Reduced graphene oxide: osteogenic potential for bone tissue engineering

Collagen (Col) type I, as the major component of the bone extracellular matrix has been broadly studied for bone tissue engineering. However,inferior mechanical properties limit its usage for load bearing applications. In this research, freeze dried Col scaffolds are coated with graphene oxide (GO) through a covalent bond of the amine Col with the graphene carboxyl groups. The prepared scaffolds were then reduced using a chemical agent. Scanning electron microscopy exhibited a porous structure for the synthesized scaffolds with an approximate pore size of 100–220 ± 12 µm, which is in the suitable range for bone tissue engineering application. Reducing the GO coating improved the compressive modulus of the Col from 250 to 970 kPa. Apatite formation was also indicated by immersing the scaffolds in simulated body fluid after five days. The cytocompatibility of the scaffolds, using human bone marrow‐derived mesenchymal stem cells, was confirmed with MTT analysis. Alkaline phosphatase assay revealed that reducing the Col–GO scaffolds can effectively activate the differentiation of hBM‐MSCs into osteoblasts after 14 days, even without the addition of an osteogenic differentiation medium. The results of this study highlight that GO and its reduced form have considerable potential as bone substitutes for orthopaedic and dental applications.Inspec keywords: molecular biophysics, tissue engineering, biochemistry, cellular biophysics, graphene, biomedical materials, bone, proteins, scanning electron microscopy, porous materials, compressive strength, biomechanicsOther keywords: human bone marrow‐derived mesenchymal stem cells, reduced graphene oxide, bone extracellular matrix, inferior mechanical properties, load bearing applications, freeze‐dried Col scaffolds, amine Col groups, graphene carboxyl groups, bone tissue engineering, collagen type I, GO‐Col scaffolds, covalent bond, scanning electron microscopy, compressive modulus, apatite formation, cytocompatibility, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide analysis, alkaline phosphatase assay, osteogenic differentiation medium, dental applications, orthopaedic applications, porous structure, time 14.0 day, CO     

Fabrication and characterisation of super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds with the unidirectional porous structure: a physicochemical,mechanical, and in vitro evaluation

Architecture and composition of Scaffolds are influential factors in the regeneration of defects. Herein, synthesised iron oxide (magnetite) nanoparticles (MNPs) by co‐precipitation technique were evenly distributed in polylactic‐co‐glycolic acid (PLGA)–gelatine Scaffolds. Hybrid structures were fabricated by freeze‐casting method to the creation of a matrix with tunable pores. The synthesised MNPs were characterised by transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and vibrating sample magnetometer analysis. Scanning electron microscopy micrographs of porous Scaffolds confirmed the formation of unidirectional microstructure, so that pore size measurement indicated the orientation of pores in the direction of solvent solidification. The addition of MNPs to the PLGA–gelatine Scaffolds had no particular effect on the morphology of the pores, but reduced slightly pore size distribution. The MNPs contained constructs demonstrated increased mechanical strength, but a reduced absorption capacity and biodegradation ratio. Stability of the MNPs and lack of iron release was the point of strength in this investigation and were determined by atomic absorption spectroscopy. The evolution of rat bone marrow mesenchymal stem cells performance on the hybrid structure under a static magnetic field indicated the potential of super‐paramagnetic constructs for further pre‐clinical and clinical studies in the field of neural regeneration.Inspec keywords: transmission electron microscopy, biodegradable materials, nanofabrication, freezing, mechanical strength, tissue engineering, X‐ray diffraction, cellular biophysics, precipitation (physical chemistry), biomedical materials, iron compounds, porosity, scanning electron microscopy, atomic absorption spectroscopy, gelatin, nanoparticles, porous materials, bone, nanocomposites, Fourier transform infrared spectraOther keywords: unidirectional microstructure, pore size measurement, mechanical strength, atomic absorption spectroscopy, hybrid structure, super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds, unidirectional porous structure, tissue engineering Scaffolds, co‐precipitation technique, polylactic‐co‐glycolic acid–gelatine Scaffolds, freeze‐casting method, transmission electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction spectroscopy, scanning electron microscopy micrographs, pore size distribution, absorption capacity, iron oxide nanoparticles, Fe₃ O₄      

