Assessment of in‐vivo biocompatibility evaluation of phytogenic gold nanoparticles on Wistar albino male rats

Nanomedicine is an interdisciplinary approach that involves toxicology and other medicinal applications. Gold nanoparticles (AuNPs) may serve as a promising model to address the size and shape‐dependent biological response because they show good biocompatibility. This study is to prepare phytosynthesis AuNPs from ten different Cassia sp. Among them, the aqueous leaf extract of C. roxburghii produced greater efficient and stable AuNPs. The AuNPs were optimised for different physicochemical conditions. Highly stable AuNPs were synthesised at pH 7.0, 37°C, 1.0 ml of C. roxburghii leaf extract and 1.0 mM concentration of HAuCl₄ with the particle size of ∼50 nm and these AuNPs were stable up to 12 months. To determine the safety profile of AuNPs in‐vivo, the nanoparticles were injected intravenously into male Wistar albino rats in varying dosages. The authors noticed no significant difference in body weights, haematological and biochemical parameters and the histopathological sections of all vital organs. Highest accumulation was seen in spleen and least in brain. The authors’ results show that the AuNPs were biocompatible and did not produce any adverse or abnormalities in‐vivo. The implications of the bioaccumulation of AuNPs need to be further studied to rule out any adverse effects on long‐term exposure.Inspec keywords: blood, nanoparticles, cellular biophysics, pH, nanomedicine, particle size, nanofabrication, gold, biomedical materialsOther keywords: in‐vivo biocompatibility evaluation, phytogenic gold nanoparticles, phytosynthesis AuNPs, physicochemical conditions, Wistar albino male rats, nanomedicine, Cassia sp., aqueous leaf extract, C. roxburghii leaf extract, particle size, bioaccumulation, temperature 37.0 degC, Au     

In vitro biological evaluation of anti‐diabetic activity of organic–inorganic hybrid gold nanoparticles

Diabetes mellitus has been considered as a heterogeneous metabolic disorder characterised by complete or relative impairment in the production of insulin by pancreatic β‐cells or insulin resistance. In the present study, propanoic acid, an active biocomponent isolated from Cassia auriculata is employed for the synthesis of propanoic acid functionalised gold nanoparticles (Pa@AuNPs) and its anti‐diabetic activity has been demonstrated in vitro. In vitro cytotoxicity of synthesised Pa@AuNPs was performed in L6 myotubes. The mode of action of Pa@AuNPs exhibiting anti‐diabetic potential was validated by glucose uptake assay in the presence of Genistein (insulin receptor tyrosine kinase inhibitor) and Wortmannin (Phosphatidyl inositide kinase inhibitor). Pa@AuNPs exhibited significant glucose uptake in L6 myotubes with maximum uptake at 50 ng/ml. Assays were performed to study the potential of Pa@AuNPs in the inhibition of protein‐tyrosine phosphatase 1B, α‐glucosidases, and α‐amylase activity.Inspec keywords: molecular biophysics, biomedical materials, sugar, enzymes, nanofabrication, gold, patient treatment, organic‐inorganic hybrid materials, biochemistry, diseases, cellular biophysics, nanoparticles, toxicology, nanomedicineOther keywords: glucose uptake assay, α‐amylase activity, organic–inorganic hybrid gold nanoparticles, diabetes mellitus, heterogeneous metabolic disorder, pancreatic β‐cells, insulin resistance, propanoic acid, antidiabetic potential, antidiabetic activity, in vitro cytotoxicity, L6 myotubes, Genistein, IRTK inhibitor, Wortmannin, P13K inhibitor, protein‐tyrosine phosphatase 1B, α‐glucosidases, Cassia auriculata, Au     

Phyto‐mediated synthesis,biological and catalytic activity studies of gold nanoparticles

