher in eyes injected with CNT-FITC-Bio and CNT-FITC-FA compared to the control eyes (P = 0.02). There was no difference in FI between eyes with CNT-FITC-Bio and CNT-FITC-FA, and FI remained stable on days 1–3 in CNT-FITC-Bio, CNT-FITC-FA, and control eyes (P > 0.05).

We observed higher FI in eyes with CNT-FITC-Bio and CNT-FITC-FA compared to control eyes, showing penetration of CNTs throughout retinoblastoma. CNTs can be a carrier candidate for imaging or therapeutic purposes in retinoblastoma.

The etiological factors for increased risk of endocrine and reproductive disorders remain largely unclear but huge number of data from in vitro, in vivo and epidemiological studies, support the association of their incidence with long term exposure to endocrine disrupting chemicals /agrochemicals in the modern world. Engineered Nanomaterials (ENMs) could be considered as new alternatives to overcome the environmental challenges of endocrine disrupting pesticides and fertilizers and to reduce human health risks of cancer and endocrine toxicity based on their unique physicochemical properties. Carbon nanotubes (CNTs) are the initiative members of the big family of ENMs used for developing “Nanotechnology Based Agrochemical” but despite remarkable detoxifying effects mediated by CNTs, a number of controversies and key questions address the toxicity and endocrine disrupting properties of these authoritative agents which may introduce to the global markets new generation of as nanofertilizers ,nanoadsorbents and nanopesticides soon .The actual issue stems from limited number of studies in valid toxicology models on CNTs related endocrine disruption and absence of systematic reviews on CNTs exposure-mediated endocrine health hazards especially with respect to epidemiological and human data. In this direction this systematic review focused on the following sub-topics: (1) an overview on CNTs applications as novel agrochemicals (2) environmental risks and benefits of CNTs 3) toxicokinetic and toxicodynamic of CNTs (4) contribution of CNTs in pathogenesis of obesity, diabetes and cardiovascular effects 4) evidence on the involvement of CNTs in developmental and reproductive toxicities from in vitro and in vivo studies (5) conclusions and perspectives.

Nowadays, multi-walled carbon nanotubes (MWCNTs) are used in various industries. Considering the exposure probability of these nanomaterials to humans, the purpose of the present study is to assess the effect of MWCNTs on cellular toxicity of human alveolar epithelial. The A549 cells were cultured and treated to various doses of MWCNTs at three different times. Finally, the Tetrazolium colorimetric (MTT) assay was implemented for evaluating the cellular viability. The results indicated that the cytotoxicity for MWCNTs on the human alveolar epithelial cells is related to dose and time of exposure. The inhibitory concentration of 50% (IC50) and non-observed adverse effect concentration (NOAEC) are calculated to be 103.6 as well as 0.65μg/mL, respectively. The findings of this present study could contribute to a better understanding of MWCNTs substances and might be useful as a basis for the future risk evaluation studies of exposed population in industries.

A carbon paste electrode modified with 4-(((4-mercaptophenyl)imino)methyl)benzene-1,2-diol (MIB) and multi-walled carbon nanotubes MIB /CNT/CPE) was prepared for determination of epinefrine (EP) in the presence of acetaminophen (AC). Cyclic voltammetry, chronoamperometry and differential pulse voltammetry (DPV) techniques were used to investigate the modified electrode for the electrocatalytic oxidation of (EP) and (AC) in aqueous solutions. The separation of the oxidation peak potential for EP- AC was 200 mV. Under the optimum conditions, the calibration curve for EP was obtained in the range of 1.0 to 25.0 µM and 25.0 to 500.0 µM. The diffusion coefficient for the oxidation of EP at the surface of modified electrode was calculated as 5.76×10-5 cm2s-1.

