Poly (vinyl alcohol)/poly (acrylamide‐ co ‐diallyldimethyl ammonium chloride) semi‐IPN hydrogels for ciprofloxacin hydrochloride drug delivery

Herein, the authors developed a new and potential semi‐interpenetrating polymer network (semi‐IPN) hydrogels of poly vinyl alcohol (PVA), acryl amide and diallyldimethyl ammonium chloride employing chemical cross‐linker N, N''‐methylene bisacrylamide (NNMBA) and ammonium persulphate as an initiator by radical polymerisation. To analyse the copolymer formation between two monomers and IPN cross‐linking reaction, the resulting hydrogel was characterised by Fourier transform infrared spectroscopy and the surface morphology was analysed using scanning electron microscopy. Differential scanning calorimetry and X‐ray diffraction studies were also carried out for investigating drug loading and distribution and swelling experiments were carried out for the uptake of water. In vitro release of ciprofloxacin hydrochloride from hydrogel was performed at intestinal conditions. The amount of PVA, NNMBA and total monomer concentration was found to strongly control the drug release behaviour from the hydrogels.Inspec keywords: hydrogels, polymer blends, biomedical materials, drug delivery systems, polymerisation, Fourier transform infrared spectra, surface morphology, scanning electron microscopy, differential scanning calorimetry, X‐ray diffraction, swelling, biological organs, ammonium compoundsOther keywords: PVA‐poly(acrylamide‐co‐diallyldimethyl ammonium chloride) semiIPN hydrogels, ciprofloxacin hydrochloride drug delivery, semiinterpenetrating polymer network hydrogels, polyvinyl alcohol, acryl amide, diallyldimethyl ammonium chloride, chemical crosslinker N,N''‐methylene bisacrylamide, ammonium persulphate, radical polymerisation initiator, NNMBA, copolymer formation, IPN crosslinking reaction, Fourier transform infrared spectroscopy, surface morphology, scanning electron microscopy, differential scanning calorimetry, X‐ray diffraction, drug loading, drug distribution, swelling, water uptake, in vitro ciprofloxacin hydrochloride release, intestinal conditions, total monomer concentration, drug release behaviour     

Polysaccharide nanofibrous scaffolds as a model for in vitro skin tissue regeneration

Tissue engineering and nanotechnology have advanced a general strategy combining the cellular elements of living tissue with sophisticated functional biocomposites to produce living structures of sufficient size and function at a low cost for clinical relevance. Xylan, a natural polysaccharide was electrospun along with polyvinyl alcohol (PVA) to produce Xylan/PVA nanofibers for skin tissue engineering. The Xylan/PVA glutaraldehyde (Glu) vapor cross-linked nanofibers were characterized by SEM, FT-IR, tensile testing and water contact angle measurements to analyze the morphology, functional groups, mechanical properties and wettability of the fibers for skin tissue regeneration. The cell-biomaterial interactions were studied by culturing human foreskin fibroblasts on Xylan/PVA Glu vapor cross-linked and Xylan/PVA/Glu blend nanofibrous scaffolds. The observed results showed that the mechanical properties (72 %) and fibroblast proliferation significantly increased up to 23 % (P < 0.05) in 48 h Glu vapor cross-linked nanofibers compared to 24 h Glu vapor cross-linked Xylan/PVA nanofibers. The present study may prove that the natural biodegradable Xylan/PVA nanofibrous scaffolds have good potential for fibroblast adhesion, proliferation and cell matrix interactions relevant for skin tissue regeneration.     

