Electronic transport properties of electrically doped cytosine‐based optical molecular switch with single‐wall carbon nanotube electrodes

This study represents an empirical model of cytosine‐based optical molecular switch. This possible biomolecular switch has been designed using the first principle approach which is based on density functional theory and non‐equilibrium Green''s function. The quantum‐ballistic transport property and current–voltage (I–V) characteristics of cytosine‐based optomolecular switch have been investigated at 25 THz operating frequency. The influence of highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gaps on the electronic transmission and I–V characteristics has been discussed in detail. The aim of this study is to highlight the minimum conformational change during a single ON–OFF switching cycle. The biomolecule comprises switching behaviour when converts from straightened to twisted form during photo‐excitement. The straightened and twisted forms of the molecule are represented as logic ‘0’ and logic ‘1’, respectively. This p and n regions of this switch has been made using electrical doping process. The current through the twisted form of the cytosine biomolecule is ∼1000 times higher than the straightened form. The maximum switching ratio 62.1 is obtained at 1 V bias. The origin of the switching behaviour of the biomolecule can be interpreted by quantum–ballistic transport model along with HOMO–LUMO gaps.Inspec keywords: ballistic transport, organic compounds, Green''s function methods, ab initio calculations, density functional theory, molecular biophysics, optical switches, single‐wall carbon nanotubes, electrochemical electrodesOther keywords: electrical doping process, cytosine biomolecule, electronic transport properties, single‐wall carbon nanotube electrodes, cytosine‐based optical molecular switch, density functional theory, electronic transmission, HOMO‐LUMO gaps, current–voltage characteristics, biomolecular switching behaviour, quantum–ballistic transport property model, electrically doped cytosine‐based optical molecular switch, first principle approach, nonequilibrium Green''s function, I‐V characteristics, highest occupied molecular orbital–lowest unoccupied molecular orbital gaps, single ON–OFF switching cycle, photoexcitement, frequency 25.0 THz, voltage 1.0 V, C     

First principle study of the self‐switching characteristics of the guanine based single optical molecular switch using carbon nanotube electrodes

The switching property of an optical single molecular switch based on a single DNA molecule guanine with a single walled carbon nanotube electrode has been investigated using density functional theory along with non‐equilibrium Green''s function based first principle approach. The semi‐empirical model of this single bio‐molecular switch has been operated at an ultra‐high 25 THz frequency in mid‐UV range. This single bio‐molecule comprises switching activity upon UV photo‐excitation. The influence of the highest occupied molecular orbital and lowest unoccupied molecular orbital gap and the quantum ballistic transmission into the switching activity are discussed in detail in this study. It has been observed that the maximum ON–OFF ratio, i.e. 327 is obtained at +0.8 V bias voltage. Theoretical results show that current through the twisted form is sufficiently larger than the straightened form, which recommends that this structure has smart prospective application in the future generation switching nanotechnology.Inspec keywords: molecular electronic states, density functional theory, ab initio calculations, DNA, organic compounds, molecular electronics, Green''s function methods, molecular biophysics, single‐wall carbon nanotubes, optical switches, orbital calculationsOther keywords: nonequilibrium Green''s function, semiempirical model, single bio‐molecular switch, UV photo‐excitation, lowest unoccupied molecular orbital gap, first principle study, single optical molecular switch, switching property, optical single molecular switch, single DNA molecule guanine, single walled carbon nanotube electrode, density functional theory, highest occupied molecular orbital gap, switching nanotechnology     

Analysis and classification of DNA‐binding sites in single‐stranded and double‐stranded DNA‐binding proteins using protein information

Single‐stranded DNA‐binding proteins (SSBs) and double‐stranded DNA‐binding proteins (DSBs) play different roles in biological processes when they bind to single‐stranded DNA (ssDNA) or double‐stranded DNA (dsDNA). However, the underlying binding mechanisms of SSBs and DSBs have not yet been fully understood. Here, the authors firstly constructed two groups of ssDNA and dsDNA specific binding sites from two non‐redundant sets of SSBs and DSBs. They further analysed the relationship between the two classes of binding sites and a newly proposed set of features (residue charge distribution, secondary structure and spatial shape). To assess and utilise the predictive power of these features, they trained a classification model using support vector machine to make predictions about the ssDNA and the dsDNA binding sites. The author''s analysis and prediction results indicated that the two classes of binding sites can be distinguishable by the three types of features, and the final classifier using all the features achieved satisfactory performance. In conclusion, the proposed features will deepen their understanding of the specificity of proteins which bind to ssDNA or dsDNA.Inspec keywords: biology computing, DNA, molecular biophysics, molecular configurations, pattern classification, proteins, support vector machinesOther keywords: dsDNA binding sites, ssDNA binding sites, support vector machine, classiflcation model, spatial shape, secondary structure, residue charge distribution, binding mechanisms, biological process, protein information, double‐stranded DNA‐binding proteins, single‐stranded DNA‐binding proteins     

