Coaxial Electrospinning Technique Research Articles

Ferromagnetic resonance and magnetic anisotropy in biocompatible Y3Fe5O12@Na0.5K0.5NbO3 core-shell nanofibers

Y3Fe5O12@Na0.5K0.5NbO3 (YIG@NKN) core-shell nanofibers were synthesized by the coaxial electrospinning technique. For comparison, samples of YIG and NKN nanofibers were prepared. Scanning Electron Microscopy (SEM) and 3D laser-scanning confocal microscopy (TDLM) of YIG@NKN nanofibers revealed long uniform size distributed fibers with the average diameter of 100–150 nm. X-Ray diffraction (XRD) examination shows the existence of the distinct peaks of orthorhombic NKN and cubic YIG. Magnetic force microscopy (MFM) of individual YIG@NKN nanofiber demonstrates a magnetic core that is extended in one half of the diameter of the fiber. These nanofibers show obvious Ferromagnetic resonance (FMR) with resonance near 2 KOe similar to YIG fibers but in such a way that it starts to increase linearly with applying magnetic field from zero up to near resonance field. Also they show a soft magnetic behavior with saturation magnetization of 10 emu/gr. Furthermore, we propose a model to explain line shape of randomly oriented fibers and extract all the magnetic anisotropy parameters from FMR data. The results rely the shape anisotropy as dominant effect, however the dipolar field among fibers should be considered. The highest degree of asymmetry observed in the case of core-shell fibers in hard direction that it can be originated from magneto electric effects. By taking into account the observed FMR, the ability of adequate control of microwave absorption by applying magnetic field and biocompatibility, the synthesized core-shell nanofibers are the most promising candidate for clinical application such as microwave cancer thermotherapy and adjustable microwave absorbers.

Solvent Effects on Morphology and Electrical Properties of Poly(3-hexylthiophene) Electrospun Nanofibers.

Herein, poly(3-hexylthiophene-2,5-diyl) (P3HT) nanofiber-based organic field-effect transistors were successfully prepared by coaxial electrospinning technique with P3HT as the core polymer and poly(methyl methacrylate) (PMMA) as the shell polymer, followed by extraction of PMMA. Three different solvents for the core polymer, including chloroform, chlorobenzene and 1,2,4-trichlorobenzene, were employed to manipulate the morphologies and electrical properties of P3HT electrospun nanofibers. Through the analyses from dynamic light scattering of P3HT solutions, polarized photoluminescence and X-ray diffraction pattern of P3HT electrospun nanofibers, it is revealed that the P3HT electrospun nanofiber prepared from the chloroform system displays a low crystallinity but highly oriented crystalline grains due to the dominant population of isolated-chain species in solution that greatly facilitates P3HT chain stretching during electrospinning. The resulting high charge-carrier mobility of 3.57 × 10−1 cm2·V−1·s−1 and decent mechanical deformation up to a strain of 80% make the P3HT electrospun nanofiber a promising means for fabricating stretchable optoelectronic devices.

Preparation and characterization of electrospun poly(lactic acid)-chitosan core-shell nanofibers with a new solvent system

Poly(lactic acid)-chitosan (PLA-CS) core-shell nanofibers were successfully fabricated by coaxial electrospinning technique using a new solvent system for the core and shell solutions, dimethylformamide for the core solution and trifluoro-acetic acid/acetic acid (90/10 v/v) for the shell solution. The formation of the core-shell structure of the nanofibers with this new solvent system was confirmed by transmission electron microscopy (TEM) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR). Morphology of the as-spun nanofibers was investigated by scanning electron microscopy (SEM) which showed bead-free smooth PLA-CS core-shell type nanofibers with an average diameter of 671 ± 172 nm and a broad diameter distribution. Thermogravimetric analysis (TGA) indicated that although PLA content was less than CS in the core-shell nanofibrous mat (20.7% PLA vs. 39% CS) the presence of PLA in the core of nanofibers significantly improved their mechanical properties. The PLA-CS core-shell nanofibers showed a two-stage release behavior of curcumin drug; an initial burst release followed by a sustained release, when the drug was incorporated in the core layer of nanofibers; hence it has potential applications in some biomedical areas such as wound dressing and drug delivery.

