Honey‐incorporated nanofibre reduces replicative senescence of umbilical cord‐derived mesenchymal stem cells

Umbilical cord‐derived mesenchymal stem cells (UCDMSC) are attractive candidates for cell‐based regenerative medicine. However, they are susceptible to replicative senescence during repetitive passaging for in‐vitro expansion and induced senescence in an oxidative, inflammatory microenvironment in vivo. Aim of this study is to investigate if honey‐incorporated matrices can be employed to reduce senescence of UCDMSC. Matrices were prepared by electrospinning solutions of honey with poly‐vinyl alcohol (PVA). PVA:honey matrices exhibited free radical scavenging activity. Culture of UCDMSC on PVA:honey matrices showed improvement in cell proliferation compared to pure PVA nanofibres. Expression of vimentin indicated that mesenchymal phenotype is preserved after culturing on these matrices. Further, UCDMSC were serially subcultured and cells of two passages (P2 and P6) were evaluated for reactive oxygen species (ROS) load and senescence parameters. P6 cells showed a higher ROS load and β‐galactosidase (β‐gal) positive senescent cells compared to P2. However, culturing on PVA:honey substrates significantly reduced both ROS and β‐gal markers compared to cells on PVA substrates. Honey contains several antioxidant and anti‐inflammatory components, which can reduce the ROS‐related senescence. Thus, it is concluded that honey containing nanofibres can be effective substrates for stem cell‐based wound healing and regenerative medicine.Inspec keywords: molecular biophysics, nanofibres, nanomedicine, polymer fibres, cellular biophysics, nanofabrication, enzymes, biochemistry, electrospinning, wounds, biomedical materialsOther keywords: pure PVA nanofibres, UCDMSC, PVA:honey substrates, PVA substrates, ROS‐related senescence, honey containing nanofibres, stem cell‐based wound healing, honey‐incorporated nanofibre, replicative senescence, umbilical cord‐derived mesenchymal stem cells, cell‐based regenerative medicine, induced senescence, PVA:honey matrices, cell proliferation, honey‐incorporated matrices, electrospinning solutions, poly‐vinyl alcohol, free radical scavenging activity, vimentin expression, mesenchymal phenotype, reactive oxygen species load, senescence parameters, P6 cells, β‐galactosidase positive senescent cells, β‐gal markers, antiinflammatory components, antioxidant components     

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     

Formulation and characterisation of poly(lactic‐co‐glycolic acid) encapsulated clove oil nanoparticles for dental applications

This study investigated synthesis and characterisation of Nano‐PLGA (poly(lactic‐co‐glycolic acid))/CO (clove‐oil) nanoparticles. The delivery of drug‐loaded nanoparticles to demineralised dentin substrates and their morphological association with a two‐step etch‐and‐rinse adhesive system was studied. The effect of Nano‐PLGA/CO pretreatment on micro‐tensile bond strength of resin‐dentin bonding was scrutinised. This study employed CO‐containing PLGA nanoparticles as a delivery vehicle for sustainable drug release inside dentinal‐tubules for potential dental applications. Emulsion evaporation resulted in uniformly distributed negatively‐charged Nano‐PLGA/Blank and Nano‐PLGA/CO nanoparticles. Scanning electron microscopy/ transmission electron microscopy revealed even spherical nanoparticles with smooth texture. High CO‐loading and encapsulation were achieved. Moreover, controlled CO‐release was evidenced after 15 days, in‐vitro and ex‐vivo. Nanoparticles exhibited low initial toxicity towards human mesenchymal stem cells with excellent antibacterial properties. Nanoparticles penetration inside dentinal‐tubules indicated a close correlation with resin‐tags. Nano‐PLGA/CO pretreatment indicated reduction in short‐term bond strength of resin‐dentin specimens. Nano‐PLGA/CO as model drug‐loaded nanoparticles showed excellent metric and antibacterial properties, low toxicity and sustained CO release. However, the loading of nanoparticles with CO up to ∼10 mg (Nano‐PLGA/CO:10) did not adversely affect short‐term bond strength values. This drug‐delivery strategy could be further expanded to deliver other pulp‐sedative agents and medications with other dental relevance.Inspec keywords: nanoparticles, dentistry, encapsulation, filled polymers, nanofabrication, nanocomposites, nanomedicine, biomedical materials, drug delivery systems, adhesives, tensile strength, biomechanics, resins, proteins, molecular biophysics, biochemistry, emulsions, evaporation, scanning electron microscopy, transmission electron microscopy, texture, cellular biophysics, antibacterial activity, bonds (chemical)Other keywords: poly(lactic‐co‐glycolic acid) encapsulated clove oil nanoparticles, dental applications, drug‐loaded nanoparticle delivery, demineralised dentin substrates, morphological association, two‐step etch‐and‐rinse adhesive system, simulated pulpal pressure, nanoPLGA‐CO pretreatment, microtensile bond strength, resin‐dentin bonded specimens, CO‐containing PLGA nanoparticles, delivery vehicle, sustainable drug release, dentinal‐tubules, potential dental applications, emulsion evaporation, uniformly‐distributed negatively‐charged nanoPLGA‐blank, scanning electron microscopy‐transmission electron microscopy, spherical nanoparticles, smooth texture, high CO‐loading, controlled CO‐release, human mesenchymal stem cells, antibacterial properties, antibiofilm properties, deep nanoparticle penetration, resin‐tags, short‐term bond strength, resin‐dentin specimens, metric properties, antibacterial properties, sustained CO release, pulp‐sedative agents, time 15 d     

