Fluorescein isothiocyanate‐dyed mesoporous silica nanoparticles for tracking antioxidant delivery

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

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     

Folate encapsulation in PEG‐diamine grafted mesoporous Fe3 O4 nanoparticles for hyperthermia and in vitro assessment

Effective and targeted delivery of the antitumour drugs towards the specific cancer spot is the major motive of drug delivery. In this direction, suitably functionalised magnetic iron oxide nanoparticles (NPs) have been utilised as a theranostic agent for imaging, hyperthermia and drug delivery applications. Herein, the authors reported the preparation of multifunctional polyethyleneglycol‐diamine functionalised mesoporous superparamagnetic iron oxide NPs (SPION) prepared by a facile solvothermal method for biomedical applications. To endow targeting ability towards tumour site, folic acid (FA) is attached to the amine groups which are present on the NPs surface by 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide hydrochloride/N‐hydroxysuccinimide chemistry. FA attached SPION shows good colloidal stability and possesses high drug‐loading efficiency of ∼ 96% owing to its mesoporous nature and the electrostatic attachment of daunosamine (NH₃ ⁺) group of doxorubicin (DOX) towards the negative surface charge of carboxyl and hydroxyl group. The NPs possess superior magnetic properties in result endowed with high hyperthermic ability under alternating magnetic field reaching the hyperthermic temperature of 43°C within 223 s at NP''s concentration of 1 mg/ml. The functionalised NPs possess non‐appreciable toxicity in breast cancer cells (MCF‐7) which is triggered under DOX‐loaded SPION.Inspec keywords: nanoparticles, nanocomposites, mesoporous materials, colloids, biochemistry, nanomagnetics, molecular biophysics, tumours, superparamagnetism, drugs, toxicology, biomedical materials, nanofabrication, hyperthermia, cancer, magnetic particles, cellular biophysics, nanomedicine, iron compounds, drug delivery systems, filled polymers, biological organs, liquid phase depositionOther keywords: NP surface, colloidal stability, drug‐loading efficiency, hydroxyl group, magnetic properties, high hyperthermic ability, magnetic field, DOX‐loaded SPION, folate encapsulation, targeted delivery, antitumour drugs, specific cancer spot, magnetic iron oxide nanoparticles, theranostic agent, drug delivery applications, multifunctional polyethyleneglycol‐diamine, facile solvothermal method, biomedical applications, tumour site, amine groups, mesoporous superparamagnetic nanoparticles, PEG‐diamine grafted mesoporous nanoparticles, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide hydrochloride‐N‐hydroxysuccinimide chemistry, daunosamine group, carboxyl group, breast cancer cells, temperature 43.0 degC, Fe₃ O₄      

Preparation and characterisation of silica‐based nanoparticles for cisplatin release on cancer brain cells

In the present work, the preparation, characterisation, and efficiency of two different silica nanostructures as release vehicles of Cisplatin are reported. The 1‐hexadeciltrimethyl‐ammonium bromide templating agent was used to obtain mesoporous silica nanoparticles which were later loaded with Cisplatin. While sol–gel silica was very fast prepared using an excess of acetic acid during the hydrolysis–condensation reactions of tetraethylorthosilicate and at the same time the Cisplatin was added. Several physicochemical techniques including spectroscopies, electronic microscopy, X‐ray diffraction, N₂ adsorption–desorption were used to characterise the silica nanostructures. An in vitro Cisplatin release test was carried out using artificial cerebrospinal fluid. Finally, the toxicity of all silica nanostructures was tested using the C6 cancer cell line. The spectroscopic results showed the suitable stabilisation of Cisplatin into the two different silica nanostructures. A large surface area was obtained for the mesoporous silica nanoparticles, while low areas were obtained in the silica nanoparticles. Cisplatin was released faster from mesoporous silica channels than from inside of aggregates nanoparticles silica. Cisplatin alone, as well as, cisplatin released from both silica nanostructures exerted a toxic effect on cancer cells. In contrast, both silica structures without the drug did not exert any toxic effect.Inspec keywords: cellular biophysics, desorption, adsorption, biomedical materials, sol‐gel processing, silicon compounds, cancer, toxicology, nanofabrication, brain, condensation, mesoporous materials, nanoparticles, X‐ray diffraction, nanomedicine, drugs, aggregates (materials)Other keywords: mesoporous silica channels, silica‐based nanoparticles, cancer brain cells, silica nanostructures, 1‐hexadeciltrimethyl‐ammonium bromide, mesoporous silica nanoparticles, sol‐gel silica, C6 cancer cell line, in vitro cisplatin release test, C6 cancer cell line, acetic acid, hydrolysis‐condensation reactions, tetraethylorthosilicate, physicochemical techniques, electronic microscopy, X‐ray diffraction, N₂ adsorption‐desorption, artificial cerebrospinal fluid, toxicity, toxic effect, N₂ , SiO₂      