La0.6Sr0.4Co0.2Fe0.8O3-δ/CeO2 Heterostructured Composite Nanofibers as a Highly Active and Robust Cathode Catalyst for Solid Oxide Fuel Cells.

The lack of highly active and robust catalysts for the oxygen reduction reaction (ORR) at the intermediate temperatures significantly hinders the commercialization of solid oxide fuel cells (SOFCs). Here, we report a novel heterostructured composite nanofiber cathode composed of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and CeO2 nanoparticles, synthesized by using a coaxial electrospinning technique, which exhibits remarkably enhanced ORR activity and durability as compared to single LSCF powder and nanofibers. This cathode achieves a polarization resistance of 0.031 Ω cm2 at 700 °C, approximately 1/5 of that for the LSCF powder cathode (0.158 Ω cm2). Such enhancement can be attributed to the continuous paths provided by nanofibers for efficient mass/charge transport and the interdiffusion of La and Ce at the heterointerface which leads to more oxygen vacancy formation. Furthermore, the anode-supported cell with the LSCF/CeO2 composite cathode shows excellent stability (0.4 V for ∼200 h at 600 °C) because of suppression of Sr segregation in LSCF by introducing CeO2 and the structure of heterogeneous nanofibers. These results indicate that the microstructure design of this heterostructured composite nanofiber for LSCF/CeO2 is extremely effective for enhancing ORR activity and stability. This finding may provide a new strategy for the microstructure design of highly active and robust ORR catalysts in SOFCs.

Abstract LB-028: Mechanically tunable 3D microenvironments modulate tumor cell phenotype: Models of mechanotransduction and drug resistance in osteosarcoma

Abstract The past few decades have seen marked improvements in survival rates of osteosarcoma due to the advent of modern chemotherapy, radiotherapy, and surgical techniques. However, for patients presenting with metastatic disease, five-year survival rates have remained dismal, hovering around 20%. Repeated failures of clinical trials to confirm potential therapeutic options highlight the need for more accurate pre-clinical testing. Currently, the field of cancer research relies heavily on monolayer culture methods on hard plastic or glass in vitro models; there is a dearth of pre-clinical models that accurately recapitulate the tumor-microenvironment interactions. Matrix stiffness has been implicated in modulating intracellular signaling pathways that promote cancer cell survival, proliferation, and stem cell fate. We have developed a novel three-dimensional (3D) tumor model with variable mechanical properties in order to determine the effect of substrate stiffness and tissue architecture on osteosarcoma cell phenotype, plasticity, and response to therapy. We employed coaxial electrospinning techniques to fabricate highly porous fibrous mesh scaffolds that mimic the bone microenvironment. By controlling the ratio of poly(ϵ-caprolactone) (PCL) and gelatin (PCL:gelatin, core:shell, respectively) in constituent fibers, we were able to manipulate the range of tensile moduli of individual fibers over three orders of magnitude, from 68.91 ± 8.77 kPa to 66.05 ± 7.61 MPa. Osteosarcoma cells cultured in these variable mechanical environments responded by modulating the localization and expression of Hippo pathway regulators. YAP downregulation correlated with decreasing fiber stiffness while both YAP and TAZ had decreasing nuclear:cytoplasmic ratio in less stiff environments. Furthermore, the IGF-1/mTOR axis was downregulated in 3D conditions compared to monolayers and a strong upregulation of Sox2, a stem cell transcription factor, was observed in all 3D conditions. Correspondingly, in the presence of agents targeting the IGF-1/mTOR axis, dose response curves to doxorubicin indicated that IC50 values increase with decreasing substrate stiffness. These phenotypic changes indicate that osteosarcoma cells respond to both stiffness and architecture by modulating the Hippo and IGF-1R/mTOR pathways and increasing cancer stem cell qualities and chemoresistance. We sought to validate our model using osteosarcoma patient biopsies. Analysis of tumor samples from 36 osteosarcoma patients confirmed that YAP/TAZ localization and nuclear pIGF-1R/IGF-1R in our 3D models recapitulated phenotypes observed in patient samples. Our models highlight the need for incorporation of mechanical and architectural cues in the preclinical study of cancer biology as these signals have drastic impacts on osteosarcoma phenotypes and responses to therapy. Citation Format: Eric R. Molina, Letitia K. Chim, Maria C. Salazar, Shail M. Mehta, Brian A. Menegaz, Salah-Eddine Cherradi-Lamhamedi, Tejus Satish, David McCall, Sana Mohiuddin, Ana Maria Zaska, Katherine Jane Grande-Allen, Joseph A. Ludwig, Antonios G. Mikos. Mechanically tunable 3D microenvironments modulate tumor cell phenotype: Models of mechanotransduction and drug resistance in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-028.