Production of a new platform based on fumed and mesoporous silica nanoparticles for enhanced solubility and oral bioavailability of raloxifene HCl

The purpose of the present study was to compare mesoporous and fumed silica nanoparticles (NPs) to enhance the aqueous solubility and oral bioavailability of raloxifene hydrochloride (RH). Mesoporous silica NPs (MSNs) and fumed silica NPs were used by freeze‐drying or spray‐drying methods. MSNs were obtained with different ratios of cetyltrimethylammonium bromide. Saturation solubility of the NPs was compared with the pure drug. The optimised formulation was characterised by scanning electron microscopy (SEM), X‐ray diffraction (XRD) and differential scanning calorimetry. The pharmacokinetic studies were done by oral administration of a single dose of 15 mg/kg of pure drug or fumed silica NPs of RH in Wistar rats. MSNs enhanced the solubility of RH from 19.88 ± 0.12 to 76.5 μg/ml. Freeze‐dried fumed silica increased the solubility of the drug more than MSNs (140.17 ± 0.45 μg/ml). However, the spray‐dried fumed silica caused about 26‐fold enhancement in its solubility (525.7 ± 93.5 μg/ml). Increasing the ratio of silica NPs enhanced the drug solubility. The results of XRD and SEM analyses displayed RH were in the amorphous state in the NPs. Oral bioavailability of NPs showed 3.5‐fold increase compared to the pure drug. The RH loaded fumed silica NPs prepared by spray‐drying technique could more enhance the solubility and oral bioavailability of RH.Inspec keywords: differential scanning calorimetry, mesoporous materials, freezing, nanofabrication, drug delivery systems, silicon compounds, drying, drugs, solubility, spraying, X‐ray diffraction, biomedical materials, scanning electron microscopy, nanoparticles, biochemistry, amorphous state, nanomedicineOther keywords: freeze‐dried fumed silica, spray‐dried, drug solubility, spray‐drying technique, fumed silica nanoparticles, mesoporous silica nanoparticles, aqueous solubility, mesoporous silica NPs, freeze‐drying, saturation solubility, differential scanning calorimetry, oral administration, fumed silica NPs     

Directional preparation of superhydrophobic magnetic CNF/PVA/MWCNT carbon aerogel

Carbon aerogels have attracted considerable attention in basic research and for their potential applications in many fields. Here, the fabrication of a magnetic cellulose nanofibre (CNF)/poly(vinyl alcohol) (PVA)/multiwalled carbon nanotubes (MWCNT) carbon aerogel (m‐CPMCA) is reported using a simple freeze‐drying followed by a carbonisation process, and direct immobilisation of Fe₃ O₄ nanoparticle on the surface of aerogels. The obtained target aerogel has the characteristics of low density (0.098 g/cm³), high porosity (>90%) and 3D interpenetrating porous structures. Furthermore, m‐CPMCA has a surprising compressive strength (about 0.35 MPa) which is obviously higher than many other cellulose‐based carbon aerogels. After Carbonization, m‐CPMCA exhibits superhydrophobicity, selective absorption for organic solvents and fire‐resistance. The m‐CPMCA also exhibited a magnetic response and can absorb oil on the water surface and can be actuated by a small magnet. More importantly, the m‐CPMCA could be recycled many times by combustion, which showed economic significance. To sum up, the authors believe that m‐CPMCA will become a very potential adsorbent for dealing with the increasingly serious problem of organic pollution.Inspec keywords: hydrophobicity, compressive strength, nanocomposites, nanofabrication, nanoparticles, porous materials, freezing, porosity, nanofibres, water, drying, aerogels, multi‐wall carbon nanotubes, filled polymersOther keywords: 3D interpenetrating porous structures, m‐CPMCA, cellulose‐based carbon aerogels, magnetic response, directional preparation, superhydrophobic magnetic CNF/PVA/MWCNT carbon aerogel, magnetic cellulose nanofibre/poly(vinyl alcohol)/multiwalled carbon nanotubes carbon aerogel, aerogel, freeze‐drying, carbonisation, direct immobilisation, Fe₃ O₄ nanoparticle, porosity, compressive strength, superhydrophobicity, fire‐resistance, combustion, Fe₃ O₄ , C     