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      

Catalytic hydrolysis of cellobiose using different acid‐functionalised Fe3 O4 magnetic nanoparticles

The present study demonstrated the preparation of three different acid‐functionalised magnetic nanoparticles (MNPs) and evaluation for their catalytic efficacy in hydrolysis of cellobiose. Initially, iron oxide (Fe₃ O₄)MNPs were synthesised, which further modified by applying silica coating (Fe₃ O₄ ‐MNPs@Si) and functionalised with alkylsulfonic acid (Fe₃ O₄ ‐MNPs@Si@AS), butylcarboxylic acid (Fe₃ O₄ ‐MNPs@Si@BCOOH) and sulphonic acid (Fe₃ O₄ ‐MNPs@Si@SO₃ H) groups. The Fourier transform infrared analysis confirmed the presence of above‐mentioned acid functional groups on MNPs. Similarly, X‐ray diffraction pattern and energy dispersive X‐ray spectroscopy analysis confirmed the crystalline nature and elemental composition of MNPs, respectively. TEM micrographs showed the synthesis of spherical and polydispersed nanoparticles having diameter size in the range of 20–80 nm. Cellobiose hydrolysis was used as a model reaction to evaluate the catalytic efficacy of acid‐functionalised nanoparticles. A maximum 74.8% cellobiose conversion was reported in case of Fe₃ O₄ ‐MNPs@Si@SO₃ H in first cycle of hydrolysis. Moreover, thus used acid‐functionalised MNPs were magnetically separated and reused. In second cycle of hydrolysis, Fe₃ O₄ ‐MNPs@Si@SO₃ H showed 49.8% cellobiose conversion followed by Fe₃ O₄ ‐MNPs@Si@AS (45%) and Fe₃ O₄ ‐MNPs@Si@BCOOH (18.3%). However, similar pattern was reported in case of third cycle of hydrolysis. The proposed approach is considered as rapid and convenient. Moreover, reuse of acid‐functionalised MNPs makes the process economically viable.Inspec keywords: scanning electron microscopy, catalysis, magnetic separation, magnetic particles, silicon compounds, iron compounds, nanomagnetics, coatings, X‐ray chemical analysis, nanoparticles, X‐ray diffraction, nanofabrication, Fourier transform infrared spectra, organic compounds, nanocompositesOther keywords: catalytic efficacy, alkylsulfonic acid, butylcarboxylic acid, energy dispersive X‐ray spectroscopy analysis, spherical polydispersed nanoparticles, cellobiose hydrolysis, acid‐functionalised MNPs, acid functional groups, cellobiose conversion, acid‐functionalised magnetic nanoparticle, silica coating, sulphonic acid, Fourier transform infrared analysis, SEM micrograph, X‐ray diffraction pattern, size 20.0 nm to 80.0 nm, Fe₃ O₄ , Si, SiO₂      

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     

Mesoporous titanium dioxide nanocatalyst: a recyclable approach for one‐pot synthesis of 5‐hydroxymethylfurfural

The present study deals with the production of 5‐hydroxymethyl furfural (HMF) from fructose by chemo‐conversion method using chemical catalyst, conventionally achieved by microwave‐assisted dehydration process. Five different chemical catalysts, namely oxalic acid, phosphotungstic acid and mesoporous titanium dioxide nanoparticles (TNPs) were compared at constant conditions of which TNPs yielded a maxima of 33.95%. The optimum temperature and catalyst loading were found to be 200°C and 20%, respectively, at a 5% optimum substrate concentration during 15 min optimum reaction time to yield 61.53% HMF. The efficiency of synthesised TNPs was investigated further through reusability studies. TNPs were properly recycled and the catalytic activity recovery was good even after a 14 batch reactions. The specific surface area of the TNP obtained is about 105.46 m² /g and its pore‐volume is about 0.42 cm³ /g according to single point adsorption. A large accessible surface area combined with a minimal pore size (15.92 nm) obtained with mesoporous TNPs is desirable for better catalyst loading, high‐yield HMF, retention and reduced diffusion constraints.Inspec keywords: mesoporous materials, recycling, production management, dissociation, nanoparticles, nanotechnologyOther keywords: mesoporous titanium dioxide nanocatalyst, recyclable approach, one‐pot synthesis, 5‐hydroxymethyl furfural production, HMF, chemo‐conversion method, chemical catalyst, microwave‐assisted dehydration process, oxalic acid, phosphotungstic acid, mesoporous titanium dioxide nanoparticles, TNP     