Structural and morphological changes in Poly(caprolactone)/poly(vinyl chloride) blends caused by UV irradiation

Films made from a blend of poly(ε-caprolactone) and poly(vinyl chloride) (PCL/PVC) retained high crystallinity in a segregated PCL phase. Structural and morphological changes produced when the films were exposed to high potency ultraviolet (UV) irradiation for 10 h were measured by UV-Vis spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). They were different to those observed with homopolymer PCL and PVC films treated under the same conditions. The FTIR spectra of the PCL/PVC blend suggest that blending decreased the susceptibility of the PCL to crystallize when irradiated. Similarly, although scanning electron micrographs of PCL showed evidence of growth of crystalline domains, particularly after UV irradiation, the images of PCL/PVC were fairly featureless. It is apparent that the degradation behavior is strongly influenced by the interaction of the two polymers in the amorphous phase.     

Fabrication of chitosan microparticles loaded in chitosan and poly(vinyl alcohol) scaffolds for tissue engineering application

In recent decades, the use of microparticle-mediated drug delivery is widely applied in the field of biomedical application. Here, we report the new dressing material with ciprofloxacin-loaded chitosan microparticle (CMP) impregnated in chitosan (CH) and poly(vinyl alcohol) (PVA) scaffold for effective delivery of drug in a sustained manner to the wound site. Moreover, the peculiar physiochemical and structural properties of the CH–CMP scaffold has proved better tensile strength and excellent swelling to achieve 82% of drug release. In vitro biocompatibility was done for both scaffold using NIH 3T3 fibroblasts and human keratinocytes (HaCaT) cell lines. In vitro fluorescent activity showed distinct biocompatibility with good cell adhesion and proliferation. However, the CH–CMP scaffold showed best result to act as promising biomaterial in effective drug delivery in tissue engineering.     

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     

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     

Porous Poly(ε‐caprolactone) Nerve Guide Filled with Porous Gelatin Matrix for Nerve Tissue Engineering

The preparation and characterization of PCL guides filled with a porous matrix of a freeze‐dried, genipin‐crosslinked gelatin sponge (GL/GP) is described. Porous guides are obtained by dip coating a rotating mandrel with a PCL/PEO blend solution followed by PEO solvent extraction. PCL/PEO 60/40 is selected as the optimal composition to obtain model porous membranes with suitable morphological properties to ensure nutrient permeation and moderate stiffness. GL/GP sponges show increased mechanical strength and water stability, compared to uncrosslinked GL sponges. GL/GP in the form of films, sponges and internal fillers support the in vitro adhesion and proliferation of Schwann like cells.     

Functionalization of poly(caprolactone) scaffolds by the surface mineralization for use in bone regeneration

The surface of a synthetic biopolymer scaffold was tailored by a mineralization with calcium phosphate for use as a functional bone tissue engineering matrix. Poly(ε-caprolactone) scaffold with a defined pore configuration constructed by a robocasting method was treated in a series of solutions involving steps of surface activation and calcium phosphate induction. The scaffold surface was completely covered with calcium phosphate nanocrystallites that had typical characteristics of bone mineral-like carbonate apatite. The scaffold with mineralized-surface demonstrated to support more favorable bone cell responses, including initial cell adhesion and proliferation and to allow higher loading of protein than the untreated-scaffold. The results suggest the developed scaffold has the potential for use as a bone regenerative matrix.     

One‐step method for the preparation of poly(methyl methacrylate) modified titanium‐bioactive glass three‐dimensional scaffolds for bone tissue engineering