Multi‐threshold and multi‐input DNA logic design style for profiling the microRNA biomarkers of real cancers

Early detection of cancer is very critical because it can reduce the treatment risk and cost. MicroRNAs (miRNAs) have been introduced in recent years as an efficient class of biomarkers for cancer early detection. Now, real‐time polymerase chain reaction has been used to profile the miRNA expression, which is costly, time consuming and low accuracy. Most recently, DNA logic gates are used to detect the miRNA expression level that is more accurate and faster than previous methods. The DNA‐based logic gates face with serious challenges such as the large complexity and low scalability. In this study, the authors proposed a methodology to design multi‐threshold and multi‐input DNA‐based logic gates in response to specific miRNA inputs in live mammalian cells. The proposed design style can simultaneously recognise multiple miRNAs with different rising and falling thresholds. The design style has been evaluated on the lung cancer biomarkers and the experimental results show the efficiency of the proposed method in terms of accuracy, efficiency and speed.Inspec keywords: DNA, logic design, biocomputing, RNA, molecular biophysics, logic gates, lung, genetics, cellular biophysics, cancer, biology computing, enzymes, biosensorsOther keywords: falling thresholds, specific miRNA inputs, multiinput DNA‐based logic gates, low scalability, DNA‐based logic gates face, miRNA expression level, DNA logic gates, low accuracy, time consuming, real‐time polymerase chain reaction, cancer early detection, treatment risk, cancers, microRNA biomarkers, multiinput DNA logic design style, multithreshold, lung cancer biomarkers     

Studies on binding of single‐stranded DNA with reduced graphene oxide–silver nanocomposites

The binding reaction of reduced graphene oxide–silver nanocomposites (rGO–AgNCs) with calf thymus single‐stranded DNA (ssDNA) was studied by ultraviolet–visible absorption, fluorescence spectroscopy and circular dichroism (CD), using berberine hemisulphate (BR) dye as a fluorescence probe. The absorbance of ssDNA increases, but the fluorescence intensity is quenched with the addition of rGO–AgNCs. The binding of rGO–AgNCs with ssDNA was able to increase the quenching effects of BR and ssDNA, and induce the changes in CD spectra. All of the evidence indicated that there was a relatively strong interaction between ssDNA and rGO–AgNCs. The data obtained from fluorescence experiments revealed that the quenching process of ssDNA caused by rGO–AgNCs is primarily due to complex formation, i.e. static quenching. The increasing trend of the binding equilibrium constant (K a) with rising temperature indicated that the binding process was an endothermic reaction. The calculated thermodynamic parameters showed that the binding process was thermodynamically spontaneous, and hydrophobic association played predominant roles in the binding of ssDNA to the surface of rGO–AgNCs.Inspec keywords: DNA, fluorescence spectroscopy, circular dichroism, nanofabrication, nanobiotechnology, silver, hydrophobicity, molecular biophysics, radiation quenching, biochemistry, nanocomposites, visible spectra, ultraviolet spectra, dyes, fluorescence, association, graphene compoundsOther keywords: ssDNA increases, fluorescence intensity, fluorescence experiments, binding equilibrium constant, binding process, reduced graphene oxide‐silver nanocomposites, binding reaction, calf thymus single‐stranded DNA, fluorescence spectroscopy, fluorescence probe, complex formation, static quenching, calculated thermodynamic parameters, rGO‐AgNCs binding, ultraviolet‐visible absorption, berberine hemisulphate dye, circular dichroism, CO‐Ag     

High thermal stability and low power dissipation PCM with nanoscale oxygen‐doped SS thin film