Functionalisation of Fe3 O4 nanoparticles by 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide enhances the apoptosis of human breast cancer MCF‐7 cells

Cancer is a major cause of death. Thus, the incidence and mortality rate of cancer is globally important. Regarding vast problems caused by chemotherapy drugs, efforts have progressed to find new anti‐cancer drugs. Pyrazole derivatives are known as components with anti‐cancer properties. In here, Fe₃ O₄ nanoparticles were first functionalized with (3‐chloropropyl) trimethoxysilane, then 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide (P) was anchored on the surface of magnetic nanoparticles (PL). The synthesized nano‐compounds were characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, Zeta potential, dynamic light scattering, and energy‐dispersive x‐ray spectrometry analyses. The cytotoxicity effect was evaluated using MTT assay, apoptosis test by Flow cytometry, cell cycle analysis, Caspase‐3 activity assay and Hoechst staining on MCF‐7 cell line. The high toxicity for tumor cells and low toxicity on normal cells (MCF10A) was considered as an important feature (selectivity index, 10.9). Based on results, the IC50 for P and PL compounds were 157.80 and 131.84 μM/ml respectively. Moreover, apoptosis inducing, nuclear fragmentation, Caspase 3 activity and induction of cell rest in sub‐G1 and S phases, were also observed. The inhibitory effect of PL was significantly higher than P, which could be due to the high penetrability of Fe₃ O₄ nanoparticles.Inspec keywords: magnetic particles, drugs, nanomedicine, biochemistry, cancer, light scattering, scanning electron microscopy, molecular biophysics, iron compounds, electrokinetic effects, nanofabrication, tumours, X‐ray diffraction, cellular biophysics, nanoparticles, biomedical materials, toxicology, nanomagnetics, Fourier transform infrared spectra, enzymes, X‐ray chemical analysisOther keywords: anticancer properties, Fe₃ O₄ magnetic nanoparticles, (3‐chloropropyl) trimethoxysilane, energy‐dispersive X‐ray spectrometry, cell cycle analysis, MCF‐7 cell line, tumour cells, human breast cancer MCF‐7 cells, mortality rate, pyrazole derivatives, 2‐((pyrazol‐4‐yl) methylene) hydrazinecarbothioamide, chemotherapy drugs, heterocyclic components, nanocompounds, X‐ray diffraction, scanning electron microscopy, Zeta potential, dynamic light scattering, cytotoxicity effect, MTT assay, apoptosis test, caspase‐3 activity assay, Hoechst staining, MCF10A nontumourigenic cells, cell rest induction, nuclear fragmentation, Fe₃ O₄      

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     

In vitro evaluation of biodegradable nHAP‐Chitosan‐Gelatin‐based scaffold for tissue engineering application

The present study focuses on fabrication and characterisation of porous composite scaffold containing hydroxyapatite (HAP), chitosan, and gelatin with an average pore size of 250–1010 nm for improving wound repair and regeneration by Electrospinning method. From the results of X ‐Ray Diffraction (XRD) study, the peaks correspond to crystallographic structure of HAP powder. The presence of functional group bonds of HAP powder, Chitosan and scaffold was studied using Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology of the scaffold was observed using Scanning Electron Microscope (SEM). The Bioactivity of the Nano composite scaffolds was studied using simulated body fluid solution at 37 ± 1°C. The biodegradability test was studied using Tris‐Buffer solution for the prepared nanocomposites [nano Chitosan, nano Chitosan gelatin, Nano based Hydroxyapatite Chitosan gelatin]. The cell migration and potential biocompatibility of nHAP‐chitosan‐gelatin scaffold was assessed via wound scratch assay and were compared to povedeen as control. Cytocompatibility evaluation for Vero Cells using wound scratch assay showed that the fabricated porous nanocomposite scaffold possess higher cell proliferation and growth than that of povedeen. Thus, the study showed that the developed nanocomposite scaffolds are potential candidates for regenerating damaged cell tissue in wound healing process.Inspec keywords: nanofabrication, tissue engineering, electrospinning, wounds, cellular biophysics, scanning electron microscopy, surface morphology, X‐ray diffraction, biomedical materials, nanomedicine, porosity, biodegradable materials, nanoporous materials, calcium compounds, gelatin, nanocomposites, Fourier transform infrared spectra, nanoparticles, precipitation (physical chemistry)Other keywords: average pore size, wound repair, crystallographic structure, HAP powder, functional group bonds, simulated body fluid solution, biodegradability test, Tris‐Buffer solution, cell migration, wound scratch assay, tissue engineering, electrospinning method, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, biocompatibility, cytocompatibility, porous nanocomposite scaffold, cell tissue, nHAP‐chitosan‐gelatin scaffold composites, wet chemical precipitation method, surface morphology, nanohydroxyapatite‐nanochitosan‐gelatin scaffold composites, cell proliferation, wound healing, (Ca₁₀ (PO₄)₆ (OH)₂)     