A novel three‐dimensional (3D) titanium (Ti)‐doping meso‐macroporous bioactive glasses (BGs)/poly(methyl methacrylate) (PMMA) composite was synthesised using PMMA and EO₂₀ PO₇₀ EO₂₀ (P₁₂₃) as the macroporous and mesoporous templates, respectively. Unlike the usual calcination method, the acid steam technique was used to improve the polycondensation of Ti‐BGs, and then PMMA was partially extracted via chloroform to induce the macroporous structure. Simultaneously, the residual PMMA which remained in the wall enhanced the compressive strength to 2.4 MPa (0.3 MPa for pure BGs). It is a simple and green method to prepare the macro‐mesoporous Ti‐BGs/PMMA. The materials showed the 3D interconnected hierarchical structure (250 and 3.4 nm), making the fast inducing‐hydroxyapatite growth and the controlled drug release. Besides mentioned above, the good antimicrobial property and biocompatible of the scaffold also ensure it is further of clinical use. Herein, the fabricated materials are expected to have potential application on bone tissue regeneration.Inspec keywords: titanium, bone, tissue engineering, glass, materials preparation, biomedical materials, polymers, porous materials, drug delivery systems, nanomedicineOther keywords: poly(methyl methacrylate), PMMA preparation, 3D titanium‐bioactive glass scaffold, bone tissue engineering, titanium‐doping mesomacroporous bioactive glass, bioactive glass‐PMMA composite, macroporous template, mesoporous template, calcination method, acid steam technique, titanium‐bioactive glass polycondensation, macroporous structure, green method, macromesoporous titanium‐bioactive glass‐PMMA, 3D interconnected hierarchical structure, fast inducing‐hydroxyapatite growth, controlled drug release, bone tissue regeneration, Ti     

Dark self-enhancement in dichromated poly(vinyl alcohol) gratings: a detailed study

Experimental results concerning the real-time hologram recording process in dichromated poly(vinyl alcohol) are presented. Self-enhancement, the increase in diffraction efficiency of the holographic gratings in the dark after recording, is also presented. The influence of the recording parameters (pH, exposure energy, dichromate concentration) on the self-enhancement gain is shown. Maximum gain was 6, and self-enhancement occurred during the 3 days following the exposure. The results and a model for the reduction of chromium ions corresponding to the formation of the grating are discussed.     

聚乙烯醇修饰的碳纳米管在缓冲溶液中的溶解过程

采用水溶性的聚乙烯醇修饰多壁碳纳米管表面,研究了聚乙烯醇修饰的碳纳米管在水浴摇床Tris-HCl缓冲溶液中的溶解过程.通过红外光谱,差示扫描量热仪,透射电镜及X光衍射的方法对聚乙烯醇修饰的碳纳米管在溶解过程中的显微结构变化进行了研究.结果表明:浸泡21d后,聚乙烯醇修饰的碳纳米管部分溶解于缓冲溶液,形成无定形碳碎片;但大部分碳纳米管没有溶解,仍然保持管状结构.揭示出聚乙烯醇修饰的碳纳米管的溶解过程为:碳-碳键在浸泡过程中发生断裂,碳纳米管的部分溶解产生了无定形碳碎片与残留纳米管层片,残留纳米管层片进一步溶解最终成为无定形碳.提出与讨论了聚乙烯醇修饰的碳纳米管在Tris-HCl缓冲溶液中可能的溶解机理是:修饰后的碳纳米管表面具有很多缺陷和断裂的碳键,在缓冲溶液中聚乙烯醇的溶解导致嫁接位置的碳管壁的碳原子的释放,最终导致其管状结构的破坏.     

Effect of chitosan-gluconic acid conjugate/poly(vinyl alcohol) cryogels as wound dressing on partial-thickness wounds in diabetic rats

We previously developed chitosan cryogels from chitosan-gluconic acid conjugate without using toxic additives for wound care. In this study, we improved physiological characteristics of the previous cryogels by incorporating poly(vinyl alcohol) that also form cryogels. Mechanical strength of the cryogels was more than two times higher than that of the previous cryogels. Furthermore, the incorporation of poly(vinyl alcohol) enhanced water retention and resistance to degradation of the gels by lysozyme. The cryogels retained the favorable biological properties of the previous cryogels that they accelerate infiltration of inflammatory cells into wound sites. Time period for repairing 50 % of initial area of partial-thickness skin wound treated with the cryogels (4.0 ± 1.1 days) was shorter than those with gauze (6.5 ± 0.3 days) or a commercial hydrogel dressing (5.7 ± 0.3 days). Finally, we confirmed that incorporation of basic fibroblast growth factor into the cryogels was effective to further accelerate wound healing (2.7 ± 1.0 days). These results demonstrate that the cryogels in this study are promising for wound care.     

