Preparation and characterisation of CNF/MWCNT carbon aerogel as efficient adsorbents

In recent years, carbon aerogels have attracted much attention in basic research and as potential applications in many fields. Herein, the authors report a novel approach using bamboo powder as raw material to fabricate cellulose nanofibers (CNFs)/multi‐walled carbon nanotubes (MWCNTs) carbon aerogels by a simple dipping and carbonisation process. The developed material exhibits many exciting properties including low density (0.056 g cm⁻³), high porosity (95%), efficient capability for separation of oily droplets from water, and high adsorption capacity for a variety of oils and organic solvents by up to 110 times its own weight. Furthermore, the CNF/MWCNT carbon aerogels (CMCA) can be recycled many times by distillation and combustion, satisfying the requirements of practical oil‐water separation. Taken together with its economical, environmentally benign manufacturing process, sustainability of the precursor and versatility of material, the CMCA developed in this study will be a promising candidate for addressing the problems arising from the spills of oily compounds.Inspec keywords: aerogels, adsorption, nanofibres, filled polymers, nanocomposites, multi‐wall carbon nanotubes, porosity, drops, distillation, combustion, nanofabrication, polymer fibresOther keywords: CNF‐MWCNT carbon aerogel, adsorbents, bamboo powder, cellulose nanofibers, multiwalled carbon nanotubes, dipping, carbonisation, density, porosity, oily droplets, adsorption capacity, organic solvents, distillation, combustion, practical oil‐water separation, manufacturing process, sustainability, C     

Determination of heavy metals in skin‐whitening cosmetics using microwave digestion and inductively coupled plasma atomic emission spectrometry

In this study, the determination of noxious heavy metals, cadmium (Cd), bismuth (Bi), mercury (Hg), titanium (Ti), lead (Pb) and metalloid arsenic (As) in skin‐whitening cosmetics were examined using microwave digestion and inductively coupled plasma atomic emission spectrometry method. A complete digestion of cosmetics samples was achieved using a mixture of hydrofluoric acid/hydrogen peroxide/nitric acid. The quantification of the target compounds was done by standard addition method. The excellent quality parameters for instance, detection limits, As (4.6 ppb), Bi (7.9 ppb), Cd (0.45 ppb), Hg (3.3 ppb), Pb (3.8 ppb), Ti (4.3 ppb), linearity (r ²  > 0.999) and run‐to‐run and day‐to‐day precisions with relative standard deviations <3% were obtained. The recovery rates for standard reference materials were found between 90 and 105%. The average concentration of heavy metals in cosmetics samples were in the range of 1.0–12.3 (μg g⁻¹, As), 33–7097 (μg g⁻¹, Bi), 0.20–0.6 (μg g⁻¹, Cd), 0.70–2700 (μg g⁻¹, Hg), 1.20–143 (μg g⁻¹, Pb) and 2.0–1650 (μg g⁻¹, Ti).Inspec keywords: cosmetics, atomic emission spectroscopyOther keywords: skin‐whitening cosmetics, microwave digestion, plasma atomic emission spectrometry, noxious heavy metals, cadmium, bismuth, mercury, titanium, lead, metalloid arsenic, hydrofluoric acid, hydrogen peroxide, nitric acid, standard addition method, standard reference materials     

Electrochemical strategy with zeolitic imidazolate framework‐8 and ordered mesoporous carbon for detection of xanthine

An accurate, safe, environmentally friendly, fast and sensitive electrochemical biosensors were developed to detect xanthine in serum. The metal‐organic framework ZIF‐8 was synthesised and elemental gold was supported on the surface of ZIF‐8 by reduction method to synthesise Ag‐ZIF‐8. The mesoporous carbon material and the synthesised Ag‐ZIF‐8 were, respectively, applied to a glassy carbon electrode to construct biosensors. The constructed biosensor has a good linear relation in the range of 1–280 μmol l⁻¹ of xanthine and the detection limit is 0.167 μmol l⁻¹. The relative standard deviation value in serum samples was <5%, and the recoveries were 96–106%, indicating the good selectivity, stability and reproducibility of this electrochemical biosensor.Inspec keywords: zeolites, electrochemical sensors, voltammetry (chemical analysis), mesoporous materials, biosensors, gold, reduction (chemical), nanosensors, nanofabrication, organic compounds, electrochemical electrodes, carbon, nanoparticlesOther keywords: xanthine, detection limit, serum samples, zeolitic imidazolate framework‐8, sensitive electrochemical biosensors, metal‐organic framework ZIF‐8, elemental gold, reduction method, mesoporous carbon material, glassy carbon electrode, linear relation, ordered mesoporous carbon, Ag, C     

Photothermal inactivation of methicillin‐resistant Staphylococcus aureus : anti‐biofilm mediated by a polypyrrole–carbon nanocomposite