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     

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     

Facile synthesis by a covalent binding reaction for pH‐responsive drug release of carboxylated chitosan coated hollow mesoporous silica nanoparticles

In this study, a promising drug nano‐carrier system consisting of mono‐dispersed and pH sensitive carboxylated chitosan‐hollow mesoporous silica nanoparticles (Ccs‐HMSNs) suitable for the treatment of malignant cells was synthesised and investigated. At neutral pH, the Ccs molecules are orderly aggregated state, which could effectively hinder the release of loaded drug molecules. However, in slightly acidic environment, Ccs chains are heavily and flexibly entangled in gel state, which would enhance the subsequent controlled release of the loaded drug. Using doxorubicin hydrochloride (DOX•HCl) as the drug model, their results demonstrated that the system had an excellent loading efficiency (64.74 μg/mg Ccs‐HMSNs) and exhibited a pH‐sensitive release behaviour. Furthermore, confocal laser scanning microscopy revealed that the Ccs‐HMSNs nanocomposite could effectively deliver and release DOX•HCl to the nucleus of HeLa cells, thereby inducing apoptosis. In addition, MTT assay also confirmed that DOX•HCl loaded Ccs‐HMSNs (DOX•HCl@Ccs‐HMSNs) exhibited a good anticancer effect on HeLa cells with a time‐dependent manner. Finally, haemolysis experiment showed Ccs‐HMSNs had no haemolytic activity at all the tested concentrations (5–320 μg/mL). Thus, this biocompatible and effective nano‐carrier system will have potential applications in controllable drug delivery and cancer therapy.Inspec keywords: drug delivery systems, mesoporous materials, silicon compounds, nanoparticles, nanocomposites, nanofabrication, drugs, nanomedicine, biomedical materials, pH, aggregation, gels, optical microscopy, cellular biophysics, cancer, filled polymersOther keywords: facile synthesis, covalent binding reaction, pH‐responsive drug release, carboxylated chitosan coated hollow mesoporous silica nanoparticles, drug nanocarrier system, monodispersed carboxylated chitosan‐hollow mesoporous silica nanoparticles, pH sensitive carboxylated chitosan‐hollow mesoporous silica nanoparticles, malignant cell treatment, neutral pH, orderly aggregated state, loaded drug molecules, acidic environment, gel state, doxorubicin hydrochloride, drug model, confocal laser scanning microscopy, nanocomposite, HeLa cells, apoptosis, MTT assay, anticancer effect, haemolysis experiment, biocompatible nanocarrier system, drug delivery, cancer therapy, SiO₂      

Honokiol–camptothecin loaded graphene oxide nanoparticle towards combinatorial anti‐cancer drug delivery