In the present study, a phyto‐mediated synthesis of gold nanoparticles (AuNPs) using an isoflavone, Dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone) isolated from the alcoholic extract of roots of Dalbergia coromandeliana is reported. It is observed that Dalspinosin itself acts both as a reducing and a capping agent in the synthesis of the nanoparticles (NPs). An ultraviolet–visible (UV–Vis) spectral study showed a surface plasmon resonance band at 526 nm confirming the formation of AuNPs. The NPs formed were characterised by UV–Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction (XRD), high‐resolution transmission electron microscopy (HR‐TEM) with energy‐dispersive x‐ray spectroscopy (EDX) and dynamic light scattering. HR‐TEM analysis showed the synthesised AuNPs were spherical in shape with a size of 7.5 nm. The AuNPs were found to be stable for seven months when tested by in vitro methods showed good antioxidant and anti‐inflammatory activities. They also showed moderate anti‐microbial activities when tested against Gram positive (Staphylococcus aureus and Streptococcus sp), Gram negative bacterial strains (Klebsiella pneumonia and Klebsiella terrigena) and fungal strain (Candida glabrata). The biosynthesised AuNPs showed significant catalytic activity in the reduction of methylene blue with NaBH₄ to leucomethylene blue.Inspec keywords: biomedical materials, catalysis, Fourier transform infrared spectra, gold, light scattering, microorganisms, nanomedicine, nanoparticles, spectrochemical analysis, surface plasmon resonance, transmission electron microscopy, ultraviolet spectra, visible spectra, X‐ray chemical analysis, X‐ray diffractionOther keywords: phyto‐mediated synthesis, biological activity studies, catalytic activity studies, dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone), alcoholic extract, roots, Dalbergia coromandeliana, ultraviolet‐visible spectral study, surface plasmon resonance band, UV‐Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction, high‐resolution transmission electron microscopy, EDX analysis, dynamic light scattering, HR‐TEM analysis, antioxidant activities, antiinflammatory activities, antimicrobial activities, Gram positive bacterial strains, Staphylococcus aureus, Streptococcus sp, Gram negative bacterial strains, wavelength 526 nm, size 7.5 nm, time 7 month, Au     

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     

Synthesis of silver nanoparticles by Bacillus subtilis T‐1 growing on agro‐industrial wastes and producing biosurfactant

In this study, culture supernatnats of Bacillus subtilis T‐1 growing on brewery effluents and molasses was used for silver nanoparticles (Ag‐NPs) synthesis. The biosurfactant production of B. subtilis T‐1 was confirmed by the detection of genes in the genome and by the identification of the product in the supernatants. The genes for synthesis of surfactin (sfp, srfAA) and iturin (ituC) were noted by PCR reactions. Also, in examined culture supernatants the presence of C₁₃, C₁₄ and C₁₅ surfactin homologues with the sodiated molecules [M + Na]⁺ at m /z 1030, 1044 and 1058 was confirmed using LC/MS/MS analysis. The formation of NPs in the culture supernatants was confirmed by UV–vis spectroscopy. The dynamic light scattering measurements and transmission electron microscopy images showed the nanometric sizes of the biosynthesised Ag‐NPs which ranged from several nm to several tens of nm depending on the used culture supernatant. Biological properties of Ag‐NPs were evaluated by binding of Ag‐NPs with DNA isolated from the Escherichia coli ATCC 25922 and B. subtilis ATCC 6633. Biogenic Ag‐NPs were actively bound to DNA in increased concentration which could be the one important mode of antibacterial action of the Ag‐NPs.Inspec keywords: silver, nanoparticles, nanofabrication, materials preparation, microorganisms, antibacterial activity, industrial waste, agrochemicals, surfactants, breweries, genomics, genetics, chromatography, mass spectroscopic chemical analysis, ultraviolet spectroscopy, visible spectroscopy, spectrochemical analysis, light scattering, transmission electron microscopy, DNA, bonds (chemical), biochemistry, molecular biophysics, nanobiotechnology, biological techniques, particle size, enzymesOther keywords: silver nanoparticle synthesis, Bacillus subtilis T‐1 growth, agro‐industrial waste, biosurfactant production, brewery effluent, molasses, Ag‐NP synthesis, B. subtilis T‐1, gene detection, genome, supernatant product identification, surfactin synthesis, sfp, srfAA, iturin synthesis, ituC, PCR reaction, C₁₃ surfactin homologue, C₁₄ surfactin homologue, C₁₅ surfactin homologue, sodiated molecules, LC‐MS‐MS analysis, UV‐vis spectroscopy, dynamic light scattering measurement, transmission electron microscopy image, Ag‐NP nanometric size range, Ag‐NP biosynthesis, used culture supernatant dependence, biological properties, DNA isolation, Escherichia coli ATCC 25922, B. subtilis ATCC 6633, biogenic Ag‐NP‐DNA binding, Ag‐NP antibacterial action, Ag     

