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A novel conductive nanohydrogel hybrid support was prepared by in situ polymerization of polyaniline nanorods on an electrospun cationic hydrogel of poly(ε-caprolactone) and a cationic phosphine oxide macromolecule. Subsequently, the cellulase enzyme was immobilized on the hybrid support. Field-emission scanning electron microscopy and Brunauer-Emmett-Teller analyses confirmed a mesoporous, rod-like structure with a slit-like pore geometry for the immobilized support and exhibiting a high immobilization capacity and reduced diffusion resistance of the substrate. For comparison, the catalytic activity, storage stability, and reusability of the immobilized and free enzymes were evaluated. The results showed that the immobilized enzymes have higher thermal stability without changes in the optimal pH (5.5) and temperature (55 °C) for enzyme activity. A high immobilization efficiency (96%) was observed for the immobilized cellulose catalysts after optimization of parameters such as the pH, temperature, incubation time, and protein concentration. The immobilized enzyme retained almost 90% of its original activity after 4 weeks of storage and 73% of its original activity after the ninth reuse cycle. These results strongly suggest that the prepared hybrid support has the potential to be used as a support for protein immobilization.

Delivery of retinal progenitor cells (RPCs) for restoring injured or diseased retinal tissue using biodegradable scaffolds is a promising treatment for retinal diseases. Blend of three polymers; poly(e-caprolactone) (PCL), poly(glycerol sebacate) (PGS), and poly(1,8-octanediol-co-citrate) (POC) was used to prepare a nanofibrous scaffold for retinal tissue engineering via electrospinning process. The PGS and POC were firstly synthesized through condensation polymerization. The combinations of PCL, PGS, and POC were then electrospun and optimized to prepare the nanofibrous scaffolds. Subsequently, hydrophilicity, degradability, and biocompatibility of the prepared scaffolds were evaluated. Morphological studies of the scaffolds showed nanofibers without any sings of beads. Tensile evaluations of the scaffolds confirmed that the prepared scaffolds could meet mechanical property requirements for retinal application. The incorporation of POC increased the hydrophilicity and degradation rate of the scaffolds. Also, in-vitro cell behavior assays revealed that human retinal pigment epithelium cells proliferated faster when the POC was added to the scaffold structure. The results suggest that the PGS/POC/PCL scaffold has the potential for retinal tissue engineering (TE) applications.

The capacity to simulate the construction of natural extracellular matrix is an effective approach to guided bone regeneration (GBR). Here, novel nanocomposite fibrous membranes of silk fibroin (SF)-Laponite® (LAP) were developed through electrospinning approach. The membranes were considered according to the physical and mechanical characteristics, degradation rate, in vitro bioactivity evaluation and biological properties. Results showed that the optimized nanocomposite fibrous membrane with meaningfully enhanced tensile strength, toughness and elastic modules was obtained via incorporation of 5 wt% LAP nanoplates into SF membrane. LAP nanoplates incorporation in the SF membrane promoted its hydrophilicity, swelling ratio, and degradation rate, while induced apatite mineralization in simulated body fluid. Moreover, nanocomposite fibrous membranes revealed meaningfully superior cellular responses compared to SF membrane. Consequently, nanocomposite SF-LAP fibrous membranes anticipated to being appealing for GBR applications.

Casein, a natural protein, has been used as a biopolymer-based resource for producing fiber. This fiber provides high comfort properties with a pH close to human skin. This study focused on evaluating the production feasibility of casein nanofiber twisted yarn with the highest protein content in the hybrid yarn, obtaining suitable spinning conditions and desirable properties of the produced yarn. The desirable yarn achieved by composing 90% casein and 10% polyethylene oxide. The yarn strengthened using several types of cross-linking methods and the best technique was obtained to spin an optimized engineered yarn. Consequently, the biodegrading test conducted on the optimized yarn (90% casein and 10% polyethylene oxide blend) in the presence of 40% di-isocyanate as strengthener additive. Observations showed that after ten days, the sample mostly degraded in the solvent and its strength massively reduced so it could be considered as an environmentally friendly, biodegradable fiber.

Design and synthesis of nanostructured responsive gels have attracted increasing attention, particularly in the biomedical domain. Polymer chain configurations and nanodomain sizes within the network can be used to steer their functions as drug carriers. Here, a catalyst-free facile one-step synthesis strategy is reported for the design of pH-responsive gels and controlled structures in nanoscale. Transparent and impurity free gels were directly synthesized from trivinylphosphine oxide (TVPO) and cyclic secondary diamine monomers via Michael addition polymerization under mild conditions. NMR analysis confirmed the consumption of all TVPO and the absence of side products, thereby eliminating post purification steps. The small-angle X-ray scattering (SAXS) elucidates the nanoscale structural features in gels, that is, it demonstrates the presence of collapsed nanodomains within gel networks and it was possible to tune the size of these domains by varying the amine monomers and the nature of the solvent. The fabricated gels demonstrate structure tunability via solvent–polymer interactions and pH specific drug release behavior. Three different anionic dyes (acid blue 80, acid blue 90, and fluorescein) of varying size and chemistry were incorporated into the hydrogel as model drugs and their release behavior was studied. Compared to acidic pH, a higher and faster release of acid blue 80 and fluorescein was observed at pH 10, possibly because of their increased solubility in alkaline pH. In addition, their release in phosphate buffered saline (PBS) and simulated body fluid (SBF) matrix was positively influenced by the ionic interaction with positively charged metal ions. In the case of hydrogel containing acid blue 90 a very low drug release (