Classification of drug molecules for oxidative stress signalling pathway

In humans, oxidative stress is involved in the development of diabetes, cancer, hypertension, Alzheimers’ disease, and heart failure. One of the mechanisms in the cellular defence against oxidative stress is the activation of the Nrf2‐antioxidant response element (ARE) signalling pathway. Computation of activity, efficacy, and potency score of ARE signalling pathway and to propose a multi‐level prediction scheme for the same is the main aim of the study as it contributes in a big amount to the improvement of oxidative stress in humans. Applying the process of knowledge discovery from data, required knowledge is gathered and then machine learning techniques are applied to propose a multi‐level scheme. The validation of the proposed scheme is done using the K‐fold cross‐validation method and an accuracy of 90% is achieved for prediction of activity score for ARE molecules which determine their power to refine oxidative stress.Inspec keywords: cancer, cellular biophysics, biochemistry, drugs, molecular biophysics, proteins, learning (artificial intelligence), medical computingOther keywords: oxidative stress, Nrf2‐antioxidant response element signalling pathway, ARE signalling pathway, diabetes, cancer, hypertension, Alzheimers’ disease, heart failure, machine learning techniques, K‐fold cross‐validation method, ARE molecules     

Colorimetric‐based detection of Ureaplasma urealyticum using gold nanoparticles

Ureaplasma urealyticum (uu) is one of the most common agents of urogenital infections and is associated with complications such as infertility, spontaneous abortion and other sexually transmitted diseases. Here, a DNA sensor based on oligonucleotide target‐specific gold nanoparticles (AuNPs) was developed, in which the dispersed and aggregated states of oligonucleotide‐functionalised AuNPs were optimised for the colorimetric detection of a polymerase chain reaction (PCR) amplicon of U. urealyticum DNA. A non‐cross‐linking approach utilising a single Au‐nanoprobe specific of the urease gene was utilised and the effect of a PCR product concentration gradient evaluated. Results from both visual and spectral analyses showed that target–Au‐nanoprobe hybrids were stable against aggregation after adding the inducer. Furthermore, when a non‐target PCR product was used, the peak position shifted and salt‐induced aggregation occurred. The assay''s limit of detection of the assay was 10 ng with a dynamic range of 10–60 ng. This procedure provides a rapid, facile and low‐cost detection format, compared to methods currently used for the identification of U. urealyticum.Inspec keywords: patient diagnosis, diseases, enzymes, nanosensors, microorganisms, molecular biophysics, DNA, nanoparticles, aggregation, cellular biophysics, colorimetry, genetics, gold, nanomedicineOther keywords: urogenital infections, infertility, spontaneous abortion, sexually transmitted diseases, DNA sensor, oligonucleotide target‐specific gold nanoparticles, oligonucleotide‐functionalised AuNPs, colorimetric detection, polymerase chain reaction amplicon, noncross‐linking approach, single Au‐nanoprobe specific, urease gene, visual analyses, spectral analyses, target–Au‐nanoprobe hybrids, nontarget PCR product, salt‐induced aggregation, rapid cost detection format, facile cost detection format, low‐cost detection format, PCR product concentration, Ureaplasma urealyticum DNA, Au     

CAD/CAM scaffolds for bone tissue engineering: investigation of biocompatibility of selective laser melted lightweight titanium

The objective of the current in‐vitro study was to evaluate the biocompatibility of a new type of CAD/CAM scaffold for bone tissue engineering by using human cells. Porous lightweight titanium scaffolds and Bio‐Oss® scaffolds as well as their eluates were used for incubation with human osteoblasts, fibroblasts and osteosarcoma cells. The cell viability was assessed by using fluorescein diazo‐acetate propidium iodide staining. Cell proliferation and metabolism was examined by using MTT‐, WST‐Test and BrdU‐ELISA tests. Scanning electron microscope was used for investigation of the cell adhesion behaviour. The number of devitalised cells in all treatment groups did not significantly deviate from the control group. According to MTT and WST results, the number of metabolically active cells was decreased by the eluates of both test groups with a more pronounced impact of the eluate from Bio‐Oss®. The proliferation of the cells was inhibited by the addition of the eluates. Both scaffolds showed a partial surface coverage after 1 week and an extensive to complete coverage after 3 weeks. The CAD/CAM titanium scaffolds showed favourable biocompatibility compared to Bio‐Oss® scaffolds in vitro. The opportunity of a defect‐specific design and rapid prototyping by selective laser melting are relevant advantages in the field of bone tissue engineering and regenerative medicine.Inspec keywords: calcium compounds, scanning electron microscopy, adhesion, titanium, CAD/CAM, tissue engineering, bone, biomedical materials, cellular biophysics, biomechanics, laser materials processing, meltingOther keywords: bone tissue engineering, human cells, porous lightweight titanium scaffolds, human osteoblasts, osteosarcoma cells, cell viability, fluorescein diazo‐acetate propidium iodide staining, cell proliferation, MTT tests, WST‐Test, BrdU‐ELISA tests, cell adhesion, devitalised cells, metabolically active cells, biocompatibility, selective laser melting, CAD‐CAM scaffolds, cell metabolism, scanning electron microscopy, Ti     