Controllable synthesis and characterisation of palladium (II) anticancer complex‐loaded colloidal gelatin nanoparticles as a novel sustained‐release delivery system in cancer therapy

Over the past few years, there have been several attempts to deliver anticancer drugs into the body. It has been shown that compared to other available carriers, colloidal gelatin nanoparticles (CGNPs) have distinct properties due to their exceptional physico‐chemical and biological characteristics. In this study, a novel water‐soluble palladium (II) anticancer complex was first synthesised, and then loaded into CGNPs. The CGNPs were synthesised through a two‐step desolvation method with an average particle size of 378 nm. After confirming the stability of the drug in the nanoparticles, the drug‐loaded CGNPs were tested for in vitro cytotoxicity against human breast cancer cells. The results showed that the average drug encapsulating efficiency and drug loading of CGNPs were 64 and 10 ± 2.1% (w/w), respectively. There was a slight shift to higher values of cumulative release, when the samples were tested in lower pH values. In addition, the in vitro cytotoxicity test indicated that the number of growing cells significantly decreased after 48 h in the presence of different concentrations of drug. The results also demonstrated that the released drug could bind to DNA by a static mechanism at low concentrations (0.57 µM) on the basis of hydrophobic and hydrogen binding interactions.Inspec keywords: cancer, drug delivery systems, drugs, palladium compounds, colloids, gelatin, nanoparticles, nanomedicine, biomedical materials, nanofabrication, nanocomposites, molecular biophysics, molecular configurations, pH, solubility, particle size, cellular biophysics, encapsulation, DNA, hydrophobicity, hydrogen bondsOther keywords: controllable synthesis, sustained‐release delivery system, cancer therapy, palladium (II) anticancer complex‐loaded colloidal gelatin nanoparticles, anticancer drug delivery, physicochemical characteristics, biological characteristics, therapeutic pathways, water‐soluble palladium (II) anticancer complex, two‐step desolvation method, particle size, drug stability, gelatin matrix, drug‐loaded CGNPs, in vitro cytotoxic activity, human breast cancer cells, average drug encapsulating efficiency, pH values, cell growth, drug concentrations, DNA, static mechanism, hydrophobic interaction, hydrogen binding interactions     

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      

Co–Sn–Cu oxides/graphene nanocomposites as green catalysts for preparing 1,8‐dioxo‐octahydroxanthenes and apoptosis‐inducing agents in MCF‐7 human breast cancer cells