This article reports on the possibility of the fabrication of conductive PEDOT (3,4 poly ethylene dioxythiophene) nanofibers through electrospinning. Electrospinning of pure PEDOT nanofibers from its solution has not yet become possible. Also in this work, the efforts to electrospin pure PEDOT or pure EDOT nanofibers proved fruitless. Hence, poly(acrylic acid) (PAA)was employed to assist the electrospinning of EDOT. EDOT:PAA nanofibers were collected in an oxidation bath, where in-situ polymerization of EDOT into PEDOT occurred. After a series of experiments, PEDOT/PAA (50:50) and PEDOT/PAA (67:33) nanofibers were successfully fabricated. The lowest average diameter of the PEDOT/PAA nanofibers was around 300 nm. An electrical conductivity of 0.16 S/cm was recorded for the PEDOT/PAA (50:50) nanofibrous web which is a considerable improvement over similar products reported in the literature. X-ray analysis showed that PEDOT/PAA nanofibers have an amorphous microstructure. FTIR analysis showed no reaction or major interactions between EDOT or PEDOT and PAA. Moreover, FTIR analysis proved successful polymerization of EDOT into PEDOT. TEM images indicated a good degree of homogeneity for PEDOT and PAA in PEDOT:PAA nanofibers.

Bacterial infection and insignificant osseointegration have been recognized as the main reasons of the failures of titanium based implants. The aim of this study was to apply titanium oxide nanotube (TNT) array on titanium using electrochemical anodization process as a more appropriate substrate for chitosan and chitosan-58S bioactive glass (BG) (58S-BG-Chitosan) nanocomposite coatings covered TNTs (TNT/Chiosan, TNT/58S-BG-Chitosan, respectively) through a conventional dip-coating process. Results showed that a TNT layer with average inner diameter of 82 ± 19 nm and wall’s thickness of 23 ± 9 nm was developed on titanium surface using electrochemical anodization process. Roughness and contact angle measurement showed that TNT with Ra = 449 nm had highest roughness and hydrophilicity which then reduced to 86 nm and 143 nm for TNT/Chitosan and TNT/58S-BG-Chitosan, respectively. In vitro bioactivity evaluation in simulated buffer fluid (SBF) solution and antibacterial activity assay predicted that TNT/58S-BG-Chitosan was superior in bone like apatite formation and antibacterial activity against both gram-positive and gram-negative bacteria compared to Ti, TNT and TNT/Chitosan samples, respectively. Results revealed the noticeable MG63 cell attachment and proliferation on TNT/58S-BG-Chitosan coating compared to those of uncoated TNTs. These results confirmed the positive effect of using TNT substrate for natural polymer coating on improved bioactivity of implant.

In the present study, we coated cotton fabrics with protein-based nanoparticles containing vitamin E (-tocopherol) by the pad-cure method. Scanning electron microscopy, Fourier transform infra-red spectroscopy, and air permeability analysis of coated samples confirmed the fixation of the nanoparticles onto the fabrics surface. The antioxidant activity of the coated fabrics was evaluated by 2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals reduction. Samples coated with nanoparticles containing the highest amount of encapsulated vitamin E (20% of the oil phase) showed the highest antioxidant activity. The protein-based coating was maintained for at least 10 washing cycles, demonstrating the reliability of the pad-cure method for the fixation of nanoparticles onto cotton surfaces. A methodology for nanoparticles release from the coated surfaces and their transfer to other substrates was demonstrated by the simple crock meter rubbing in the presence of sweat and protease. A high amount of material can be transferred and released to other substrates, such as textiles and skin, through the synergistic effect of sweat/protease and abrasion. An array of cosmetic and medical applications are possible with the developed coating and release methodology in which vitamin E would impart vital benefits as skin protection, anti-aging product, or skin moisturizer., This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER006684) and BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 − Programa Operacional Regional do Norte. Artur Ribeiro thanks FCT for the SFRH\BPD\98388\2013 grant. Fatemeh Shahmoradi Ghaheh thanks the Iran Ministry of Science, Research and Technology for the monetary support., info:eu-repo/semantics/publishedVersion

Nowadays, economic and environmental friendly approaches such as adsorbing to refine wastewater have found great attention. In this regard, nylon-polyaniline nanocomposite web with high dye adsorption capacity is developed. This is implemented through in-situ polymerization of polyaniline on the surface of electrospun nylon-6 nanofibers. The produced nylon-6-polyaniline nanocomposite web successfully adsorbed up to 370 mg/g methyl orange as an anionic dye. Further experiment showed that the web has good potential for reusability due to re-chargeability of the web after desorption of adsorbed dye. SEM, N 2 adsorption/desorption and electrical conductivity results demonstrated that nylon nanofibers provide a substrate with high specific surface area and high affinity to polyaniline chains, both of which allow small connected polyaniline particles to be deposited on the surface of nylon nanofibers. Furthermore, it was found that dopant pH is a crucial factor to enhance the dye adsorption efficiency. In this respect, the highest efficiency is achieved with adsorbents doped at pH = 1. Overall, one can witness that in-situ polymerization on a substrate composed of nanofibers is a clean and economic technique to achieve interfaces with highly efficient dye adsorption. To our knowledge, this is the first time in which this technique has gained attention.