Diffusion-based model to predict the conservation of gratings recorded in poly(vinyl alcohol)-acrylamide photopolymer

Photopolymers are interesting materials for use in recording information in holography. We study the holographic behavior and stability of volume holograms recorded in poly(vinyl alcohol)--acrylamide photopolymers with and without a cross linker. Using a first-harmonic diffusion model, we analyze the residual monomer that remains when volume diffraction gratings are recorded in photopolymer materials. The importance of this residual monomer to the stability of the gratings is evaluated.     

Cytotoxicity and Cell Cycle Effects of Bare and Poly(vinyl alcohol)‐Coated Iron Oxide Nanoparticles in Mouse Fibroblasts

Super‐paramagnetic iron oxide nanoparticles (SPIONs) are recognized as powerful biocompatible materials for use in various biomedical applications, such as drug delivery, magnetic‐resonance imaging, cell/protein separation, hyperthermia and transfection. This study investigates the impact of high concentrations of SPIONs on cytotoxicity and cell‐cycle effects. The interactions of surface‐saturated (via interactions with cell medium) bare SPIONs and those coated with poly(vinyl alcohol) (PVA) with adhesive mouse fibroblast cells (L929) are investigated using an MTT assay. The two SPION formulations are synthesized using a co‐precipitation method. The bare and coated magnetic nanoparticles with passivated surfaces both result in changes in cell morphology, possibly due to clustering through their magnetostatic effect. At concentrations ranging up to 80 × 10^?3 M , cells exposed to the PVA‐coated nanoparticles demonstrate high cell viability without necrosis and apoptosis. In contrast, significant apoptosis is observed in cells exposed to bare SPIONs at a concentration of 80 × 10^?3 M . Nanoparticle exposure (20–80 × 10^?3 M ) leads to variations in both apoptosis and cell cycle, possibly due to irreversible DNA damage and repair of oxidative DNA lesions, respectively. Additionally, the formation of vacuoles within the cells and granular cells indicates autophagy cell death rather than either apoptosis or necrosis.     

Encapsulation of the reductase component of p ‐hydroxyphenylacetate hydroxylase in poly(lactide‐co ‐glycolide) nanoparticles by three different emulsification techniques

p ‐Hydroxyphenylacetate 3‐hydroxylase component 1 (C ₁) is a useful enzyme for generating reduced flavin and NAD⁺ intermediates. In this study, poly(lactide‐co‐glycolide) (PLGA) nanoparticles (NPs) were used to encapsulate the C ₁ (PLGA‐C ₁ NPs). Enzymatic activity, stability, and reusability of PLGA‐C ₁ NPs prepared using three different methods [oil in water (o/w), water in oil in water (w/o/w), and solid in oil in water (s/o/w)] were compared. The s/o/w provided the optimal conditions for encapsulation of C ₁ (PLGA‐C _1,s NPs), giving the highest enzyme activity, stability, and reusability. The s/o/w method improves enzyme activity ∼11 and 9‐fold compared to w/o/w (PLGA‐C _1,w NPs) and o/w (PLGA‐C _1,o NPs). In addition, s/o/w prepared PLGA‐C _1,s NPs could be reused 14 times with nearly 50% activity remaining, a much higher reusability compared to PLGA‐C _1,o NPs and PLGA‐C _1,w NPs. These nanovesicles were successfully utilised to generate reduced flavin mononucleotide (FMN) and supply this cofactor to a hydroxylase enzyme that has application for synthesising anti‐inflammatory compounds. Therefore, this recycling biocatalyst prepared using the s/o/w method is effective and has the potential for use in combination with other enzymes that require reduced FMN. Application of PLGA‐C _1,s NPs may be possible in additional biocatalytic processes for chemical or biochemical production.Inspec keywords: nanoparticles, enzymes, biotechnology, biochemistry, recycling, catalysts, nanofabrication, encapsulationOther keywords: reductase component, poly(lactide‐co‐glycolide) nanoparticles, emulsification techniques, p‐hydroxyphenylacetate 3‐hydroxylase component, NAD⁺ intermediates, PLGA, enzymatic activity, PLGA‐C₁ reusability, water in oil in water methods, solid in oil in water methods, oil in water methods, optimal conditions, encapsulation, enzyme stability, enzyme reusability, s/o/w method, reduced flavin mononucleotide, hydroxylase enzyme, anti‐inflammatory compounds, recycling biocatalyst, FMN, biocatalytic processes, biochemical production, chemical production     