Effect of chitosan with different molecular weight on the stability,antioxidant and anticancer activities of well‐dispersed selenium nanoparticles

This study was designed to evaluate and compare the stability, antioxidant and anticancer activities of selenium nanoparticles (SeNPs) decorated with different molecular weight (MW) of chitosan (CS) (1500 Da, 48 kDa, 510 kDa). The size range of well‐dispersed SeNPs was effectively controlled by I⁻ first and then coated with CS. The morphology, size and surface charge of generated SeNPs were characterised by several technologies. Fourier transform infrared spectroscopy was used to investigate the relationship between SeNPs and CS. SeNPs decorated with CS (510 kDa) can keep stable for more than 45 days. As observed from the results of a simple photometric system, the antioxidant activities of decorated SeNPs were enhanced compared to undecorated SeNPs. SeNPs coated with higher MW of CS (510 kDa) showed the strongest antioxidant activities. Moreover, the treatments of SeNPs decorated with CS inhibited the growth of HepG2 cells in a time‐ and dose‐dependent manner. The proposed results demonstrated the critical roles of the MW of CS on the stability, antioxidant and anticancer properties of CS‐coated SeNPs, which provided an important design cue for future applications of functional foods and additives.Inspec keywords: selenium, drug delivery systems, cellular biophysics, nanoparticles, molecular biophysics, cancer, biomedical materials, biochemistry, polymers, nanomedicine, Fourier transform infrared spectra, surface charging, surface morphologyOther keywords: chitosan, surface charge, anticancer properties, anticancer activities, antioxidant activities, molecular weight, selenium nanoparticles, CS‐coated SeNP, Fourier transform infrared spectroscopy, photometric system, HepG2 cells, time 45.0 d, Se     

Preparation and characterisation of zein/polyphenol nanofibres for nerve tissue regeneration

Bridging strategies are required to repair peripheral nerve injuries that result in gaps >5–8 mm. Limitations such as donor‐site morbidity and size mismatches with receptor sites for autografts, together with immunological problems associated with allografts and xenografts, have created an increased interest in the field of manufactured nerve guide conduits. In this study, zein, a plant protein‐based polymer, was electrospun to prepare nanofibrous mats. An important challenge with zein mats is the rapid change from fibre to film under aqueous conditions. Tannic acid (TA), which is a polyphenol, was selected to prepare a blend of zein/TA with different weight ratios to investigate its effect on the wetting resistance of nanofibres. The electrospun mats were characterised and evaluated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). Also, degradation and mechanical properties of the mats were studied. Results showed that TA had a significant effect on the resistance to film formation in nanofibres. Moreover, the degradation and elongation at break of mats were increased with increase in TA concentration. For the investigation of the peripheral nerve regeneration potential, Schwann cells were selected for cytotoxicity evaluation by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5 diphenyltetrazolium bromide assay and cell morphology by SEM. Schwann cells had good biocompatibility with zein/TA blends (%) of 90/10 and 80/20.Inspec keywords: polymer fibres, biomedical materials, electrospinning, cellular biophysics, tissue engineering, proteins, molecular biophysics, neurophysiology, nanofibres, injuries, nanomedicine, toxicology, scanning electron microscopy, nanofabrication, polymer blends, polymer films, wetting, Fourier transform infrared spectra, elongationOther keywords: SEM, Schwann cells, nerve tissue regeneration, peripheral nerve injuries, donor‐site morbidity, size mismatches, receptor sites, immunological problems, allografts, xenografts, manufactured nerve guide conduits, plant protein‐based polymer, nanofibrous mats, zein mats, aqueous conditions, tannic acid, wetting resistance, electrospun mats, scanning electron microscopy, film formation, TA concentration, peripheral nerve regeneration potential, cell morphology, weight ratios, zein‐polyphenol nanofibres, electrospinning, zein‐TA blends, Fourier transform infrared spectroscopy, mechanical properties, elongation‐at‐break, cytotoxicity evaluation, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5 diphenyltetrazolium bromide assay, biocompatibility     