Widespread resistance to antibiotics amongst pathogens has become a tremendous challenge of high morbidity and mortality rates which increases the needs to exploring novel methods of treatment. An efficient antimicrobial procedure to root out pathogenic bacteria is photothermal therapy. In this study, antimicrobial effects of a polypyrrole–carbon nanocomposite (PPy‐C) upon laser irradiation in order to destroy the pathogenic gram‐positive bacterium, methicillin‐resistant Staphylococcus aureus (MRSA) were assessed. The bacterial cells were incubated with 500, 750 and 1000 μg ml⁻¹ concentrations of PPy‐C and irradiated with an 808‐nm laser at a power density of 1.0 W cm⁻². To indicate the biocompatibility and toxic effect of the nanocomposite without and with laser irradiation, the authors counted the number of CFUs and compared it to an untreated sample. Antibacterial mechanisms of PPy‐C were assessed through temperature increment, reactive oxygen species production, and protein and DNA leakages. Photothermal heating assay showed that 26°C temperature increases in the presence of 1000 µg ml⁻¹ PPy‐C led to >98% killing of MRSA. Furthermore, 20 min radiation of near‐infrared light to PPy‐C in different concentrations indicated destruction and reduction in the MRSA biofilm formation. Therefore, PPy‐C was introduced as a photothermal absorber with a bactericidal effect in MRSA.Inspec keywords: laser applications in medicine, biomedical materials, DNA, nanofabrication, biochemistry, nanocomposites, microorganisms, nanomedicine, cellular biophysics, antibacterial activity, molecular biophysics, proteinsOther keywords: photothermal inactivation, staphylococcus aureus, anti‐biofilm, polypyrrole–carbon nanocomposite, widespread resistance, bacterial pathogens, high morbidity, mortality rates, efficient antimicrobial procedure, pathogenic bacteria, photothermal therapy, antimicrobial effects, PPy‐C, laser irradiation, pathogenic gram‐positive bacterium, bacterial cells, biocompatibility, toxic effect, reactive oxygen species production, photothermal heating assay, MRSA biofilm formation, photothermal absorber, bactericidal effect, methicillin‐resistance, temperature 26.0 degC, time 20.0 min     

Antibacterial,anti‐inflammatory and antioxidant effects of acetyl‐11‐α‐keto‐β‐boswellic acid mediated silver nanoparticles in experimental murine mastitis

Mastitis is an important economic disease causing production losses in dairy industry. Antibiotics are becoming ineffective in controlling mastitis due to the emergence of resistant strains requiring the development of novel therapeutic agents. In this study, the authors present the phytochemical synthesis of silver nanoparticles (AgNPs) with acetyl‐11‐α‐keto‐β‐boswellic acid and evaluation of their activity in Staphylococcus aureus induced murine mastitis. Boswellic acid mediated AgNP (BANS) were oval, polydispersed (99.8 nm) with an minimum inhibitory concentration of 0.033 µg ml⁻¹ against S. aureus, inhibitory concentration (IC₅₀) of 30.04 µg ml⁻¹ on mouse splenocytes and safe at an in vivo acute oral dose of 3.5 mg kg⁻¹ in mice. Mastitis was induced in lactating mice by inoculating S. aureus (log₁₀ 5.60 cfu) and treated 6 h post‐inoculation with BANS (0.12 mg kg⁻¹, intramammary and intraperitoneal), and cefepime (1 mg kg⁻¹, intraperitoneal). S. aureus inoculated mice showed increased bacterial load, neutrophil infiltration in mammary glands and elevated C‐reactive protein (CRP) in serum. Oxidative stress was also observed with elevated malondialdehyde level, superoxide dismutase (SOD) and catalase (CAT) activities. BANS treatment significantly (P  < 0.05) reduced bacterial load, CRP, SOD, CAT activities and neutrophil infiltration in affected mammary glands. BANS could be a potential therapeutic agent for managing bovine mastitis.Inspec keywords: nanomedicine, nanoparticles, silver, antibacterial activity, drugs, diseases, enzymesOther keywords: antibacterial effects, antiinflammatory effects, antioxidant effects, acetyl‐11‐α‐keto‐β‐boswellic acid, mediated silver nanoparticles, experimental murine mastitis, economic disease, dairy industry, resistant strains, phytochemical synthesis, Staphylococcus aureus, minimum inhibitory concentration, inoculating S. aureus, neutrophil infiltration, mammary glands, elevated C‐reactive protein, superoxide dismutase, catalase, bovine mastitis, Ag     