Biocompatible Smart Microcapsules Based on Chitosan‐Poly(vinyl alcohol) Copolymers for Cultivation of Animal Cells

In this study, two novel chitosan‐graft‐poly(vinyl alcohol) copolymers are synthesized and used as water‐soluble at physiological conditions polycations for preparation of smart microcapsules. The microcapsules provide growth and proliferation of eight mammalian cell lines, including hybridoma and tumor cells, at long‐term cell cultivation in vitro. The microcapsules are stable in cell culture medium but can be dissolved by changing pH value of the medium (up to 8.0–8.2), thus making possible a simple release of the entrapped cells. Monoclonal antibody production by encapsulated hybridoma cells is demonstrated. Cultivation of tumor cells within the microcapsules allows the formation of 3D multicellular spheroids, which can be proposed as an in vitro model for anticancer drug screening.     

Luteinizing hormone‐releasing hormone targeted poly(methyl vinyl ether maleic acid) nanoparticles for doxorubicin delivery to MCF‐7 breast cancer cells

The purpose of this study was to design a targeted anti‐cancer drug delivery system for breast cancer. Therefore, doxorubicin (DOX) loaded poly(methyl vinyl ether maleic acid) nanoparticles (NPs) were prepared by ionic cross‐linking method using Zn²⁺ ions. To optimise the effect of DOX/polymer ratio, Zn/polymer ratio, and stirrer rate a full factorial design was used and their effects on particle size, zeta potential, loading efficiency (LE, %), and release efficiency in 72 h (RE₇₂, %) were studied. Targeted NPs were prepared by chemical coating of tiptorelin/polyallylamin conjugate on the surface of NPs by using 1‐ethyl‐3‐(3‐dimethylaminopropyl) carboiimid HCl as cross‐linking agent. Conjugation efficiency was measured by Bradford assay. Conjugated triptorelin and targeted NPs were studied by Fourier‐transform infrared spectroscopy (FTIR). The cytotoxicity of DOX loaded in targeted NPs and non‐targeted ones were studied on MCF‐7 cells which overexpress luteinizing hormone‐releasing hormone (LHRH) receptors and SKOV3 cells as negative LHRH receptors using Thiazolyl blue tetrazolium bromide assay. The best results obtained from NPs prepared by DOX/polymer ratio of 5%, Zn/polymer ratio of 50%, and stirrer rate of 960 rpm. FTIR spectrum confirmed successful conjugation of triptorelin to NPs. The conjugation efficiency was about 70%. The targeted NPs showed significantly less IC₅₀ for MCF‐7 cells compared to free DOX and non‐targeted NPs.Inspec keywords: nanoparticles, polymer blends, cancer, cellular biophysics, drug delivery systems, drugs, biomedical materials, zinc, positive ions, Fourier transform infrared spectra, nanomedicine, proteinsOther keywords: luteinizing hormone‐releasing hormone, poly(methyl vinyl ether maleic acid), doxorubicin delivery, MCF‐7 breast cancer cell, anticancer drug delivery system, doxorubicin‐loaded PVM‐MA nanoparticle, ionic cross‐linking method, zinc ion, doxorubicin‐polymer ratio effect, zinc‐polymer ratio effect, particle size, zeta potential, loading efficiency, release efficiency, chemical coating, tiptorelin‐polyallylamin conjugation, PVM‐MA nanoparticle surface, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carboiimid HCl, cross‐linking agent, Bradford assay, Fourier transform infrared spectroscopy, cytotoxicity, LHRH receptor, SKOV3 cell, Thiazolyl blue tetrazolium bromide assay, conjugation efficiency, time 72 h, Zn²⁺      