To improve thermal stability and reduce power dissipation of phase‐change memory (PCM), the oxygen‐doped Sn₁₅ Sb₈₅ (SS) thin film is proposed by magnetron sputtering in this study. Comparing to undoped Sn15Sb85(SS), the oxygen‐doped‐SS thin film has superior thermal stability and better data retention. Meanwhile, the electrical conductivity of crystallisation oxygen‐doped‐SS thin film is also lower than that of SS, which means its less power consuming in PCM. The electrical conductivity ratio between amorphous and crystalline states for oxygen‐doped SS reaches up to two orders of magnitude. After oxygen doping, the root‐mean‐square surface roughness from amorphous (0.29 nm) to crystalline (0.46 nm) state for oxygen‐doped‐SS thin films becomes smaller. The switching time of amorphisation process for the oxygen‐doped‐SS thin film (∼2.07 ns) is shorter than Ge₂ Sb₂ Te₅ (GST) (∼3.05 ns). X‐ray diffractometer is recorded to investigate the change of crystalline structure. Thus, the authors infer that oxygen‐doped SS is a promising phase‐change thin film for PCM.Inspec keywords: sputter deposition, antimony compounds, X‐ray diffraction, phase change memories, thin films, surface roughness, doping, electrical conductivity, amorphisation, crystallisation, thermal stability, amorphous state, crystal structure, nanostructured materials, nanofabrication, oxygenOther keywords: oxygen doping, low power dissipation, high thermal stability, phase‐change memory, magnetron sputtering, nanoscale oxygen‐doped Sn15Sb85 thin film, electrical conductivity, crystallisation, crystalline state, amorphous state, root‐mean‐square surface roughness, amorphisation process, X‐ray diffractometry, crystalline structure, Sn₁₅ Sb₈₅      

Design of synthetic biological logic circuits based on evolutionary algorithm

The construction of an artificial biological logic circuit using systematic strategy is recognised as one of the most important topics for the development of synthetic biology. In this study, a real‐structured genetic algorithm (RSGA), which combines general advantages of the traditional real genetic algorithm with those of the structured genetic algorithm, is proposed to deal with the biological logic circuit design problem. A general model with the cis ‐regulatory input function and appropriate promoter activity functions is proposed to synthesise a wide variety of fundamental logic gates such as NOT, Buffer, AND, OR, NAND, NOR and XOR. The results obtained can be extended to synthesise advanced combinational and sequential logic circuits by topologically distinct connections. The resulting optimal design of these logic gates and circuits are established via the RSGA. The in silico computer‐based modelling technology has been verified showing its great advantages in the purpose.Inspec keywords: biocomputing, biological techniques, combinational circuits, genetic algorithms, logic design, logic gates, sequential circuitsOther keywords: in silico computer‐based modelling, RSGA, sequential logic circuits, XOR gates, NOR gates, NAND gates, OR gates, AND gates, Buffer gates, NOT gates, fundamental logic gates, cis‐regulatory input function, real‐structured genetic algorithm, artiflcial biological logic circuit design     

Ketoconazole‐conjugated ZnO nanoparticles based semi‐solid formulation and study their impacts on skin disease

In this study, the ketoconazole‐conjugated zinc oxide (ZnO) nanoparticles were prepared in a single‐step approach using dextrose as an intermediate compound. The physical parameters confirmed the drug conjugation with ZnO and their size was around 70–75 nm. The drug loading and in vivo drug release studies indicated that the –CHO group from the dextrose increase the drug loading up to 65% and their release kinetics were also studied. The anti‐fungal studies indicated that the prepared nanoparticles exhibit strong anti‐fungal activity and the minimum concentration needed is 10 mg/ml. The nanoparticles loaded semi‐solid gel was prepared using carbopol, methylparaben, propyl paraben and propylene glycol. The in vitro penetration of the ketoconazole‐conjugated nanoparticles was studied using the skin. The results indicated that the semi‐solid gel preparations influenced the penetration and also favoured the accumulation into the skin membrane. The veterinary clinical studies indicated that the prepared gel is highly suitable for treatment of Malassezia.Inspec keywords: II‐VI semiconductors, skin, biomedical materials, antibacterial activity, wide band gap semiconductors, drug delivery systems, nanomedicine, drugs, diseases, gels, nanofabrication, nanoparticles, zinc compounds, biomembranes, veterinary medicineOther keywords: strong anti‐fungal activity, propyl paraben, propylene glycol, semisolid gel preparations, skin membrane, veterinary clinical studies, semisolid formulation, skin disease, ketoconazole‐conjugated zinc oxide nanoparticles, single‐step approach, physical parameters, drug conjugation, drug loading, release kinetics, dextrose, in vivo drug release studies, carbopol, methylparaben, in vitro penetration, Malassezia, ZnO     

Lamivudine‐conjugated and efavirenz‐loaded G2 dendrimers: Novel anti‐retroviral nano drug delivery systems