Biogenic synthesis and thermo‐magnetic study of highly porous carbon nanotubes

Nanomaterials synthesis using natural sources is the technology to up come with advanced materials through extracts of plant, microorganisms, poultry waste etc. In this study, the authors report the synthesis of porous carbon nanotubes using high‐temperature decomposition technique facilitated by cobalt salt using chicken fats, a poultry waste as a precursor. Since chicken fats contain fatty acids which can decompose into short hydrocarbon chains and cobalt can act as the catalyst. The formation of carbon nanotubes was confirmed by Raman spectra, peaks at 1580 and 1350.46 cm⁻¹ confirmed the graphite mode G‐band and structural imperfections defect mode D‐band, respectively. Transmission electron microscopy showed the formation of tube‐like structures. Nitrogen adsorption–desorption studies showed the high‐surface area of 418.1 m² g⁻¹ with an estimated pore diameter of 8.1 nm. Thermogravimetry analysis–derivative thermogravimetric analysis–differential thermal analysis showed the instant weight loss at 517°C attributed to the rapid combustion of nanotubes. A vibrating‐sample magnetometer showed the paramagnetic nature of the so‐formed carbon nanotubes formed.Inspec keywords: transmission electron microscopy, infrared spectra, nanomagnetics, pyrolysis, decomposition, adsorption, desorption, carbon nanotubes, differential thermal analysis, thermal analysis, nanofabrication, Raman spectra, X‐ray diffraction, scanning electron microscopy, paramagnetic materialsOther keywords: biogenic synthesis, highly porous carbon nanotubes, microorganisms, high‐temperature decomposition technique, cobalt salt, chicken fats, fatty acids, short hydrocarbon chains, Raman spectra, graphite mode G‐band, structural imperfections defect mode D‐band, transmission electron microscopy, paramagnetic nature, thermo‐magnetic properties, poultry waste, nitrogen adsorption‐desorption studies, thermogravimetry analysis, differential thermal analysis, carbon nanotubes, temperature 517.0 degC, C     

Preparation of alginate oligosaccharide nanoliposomes and an analysis of their inhibitory effects on Caco‐2 cells

The conditions were optimised for preparing Alginate oligosaccharide (AOS) nanoliposomes, and Caco‐2 cell experiments were carried out to examine their antitumour effects. The optimal formulation of AOS nanoliposomes was as follows: a phosphatidylcholine‐to‐cholesterol ratio of 5.12, AOS concentration of 8.44 mg/mL, Tween 80 concentration of 1.11%, and organic phase to aqueous phase ratio of 5.25. Under the above conditions, the experimental encapsulation efficiency was 65.84%, and the AOS nanoliposomes exhibited a small particle size of 323 nm. After Caco‐2 cells were treated with AOS liposomes and AOS for 24 h, AOS nanoliposomes inhibited the growth of Caco‐2 cells to a greater extent than AOS at concentrations of 0.0625, 0.125, 0.25, 0.5 and 1 mg/mL (P  <  0.01). LDH leakage exhibited a concentration‐dependent increase following treatment with 0.5‐1 mg/mL AOS nanoliposomes, and the inhibitory effect of AOS nanoliposomes exhibited a more significant difference than AOS (P  <  0.01). Cells treated with 0.5 mg/mL and 1 mg/mL AOS nanoliposomes displayed a substantial and significant increase in activity compared with AOS (P  < 0.01). Based on these results, AOS nanoliposomes exerted a more significant effect on inhibiting Caco‐2 cell proliferation than AOS.Inspec keywords: evaporation, cellular biophysics, biomedical materials, biomembranes, nanomedicine, enzymes, biochemistry, drug delivery systems, particle size, response surface methodology, molecular biophysics, encapsulation, drugs, lipid bilayers, nanofabrication, materials preparation, polymers, nanostructured materialsOther keywords: reverse‐phase evaporation method, response surface methodology, alginate oligosaccharide nanoliposomes, mitochondrial function, AOS concentration, AOS liposomes, Caco‐2 cell proliferation, AOS nanoliposomes, methyl thiazolyl tetrazolium assay, cell counting kit‐8, lactate dehydrogenase, LDH assay, phosphatidylcholine‐to‐cholesterol ratio, size 323.0 nm, time 24.0 hour     

Formulation and characterisation of a self‐nanoemulsifying drug delivery system of amphotericin B for the treatment of leishmaniasis

This study was aimed to develop a self‐nanoemulsifying drug delivery system (SNEDDS) for amphotericin B (AmB) potential use in leishmaniasis through topical and oral routes. Two formulations, formulation A and formulation B (FA and FB) of AmB loaded SNEDDS were developed by mixing their excipients through vortex and sonication. The SNEDDS formulation FA and FB displayed a mean droplet size of 27.70 ± 0.5 and 30.17 ± 0.7 nm and zeta potential −11.4 ± 3.25 and −13.6 ± 2.75 mV, respectively. The mucus permeation study showed that formulation FA and FB diffused 1.45 and 1.37%, respectively in up to 8 mm of mucus. The cell permeation across Caco‐2 cells monolayer was 10 and 11%, respectively. Viability of Caco‐2 cells was 89% for FA and 86.9% for FB. The anti‐leishmanial activities of FA in terms of IC₅₀ were 0.017 µg/ml against promastigotes and 0.025 µg/ml against amastigotes, while IC₅₀ values of FB were 0.031 and 0.056 µg/ml, respectively. FA and FB killed macrophage harboured Leishmania parasites in a dose‐dependent manner and a concentration of 0.1 µg/ml killed 100% of the parasites. These formulations have the potential to provide a promising tool for AmB use through oral and topical routes in leishmaniasis therapy.Inspec keywords: nanomedicine, drops, microorganisms, electrokinetic effects, cellular biophysics, drug delivery systems, monolayers, drugs, diseasesOther keywords: self‐nanoemulsifying drug delivery system, topical routes, oral routes, SNEDDS formulation, mucus permeation study, cell permeation, leishmaniasis treatment, amphotericin B, zeta potential, Caco‐2 cell monolayer, vortex, sonication, droplet size, Caco‐2 cell viability, antileishmanial activity, promastigotes, amastigotes, Leishmania parasites     