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     

Micro RNA‐30b (inhibitor) nanoparticles suppressed the lipopolysaccharide (LPS)‐induced acute kidney injury

The main aim of present study is to evaluate the effect of miR‐30b on the function of human proximal tubular epithelial cell line HK‐2 cells. For this purpose, miRNA was loaded in an ionically cross‐linked polysaccharide nanoparticle. The authors have demonstrated the influence of miR‐30b mimic and inhibitor in HK‐2 cell killing effect. Lipopolysaccharide (LPS) significantly increased the level of inflammatory cytokines of TNF‐α, IL‐1β and level was further increased with the treatment of PAg‐miR mimic consistent with the cell viability assay. Interestingly, PAg‐miR inhibitor significantly downregulated the expression of inflammatory cytokines and thereby reduced the inflammation in the body. Western blot analysis showed that LPS induced severe apoptosis of HK‐2 cells and the apoptosis was further promoted by the PAg‐miR (mimic). In contrast, PAg‐miR (inhibitor) alleviated the apoptosis of HK‐2 cells as indicated in the significantly reduced levels of Bax and c‐Caspase‐3 proteins. Overall, miR‐30b promoted LPS‐induced HK‐2 cell inflammatory injury by inducing the apoptosis and by releasing inflammatory cytokines, as well as by impairing autophagy process.Inspec keywords: biomedical materials, nanoparticles, molecular biophysics, enzymes, toxicology, injuries, nanomedicine, RNA, cellular biophysics, kidney, proteins, drugs, biochemistryOther keywords: microRNA‐30b, nanoparticles suppressed the lipopolysaccharide (LPS)‐induced, main aim, human proximal tubular epithelial cell line HK‐2 cells, polysaccharide nanoparticle, HK‐2 cell killing effect, inflammatory cytokines, IL‐1β, cell viability assay, PAg‐miR inhibitor, apoptosis, reduced levels, LPS‐induced HK‐2 cell inflammatory injury     

Chitosan nanoparticles loaded with aspirin and 5‐fluororacil enable synergistic antitumour activity through the modulation of NF‐κB/COX‐2 signalling pathway

Based on the enhancement of synergistic antitumour activity to treat cancer and the correlation between inflammation and carcinogenesis, the authors designed chitosan nanoparticles for co‐delivery of 5‐fluororacil (5‐Fu: an as anti‐cancer drug) and aspirin (a non‐steroidal anti‐inflammatory drug) and induced synergistic antitumour activity through the modulation of the nuclear factor kappa B (NF‐κB)/cyclooxygenase‐2 (COX‐2) signalling pathways. The results showed that aspirin at non‐cytotoxic concentrations synergistically sensitised hepatocellular carcinoma cells to 5‐Fu in vitro. It demonstrated that aspirin inhibited NF‐κB activation and suppressed NF‐κB regulated COX‐2 expression and prostaglandin E2 (PGE2) synthesis. Furthermore, the proposed results clearly indicated that the combination of 5‐Fu and aspirin by chitosan nanoparticles enhanced the intracellular concentration of drugs and exerted synergistic growth inhibition and apoptosis induction on hepatocellular carcinoma cells by suppressing NF‐κB activation and inhibition of expression of COX‐2.Inspec keywords: proteins, molecular biophysics, cellular biophysics, biomedical materials, cancer, nanoparticles, drug delivery systems, enzymes, tumours, nanomedicine, drugsOther keywords: chitosan nanoparticles, aspirin, 5‐fluororacil, synergistic antitumour activity, anticancer drug, nonsteroidal antiinflammatory drug, hepatocellular carcinoma cells, NF‐κB activation, NF‐κB regulated COX‐2 expression, PGE2, synergistic growth inhibition, apoptosis induction, prostaglandin E2 synthesis, intracellular concentration, noncytotoxic concentrations, NF‐κB‐cyclooxygenase‐2 signalling pathways, cyclooxygenase‐2, nuclear factor kappa B     