Infection with human immunodeficiency virus (HIV)‐1 causes immunological disorders and death worldwide which needs to be further assisted by novel anti‐retroviral drug delivery systems. Consequently, finding newer anti‐retroviral pharmaceuticals by using biocompatible, biodegradable nanomaterials comprising a nanoparticle as core and a therapeutic agent is of high global interest. In this experiment, a second generation of a negatively charged nano‐biopolymer linear globular G2 dendrimer was carefully conjugated and loaded with well‐known anti‐HIV drugs lamivudine and efavirenz, respectively. They were characterised by a variety of analytical methods such as Zetasizer, Fourier‐transform infrared spectroscopy, elemental analysis and liquid chromatography‐mass spectroscopy. Additionally, conjugated lamivudine and loaded efazirenz with globular PEGylated G2 dendrimer were tested on an HEK293 T cell infected by single‐cycle replicable HIV‐1 virion and evaluated using XTT test and HIV‐1 P24 protein load. The results showed that lamivudine‐conjugated G2 significantly decreased retroviral activity without any cell toxicity. This effect was more or less observed by efavirenz‐loaded G2. These nano‐constructs are strongly suggested for further in vivo anti‐HIV assays.     

Nano‐biosensor based on reduced graphene oxide and gold nanoparticles,for detection of phenylketonuria‐associated DNA mutation

Phenylketonuria (PKU)‐associated DNA mutation in newborn children can be harmful to his health and early detection is the best way to inhibit consequences. A novel electrochemical nano‐biosensor was developed for PKU detection, based on signal amplification using nanomaterials, e.g. gold nanoparticles (AuNPs) decorated on the reduced graphene oxide sheet on the screen‐printed carbon electrode. The fabrication steps were checked by field emission scanning electron microscope imaging as well as cyclic voltammetry analysis. The specific alkanethiol single‐stranded DNA probes were attached by self‐assembly methodology on the AuNPs surface and Oracet blue was used as an intercalating electrochemical label. The results showed the detection limit of 21.3 fM and the dynamic range of 80–1200 fM. Moreover, the selectivity results represented a great specificity of the nano‐biosensor for its specific target DNA oligo versus other non‐specific sequences. The real sample simulation was performed successfully with almost no difference than a synthetic buffer solution environment.Inspec keywords: biosensors, nanosensors, nanoparticles, graphene compounds, gold, nanomedicine, DNA, molecular biophysics, biomedical equipment, electrochemical sensors, electrochemical electrodes, field emission scanning electron microscopy, voltammetry (chemical analysis), self‐assembly, biochemistryOther keywords: reduced graphene oxide, gold nanoparticles, phenylketonuria‐associated DNA mutation, newborn children, electrochemical nanobiosensor, signal amplification, nanomaterials, reduced graphene oxide sheet, screen‐printed carbon electrode, field emission scanning electron microscopy imaging, cyclic voltammetry, alkanethiol single‐stranded DNA probes, self‐assembly methodology, Oracet blue, intercalating electrochemical label, Au‐CO     

Synthesis,radiolabelling, and biological assessment of folic acid‐conjugated G‐3 99m Tc‐dendrimer as the breast cancer molecular imaging agent

Hence, in this study, the authors aimed to develop a dendrimer‐based imaging agent comprised of poly(ethylene glycol) (PEG)‐citrate, technetium‐99 m (^99m Tc), and folic acid. The dendrimer‐G3 was synthesised and conjugated with folic acid, which confirmed by Fourier transform infrared, proton nuclear magnetic resonance, dynamic light scattering, and transition electron microscopy. 2,3‐bis‐(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐Tetrazolium‐5‐Carboxanilide cytotoxicity assay kit was used to measure the cellular toxicity of dendrimer. Imaging and biodistribution studies were conducted on the mice bearing tumour. The results showed that the fabricated dendrimer‐G3 has a size of 90 ± 3 nm, which was increased to 100 ± 4 nm following the conjugation with folic acid. The radiostablity investigation showed that the fabricated dendrimers were stable in the human serum at various times. Toxicity assessment confirmed no cellular toxicity against HEK‐293 cells at 0.25, 0.5, 1, 2, 4, and 8 mg/μl concentrations. The in vivo studies demonstrated that the synthesised dendrimers were able to provide a bright SPECT image applicable for tumour detection. In conclusion, the authors’ study documented the positive aspects of PEG‐citrate dendrimer conjugated with folic acid as the SPECT contrast agent for breast cancer detection.Inspec keywords: toxicology, single photon emission computed tomography, technetium, cancer, bone, polymers, biochemistry, tumours, electrospinning, biomedical materials, light scattering, cellular biophysics, Fourier transform infrared spectra, proton magnetic resonance, transmission electron microscopy, biological organsOther keywords: biodistribution, toxicity assessment, cellular toxicity, bright SPECT image, PEG‐citrate dendrimer, breast cancer molecular imaging agent, proton nuclear magnetic resonance, dendrimer‐based imaging agent, folic acid‐conjugated G‐^399m Tc‐dendrimer, dendrimer‐G3, poly(ethylene glycol)‐citrate, Fourier transform infrared spectra, dynamic light scattering, transition electron microscopy, 2,3‐bis‐(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5‐carboxanilide cytotoxicity assay, human serum, tumour detection     