In this work, Co–Sn–Cu oxides/graphene nanocomposite, 30–40 ± 0.5 nm in size, was synthesized by solid‐state microwave irradiation. This method presents several advantages such as operational simplicity, fast, low cost, safe and energy efficient, and suitability for production of high purity of nanoparticles. Other advantages of this method are there is no need for the use of solvent, fuel, and surfactant. Co–Sn–Cu oxides/graphene nanocomposites have been characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, energy‐dispersive X–ray spectroscopy, and UV–Vis spectroscopy. The synthesized nanocomposites were used as novel highly efficient catalysts for the synthesis of 1,8‐dioxo‐octahydroxanthenes at room temperature. The catalysts are recoverable and can be reused for six runs without loss of their activity. Also, the obtained nanocomposites exhibited significant anticancer activity against breast cancer cells and they could induce apoptosis in cancer cells.     

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      

Synthesis of biotin‐targeted chitosan/poly (methyl vinyl ether‐alt ‐maleic acid) copolymeric micelles for delivery of doxorubicin

Biotinylated chitosan/poly(methyl vinyl ether‐alt ‐maleic acid) (PMVEMA) copolymer was synthesised by an amide reaction in two steps. Structural characterisation was performed using ¹ HNMR and Fourier transform infra‐red (FTIR) spectra. Critical micelle concentration (CMC) of the copolymer was determined by pyrene as a fluorescent probe. Doxorubicin (DOX) was loaded in the micelles by the direct dissolution method. The effects of different variables including type of copolymer, copolymer concentration, stirring rate and stirring time were studied on the physicochemical properties of the micelles including: particle size, zeta potential, release efficiency and loading efficiency of nanoparticles using an irregular factorial design. The in vitro cytotoxicity of DOX‐loaded biotin‐targeted micelles was studied in HepG2 cells which over express biotin receptors by 3, 5‐[dimethylthiazol‐2‐yl]‐2, 5‐diphenyl tetrazolium bromide assay. The successful synthesis of the biotinylated copolymer of chitosan/PMVEMA was confirmed by FTIR and ¹ HNMR. The optimised micelles showed the CMC of 33 μg/ml, particle size of 247 ± 2 nm, zeta potential of +9.46 mV, polydispersity index of 0.22, drug‐loading efficiency of 71% and release efficiency of 84.5 ± 1.6%. The synthesised copolymer was not cytotoxic. The cytotoxicity of DOX‐loaded in targeted micelles on HepG2 cell line was about 2.2‐fold compared with free drug.Inspec keywords: biomedical materials, cellular biophysics, dissolving, drug delivery systems, drugs, electrokinetic effects, fluorescence, Fourier transform infrared spectra, particle size, polymer blends, spectrochemical analysis, toxicologyOther keywords: ¹ HNMR spectra, biotin‐targeted chitosan‐poly (methyl vinyl ether‐alt‐maleic acid) copolymeric micelles, doxorubicin delivery, amide reaction, structural characterisation, Fourier transform infrared spectra, pyrene, fluorescent probe, direct dissolution method, physicochemical properties, particle size, zeta potential, nanoparticles, irregular factorial design, in vitro cytotoxicity, DOX‐loaded biotin‐targeted micelles, 3, 5‐[dimethylthiazol‐2‐yl]‐2, 5‐diphenyl tetrazolium bromide assay, polydispersity index, drug‐loading efficiency, HepG2 cell line, voltage 9.46 mV     

Electrospinning of gelatin and gelatin/poly(l-lactide) blend and its characteristics for wound dressing

Gelatin nanofibres were electrospun from its aqueous acetic acid solution. Electrospinning parameters, such as concentration of aqueous acetic acid and gelatin solutions, electric field and spinning distance, were examined to investigate the electrospinnability of gelatin solutions and the morphology of gelatin nanofibrous mats. Nanofibrous mats from poly(l-lactide) (PLLA) and gelatin/PLLA solutions were obtained. The electrospun mats showed controlled evaporative water loss, promoted fluid drainage ability, and excellent biocompatibility, and therefore have a potential application as wound dressing.     