5 Fluorouracil‐loaded biosynthesised gold nanoparticles for the in vitro treatment of human pancreatic cancer cell

In this study, green synthesis of gold nanoparticles (AuNPs) was performed by a sunlight irradiation method using the Borassus flabellifer fruit extract as a reducing agent. 5‐Fluorouracil (5‐FU)‐loaded GG capped AuNPs (5FU‐G‐AuNPs) was prepared. The nanoparticles was further characterised by UV‐visible spectra, particle size analysis, zeta potential, SAED, HRTEM, and XRD. The MTT assay results showed the suitability 5‐FU‐G‐AuNPs. In this study, 5‐FU‐G‐AuNPs exhibited potential cytotoxic and apoptotic effects on (MiaPaCa‐2) cell line.Inspec keywords: gold, biochemistry, X‐ray diffraction, nanofabrication, biomedical materials, transmission electron microscopy, toxicology, electrokinetic effects, particle size, nanoparticles, cancer, visible spectra, cellular biophysics, ultraviolet spectra, nanomedicine, patient treatment, organic compoundsOther keywords: 5FU‐G‐AuNPs, suitability 5‐FU‐G‐AuNPs, human pancreatic cancer cell, green synthesis, sunlight irradiation method, 5‐Fluorouracil‐loaded GG, in vitro treatment, 5 fluorouracil‐loaded biosynthesised gold nanoparticles, borassus flabellifer fruit extract, reducing agent, UV‐visible spectra, particle size analysis, zeta potential, SAED, HRTEM, XRD, MTT assay, apoptotic effects, cytotoxic effects, MiaPaCa‐2 cell line, Au     

Preparation and in vitro evaluation of novel cross‐linked chondroitin sulphate nanoparticles by aluminium ions for encapsulation of green tea flavonoids

Chondroitin sulphate is a sulphated glycosaminoglycan biopolymer composed over 100 individual sugars. Chondroitin sulphate nanoparticles (NPs) loaded with catechin were prepared by an ionic gelation method using AlCl₃ and optimised for polymer and cross‐linking agent concentration, curing time and stirring speed. Zeta potential, particle size, loading efficiency, and release efficiency over 24 h (RE₂₄ %) were evaluated. The surface morphology of NPs was investigated by scanning electron microscopy and their thermal behaviour by differential scanning calorimetric. Antioxidant effect of NPs was determined by chelating activity of iron ions. The cell viability of mesenchymal stem cells was determined by 3‐[4, 5‐dimethylthiazol‐2‐yl]‐2, 5‐diphenyl tetrazolium bromide assay and the calcification of osteoblasts was studied by Alizarin red staining. The optimised NPs showed particle size of 176 nm, zeta potential of −20.8 mV, loading efficiency of 93.3% and RE₂₄ % of 80.6%. The chatechin loaded chondroitin sulphate NPs showed 70‐fold more antioxidant activity, 3‐fold proliferation effect and higher calcium precipitation in osteoblasts than free catechin.Inspec keywords: nanoparticles, encapsulation, biomedical materials, particle size, nanofabrication, nanomedicine, electrokinetic effects, cellular biophysics, polymer blends, molecular biophysics, molecular configurations, biochemistry, curing, surface morphology, scanning electron microscopy, differential scanning calorimetry, dyes, precipitationOther keywords: in vitro evaluation, cross‐linked chondroitin sulphate nanoparticles, aluminium ions, nanoparticles, green tea flavonoids, sulphated glycosaminoglycan biopolymer, sugars, catechin, ionic gelation method, cross‐linking agent concentration, curing time, size 176 nm, time 24 h, calcium precipitation, 3‐fold proliferation effect, antioxidant activity, chatechin loaded chondroitin sulphate NPs, Alizarin red staining, osteoblasts, calcification, 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazolium bromide assay, mesenchymal stem cells, cell viability, chelating activity, differential scanning calorimetry, thermal behaviour, scanning electron microscopy, surface morphology, release efficiency, loading efficiency, particle size, zeta potential, stirring speed     