Background & Aims of the Study: Azo Dyes are the most hazardous materials in different industries. Dyes and pigments used in industries for applications such as textiles, leathers, papers, foodstuffs, additives, etc. Application amounts of azo dyes in industries which can cause severe health problems in human and environmental pollutant problems. So, color wastewaters decomposition plan are necessary. The purpose of this study, is the application statistical experimental design: photocatalytic decomposition of azo dye Acid Red 14 (AR14) from aqueous solutions using multi walled carbon nanotubes (MWCNTs) particles which was used UV/H2O2 process in photoreactor.
MWCNTs particles as a catalyst used for the degradation of dye in aqueous solution. MWCNTs particles have been characterized by scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier transform infrared (FT-IR). Design of experimental (DOE) based design matrix was exerted for measure the effect of these three factors such as: A) pH, B) catalyst amount and C) H2O2 concentration at two levels. The full factorial experimental design (23) was utilized in this process. The significant effects of each factor and interactions determined using analysis of variance (ANOVA) method. The decomposition kinetic of dye was studied.
The maximum photocatalytic degradation efficiency of dye obtained in this study was found 90.65%, corresponding to the optimal conditions of 3, 30 mg L-1 and 20 ppm respectively, for the pH, catalyst amount and H2O2 concentration. The most effective parameter in the photocatalytic degradation efficiency was H2O2 concentration. The interaction between pH×H2O2 concentration was the most effective interaction. A pseudo first order reaction with a rate constant (k=0.0696 min−1) was observed for the photocatalytic degradation of dye.
The results showed that photodegradation process can be suitable alternative to degradation dyes in aqueous solutions.

Plasmonic photo thermal therapy (PPTT) is a therapeutic method in which the photon energy is rapidly transformed into heat via a series of radiative and non-radiative phenomena to ablate cancer. Plasmonic NPs, such as silver NPs (Ag NPs), have considerable properties in optical absorbance. Furthermore, good thermal conductivity and cell penetration ability of carbon nanotubes (CNTs) could improve the efficacy of Ag NPs for PPTT. Decoration of the multi-walled carbon nanotubes (MWCNTs) with silver has been developed to enhance thermal conductivity of the MWCNT particles.
The Ag NPs were decorated on the CNTs and the ability of these particles (CNT/Ag NPs) in reduction of melanoma tumor size after PTT was evaluated experimentally. For comparison, the PTT of silver nanorods (Ag NRs) and CNTs were investigated. The melanoma tumor was induced by injection of B16/F10 cell line to the inbred mice. Different NPs were injected into the tumors and then irradiated via laser diode (λ=670 nm, P=500 mW, and I= 3.5 W/cm2) at scheduled time.
Monitoring of tumor sizes showed that integration of CNTs with silver could enhance the optical absorption of CNTs and improve tumor destruction in PPTT technique.
The CNT/Ag NPs could act as a potent agent in PPTT method in curing solid tumors.

Anandamide (AEA) has shown a wide spectrum of pharmacological activities including the effects against the peptic ulcer, meanwhile, the poor solubility or short half-life may negatively affect the effectiveness of this valuable cannabinoid. Based on the superior properties of carbon nanotubes (CNTs) for controlled drug delivery, we aimed to prepare AEA-CNTs complex and evaluate its therapeutic potential in an experimental model of gastric ulcer.
Amino-functionalized multi-walled CNTs-AEA (MWCNTs-AEA) complex was prepared using COOH-MWCNTs and then characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. Gastric ulcer was induced by water immersion and restrain stress (WRS) for 3.5 and 6 h in rats and the gastric lesion and oxidative stress were evaluated.
AEA at higher doses reduced the gastric ulcer area and malondialdehyde content and elevated glutathione level and superoxide dismutase and catalase activities after 3.5-h WRS but it was ineffective after 6-h WRS. MWCNTs-AEA complex showed therapeutic effects after both 3.5- and 6-h WRS.
Aminated MWCNTs are suitable carriers for AEA as they provide longer lasting effects for this cannabinoid. The antioxidant mechanism may be involved in the gastroprotective effects of MWCNTs-AEA complex.