Biogenic gold nanoparticles for reduction of 4‐nitrophenol to 4‐aminophenol: an eco‐friendly bioremediation

The present study investigated the synthesis of gold nanoparticles (AuNPs) using mangrove plant extract from Avicennia marina as bioreductant for eco‐friendly bioremediation of 4‐nitrophenol (4‐NP). The AuNPs synthesised were confirmed by UV spectrum, transmission electron microscopy (TEM), X‐ray diffraction, Fourier transmission infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential. The AuNPs were found to be spherical in shape with size ranging from 4 to 13 nm, as evident by TEM and DLS. Further, the AuNPs were encapsulated with sodium alginate in the form of gold nano beads and used as heterogeneous catalyst and degrading agent to reduce 4‐NP. This reduction in 4‐NP into 4‐aminophenol was confirmed by UV and FTIR. The aqueous solution of 4‐NP peaked its absorbance at 320 nm, and shifted to 400 nm, with an intense yellow colour, appeared due to formation of 4‐nitrophenolate ion. After the addition of AuNps, the 4‐NP solution became colourless and peaked at 400 nm and reduced to 290 nm corresponding to the formation of 4‐aminophenol. Hence, the present work suggested the AuNPs as the potent, eco‐friendly bionanocomposite catalyst for bioremediation of 4‐NP.Inspec keywords: gold, nanoparticles, nanobiotechnology, nanofabrication, ultraviolet spectra, transmission electron microscopy, X‐ray diffraction, Fourier transform spectra, infrared spectra, electrokinetic effects, catalysts, nanocomposites, biochemistryOther keywords: biogenic gold nanoparticles, 4‐nitrophenol, 4‐aminophenol, eco‐friendly bioremediation, mangrove plant extract, Avicennia marina, bioreductant, UV spectrum, transmission electron microscopy, TEM, X‐ray diffraction, Fourier transmission infrared spectroscopy, FTIR, dynamic light scattering, DLS, zeta potential, degrading agent, 4‐nitrophenolate, bionanocomposite catalyst, size 4 nm to 13 nm, wavelength 400 nm, wavelength 290 nm, Au     

Polyethylenimine‐modified curcumin‐loaded mesoporus silica nanoparticle (MCM‐41) induces cell death in MCF‐7 cell line

Breast cancer accounts for the first highest mortality rate in India and second in world. Though current treatment strategies are effectively killing cancer cells, they also end in causing severe side effects and drug resistance. Curcumin is a nutraceutical with multipotent activity but its insolubility in water limits its therapeutic potential as an anti‐cancer drug. The hydrophilicity of curcumin could be increased by nanoformulation or changing its functional groups. In this study, curcumin is loaded on mesoporous silica nanoparticle and its anti‐cancer activity is elucidated with MCF‐7 cell death. Structural characteristics of Mobil Composition of Matter ‐ 41(MCM‐41) as determined by high‐resolution transmission electron microscopy (HR‐TEM) shows that MCM‐41 size ranges from 100 to 200 nm diameters with pore size 2–10 nm for drug adsorption. The authors found 80–90% of curcumin is loaded on MCM‐41 and curcumin is released efficiently at pH 3.0. The 50 µM curcumin‐loaded MCM‐41 induced 50% mortality of MCF‐7 cells. Altogether, their results suggested that increased curcumin loading and sustained release from MCM‐41 effectively decreased cell survival of MCF‐7 cells in vitro.Inspec keywords: cancer, cellular biophysics, nanoparticles, nanomedicine, biomedical materials, polymers, mesoporous materials, transmission electron microscopy, drugs, adsorptionOther keywords: polyethylenimine‐modified curcumin‐loaded mesoporus silica nanoparticle, MCF‐7 cell line, breast cancer, cancer cells, drug resistance, multipotent activity, therapeutic potential, anticancer drug, mesoporous silica nanoparticle, MCF‐7 cell death, high‐resolution transmission electron microscopy, drug adsorption, curcumin‐loaded MCM‐41, nutraceutical curcumin, size 2 nm to 10 nm, size 100 nm to 200 nm     