Evaluation of the toxicities of silver and silver sulfide nanoparticles against Gram‐positive and Gram‐negative bacteria

In this study, the endogenous lipid signalling molecules, N ‐myristoylethanolamine, were explored as a capping agent to synthesise stable silver nanoparticles (AgNPs) and Ag sulphide NPs (Ag₂ S NPs). Sulphidation of the AgNPs abolishes the surface plasmon resonance (SPR) maximum of AgNPs at 415 nm with concomitant changes in the SPR, indicating the formation of Ag₂ S NPs. Transmission electron microscopy revealed that the AgNPs and Ag₂ S NPs are spherical in shape with a size of 5–30 and 8–30 nm, respectively. AgNPs and Ag₂ S NPs exhibit antimicrobial activity against Gram‐positive and Gram‐negative bacteria. The minimum inhibitory concentrations (MIC) of 25 and 50 μM for AgNPs and Ag₂ S NPs, respectively, were determined from resazurin microtitre plate assay. At or above MIC, both AgNPs and Ag₂ S NPs decrease the cell viability through the mechanism of membrane damage and generation of excess reactive oxygen species.Inspec keywords: cellular biophysics, biomembranes, transmission electron microscopy, nanomedicine, microorganisms, molecular biophysics, antibacterial activity, nanofabrication, silver, biomedical materials, surface plasmon resonance, nanoparticles, materials preparation, silver compounds, lipid bilayersOther keywords: Gram‐negative bacteria, Gram‐positive bacteria, endogenous lipid signalling molecules, N‐myristoylethanolamine, capping agent, silver nanoparticles, Ag sulphide NPs, sulphidation, surface plasmon resonance, concomitant changes, transmission electron microscopy, minimum inhibitory concentrations, resazurin microtitre plate assay, cell viability, membrane damage, reactive oxygen species, Ag toxicities, Ag, Ag₂ S     

Redox/pH dual stimuli‐responsive ZnO QDs‐gated mesoporous silica nanoparticles as carriers in cancer therapy

New drug delivery system (ZnO@CMS) of the redox and pH dual‐stimuli responsive based on colloidal mesoporous silica nanoparticles (CMS) has been designed, in which zinc oxide quantum dots (ZnO QDs) as a capping agent was conjugated on the surface of nanoparticles by amide bonds. The release behaviour of doxorubicin (DOX) as the model drug from ZnO@CMS (ZnO@CMS‐DOX) indicated the redox and pH dual‐stimuli responsive properties due to the acidic dissolution of ZnO QDs and cleavage of the disulphide bonds. The haemolysis and bovine serum albumin adsorption assays showed that the modification of ZnO QDs on the mesoporous silica nanoparticles modified by mercapto groups (CMS‐SH)(ZnO@CMS) had better biocompatibility compared to CMS‐SH. The cell viability and cellular uptake tests revealed that the ZnO@CMS might achieve the antitumour effect on cancer cells due to the cytotoxicity of ZnO QDs. Therefore, ZnO@CMS might be potential nanocarriers of the drug delivery system in cancer therapy. The in vivo evaluation of ZnO@CMS would be carried out in future work.Inspec keywords: biochemistry, nanomedicine, cellular biophysics, pH, toxicology, tumours, semiconductor quantum dots, proteins, colloids, II‐VI semiconductors, mesoporous materials, silicon compounds, oxidation, cancer, drug delivery systems, zinc compounds, adsorption, molecular biophysics, nanomagnetics, drugs, biomedical materials, nanofabrication, nanoparticles, nanoporous materialsOther keywords: cancer therapy, drug delivery system, amide bonds, haemolysis, bovine serum albumin adsorption assays, mercapto groups, cancer cells, cytotoxicity, antitumour effect, redox/pH dual stimuli‐responsive zinc oxide quantum dots‐gated colloidal mesoporous silica nanoparticles, ZnO, SiO₂      