Hepatic histopathological and ultrastructural alterations induced by 10 nm silver nanoparticles

Silver nanoparticles (Ag NPs) are invested in various sectors and are becoming more persistent in our ambient environment with potential risk on our health and the ecosystems. The current study aims to investigate the histological, histochemical and ultrastructural hepatic changes that might be induced by 10 nm silver nanomaterials. Male mice (BALB/C) were exposed for 35 injections of daily dose of 10 nm Ag NPs (2 mg/kg). Liver tissues were subjected to examination by light and electron microscopy for histological, histochemical and ultrastructural alterations. Exposure to Ag NPs induced Kupffer cells hyperplasia, sinusoidal dilatation, apoptosis, ground glass hepatocytes appearance, nuclear changes, inflammatory cells infiltration, hepatocytes degeneration and necrosis. In addition, 10 nm Ag NPs induced histochemical alterations mainly glycogen depletion with no hemosiderin precipitation. Moreover, these nanomaterials exhibited ultrastructure alterations including mitochondrial swelling and cristolysis, cytoplasmic vacuolation, apoptosis, multilammellar myelin figures formation and endoplasmic destruction and reduction. The findings revealed that Ag NPs can induce alterations in the hepatic tissues, the chemical components of the hepatocytes and in the ultrastructure of the liver. One may also conclude that small size Ag NPs, which are increasingly used in human products could cause various toxigenic responses to all hepatic tissue components.Inspec keywords: liver, electron microscopy, molecular biophysics, optical microscopy, toxicology, biochemistry, silver, biological tissues, nanofabrication, cellular biophysics, biomedical materials, nanoparticles, nanomedicineOther keywords: hepatic histopathological alterations, ultrastructural alterations, silver nanoparticles, histological changes, histochemical changes, ultrastructural hepatic changes, silver nanomaterials, male mice, liver tissues, electron microscopy, histological alterations, histochemical alterations, Kupffer cells hyperplasia, sinusoidal dilatation, apoptosis, ground glass hepatocytes appearance, inflammatory cells infiltration, hepatocyte degeneration, necrosis, ultrastructure alterations, Ag, size 10.0 nm, hepatic tissue components, cytoplasmic vacuolation     

Behavioural alterations induced by chronic exposure to 10 nm silicon dioxide nanoparticles

Silicon dioxide nanoparticles (SiO₂ NPs) are widely invested in medicine, industry, agriculture, consuming products, optical imaging agents, cosmetics, and drug delivery. However, the toxicity of these NPs on human health and the ecosystem have not been extensively studied and little information is available about their behavioural toxicities. The current study aimed to find out the behavioural alterations that might be induced by chronic exposure to 10 nm SiO₂ NPs. BALB/C mice were subjected to 36 injections of SiO₂ NPs (2 mg/kg Bw) and subjected to 11 neurobehavioural tests: elevated plus‐maze test, elevated zero‐maze test, multiradial maze test, open field test, hole‐board test, light‐dark box test, forced swimming test, tail‐suspension test, Morris water‐maze test, Y‐maze test and multiple T‐maze test. Treated mice demonstrated anxiety‐like effect, depression tendency, behavioural despair stress, exploration and locomotors activity reduction with error induction in both reference and working memories. The findings may suggest that silica NPs are anxiogenic and could aggravate depression affecting memory, learning, overall activity and exploratory behaviour. Moreover, the findings may indicate that these nanomaterials (NMs) may induce potential oxidative stress in the body leading to neurobehavioural alterations with possible changes in the vital organ including the central nervous system.     