In this study, in order to improve the biological, chemical, and mechanical properties of titanium, poly (e-caprolactone) (PCL) - Gelatin (Gel) - forsterite nano composite coating is performed on the titanium substrates. First, a uniform suspension of PCL-Gel-forsterite nano composite was prepared and then, titanium substrates were dip coated in it and then an individual nanofiber coating was employed on the first layer coating via electrospinning method. The characterization of PCL-Gel-forsterite nano composite coated samples was determined through scanning electron microscopy (SEM), X-ray diffraction (XRD). The outcome indicates a uniform nanofibrous coating containing 2 wt % forsterite nanoparticles and various amounts of the PCL were produced. The corrosion resistance of the ceramic-polymer nano fibrous coating was investigated in phosphate buffered saline solution (PBS) using electrochemical impedance spectroscopy (EIS) and it is proved that the nanofibrous coating significantly improve the corrosion resistance of the titanium substrate. At the end the cellular responses of produced nanofibers to MG63 cells were evaluated and cell viability results showed that bioactivity improved with decreasing GEL content confirming the potential application of PCL-Gel-forsterite nanofibrous composite coating for biomedical applications.

Polymer-based drug delivery systems are suitable to optimize the therapeutic properties of drugs and to render them safer, more effective and reliable. Long-term or repeated use of oral administration of fluconazole for treating chronic candidiasis in the patient and partially abandoned treatment lead to the resistant strains of the fungus Candida albicans and severity of the disease. In this study, the use of nanofibers and microfibers containing fluconazole for local drug delivery to increase the efficiencies and reduce the side effects caused by taking the drug was studied. Morphology, microstructure and chemical composition of PVA nanofibers containing fluconazole were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). As well as, the DSC test was indicated presence of fluconazole in PVA fibrous mats. The rate of drug release was investigated by UV–Vis spectrophotometery and swelling technique. SEM images showed that the nanofibers with uniform structure without beads were produced. The mechanical properties of the pristine PVA nanofiber and fibrous mat containing drug were evaluated. The release of fluconazole from PVA nanofibers in pH of 7.4 and at 37 °C was investigated. The results presented that the drug release rate is dependent on the morphology and structure of PVA nanofibers and could be adjusted in desired dosage. The presented products are applicable in the high production form for medical textile industry.

Nanoparticles of bovine serum albumin (BSA) and silk fibroin (SF) with entrapped α-tocopherol were produced via ultrasonic emulsification. Populations with particle size of 200300 nm and highly negatively charged were obtained for all the tested formulations. Entrapment efficiencies of around 99% revealed the effective encapsulation of α-tocopherol into the produced nanoformulations. Generally, these nanodevices did not induce significant cytotoxicity to human skin keratinocytes for all the concentrations tested. The developed formulations showed free radical scavenging of ABTS.+ ability resulting from the synergistic effect between proteins in formulation and the entrapped tocopherol. Overall, the results contribute for the establishment of BSA:VO and BSA:SF:VO as biodegradable and non-toxic nanoformulations for the functionalization of textile devices and controlled delivery of tocopherol into the skin., This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE2020 (POCI-01-0145FEDER-006684) and BioTecNorte operation (NORTE-01-0145FEDER-000004) funded by European Regional Development Fund under the scope of Norte 2020-Programa Operacional Regional do Norte. Artur Ribeiro thanks FCT for the SFRH\BPD\98388\2013 grant. Fatemeh Shahmoradi would like to acknowledge the Iran Ministry of Science, Research and Technology (MSRT) for the monetary support., info:eu-repo/semantics/publishedVersion

Propolis as a natural antibacterial agent was incorporated into the poly(vinyl alcohol) (PVA) in different forms of nanofiber, microfiber, and film. The successful fabrication of uniform nanofibers with 85–314 nm diameters and microfibers with 2.02 μm diameter was proved by scanning electron microscopy. Structural analysis by Fourier transform infrared spectroscopy and X-ray diffraction and swelling properties confirmed the formation PVA hydrogel and its H-bonding to the propolis. Evaluation and comparison of antimicrobial properties of produced samples against Staphylococcus aureus strains revealed that nanofiber mat with 19 mm inhibition zone has 11.76 and 26.67% higher efficiency against bacteria than microfiber mat and film with 17 and 15 mm inhibition zone, respectively. Nanofibrous mat showed sustained release during 96 h by maintaining full antibacterial activity up to 51 h which is of great importance in burn wounds. These results confirm the advanced performance of natural propolis in the form of nanofiber substrate as wound dressing. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 45794.