Honokiol (HK) is a natural product isolated from the bark, cones, seeds and leaves of plants belonging to the genus Magnolia. It possesses anti‐cancer activity which can efficiently impede the growth and bring about apoptosis of a diversity of cancer cells. The major concerns of using HK are its poor solubility and lack of targeted drug delivery. In this study, a combinatorial drug is prepared by combining HK and camptothecin (CPT). Both CPT and HK belong to the Magnolian genus and induce apoptosis by cell cycle arrest at the S‐phase and G1 phase, respectively. The combinatorial drug thus synthesised was loaded onto a chitosan functionalised graphene oxide nanoparticles, predecorated with folic acid for site‐specific drug delivery. The CPT drug‐loaded nanocarrier was characterised by X‐ray diffractometer, scanning electron microscope, transmission electron microscope, UV–vis spectroscopy and fluorescence spectroscopy, atomic force microscopy. The antioxidant properties, haemolytic activity and anti‐inflammatory activities were analysed. The cellular toxicity was analysed by 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐Diphenyltetrazolium Bromide (MTT assay) and Sulforhodamine B (SRB) assay against breast cancer (MCF‐7) cell lines.Inspec keywords: nanofabrication, cancer, nanoparticles, atomic force microscopy, graphene, scanning electron microscopy, cellular biophysics, toxicology, transmission electron microscopy, drug delivery systems, nanomedicine, tumours, solubilityOther keywords: targeted drug delivery, combinatorial drug, Magnolian genus, apoptosis, cell cycle, chitosan functionalised graphene oxide nanoparticles, site‐specific drug delivery, CPT drug‐loaded nanocarrier, transmission electron microscope, fluorescence spectroscopy, haemolytic activity, antiinflammatory activities, breast cancer cell lines, honokiol–camptothecin loaded graphene oxide nanoparticle, combinatorial anti‐cancer drug delivery, natural product, genus Magnolia, anticancer activity, cancer cells     

High‐efficiency Ni2+ ‐NTA/PAA magnetic beads with specific separation on His‐tagged protein

To effective capture and universal enrichment of His‐tagged protein, polyacrylic acid (PAA) brushes were used to encapsulate Fe₃ O₄ nanoparticles, connect NTA, and Ni²⁺ to prepare magnetic beads. These materials provide many advantages, such as excellent stability, tuneable particle size, and a surface for further functionalisation with biomolecules. His‐tagged green fluorescence protein (GFP) was separated efficiently, and the binding capacity of Fe₃ O₄ /MPS@PAA/NTA‐Ni²⁺ was 93.4 mg/g. Compared with High‐Affinity Ni‐NTA Resin and Ni‐NTA Magnetic Agarose Beads, Fe₃ O₄ /MPS@PAA/NTA‐Ni²⁺ nanocomposites exhibited higher separation efficiency and binding capacity towards His‐tagged GFP. Moreover, the selectivity and recyclability of them for the target proteins were maintained well after six cycles. This study would widen the application of PAA in constructing multifunctional nanocomposites for biomedical fields.Inspec keywords: polymers, proteins, nickel, particle size, biochemistry, resins, nanocomposites, molecular biophysics, nanofabrication, separation, nanoparticles, encapsulation, iron compounds, nanomedicine, biomedical materials, nanomagneticsOther keywords: polyacrylic acid brushes, His‐tagged green fluorescence protein, binding capacity, separation efficiency, His‐tagged GFP, target proteins, Ni‐NTA magnetic agarose beads, nanoparticles, biomolecules, high‐affinity Ni‐NTA resin, nanocomposites, particle size, Fe₃ O₄ ‐Ni     

In vivo study of anti‐epidermal growth factor receptor antibody‐based iron oxide nanoparticles (anti‐EGFR‐SPIONs) as a novel MR imaging contrast agent for lung cancer (LLC1) cells detection

Superparamagnetic iron oxide nanoparticles (SPIONs) conjugated with anti‐epidermal growth factor receptor monoclonal antibody (anti‐EGFR‐SPIONs) were characterised, and its cytotoxicity effects, ex vivo and in vivo studies on Lewis lung carcinoma (LLC1) cells in C57BL/6 mice were investigated. The broadband at 679.96 cm⁻¹ relates to Fe–O, which verified the formation of the anti‐EGFR‐Mab with SPIONs was obtained by the FTIR. The TEM images showed spherical shape 20 and 80 nm‐sized for nanoparticles and the anti‐EGFR‐SPIONs, respectively. Results of cell viability at 24 h after incubation with different concentrations of nanoprobe showed it has only a 20% reduction in cell viabilities. The synthesised nanoprobe administered by systemic injection into C57BL/6 mice showed good Fe tumour uptake and satisfied image signal intensity under ex vivo and in vivo conditions. A higher concentration of nanoprobe was achieved compared to non‐specific and control, indicating selective delivery of nanoprobe to the tumour. It is concluded that the anti‐EGFR‐SPIONs was found to be as an MR imaging contrast nanoagent for lung cancer (LLC1) cells detection.Inspec keywords: toxicology, biomedical MRI, lung, magnetic particles, biomedical materials, nanofabrication, nanomagnetics, transmission electron microscopy, nanomedicine, superparamagnetism, nanoparticles, iron compounds, proteins, cellular biophysics, molecular biophysics, cancer, tumours, Fourier transform infrared spectraOther keywords: MR imaging contrast agent, LLC1, superparamagnetic iron oxide nanoparticles, Lewis lung carcinoma cells, ex vivo conditions, cell viability, antiepidermal growth factor receptor antibody‐based iron oxide nanoparticles, antiEGFR‐SPION, lung cancer cell detection, antiepidermal growth factor receptor monoclonal antibody, cytotoxicity effects, C57BL‐6 mice, antiEGFR‐Mab, FTIR spectra, TEM, spherical shape, incubation, nanoprobe concentrations, systemic injection, Fe tumour uptake, image signal intensity, in vivo conditions, time 24.0 hour, Fe₃ O₄      