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

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

Facile nano‐free electrochemiluminescence biosensor for detection of sulphamethoxazole via tris(2,2′‐bipyridyl)ruthenium(II) and N ‐methyl pyrrolidone recognition

The electrochemiluminescence (ECL) system based on the ruthenium complex has become a powerful tool in the field of analytical chemistry. However, the non‐aqueous ECL luminescence system, which does not involve complex nano‐modification, has not been widely used for the determination of analytes. In this study, N ‐methyl pyrrolidone was selected as the solvent, and it could also act as a co‐reactant of Rubpy32+. Based on this, a simple ECL system without nanomaterials was established. Strong ECL was generated. Furthermore, a quenching effect between the excited state of Rubpy32+ and sulphamethoxazole (SMZ) was observed. Based on this, a sensitive ECL sensor for detecting SMZ is constructed. A linear relationship between ECL signal quenching intensity (ΔI) and the logarithm of SMZ concentration (log C) in the concentration range of 1 × 10⁻⁷ –1 × 10⁻⁵ mol/l is obtained. The limit of detection is as low as 3.33 × 10⁻⁹ mol/l. The method has been applied to the detection of SMZ in tap water samples with different concentration levels with satisfactory results, and the recovery was 95.3–102.6%.Inspec keywords: biosensors, electrochemical sensors, electroluminescence, chemiluminescence, organic compounds, electrochemistryOther keywords: ruthenium complex, analytical chemistry, nonaqueous ECL luminescence system, complex nanomodification, quenching effect, ECL signal quenching intensity, ECL sensor system, nanofree electrochemiluminescence biosensor system, sulphamethoxazole detection, tris(2,2′‐bipyridyl)ruthenium(II), N‐methyl pyrrolidone recognition, analyte determination, nanomaterials, SMZ concentration detection     

Effect of nanofiber on material properties of vapor-grown carbon nanofiber reinforced thermoplastic polyurethane (TPU/CNF) nanocomposites prepared by melt compounding

The present work deals with the preparation of the CNF based TPU nanocomposites by melt blending to explore the effect of state of dispersion and wt.% loading of CNF on material properties. In addition, the morphology, mechanical, thermal, rheological, and electrical properties of the nanocomposites have been evaluated through various characterization techniques with an aim to find the suitability of the nanocomposites for industrial applications. Transmission electron microscopy (TEM) study reveals that the CNFs exhibited a uniformly dispersed in TPU matrix. The thermal stability of the TPU evaluated by thermogravimetric analysis (TGA) showed significant increase with increased CNF content. It is observed that storage modulus (E′) and glass transition temperature (T_g) of the TPU matrix increases by the incorporation of CNF. The melting point (T_m) and the T_g of soft segments observed from the differential scanning calorimetry (DSC) were found to shift towards higher temperature with the inclusion of CNF.     

Effect of GNP functionalisation and multiple N ‐methylation of β ‐amyloid residue (32–37) on Gram‐positive bacterium

In the previous report, the authors showed the gold nanoparticle (GNP) functionalised multiple N ‐methylated fragments of the residue (32–37) of beta (β)‐amyloid protein (1–42), CGGIGLMVG and CGGGGGIGLMVG toward disruption of β ‐amyloid (1–42), the predominant component of senile plaques. Herein the in vitro antimicrobial activities of both normal and multiple N ‐methylated sequences of CGGIGLMVG and CGGGGGIGLMVG were screened and it was found that all the eight sequences including four (non‐functionalised with GNP) to possess activity against both Gram‐positive [Staphylococcus aureus (ATCC 43300) and Enterococcus faecalis (ATCC 5129)] and Gram‐negative [Escherichia coli (ATCC 35218), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 700603)] bacteria. Among them, N ‐methylated sequences CGGIGLMVG and CGGGGGIGLMVG shown remarkable activity against Gram‐positive bacteria.Inspec keywords: microorganisms, gold, nanoparticles, nanomedicineOther keywords: GNP functionalisation, N‐methylation, β‐amyloid residue, Gram‐positive bacterium, gold nanoparticle functionalised multiple N‐methylated fragments, beta β‐amyloid protein, CGGGGGIGLMVG, Staphylococcus aureus, ATCC 43300, Enterococcus faecalis, ATCC 5129, Escherichia coli, ATCC 35218, Pseudomonas aeruginosa, ATCC 27853, Klebsiella pneumoniae, ATCC 700603, Au     