Cu‐induced assembly of methanobactin‐modified gold nanoparticles and its peroxidase mimic activity

Methanobactin (Mb) is a small copper‐chelating molecule that functions as an agent for copper acquisition, uptake and copper‐containing methane monooxygenase catalysis in methane‐oxidising bacteria. The UV–visible spectral and fluorescence spectral suggested that Mb/Cu coordination complex as a monomer (Mb‐Cu), dimmer (Mb₂ ‐Cu) and tetramer (Mb₄ ‐Cu) could be obtained at different ratios of Mb to Cu (II). The kinetics of the oxidation of hydroquinone with hydrogen peroxide catalysed by the different Mb/Cu coordination complex were investigated. The results suggested that Mb₂ ‐Cu coordination form has highest catalytic capacity. Further, Mb‐modified gold nanoparticles (AuNPs) were obtained by ligand exchange and assembled into two‐ and three‐D nanocluster structure by metal‐organic coordination as driving force. It has been found that AuNPs increased the catalytic activity of Mb₂ ‐Cu on AuNPs. The more significant catalytic activity was exhibited by the nanocluster assembly with multi‐catalytic centres. This may be attributed to the multivalent collaborative characteristics of the catalytic active centres in the nanocluster network assembly. The assembly of Mb‐modified AuNPs can act as excellent nanoenzyme models for imitating peroxidase.Inspec keywords: nanoparticles, catalysis, oxidation, enzymes, microorganisms, nanobiotechnology, gold, organic compounds, reduction (chemical), visible spectra, molecular biophysics, ultraviolet spectra, biochemistry, copper, nanofabrication, fluorescenceOther keywords: Mb‐modified gold nanoparticles, catalytic active centres, Mb‐modified AuNPs, Cu‐induced assembly, methanobactin‐modified gold nanoparticles, peroxidase mimic activity, copper‐chelating molecule, copper‐containing methane monooxygenase catalysis, methane‐oxidising bacteria, fluorescence, Mb/Cu coordination complex, catalytic activity, UV–visible spectra, nanocluster assembly, Cu, Au     

Synthesis,characterisation and potential biomedical applications of magnetic core–shell structures: carbon‐, dextran‐, SiO2 ‐ and ZnO‐coated Fe3 O4 nanoparticles

Due to the strong effect of nanoparticles'' size and surface properties on cellular uptake and bio‐distribution, the selection of coating material for magnetic core–shell nanoparticles (CSNPs) is very important. In this study, the effects of four different biocompatible coating materials on the physical properties of Fe₃ O₄ (magnetite) nanoparticles (NPs) for different biomedical applications are investigated and compared. In this regard, magnetite NPs are prepared by a simple co‐precipitation method. Then, CSNPs including Fe₃ O₄ as a core and carbon, dextran, ZnO (zincite) and SiO₂ (silica) as different shells are synthesised using simple one‐ or two‐step methods. A comprehensive study is carried out on the prepared samples using X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy and Fourier transform infrared spectroscopy analyses. According to the authors'' findings, it is suggested that carbon‐ and dextran‐coated magnetite NPs with high M _s have great potential in the application of magnetic resonance imaging contrast agents. Moreover, silica‐coated magnetite NPs with high coercivity are potentially suitable candidates for hyperthermia and ZnO‐coated Fe₃ O₄ is potentially suitable for photothermal therapy.Inspec keywords: iron compounds, carbon, silicon compounds, zinc compounds, nanomedicine, biomedical materials, nanofabrication, nanoparticles, magnetic particles, coatings, X‐ray diffraction, magnetometry, transmission electron microscopy, Fourier transform spectra, infrared spectra, biomedical MRI, hyperthermia, radiation therapyOther keywords: biomedical applications, magnetic core‐shell nanoparticles, CSNP, cellular uptake, biodistribution, coating material, biocompatible coating materials, co‐precipitation, dextran, zincite, silica, X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy, Fourier transform infrared spectroscopy, magnetic resonance imaging contrast agents, hyperthermia, photothermal therapy, SiO₂ ‐Fe₃ O₄ , ZnO‐Fe₃ O₄      

MPGraph: multi‐view penalised graph clustering for predicting drug–target interactions