Alleviation of diabetic nephropathy by zinc oxide nanoparticles in streptozotocin‐induced type 1 diabetes in rats

This study examines the effect of nanoparticles with zinc oxides (ZnONPs) on diabetic nephropathy, which is the primary cause of mortality for diabetic patients with end‐stage renal disease. Diabetes in adult male rats was induced via intraperitoneal injection of streptozotocin. ZnONPs were intraperitoneally administered to diabetic rats daily for 7 weeks. Diabetes was associated with increases in blood glucose level, 24‐h urinary albumin excretion rate, glomerular basement membrane thickness, renal oxidative stress markers, and renal mRNA or protein expression of transforming growth factor‐β1, fibronectin, collagen‐IV, tumour necrosis factor‐α and vascular endothelial growth factor‐A. Moreover, the expression of nephrin and podocin, and the mRNA expression of matrix metalloproteinase‐9 were decreased in the diabetic group. These changes were not detected in the control group and were significantly prevented by ZnONP treatment. These results provide evidence that ZnONPs ameliorate the renal damage induced in a diabetic rat model of nephropathy through improving renal functionality; inhibiting renal fibrosis, oxidative stress, inflammation and abnormal angiogenesis; and delaying the development of podocyte injury. The present findings may help design the clinical application of ZnONPs for protection against the development of diabetic nephropathy.     

Biosynthesis of AgNPs using aqueous leaf extract of Ipomoea eriocarpa and their anti‐inflammatory effect on carrageenan‐induced paw edema in male Wistar rats

Silver nanoparticles (AgNPs) were synthesised from aqueous Ag nitrate through a simple, competent and eco‐friendly method using the leaf extract of Ipomoea eriocarpa as reducing as well as capping agent. Ultraviolet–visible absorption spectroscopy was used to confirm the formation of AgNPs which displayed the substantiation of surface plasmon bands at 425 nm. The NPs were also characterised using Fourier transformer infrared spectroscopy, X‐ray diffraction method, transmission electron microscope and zeta potential. The characterisation study confirmed the formation of AgNPs, their spherical shape and average diameter of 12.85 ± 8.65 nm. Zeta potential value of −20.5 mV suggested that the AgNPs are stable in the suspension. The aqueous extract and the AgNPs were further screened for in vivo anti‐inflammatory activity using carrageenan‐induced paw edema in male Wistar rats. The study demonstrated that the AgNPs (1 ml kg⁻¹) had a significant (p  < 0.05) anti‐edemic effect and inhibition was observed from the first hour (21.31 ± 1.34) until the sixth hour (52.67 ± 1.41), when the inhibitory effect was greatest and superior to the aqueous extract and the standard, diclofenac.Inspec keywords: silver, nanoparticles, nanofabrication, ultraviolet spectra, visible spectra, absorption coefficients, surface plasmons, Fourier transform infrared spectra, X‐ray diffraction, transmission electron microscopy, suspensions, drugs, nanomedicineOther keywords: biosynthesis, aqueous leaf extract, ipomoea eriocarpa, antiinflammatory effect, carrageenan‐induced paw edema, male Wistar rats, silver nanoparticles, aqueous nitrate, capping agent, ultraviolet‐visible absorption spectroscopy, surface plasmon band, Fourier transformer infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, zeta potential, spherical shape, suspension, aqueous extract, in vivo antiinflammatory activity, antiedemic effect, inhibitory effect, diclofenac, wavelength 425 nm, size 12.85 nm to 8.65 nm, Ag     

Zinc oxide nanoparticles augment CD4, CD8, and GLUT‐4 expression and restrict inflammation response in streptozotocin‐induced diabetic rats