Effect of green GO/Au nanocomposite on in‐vitro amplification of human DNA

Recently nanomaterials have attracted interest for increasing efficiency of polymerase chain reaction (PCR) systems. Here, the authors report on the usefulness of green graphene oxide/gold (GO/Au) nanocomposites for enhancement of PCR reactions. In this study, green GO/Au nanocomposite was prepared with Matricaria chamomilla extract as reducing/capping agent for site‐directed nucleation of Au^o atoms on surface of GO sheets. The as‐prepared green GO/Au nanocomposites were then characterised with UV–VIS spectrophotometer and scanning electron microscopy. Later, the effect of these nanocomposites was studied on end‐point and real‐time PCR employed for amplification of human glyceraldehyde‐3‐phosphate dehydrogenase gene. The results indicated that GO/Au nanocomposite can improve both end‐point and real‐time PCR methods at the optimum concentrations, possibly through interaction between GO/Au nanocomposite and the materials in PCR reaction, and through providing increased thermal convection by the GO surface as well as the Au nanostructures. In conclusion, it can be suggested that green GO/Au nanocomposite is a biocompatible and eco‐friendly candidate as enhancer of in‐vitro molecular amplification strategies.Inspec keywords: graphene, molecular biophysics, nucleation, enzymes, gold, nanofabrication, nanocomposites, scanning electron microscopy, nanoparticles, DNA, nanomedicine, ultraviolet spectra, visible spectra, graphene compoundsOther keywords: green GO/Au nanocomposite, polymerase chain reaction systems, green graphene oxide/gold, PCR reaction, as‐prepared green GO/Au nanocomposites, real‐time PCR methods, Au nanostructures, in‐vitro amplification, human DNA, Matricaria chamomilla extract, site‐directed nucleation, Au, CO, CO‐Au     

Liposome nano‐formulation with cationic polar lipid DOTAP and cholesterol as a suitable pH‐responsive carrier for molecular therapeutic drug (all‐trans retinoic acid) delivery to lung cancer cells

The molecular targeted drug ATRA demands a suitable carrier that delivers to the cancer site due to its poor bioavailability and drug resistance. ATRA, being a lipid with carboxylic acid, has been nano‐formulated as a cationic lipo‐ATRA with DOTAP:cholesterol:ATRA (5:4:1) and its pH‐responsive release, intracellular drug accumulation, and anticancer effect on human lung cancer (A549) cell line analysed. The analysis of the physicochemical characteristics of the developed lipo‐ATRA (0.8 µmol) revealed that the size of 231 ± 2.35 d.nm had a zeta potential of 6.4 ± 1.19 and an encapsulation efficiency of 93.7 ± 3.6%. The ATRA release from lipo‐ATRA in vitro was significantly (p ≤ 0.05) higher at acidic pH 6 compared to pH 7.5. The intracellular uptake of ATRA into lipo‐ATRA‐treated A549 cells was seven‐fold higher (0.007 ± 0.001 mg/ml) while only three‐fold uptake was observed in free ATRA treatment (0.003 ± 0.002 mg/ml). The lipo‐ATRA treatment caused a highly significant (p ≤ 0.001) decrease in percent cell viability at 48 h when compared with the free ATRA treatment. Overall, the results proved that the developed lipo‐ATRA has suitable physicochemical properties with enhanced ATRA release at acidic pH, while maintaining stability at physiologic pH and temperature. This resulted in an increased ATRA uptake by lung cancer cells with enhanced treatment efficiency. Hence, it is concluded that DOTAP lipo‐ATRA is a suitable carrier for ATRA delivery to solid cancer cells.     