Facile synthesis of multi‐walled carbon nanotube via folic acid grafted nanoparticle for precise delivery of doxorubicin

The motive of work was to develop a multi‐walled carbon nanoplatform through facile method for transportation of potential anticancer drug doxorubicin (DOX). Folic acid (FA)‐ethylene diamine (EDA) anchored and acid functionalised MWCNTs were covalently grafted with DOX via π–π stacking interaction. The resultant composite was corroborated by ¹ H NMR, FTIR, XRD, EDX, SEM, and DSC study. The drug entrapment efficiency of FA‐conjugated MWCNT was found high and stability study revealed its suitability in biological system. FA‐EDA‐MWCNTs‐DOX conjugate demonstrated a significant in vitro anticancer activity on human breast cancer MCF‐7 cells. MTT study revealed the lesser cytotoxicity of folate‐conjugated MWCNTs. The obtained results demonstrated the targeting specificity of FA‐conjugate via overexpressed folate receptor deemed greater scientific value to overcome multidrug protection during cancer therapy. The proposed strategy is a gentle contribution towards development of biocompatible targeted drug delivery and offers potential to address the current challenges in cancer therapy.Inspec keywords: toxicology, nanoparticles, biomedical materials, scanning electron microscopy, drug delivery systems, nanofabrication, nanomedicine, nanocomposites, cellular biophysics, cancer, drugs, multi‐wall carbon nanotubes, Fourier transform infrared spectra, X‐ray chemical analysis, differential scanning calorimetry, proton magnetic resonance, organic compoundsOther keywords: facile synthesis, multiwalled carbon nanotube, precise delivery, multiwalled carbon nanoplatform, drug entrapment efficiency, FA‐conjugated MWCNT, stability study, biological system, human breast cancer MCF‐7 cells, MTT study, folate‐conjugated MWCNTs, overexpressed folate receptor, cancer therapy, biocompatible targeted drug delivery, anticancer drug doxorubicin, π‐π stacking interaction, composite material, ¹ H NMR, in vitro anticancer activity, folic acid grafted nanoparticle, folic acid‐ethylene diamine, acid functionalised MWCNT, FTIR spectra, XRD, EDX, SEM, FA‐EDA‐MWCNT‐DOX conjugate, cytotoxicity, DSC, C     

Engineering molecular communications integrated with carbon nanotubes in neural sensor nanonetworks

There have been recent advances in the engineering of molecular communication (MC)‐based networks for nanomedical applications. However, the integration of MC with biomaterials such as carbon nanotubes (CNTs) presents various critical research challenges. In this study, the authors envisaged integrating MC‐based nanonetwork with CNTs to optimise nanonetwork performance. In neural networks, a chronic reduction in the concentration of the neurotransmitter acetylcholine (ACh) eventually leads to the development of neurodegenerative diseases; therefore, they used CNTs as a molecular switch to optimise ACh conductivity supported by artificial MC. Furthermore, MC enables communication between transmitter neurons and receiver neurons for fine‐tuning the ACh release rate according to the feedback concentration of ACh. Subsequently, they proposed a min/max feedback scheme to fine‐tune the expected throughput and ACh transmission efficiency. For demonstration purposes, they deduced analytical forms for the proposed schemes in terms of throughput, incurred traffic rates, and average packet delay.Inspec keywords: carbon nanotubes, cellular biophysics, diseases, feedback, nanomedicine, nanosensors, neural nets, neurophysiologyOther keywords: carbon nanotubes, neural sensor nanonetworks, nanomedical applications, biomaterials, molecular communication‐based nanonetwork, neural networks, neurotransmitter acetylcholine, neurodegenerative diseases, transmitter neurons, receiver neurons     

Fluorescein isothiocyanate‐dyed mesoporous silica nanoparticles for tracking antioxidant delivery