Identifying drug–target interactions has been a key step for drug repositioning, drug discovery and drug design. Since it is expensive to determine the interactions experimentally, computational methods are needed for predicting interactions. In this work, the authors first propose a single‐view penalised graph (SPGraph) clustering approach to integrate drug structure and protein sequence data in a structural view. The SPGraph model does clustering on drugs and targets simultaneously such that the known drug–target interactions are best preserved in the clustering results. They then apply the SPGraph to a chemical view with drug response data and gene expression data in NCI‐60 cell lines. They further generalise the SPGraph to a multi‐view penalised graph (MPGraph) version, which can integrate the structural view and chemical view of the data. In the authors'' experiments, they compare their approach with some comparison partners, and the results show that the SPGraph could improve the prediction accuracy in a small scale, and the MPGraph can achieve around 10% improvements for the prediction accuracy. They finally give some new targets for 22 Food and Drug Administration approved drugs for drug repositioning, and some can be supported by other references.Inspec keywords: graphs, drug delivery systems, drugs, proteins, molecular biophysics, molecular configurations, optimisation, eigenvalues and eigenfunctions, Laplace equations, cancer, cellular biophysics, gene therapy, medical computingOther keywords: MPGraph, multiview penalised graph clustering, drug‐target interactions, drug repositioning, drug discovery, drug design, computational methods, single‐view penalized graph clustering approach, drug structure, protein sequence data, SPGraph model, optimisation problem, spectral clustering, eigenvalue decomposition, Laplacian model, gene expression data, NCI‐60 cell lines     

Tip‐mould microcontact printing for functionalisation of optical microring resonator

We present an approach to functionalise optical microring resonators as hybridisation platforms, using tip‐mould reactive microcontact printing process. Derived from reactive microcontact printing using an ad hoc mould of polydimethylsiloxane (PDMS), the method functionalises single microring resonator with a target‐specific capture agent. The authors report the functionalisation of silicon nitride (SiN) 200μm diameter microring resonator with single‐strand DNA and the hybridisation detection of 100 nM target analyte, while concurrently monitoring not‐functionalised microring as a control sensor. Results show that the functionalisation approach permits to address single microring resonators with mutual distance lower than 100μm with high precision, enabling a better integration of multiple spotting zones on the chip concerning traditional functionalisation procedures.Inspec keywords: DNA, molecular biophysics, biosensors, microsensors, optical resonators, microcavities, soft lithography, polymers, silicon compounds, integrated optics, optical sensors, micro‐opticsOther keywords: tip‐mould reactive microcontact printing, optical microring resonator, hybridisation platforms, polydimethylsiloxane, PDMS, target‐specific capture agent, single‐strand DNA, hybridisation detection, multiple spotting zones, chip, size 200 mum, SiN     

Development of tamoxifen‐loaded surface‐modified nanostructured lipid carrier using experimental design: in vitro and ex vivo characterisation

The present study aimed to develop a surface‐modified biocompatible nanostructured lipid carrier (NLCs) system using polyoxyethylene (40) stearate (POE‐40‐S) to improve the oral bioavailability of poorly water‐soluble Biopharmaceutics Classification System class‐II drug like tamoxifen (TMX). Also aimed to screen the most influential factors affecting the particle size (PS) using Taguchi (L₁₂ (2¹¹)) orthogonal array design (TgL₁₂ OA). Then, to optimize the TMX loaded POE‐40‐S (P) surface‐modified NLCs (TMX‐loaded‐PEG‐40‐S coated NLC (PNLCs) or PNLCs) by central composite design (CCD) using a four‐factor, five‐level model. The most influential factors affecting the PS was screened and optimized. The in‐vitro study showed that increased drug‐loading (DL) and encapsulation efficiency (EE), decreased PS and charge, sustained drug release for the prolonged period of the time with good stability and suppressed protein adsorption. The Ex‐vivo study showed that decreased mucous binding with five‐fold enhanced permeability of PNLC formulation after surface modification with POE‐40‐S. The in‐vitro cytotoxicity study showed that the blank carrier is biocompatible and cytotoxicity of the formulation was dependent on the concentration of the drug. Finally, it can be concluded that the surface‐modified PNLCs formulation was an effective, biocompatible, stable formulation in the enhancement of dissolution rate, solubility, stability with reduced mucus adhesion and increased permeability thereby which indicates its enhanced oral bioavailability.Inspec keywords: nanoparticles, cellular biophysics, solubility, drug delivery systems, toxicology, adsorption, adhesion, dissolving, biomedical materials, encapsulation, polymers, proteins, nanomedicine, permeability, particle size, electrokinetic effectsOther keywords: water‐soluble BCS class‐II, TgL₁₂ OA, TMX‐loaded POE‐40‐S surface‐modified NLC, surface‐modified PNLC formulation, lipid‐based NLC system, oral bioavailability, stable formulation, biocompatible formulation, blank carrier, in vitro cytotoxicity, surface modification, PNLC formulation, drug release, central composite design, orthogonal array design, encapsulation efficiency, steric stabilisation effect, particle size, dissolution rate, polyoxyethylene stearate, surface‐modified biocompatible carrier system, systemic toxicity, water‐soluble drug, tamoxifen‐loaded surface‐modified nanostructured lipid carrier     