Trastuzumab‐conjugated nanoparticles composed of poly(butylene adipate‐co ‐butylene terephthalate) prepared by electrospraying technique for targeted delivery of docetaxel

Human epidermal growth factor receptor 2 (HER‐2) is overexpressed in 20–30% of human breast cancers, associated with poor prognosis and tumour aggression. The aim of this study was the production of trastuzumab‐targeted Ecoflex nanoparticles (NPs) loaded with docetaxel and in vitro evaluation of their cytotoxicity and cellular uptake. The NPs were manufactured by electrospraying and characterised regarding size, zeta potential, drug loading, and release behaviour. Then their cytotoxicity was evaluated by MTT assay against an HER‐2‐positive cell line, BT‐474, and an HER‐2‐negative cell line, MDA‐MB‐468. The cellular uptake was studied by flow cytometry and fluorescent microscope. The particle size of NPs was in an appropriate range, with relatively high drug entrapment and acceptable release efficiency. The results showed no cytotoxicity for the polymer, but the significant increment of cytotoxicity was observed by treatment with docetaxel‐loaded NPs in both HER‐2‐positive and HER‐2‐negative cell lines, in comparison with the free drug. The trastuzumab‐targeted NPs also significantly enhanced cytotoxicity against BT‐474 cells, compared with non‐targeted NPs.Inspec keywords: cancer, proteins, biomedical materials, nanofabrication, drug delivery systems, cellular biophysics, biological organs, nanomedicine, toxicology, tumours, nanoparticles, biomedical optical imaging, fluorescence, particle sizeOther keywords: human breast cancers, tumour aggression, trastuzumab‐targeted Ecoflex nanoparticles, cellular uptake, zeta potential drug loading, HER‐2‐positive cell line, HER‐2‐negative cell line, MDA‐MB‐468, particle size, trastuzumab‐conjugated nanoparticles, electrospraying technique, human epidermal growth factor receptor, cytotoxicity, nontargeted nanoparticles, butylene adipate‐co‐butylene terephthalate, trastuzumab‐targeted NP, docetaxel‐loaded NP     

Fabrication of novel nanofiber scaffolds from gum tragacanth/poly(vinyl alcohol) for wound dressing application: In vitro evaluation and antibacterial properties

Gum tragacanth (GT) is one of the most widely used natural gums which has found applications in many areas because of its attractive features such as biodegradability, nontoxic nature, natural availability, higher resistance to microbial attacks and long shelf-life properties. GT and poly(vinyl alcohol) (PVA) were dissolved in deionized water in different ratios i.e., 0/100, 30/70, 60/40, 50/50, 40/60, 70/30, 0/100 mass ratio of GT/PVA. Nanofibers were produced from these solutions using electrospinning technique. The effect of different electrospinning parameters such as extrusion rate of polymer solutions, solution concentration, electrode spacing distance and applied voltage on the morphology of nanofibers was examined. The antibacterial activity of nanofibers and GT solution against Staphylococcus aureus and Pseudomonas aeruginosa was examined and these nanofibers showed good antibacterial property against Gram-negative bacteria. FTIR data showed that these two polymers may be having hydrogen bonding interactions. DSC data revealed that the exothermic peak at about 194 °C for PVA shifted to a lower temperature in GT/PVA blend. Human fibroblast cells adhered and proliferated well on the GT/PVA nanofiber scaffolds. MTT assay was carried out on the GT/PVA nanofiber to investigate the proliferation rate of fibroblast cells on the scaffolds.