This study investigated the cellular uptake of fluorescein isothiocyanate‐labelled mesoporous silica nanoparticles (FITC‐MSNs), amine‐functionalised FITC‐MSNs (AP‐FITC‐MSNs) and their gallic acid (GA)‐loaded counterparts. Mesoporous silica nanoparticles were labelled with fluorescein isothiocyanate, functionalised by 3‐aminopropyltriethoxysilane (APTES) (AP‐FITC‐MSNs) and then loaded by GA. All nanoparticles were characterised by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X‐ray diffraction. The cytotoxicity of different concentrations of dyed nanoparticles was investigated using (3‐(4,5‐trihydroxybenzoic acid, dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay and flow cytometry. TEM images showed that the average particle sizes of FITC‐MSNs and AP‐FITC‐MSNs were about 100 and 110 nm, respectively. These nanoparticles were internalised by Caco‐2 cells, accumulated and dispersed into the cytoplasm, nucleus, and subcellular organelles. Nanoparticles containing GA clearly decreased the viability of cells. FITC‐MSNs showed no toxicity on Caco‐2 cells at concentrations of ≤50 µg/ml. Functionalisation of FITC‐MSNs using APTES decreased toxicity effects on the cells. It was found that FITC‐MSNs can be applied at low concentrations as a marker in the cells. In addition, AP‐FITC‐MSNs showed better biocompatibility with Caco‐2 cells than FITC‐MSNs, because of their positive surface charges.Inspec keywords: mesoporous materials, porosity, nanoparticles, dyes, silicon compounds, nanocomposites, nanofabrication, nanomedicine, cellular biophysics, molecular biophysics, biochemistry, transmission electron microscopy, Fourier transform infrared spectra, X‐ray diffraction, toxicology, particle size, biomedical materials, surface charging, cancerOther keywords: fluorescein isothiocyanate‐dyed mesoporous silica nanoparticles, antioxidant delivery tracking, cellular uptake, amine‐functionalised FITC‐MSNs, gallic acid‐loaded counterparts, 3‐aminopropyltriethoxysilane, transmission electron microscopy, TEM, Fourier transform infrared spectroscopy, X‐ray diffraction, cytotoxicity, dyed nanoparticles, (3‐(4,5‐trihydroxybenzoic acid‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay, flow cytometry, particle sizes, AP‐FITC‐MSNs, Caco‐2 cells, cytoplasm, subcellular organelles, cell viability, biocompatibility, positive surface charges, SiO₂      

Catalytic degradation of methylene blue by biosynthesised copper nanoflowers using F. benghalensis leaf extract

This study reports the unprecedented, novel and eco‐friendly method for the synthesis of three‐dimensional (3D) copper nanostructure having flower like morphology using leaf extract of Ficus benghalensis. The catalytic activity of copper nanoflowers (CuNFs) was investigated against methylene blue (MB) used as a modal dye pollutant. Scanning electron micrograph evidently designated 3D appearance of nanoflowers within a size range from 250 nm to 2.5 μm. Energy‐dispersive X‐ray spectra showed the presence of copper elements in the nanoflowers. Fourier‐transform infrared spectra clearly demonstrated the presence of biomolecules which is responsible for the synthesis of CuNFs. The catalytic activity of the synthesised CuNFs was monitored by ultraviolet–visible spectroscopy. The MB was degraded by 72% in 85 min on addition of CuNFs and the rate constant (k) was found to be 0.77 × 10⁻³ s⁻¹. This method adapted for synthesis of CuNFs offers a valuable contribution in the area of nanomaterial synthesis and in water research by suggesting a sustainable and an alternative route for removal of toxic solvents and waste materials.Inspec keywords: catalysis, dyes, nanostructured materials, nanofabrication, scanning electron microscopy, X‐ray chemical analysis, copper, Fourier transform infrared spectra, visible spectra, ultraviolet spectra, molecular biophysicsOther keywords: catalytic degradation, methylene blue, biosynthesised copper nanoflowers, F. benghalensis leaf extract, three‐dimensional copper nanostructure synthesis, 3D copper nanostructure synthesis, flower like morphology, Ficus benghalensis leaf extract, modal dye pollutant, electron micrograph, 3D appearance, energy‐dispersive X‐ray spectra, copper elements, Fourier‐transform infrared spectra, biomolecules, ultraviolet‐visible spectroscopy, toxic solvent removal, waste materials, size 250 nm to 2.5 mum, Cu     

Facile synthesis of gold nanoparticles using carbon dots for electrochemical detection of neurotransmitter,dopamine in human serum and as a chemocatalyst for nitroaromatic reduction