Nucleic acid detection strategy using gold nanoprobe of two diverse origin

In recent years, nanoparticles especially with gold and silver nanoparticles based point of care diagnostic methods is being developed for the lethal diseases like dengue. This study focused to work on the dengue virus detection in a simplest method using gold nanoparticles probe (AuNPs) with thiol tagged single strand DNA (ss‐DNA). A sensitive, fluorescence‐based detection strategy was designed to examine and quantified the hybridisation process and also elucidated the behaviour of AuNPs before and after interaction of biomolecule. The detection process was focused on aggregation of gold nanoprobe in the presence of complementary strand (target region). Hence the percentage of aggregation was measured and as a result, the limit of detection was found to be 10⁻⁶ dilutions. Current detection method was highly sensitive, easy to perform and the reaction timing is rapid between 5 and 10 min, and it can be observed through naked eye.Inspec keywords: patient diagnosis, microorganisms, nanomedicine, gold, fluorescence, nanosensors, DNA, nanoparticles, molecular biophysics, diseases, optical sensorsOther keywords: nucleic acid detection strategy, gold nanoprobe, silver nanoparticles, lethal diseases, dengue virus detection, gold nanoparticles probe, thiol tagged single strand DNA, hybridisation process, detection process, aggregation, complementary strand, current detection method, point‐of‐care diagnostic methods, fluorescence‐based detection strategy, 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     

Overcoming the blood–brain barrier in neurodegenerative disorders and brain tumours

Drug delivery is one of the major challenges in the treatment of central nervous system disorders. The brain needs to be protected from harmful agents, which are done by the capillary network, the so‐called blood–brain barrier (BBB). This protective guard also prevents the delivery of therapeutic agents to the brain and limits the effectiveness of treatment. For this reason, various strategies have been explored by scientists for overcoming the BBB from disruption of the BBB to targeted delivery of nanoparticles (NPs) and cells and immunotherapy. In this review, different promising brain drug delivery strategies including disruption of tight junctions in the BBB, enhanced transcellular transport by peptide‐based delivery, local delivery strategies, NP delivery, and cell‐based delivery have been fully discussed.Inspec keywords: drugs, tumours, neurophysiology, blood, biochemistry, brain, drug delivery systems, nanoparticles, biomedical materials, molecular biophysics, cellular biophysics, nanomedicine, diseases, proteins, reviewsOther keywords: blood–brain barrier, neurodegenerative disorders, central nervous system disorders, BBB, therapeutic agents, targeted delivery, peptide‐based delivery, local delivery strategies, NP delivery, cell‐based delivery, brain drug delivery strategies, brain tumours, nanoparticles, immunotherapy, review     

Fabrication and characterization of biodegradable PHBV/SiO2 nanocomposite for thermo‐mechanical and antibacterial applications in food packaging

In the present study, biogenic silica nanoparticles (bSNPs) were synthesized from groundnut shells, and thoroughly characterized to understand its phase, and microstructure properties. The biopolymer was synthesized from yeast Wickerhamomyces anomalus and identified as Poly (3‐hydroxybutyrate‐co ‐3‐hydroxyvalerate) (PHBV) by GC‐MS and NMR analysis. The bSNPs were reinforced to fabricate PHBV/SiO₂ nanocomposites via solution casting technique. The fabricated PHBV/SiO₂ nanocomposites revealed intercalated hybrid interaction between the bSNPs and PHBV matrix through XRD analysis. PHBV/SiO₂ nanocomposites showed significant improvement in physical, chemical, thermo‐mechanical and biodegradation properties as compared to the bare PHBV. The cell viability study revealed excellent biocompatibility against L929 mouse fibroblast cells. The antibacterial activity of PHBV/SiO₂ nanocomposites was found to be progressively improved upon increasing bSNPs concentration against E. coli and S. aureus.Inspec keywords: X‐ray diffraction, microorganisms, antibacterial activity, nanoparticles, cellular biophysics, nanofabrication, silicon compounds, nanocomposites, filled polymers, nanomedicine, biomedical materials, casting, biodegradable materials, food packaging, food safety, biological NMROther keywords: antibacterial applications, poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate), PHBV matrix, biodegradable PHBV‐SiO₂ nanocomposite, thermomechanical biodegradation properties, biogenic silica nanoparticles, groundnut shells, microstructure properties, biopolymer, yeast Wickerhamomyces anomalus, GC‐MS, NMR analysis, food packaging, intercalated hybrid interaction, XRD analysis, cell viability study, solution casting, SiO₂