This study evaluated the biochemical, molecular, and histopathological mechanisms involved in the hypoglycaemic effect of zinc oxide nanoparticles (ZnONPs) in experimental diabetic rats. ZnONPs were prepared by the sol–gel method and characterised by scanning and transmission electron microscopy (SEM and TEM). To explore the possible hypoglycaemic and antioxidant effect of ZnONPs, rats were grouped as follows: control group, ZnONPs treated group, diabetic group, and diabetic + ZnONPs group. Upon treatment with ZnONPs, a significant alteration in the activities of superoxide dismutase, glutathione peroxidase, and the levels of insulin, haemoglobin A1c, and the expression of cluster of differentiation 4+ (CD4+), CD8+ T cells, glucose transporter type‐4 (GLUT‐4), tumour necrosis factor, and interleukin‐6 when compared to diabetic and their control rats. ZnONPs administration to the diabetic group showed eminent blood glucose control and restoration of the biochemical profile. This raises their active role in controlling pancreas functions to improve glycaemic status as well as the inflammatory responses. Histopathological investigations showed the non‐toxic and therapeutic effect of ZnONPs on the pancreas. TEM of pancreatic tissues displayed restoration of islets of Langerhans and increased insulin‐secreting granules. This shows the therapeutic application of ZnONPs as a safe anti‐diabetic agent and to have a potential for the control of diabetes.Inspec keywords: nanoparticles, transmission electron microscopy, cellular biophysics, sugar, nanomedicine, nanofabrication, zinc compounds, molecular biophysics, biochemistry, tumours, enzymes, biomedical materials, biological organs, blood, diseases, patient treatment, II‐VI semiconductors, wide band gap semiconductors, scanning electron microscopy, sol‐gel processing, semiconductor growthOther keywords: molecular mechanisms, histopathological mechanisms, zinc oxide nanoparticles, experimental diabetic rats, hypoglycaemic effect, antioxidant effect, control group, diabetic group, CD4+, CD8+ T cells, glucose transporter type‐4, control rats, GLUT‐4 expression, streptozotocin‐induced diabetic rats, biochemical mechanisms, safe antidiabetic agent, inflammation response, sol‐gel method, transmission electron microscopy, scanning electron microscopy, SEM, TEM, superoxide dismutase, glutathione peroxidase, insulin levels, haemoglobin A1c, differentiation 4+ T cells, tumour necrosis factor, interleukin‐6, blood glucose control, pancreas functions, glycaemic status, therapeutic effect, pancreatic tissues, Langerhans islets, insulin‐secreting granules, ZnO     

Nephroprotective role of nanoencapsulated Tinospora cordifolia (Willd.) using polylactic acid nanoparticles in streptozotocin‐induced diabetic nephropathy rats

Currently, the field of nanomedicine, which uses active compounds from medicinal plants, has emerged as a therapy for diabetic nephropathy. From this study, the renoprotective effect of TC‐loaded PLA Nanoparticles (TC‐PLA NPs) on streptozotocin (STZ)‐induced diabetic nephropathy rats was investigated. The results showed that the nephroprotective effect of TC‐PLA NPs reduces the blood glucose level, regulates the renal parameters, decreases the cytokine levels and reduces the mRNA expressions level of different genes related to diabetic nephropathy.     

Non‐linear feedback control of the p 53 protein–mdm 2 inhibitor system using the derivative‐free non‐linear Kalman filter