Herein, the authors reported a carbon dots mediated synthesis of gold nanoparticles (AuNPs) at room temperature. Transmission electron microscopy revealed that the AuNPs are spherical in shape with a size of 10 nm. As‐prepared AuNPs was immobilised on carbon paste electrode and subjected to electrochemical sensing of an important neurotransmitter dopamine. Differential pulse voltammetry studies revealed sensitive and selective determination of dopamine in the presence of commonly interfering ascorbic acid and uric acid. The linear detection range was 10–600 μM and the limit of detection was 0.7 ± 0.18 μM. The practical application was demonstrated by measuring dopamine in human blood serum and urine samples. The catalytic activity of AuNPs was evaluated by sodium borohydride mediated reduction of nitroaromatic compounds. The reduction kinetics was found to be pseudo‐first‐order kinetics. All the tested nitroaromatics reduced to corresponding amines in <10 min.Inspec keywords: voltammetry (chemical analysis), electrochemical sensors, biosensors, nanosensors, reduction (chemical), organic compounds, nanofabrication, gold, catalysis, transmission electron microscopy, electrochemical electrodes, blood, nanoparticles, carbon, chemical variables measurement, catalysts, particle sizeOther keywords: nitroaromatic compounds, reduction kinetics, gold nanoparticles, chemocatalyst, nitroaromatic reduction, carbon dots mediated synthesis, room temperature, transmission electron microscopy, carbon paste electrode, electrochemical sensing, ascorbic acid, uric acid, linear detection range, human blood serum, urine samples, sodium borohydride mediated reduction, neurotransmitter dopamine, differential pulse voltammetry, catalytic activity, pseudofirst‐order kinetics, amines, temperature 293 K to 298 K, C‐Au     

High‐performance immunosensor for urine albumin using hybrid architectures of ZnO nanowire/carbon nanotube

In this work, the authors reported the hybrid architecture of carbon nanotube (CNT)–zinc oxide (ZnO) nanowire as a multi‐functional probe in amperometric immunosensor for the detection of urine albumin. Low‐cost substrate such as glass is possible because of novel low‐temperature growth process of CNT/ZnO nanowires as a multi‐function electrode in this sensor. Based on Schottky like behaviour this structure exhibit excellent high current density to achieve higher performance. Measurement of urine albumin is a new way for early detection of diabetic and also low concentration of it in culture media is also considered in order to verify the conversion of stem cells to liver cells. Human albumin serum antibody is used as a selective and sensitive part. The amperometric performance of immunosensor is studied and showed excellent performance for detection of albumin in urine samples. Very high linear range (from 3.3 ng/µl to 3.3 mg/µl) with a correlation coefficient of 0.825 and low detection limit (3.3 ng/µl or 4.96 × 10⁻⁸ mol l⁻¹) are the main characteristics of this sensor. Due to the high dynamic range and sensitivity, this sensor was also used in medical diagnosis and biomedical applications.Inspec keywords: biosensors, zinc compounds, wide band gap semiconductors, nanosensors, nanowires, carbon nanotubes, amperometric sensors, II‐VI semiconductors, electrochemical electrodes, Schottky effect, current density, chemical variables measurementOther keywords: amperometric immunosensor, low‐temperature growth process, current density, multifunction electrode probe, nanowire‐carbon nanotube architectures, CNT, human albumin serum antibody detection, Schottky like behaviou, urine albumin measurement, diabetic detection, stem cell conversion, liver cell conversion, medical diagnosis, biomedical applications, ZnO‐C     

Photo‐stimulatory effect of LLLT on the proliferation rate of human monocytic leukaemia cells

Low‐level laser therapy (LLLT) is a form of phototherapy used to promote cell proliferation. This study investigates the potential role of LLLT in cellular proliferation of human monocytic leukaemia cells Tamm‐Horsfall Protein 1 (THP‐1) under in vitro conditions. Cells were irradiated with an 850 nm diode laser and exposed to doses ranging from 0 to 26.8 J/cm². After irradiation, cells were incubated for 12 and 24 h to allow time for proliferation. Comet assay was conducted to evaluate genotoxicity of the irradiated cells. Trypan blue was used to estimate cytotoxicity, which peaked at the highest dose as expected. Preliminary results suggest that cell counts increase at low doses, whereas a decrease in cell number at high doses was noted compared with controls. Comet assay showed no significant difference between irradiated and non‐irradiated cells at low doses. In contrast, DNA damage increased at doses ≥8.9 J/cm² and was comparable with the 100 μM hydrogen peroxide positive control at the highest fluence. It could be concluded that LLLT has the ability to stimulate the THP‐1 cell line to proliferate if supplied with the correct energy and dose.Inspec keywords: photodynamic therapy, laser applications in medicine, cellular effects of radiation, biological effects of laser radiation, DNA, diseases, semiconductor lasersOther keywords: photo‐stimulatory effect, LLLT, human monocytic leukaemia cells, cell proliferation rate, low‐level laser therapy, phototherapy, THP‐1, Comet assay, Trypan blue, cytotoxicity, DNA damage, wavelength 850 nm, time 12 h, time 24 h     

Green preparation of seaweed‐based silver nano‐liquid for cotton pathogenic fungi management