Signal amplification strategy using gold/N ‐trimethyl chitosan/iron oxide magnetic composite nanoparticles as a tracer tag for high‐sensitive electrochemical detection

This study presents a novel signal amplification method for high‐sensitive electrochemical immunosensing. Gold (Au)/N ‐trimethyl chitosan (TMC)/iron oxide (Fe₃ O₄) (shell/shell/core) nanocomposite was used as a tracing tag to label antibody. The tag was shown to be capable of amplifying the recognition signal by high‐density assembly of Au nanoparticles (NPs) on TMC/Fe₃ O₄ particles. The remarkable conductivity of AuNPs provides a feasible pathway for electron transfer. The method was found to be simple, reliable and capable of high‐sensitive detection of human serum albumin as a model, down to 0.2 pg/ml in the range of 0.25–1000 pg/ml. Findings of the present study would create new opportunities for sensitive and rapid detection of various analytes.Inspec keywords: gold, filled polymers, conducting polymers, iron compounds, magnetic particles, nanoparticles, nanocomposites, nanosensors, electrochemical sensors, proteins, molecular biophysics, biomagnetism, biosensorsOther keywords: signal amplification strategy, gold‐N‐trimethyl chitosan‐iron oxide magnetic composite nanoparticles, tracer tag, high‐sensitive electrochemical detection, high‐sensitive electrochemical immunosensing, antibody, high‐density assembly, AuNP conductivity, electron transfer, human serum albumin, FeO‐Au     

Enhanced stability of L‐asparaginase by its bioconjugation to poly(styrene‐co‐maleic acid) and Ecoflex nanoparticles

Acute lymphoblastic leukemia (ALL) is the white blood cell cancer in children. L‐asparaginase (L‐ASNase) is one of the first drugs used in ALL treatment. Anti‐tumor activity of L‐ASNase is not specific and indicates limited stability in different biological environments, in addition to its quick clearance from blood. The purpose of the present study was to achieve a new L‐ASNase polymer bioconjugate to improve pharmacokinetic, increase half‐life and stability of the enzyme. The conjugations were achieved by the cross‐linking agent of 1‐ethyl‐3‐(3‐ dimethylaminopropyl) carbodiimide (EDC) which activates the carboxylic acid groups of polymeric nanoparticles to create amide bond. EDC conjugated the L‐ASNase to two biodegradable polymers including; Ecoflex^® and poly (styrene‐co‐maleic acid) (PSMA) nanoparticles. To achieve optimal L‐ASNase nanoparticles the amounts of each polymer and the crosslinker were optimized and the nanoparticles were characterized according to their particle size, zeta potential and percent of conjugation of the enzyme. The results showed that conjugated enzyme had more stability against pH changes and proteolysis. It had lower Km value (indicating more affinity to the substrate) and greater half‐life in plasma and phosphate buffered saline, in comparison to native enzyme. Generally, the conjugated enzyme to PSMA nanoparticles showed greater results than Ecoflex^® nanoparticles.Inspec keywords: enzymes, polymer blends, nanomedicine, biomedical materials, blood, nanoparticles, cancer, molecular biophysics, molecular configurations, biochemistry, conducting polymers, electrokinetic effects, particle size, bonds (chemical), biodegradable materials, pHOther keywords: enhanced stability, L‐asparaginase, bioconjugation, poly(styrene‐co‐maleic acid), Ecoflex nanoparticles, acute lymphoblastic leukaemia, white blood cell cancer, children, drugs, ALL treatment, antitumour activity, biological environments, L‐ASNase polymer bioconjugate, pharmacokinetic, enzyme, crosslinking agent, amide bond, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide, carboxylic acid groups, polymeric nanoparticles, EDC conjugation, biodegradable polymers, PSMA nanoparticles, optimal L‐ASNase nanoparticles, particle size, zeta potential, pH changes, proteolysis, native enzyme, conjugated enzyme     

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