It is proven that the model of the p 53–mdm 2 protein synthesis loop is a differentially flat one and using a diffeomorphism (change of state variables) that is proposed by differential flatness theory it is shown that the protein synthesis model can be transformed into the canonical (Brunovsky) form. This enables the design of a feedback control law that maintains the concentration of the p 53 protein at the desirable levels. To estimate the non‐measurable elements of the state vector describing the p 53–mdm 2 system dynamics, the derivative‐free non‐linear Kalman filter is used. Moreover, to compensate for modelling uncertainties and external disturbances that affect the p 53–mdm 2 system, the derivative‐free non‐linear Kalman filter is re‐designed as a disturbance observer. The derivative‐free non‐linear Kalman filter consists of the Kalman filter recursion applied on the linearised equivalent of the protein synthesis model together with an inverse transformation based on differential flatness theory that enables to retrieve estimates for the state variables of the initial non‐linear model. The proposed non‐linear feedback control and perturbations compensation method for the p 53–mdm 2 system can result in more efficient chemotherapy schemes where the infusion of medication will be better administered.Inspec keywords: proteins, molecular biophysics, biochemistry, Kalman filters, inverse problems, perturbation theoryOther keywords: nonlinear feedback control, p53 protein‐mdm2 inhibitor system, derivative‐free nonlinear Kalman filter, differential flatness theory, protein synthesis loop, diffeomorphism, protein synthesis model, feedback control law, nonmeasurable elements, modelling uncertainties, inverse transformation, nonlinear model, perturbation compensation method, chemotherapy schemes, medication infusion     

Characterisation of sol–gel method synthesised MgZnFe2 O4 nanoparticles and its cytotoxic effects on breast cancer cell line,MDA MB‐231 in vitro

In this study, nanocrystalline magnesium zinc ferrite nanoparticles were successfully prepared by a simple sol–gel method using copper nitrate and ferric nitrate as raw materials. The calcined samples were characterised by differential thermal analysis/thermogravimetric analysis, Fourier transform infrared spectroscopy and X‐ray diffraction. Transmission electron microscopy revealed that the average particle size of the calcined sample was in a range of 17–41 nm with an average of 29 nm and has spherical size. A cytotoxicity test was performed on human breast cancer cells (MDA MB‐231) and (MCF‐7) at various concentrations starting from (0 µg/ml) to (800 µg/ml). The sample possessed a mild toxic effect toward MDA MB‐231 and MCF‐7 after being examined with MTT (3‐[4, 5‐dimethylthiazol‐2‐yl]‐2, 5 diphenyltetrazolium bromide) assay for up to 72 h of incubation. Higher reduction of cells viability was observed as the concentration of sample was increased in MDA MB‐231 cell line than in MCF‐7. Therefore, further cytotoxicity tests were performed on MDA MB‐231 cell line.Inspec keywords: sol‐gel processing, nanoparticles, nanofabrication, magnesium compounds, zinc compounds, toxicology, biological organs, cancer, cellular biophysics, nanomedicine, calcination, differential thermal analysis, Fourier transform infrared spectra, X‐ray diffraction, transmission electron microscopy, particle size, organic compoundsOther keywords: sol‐gel method, cytotoxic effects, breast cancer cell line, MDA MB‐231 in vitro, nanocrystalline magnesium zinc ferrite nanoparticles, copper nitrate, ferric nitrate, raw materials, calcined samples, differential thermal analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, average particle size, cytotoxicity testing, human breast cancer cells, mild toxic effect, 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5 diphenyltetrazolium bromide) assay, cell viability, MCF‐7, MDA MB‐231 cell line, size 17 nm to 41 nm     

Determination of the potency of hexyl‐ciprofloxacin molecules that interact with gold nanoparticles in a reversible manner

This work determined the potency of hexyl‐ciprofloxacin molecules that reversibly interact with gold nanoparticles (AuNPs) passivated with 11‐mercaptoundecanoic acid (MUA) on Escherichia coli cells. For this, partition of modified antibiotic between different compartments of the gold colloid was determined using analytical techniques. First, concentration of hexyl‐ciprofloxacin was determined in the continuous phase of the colloid. Subsequently, the colloid was exposed to a volume of organic immiscible solvent and concentration of the transferred molecules was determined in the organic phase. Comparison of the amount of hexyl‐ciprofloxacin in each phase revealed that interaction between molecules and nanoparticles was reversible. Later, this work determined the potency of a population of hexyl‐ciprofloxacin molecules contained in a volume of the colloid, and the potency of other population of molecules that only interact with the continuous phase of the colloid. The absolute difference between these two values was proportional to the potency of a number of molecules that interact with the nanoparticles of the colloid.Inspec keywords: organic compounds, nanoparticles, gold, colloids, microorganisms, molecular biophysics, drug delivery systems, nanomedicineOther keywords: continuous phase, hexyl‐ciprofloxacin molecules, gold nanoparticles, gold colloid, 11‐mercaptoundecanoic acid, Escherichia coli cells, modified antibiotics, RP‐HPLC, organic immiscible solvent, reversible interaction, Au     