Silver nanoparticles (Ag NPs) were synthesised using the crude ethyl acetate extracts of Ulva lactuca and evaluated their bioefficacy against two crop‐damaging pathogens. The sets of lattice planes in the XRD spectrum for the Ag NPs were indexed to the 111, 200, 220 and 311 orientations and support the crystalline nature of the Ag NPs. The 3414 and 2968 cm⁻¹ peaks were observed in crude algal thallus extract and they were characteristic of terpenoids. Further, a peak at 1389 cm⁻¹ was observed as fatty acids. The marine macroalgae terpenoids and palmitic acid acted as reducing agent and stabiliser, respectively. The size (3 and 50 nm) and shape (spherical) of Ag NPs were recorded. The energy‐dispersive X‐ray spectroscopy analysis exemplified the presence of silver in its elemental nature. Moreover, U. lactuca Ag NPs were effective against two cotton phytopathogens namely Fusarium oxysporum f.sp. vasinfectum (FOV) and Xanthomonas campestris pv. malvacearum (XAM). The minimum inhibitory concentration was found to be 80.0 and 43.33 μg ml⁻¹ against FOV and XAM, respectively. Results confirmed the anti‐microbial activity of green nanoparticles against select pathogens and suggest their possible usage in developing antifungal agents for controlling destructive pathogens in a cotton agroecosystem.Inspec keywords: nanoparticles, biotechnology, antibacterial activity, silver, microorganisms, X‐ray chemical analysis, crops, X‐ray diffraction, cottonOther keywords: crude ethyl acetate extracts, crop‐damaging pathogens, lattice planes, XRD spectrum, crystalline nature, crude algal thallus, fatty acids, marine macroalgae terpenoids, palmitic acid, energy‐dispersive X‐ray spectroscopy analysis, elemental nature, cotton phytopathogens, green nanoparticles, destructive pathogens, cotton agroecosystem, green preparation, seaweed‐based silver nanoliquid, cotton pathogenic fungi management, silver nanoparticles, Ag NP, Ag     

Objective measurement of isoniazid levels: practical approach for monitoring tuberculosis drug treatment adherence

Drug treatment adherence is one of the biggest issues in tuberculosis (TB) treatment. Including DOTS (Directly Observed Treatment, Short‐course) program, many programs for TB cases have yielded marginal success and the new drug resistance varieties of TB persist. During the 1960s, researchers have projected naphthoquinone–mercuric chloride (N‐M) test as the single most way to objectively track the presence of isoniazid (INH) in urine and hence treatment adherence. INH is metabolised by cytochrome P450s and usually cleared from body within 8 h. Hence, the typical INH levels in biological fluids are within 1–5 μg/ml. The N‐M test practically works at 10–50 μg/ml and the authors developed the sodium polyacrylate (SPA) as a solid surface to improve detection limit of INH by 6–10 fold. The modification involves absorbing the reagents of N‐M test on the SPA surface and lyophilised material is directly used for diagnosis. The dry beads can detect 1–2 μg/ml of INH in saliva. The test performed with spiked as well as clinical samples and the results have good correlation. This new test has a realistic chance of tracking the TB treatment adherence remotely and in that direction a system was projected for implementation.Inspec keywords: biochemistry, diseases, drugs, patient treatment, proteins, molecular biophysicsOther keywords: objective isoniazid level measurement, tuberculosis drug treatment adherence monitoring, DOTS, directly observed treatment short‐course program, naphthoquinone‐mercuric chloride test, urine, cytochrome P450s, biological fluids, sodium polyacrylate, lyophilisation, metabolism, saliva, medical diagnosis, mycobacterium TB treatment adherence     

Low auto‐fluorescence fabrication methods for plastic nanoslits

Plastic nanofluidic devices are becoming increasingly important for biological and chemical applications. However, they suffer from high auto‐fluorescence when used for on‐chip optical detection. In this study, the auto‐fluorescence problem of plastic nanofluidic devices was remedied by newly developed fabrication methods that minimise their auto‐fluorescence: one by depositing a gold (Au) layer on them, the other by making them ultra‐thin. In the first method, the Au layer [minimum thickness is 40 nm on 150 μm SU‐8, 50 nm on 1 mm polyethylene terephthalate (PET), and 40 on 2 nm polymethyl methacrylate (PMMA)] blocks the auto‐fluorescence of the polymer; in the second method, auto‐fluorescence is minimised by making the chips ultra‐thin, selected operating thickness of SU‐8 is 20 μm, for PET it is 150 μm, and for PMMA it is 0.8 mm.Inspec keywords: nanofluidics, nanofabrication, plastics, optical sensors, nanosensors, biological techniques, gold, biosensorsOther keywords: autofluorescence fabrication methods, plastic nanoslits, plastic nanofluidic devices, biological applications, chemical applications, on‐chip optical detection, gold layer, SU‐8, polyethylene terephthalate, size 20 mum, size 150 mum, size 0.8 mm, Au     