Catalytic reduction in 4‐nitrophenol using Actinodaphne madraspatana Bedd leaves‐mediated palladium nanoparticles

There is a growing demand for the development of non‐toxic, cost‐effective, and environmentally benign green synthetic strategy for the production of metal nanoparticles. Herein, the authors have reported Actinodaphne madraspatana Bedd (AMB) leaves as the bioreducing agent for the synthesis of palladium nanoparticles (PdNPs) and its catalytic activity was evaluated for the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol with undisruptive effect on human health and environment. The broad and continuous absorbance spectrum obtained in the UV–visible region indicated the formation of PdNPs. The synthesized PdNPs were found to be crystalline, spherical, and quasi‐spherical in shape with an average particle size of 13 nm was confirmed by X‐ray diffractometer and transmission electron microscope. Fourier transform infrared spectra revealed the active photo constituents present in the aqueous extract of AMB involved in the bioreduction of palladium ions to PdNPs. The catalytic activity of biosynthesized PdNPs was demonstrated for the reduction of 4‐NP via electron‐relay process. Also, the influential parameters such as catalyst dosage, concentration of 4‐NP, and sodium borohydride were studied in detail. From the present study, PdNPs were found to be a potential nanocatalyst for nitro compound reduction and also for environmental remediation of wastewater effluents from industries.Inspec keywords: palladium, nanoparticles, particle size, nanofabrication, catalysis, catalysts, reduction (chemical), organic compounds, ultraviolet spectra, visible spectra, X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectraOther keywords: nitro compound reduction, environmental remediation, wastewater effluents, Pd, nanocatalyst, sodium borohydride, 4‐NP concentration, catalyst dosage, electron‐relay process, bioreduction, aqueous extract, Fourier transform infrared spectra, transmission electron microscopy, X‐ray diffractometry, particle size, quasispherical shape, spherical shape, crystalline shape, UV‐visible abosprtion spectra, human environment, human health, 4‐aminophenol, catalytic activity, bioreducing agent, metal nanoparticles, Actinodaphne madraspatana Bedd leaves‐mediated palladium nanoparticles, 4‐nitrophenol, catalytic reduction     

Biogenic synthesis of biopolymer‐based Ag–Au bimetallic nanoparticle constructs and their anti‐proliferative assessment

This study reports an eco‐friendly‐based method for the preparation of biopolymer Ag–Au nanoparticles (NPs) by using gum kondagogu (GK; Cochlospermum gossypium), as both reducing and protecting agent. The formation of GK‐(Ag–Au) NPs was confirmed by UV‐absorption, fourier transformed infrared (FTIR), atomic force microscopy (AFM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The GK‐(Ag–Au) NPs were of 1–12 nm in size. The anti‐proliferative activity of nanoparticle constructs was assessed by MTT assay, confocal microscopy, flow cytometry and quantitative real‐time polymerase chain reaction (PCR) techniques. Expression studies revealed up‐regulation of p53, caspase‐3, caspase‐9, peroxisome proliferator‐activated receptors (PPAR) PPARa and PPARb, genes and down‐regulation of Bcl‐2 and Bcl‐x(K) genes, in B16F10 cells treated with GK‐(Ag–Au) NPs confirming the anti‐proliferative properties of the nanoparticles.Inspec keywords: nanomedicine, transmission electron microscopy, genetics, cellular biophysics, molecular biophysics, enzymes, nanofabrication, gold, silver, scanning electron microscopy, nanoparticles, Fourier transform infrared spectra, atomic force microscopy, biomedical materialsOther keywords: size 1.0 nm to 12.0 nm, Ag‐Au, anti‐proliferative assessment, eco‐friendly‐based method, anti‐proliferative activity, anti‐proliferative properties, biopolymer‐based Ag–Au bimetallic nanoparticle, Cochlospermum gossypium, gum kondagogu, biopolymer preparation, biogenic synthesis, UV‐absorption, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, MTT assay, confocal microscopy, flow cytometry, caspase‐3, caspase‐9, peroxisome proliferator‐activated receptors, Bcl‐2 gene, Bcl‐x(K) gene, B16F10 cells