Synthesis and comparative assessment of antiradical activity,toxicity, and biodistribution of κ‐carrageenan‐capped selenium nanoparticles of different size: in vivo and in vitro study

In the present study, water‐soluble hybrid selenium‐containing nanocomposites have been synthesised via soft oxidation of selenide‐anions, preliminarily generated from elemental bulk‐selenium in the base‐reduction system ‘N₂ H₄ –NaOH’. The nanocomposites obtained consist of Se⁰ NPs (4.6–24.5 nm) stabilised by κ‐carrageenan biocompatible polysaccharide. The structure of these composite nanomaterials has been proven using complementary physical–chemical methods: X‐ray diffraction analysis, transmission electron microscopy, optical spectroscopy, and dynamic light scattering. Optical ranges of ‘emission/excitation’ of aqueous solutions of nanocomposites with Se⁰ NPs of different sizes are established and the most important parameters of their luminescence are determined. For the obtained nanocomposites, the expressed antiradical activity against free radicals 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid has been found, the value of which depends on the size of selenium nanoparticles. It is experimentally revealed that all obtained nanocomposites are low toxic (LD₅₀ >2000 mg/kg). It is also found that small selenium nanoparticles (6.8 nm), in contrast to larger nanoparticles (24.5 nm), are accumulated in organisms to significantly increase the level of selenium in the liver, kidneys, and brain (in lesser amounts) of rats.Inspec keywords: nanobiotechnology, free radical reactions, oxidation, enzymes, selenium, solubility, nanofabrication, transmission electron microscopy, X‐ray diffraction, free radicals, reduction (chemical), biomedical materials, nanoparticles, nanomedicine, light scattering, organic‐inorganic hybrid materials, biochemistry, nanocompositesOther keywords: κ‐carrageenan biocompatible polysaccharide, composite nanomaterials, complementary physical–chemical methods, X‐ray diffraction analysis, transmission electron microscopy, optical spectroscopy, dynamic light scattering, optical ranges, expressed antiradical activity, 2,2‐diphenyl‐1‐picrylhydrazyl, 3‐ethylbenzothiazoline‐6‐sulphonic acid, comparative assessment, toxicity, κ‐carrageenan‐capped selenium nanoparticles, water‐soluble hybrid selenium‐containing nanocomposites, soft oxidation, selenide‐anions, elemental bulk‐selenium, base‐reduction system, free radicals, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid, selenium nanoparticles, nanocomposites, liver, kidneys, brain, luminescence, size 4.6 nm to 24.5 nm     

Suppression of Transverse Mode Responses in Ultra-Wideband SAW Resonators Fabricated on a Cu-Grating/15°YX-LiNbO 3 Structure

This paper discusses a technique to suppress spurious transverse mode responses appearing in ultra-wideband SAW resonators fabricated on a Cu- grating/15degYX-LiNbO₃ structure. The basic idea of the technique is inserting length- and width-weighted dummy electrodes between a bus-bar and interdigital electrodes. For practical device design, an analysis was made to show how the profile (field distribution) of both dominant and spurious transverse modes depends on the length and width (equivalent to SAW velocity) of the dummy electrodes. IDT-type SAW resonators were fabricated on a Cu- grating/15degYX-LiNbO₃ structure using the length- and width-weighted dummy electrodes. The experimental results were in good agreement with the theoretical analysis and prediction, showing that the proposed technique is effective in suppressing the spurious responses caused by the transverse modes.