In vitro antibacterial activity of ceftazidime,unlike ciprofloxacin,improves in the presence of ZnO nanofluids under acidic conditions

The development of antibiotic resistance among hospital pathogens has provided a great need for new antimicrobial agents. Zinc oxide nanoparticles (ZnO NPs) in combination with various antibiotics can act as a reducing agent for antibiotic resistance. The aim of this study was to investigate the influence and the mechanism of ZnO NPs on the antimicrobial activity of ciprofloxacin (CP) and ceftazidime (CAZ) against Enterococcus faecalis (E. faecalis) and Acinetobacter baumannii (A. baumannii) bacteria in acidic conditions (pH 5.5). ZnO NPs were synthesised using the solvothermal method and characterised. The MIC90 value of ZnO NPs against A. baumannii was 0.25 mg ml⁻¹ and its highest growth‐inhibitory activity was observed at 0.125 mg ml⁻¹ for E. faecalis. The Fourier transform infrared spectroscopy spectra of ZnO NPs treated with antibiotics showed the interaction between ZnO NPs and each of the two antibiotics. ZnO NPs at a sub‐inhibitory concentration had no effect on the antibacterial activity of CP and CAZ against E. faecalis and CP against A. baumannii. The action mechanism of ZnO NPs for enhancing the antibacterial efficacy of CAZ against A. baumannii was evaluated. ZnO NPs caused to increase in the antibacterial activity of CAZ against A. baumannii, possibly through the release of Zn²⁺ and increasing of membrane permeability.Inspec keywords: nanofluidics, antibacterial activity, drugs, nanoparticles, nanomedicine, microorganisms, pH, zinc compounds, II‐VI semiconductors, wide band gap semiconductors, semiconductor growth, X‐ray diffraction, light scattering, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, ultraviolet spectra, visible spectra, DNA, molecular biophysics, biochemistry, atomic absorption spectroscopy, membranes, permeability, nanofabricationOther keywords: in vitro antibacterial activity, ceftazidime, nanofluids, acidic conditions, antibiotic resistance, hospital pathogens, antimicrobial agents, zinc oxide nanoparticles, reducing agent, antimicrobial activity, ciprofloxacin, Enterococcus faecalis bacteria, Acinetobacter baumannii bacteria, pH, solvothermal method, X‐ray diffraction, dynamic light scattering, ultraviolet‐visible spectrum, scanning electron microscopy, transmission electron microscopy, MIC90 value, growth‐inhibitory activity, Fourier transform infrared spectroscopy, subinhibitory concentration, reactive oxygen species measurement, DNA fragmentation, atomic absorption spectroscopy, SEM, membrane permeability, glycerol‐ammonium citrate. mixture, ZnO     

Efavirenz oral delivery via lipid nanocapsules: formulation,optimisation, and ex‐vivo gut permeation study

Present investigation aimed to prepare, optimise, and characterise lipid nanocapsules (LNCs) for improving the solubility and bioavailability of efavirenz (EFV). EFV‐loaded LNCs were prepared by the phase‐inversion temperature method and the influence of various formulation variables was assessed using Box–Behnken design. The prepared formulations were characterised for particle size, polydispersity index (PdI), zeta potential, encapsulation efficiency (EE), and release efficiency (RE). The biocompatibility of optimised formulation on Caco‐2 cells was determined using 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay. Then, it was subjected to ex‐vivo permeation using rat intestine. EFV‐loaded LNCs were found to be spherical shape in the range of 20–100 nm with EE of 82–97%. The best results obtained from LNCs prepared by 17.5% labrafac and 10% solutol HS15 when the volume ratio of the diluting aqueous phase to the initial emulsion was 3.5. The mean particle size, zeta potential, PdI, EE, drug loading%, and RE during 144 h of optimised formulation were confirmed to 60.71 nm, −35.93 mV, 0.09, 92.60, 7.39 and 55.96%, respectively. Optimised LNCs increased the ex vivo intestinal permeation of EFV when compared with drug suspension. Thus, LNCs could be promising for improved oral delivery of EFV.Inspec keywords: biomedical materials, solubility, drugs, encapsulation, emulsions, nanoparticles, particle size, nanofabrication, suspensions, toxicology, nanomedicine, cellular biophysics, lipid bilayers, electrokinetic effects, drug delivery systems, molecular biophysicsOther keywords: ex‐vivo permeation, diluting aqueous phase, mean particle size, zeta potential, drug loading, optimised formulation, ex vivo intestinal permeation, improved oral delivery, efavirenz oral delivery, optimisation, ex‐vivo gut permeation study, solubility, bioavailability, phase‐inversion temperature method, formulation variables, Box–Behnken design, polydispersity index, encapsulation efficiency, Caco‐2 cells, lipid nanocapsules, 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay, EFV‐loaded LNC, drug suspension, size 20.0 nm to 100.0 nm, time 144.0 hour, size 60.71 nm, voltage ‐35.93 mV