Magnetic nanobiosorbent (MG‐Chi/Fe3O4) for dispersive solid‐phase extraction of Cu(II), Pb(II), and Cd(II) followed by flame atomic absorption spectrometry determination

Trace amounts of Cu (II), Pb (II), and Cd (II) in a wastewater sample were preconcentrated with a novel cross‐linked magnetic chitosan modified with a new synthesised methionine‐glutaraldehyde Schiff''s base (MG‐Chi/Fe₃O₄) as a dispersive solid‐phase extraction (DSPE) adsorbent. The adsorbed metal ions were then eluted with a specific volume of suitable solution and determined by flame atomic absorption spectrometry (FAAS). Various parameters affecting the extraction efficiency of the metal ions were investigated and optimised, including pH, amount of adsorbent, extraction time, type and volume rate of eluent, elution time, sample volume, and effect of interfering ions. The adsorption kinetics are more consistent with the pseudo‐second order model. The results were statistically interpreted and the analytical performance of the proposed method was found to have preconcentration factors of 55, 60, and 50 μg L⁻¹ for Cu(II), Pb(II), and Cd(II), respectively, limits of detection were 0.22, 0.24, and 0.10 μg L⁻¹ for Cu(II), Pb(II), and Cd(II), respectively, with a relative standard deviation (1.5%‐2.8 %), and the liner range was 5–1000 for Cu(II) and Pb(II) and 2.5–1000 for Cd(II). It was concluded that this method was suitable for successful simultaneous determination of Cu(II), Pb(II), and Cd(II) in industrial wastewater samples.     

Cytotoxicity of carboxyl carbon nanotubes on human embryonic lung fibroblast cells and its mechanism

The wide use in various fields and the great potentials in biomedical applications of carbon nanotubes highlight the need to study their toxicity and biocompatibility for recent years. This work aimed to investigate the cytotoxicity of carbon nanotubes on human embryonic lung fibroblast cells and their inter-related affecting factors. Three carboxyl modified carbon nanotubes, short carboxyl single-walled carbon nanotubes (SWCNTs-COOH), short carboxyl double-walled carbon nanotubes (DWCNTs-COOH) and short carboxyl multi-walled carbon nanotubes (MWCNTs-COOH) were chosen as subjects for the evaluation of carbon nanotubes cytotoxity. Different concentrations of carboxyl carbon nanotubes were incubated with human embryonic lung fibroblast (HELF) cells for 48?h, respectively, and the electron microscopy was used to observe the cell growth and morphology. The results showed that MWCNTs-COOH, which had a better dispersion in water was much more cytotoxic than the other two carbon nanotubes. From Cell Counting Kit-8 assay and acridine orange staining, MWCNTs-COOH could inhibit the cell growth and induce cell apoptosis with a dose–effect relationship and oxidative stress may be one of the mechanisms.     

Cell/surface interactions of human osteo-sarcoma (HOS) cells and micro-patterned polydimelthylsiloxane (PDMS) surfaces

This paper presents the results of an experimental study of the effects of three-dimensional micro-pattern geometry on cell/surface interactions and the adhesion between HOS cells and PDMS surfaces. Micro-grooves with well-controlled ridges and spacings were fabricated by curing poly-di-methy-siloxane (PDMS) in silicon molds produced by photolithography. HOS cells were then cultured onto these surfaces for durations of 6, 12 and 48 h. In cases, where the groove spacing was comparable to the spread cell size, the cells align well in the directions of microgrooves. However, as the ridge separation increases, the cell orientations become more random, and less dependent on ridge height and spacing. The actin cytoskeletal structure and the distribution of focal adhesions are also elucidated by immuno-fluorescence staining.     

Characterization of a PLGA sandwiched cell/fibrin tubular construct and induction of the adipose derived stem cells into smooth muscle cells

A poly(dl-lactic-co-glycolic acid) (PLGA) sandwiched adipose derived stem cell (ADSC)/fibrin tubular construct, fabricated using a step-by-step mold/extraction method, was characterized in this work. The ADSCs were also induced into smooth-muscle-like cells using growth factors such as hepatocyte growth factor (HGF), platelet-derived growth factor BB (PDGF-BB), transforming growth factor β1 (TGFβ1), and basic fibroblast growth factor (b-FGF). Compared with the non-induced cells, the proliferation ability of induced cells was much smaller. The PLGA sandwiched cell/hydrogel construct was shown to be useful for controlling the cellular microenvironment and cellular behaviors such as growth, migration, proliferation and differentiation. This strategy seems promising in tissue engineering and organ manufacturing.