Facile synthesis of flexible Pt/NiO 1D nanohybrids with high electrical properties using electrospinning

The push towards miniaturized electronics requires the development of microelectrode constituents that can effectively operate electronic devices for applications such as micro supercapacitors, micro fuel cells and field-effect transistors. Despite platinum (Pt) is considered as an attractive choice for electrode in micro-electrochemical devices, the difficulty of fabricating continuous one-dimensional (1D) Pt electrode with high electrical properties prevents its extensive use. Herein, nanohybrids electrodes consisting of high concentration Pt and low loading NiO with high flexibility are fabricated by the facile coaxial electrospinning technique. By means of controlling the core/shell liquid flow rates and sintering process, continuous nanobelts or nanotubes structure could be easily obtained. Ultrahigh conductivities are observed in Pt/NiO nanobelts and nanotubes with the value of 3.95 × 103 S/cm and 4.73 × 103 S/cm, respectively. The application of testing conductivity of film electrolyte and good catalytic performance prove the promising prospect of Pt/NiO 1D nanohybrids as electrode materials.

<p>Anesthetics and human epidermal growth factor incorporated into anti-adhesive nanofibers provide sustained pain relief and promote healing of surgical wounds</p>

Background: This study exploited sheath-core-structured lidocaine/human EGF (hEGF)-loaded anti-adhesive poly[(d,l)-lactide-co-glycolide] (PLGA) nanofibrous films for surgical wounds via a co-axial electrospinning technique.Materials and methods: After spinning, the properties of the co-axially spun membranes were characterized by scanning electron microscopy, laser-scanning confocal microscopy, Fourier Transform Infrared spectrometry, water contact angle measurements, and tensile tests. Furthermore, a HPLC analysis and an ELISA evaluated the in vitro and in vivo release curves of lidocaine and hEGF from the films.Results: PLGA anti-adhesion nanofibers eluted high levels of lidocaine and hEGF for over 32 and 27 days, respectively, in vitro. The in vivo evaluation of post-surgery recovery in a rat model demonstrated that no adhesion was noticed in tissues at 2 weeks after surgery illustrating the anti-adhesive performance of the sheath-core-structured nanofibers. Nanofibrous films effectively released lidocaine and hEGF for >2 weeks in vivo. In addition, rats implanted with the lidocaine/hEGF nanofibrous membranes exhibited greater activities than the control demonstrating the pain relief efficacy of the films.Conclusion: The empirical outcomes suggested that the anti-adhesive nanofibrous films with extended release of lidocaine and hEGF offer post-operative pain relief and wound healing.

An electrospun hygroscopic and electron-conductive core-shell silica@carbon nanofiber for microporous layer in proton-exchange membrane fuel cell

In this study, a novel core-shell silica@carbon nanofiber (SiO2@C) is successfully prepared via coaxial electrospinning technique with optimized parameters followed by heat treatment. The characterizations of the nanofiber are carried out by a combination of X-ray diffraction measurement, electrical conductivity test, tensile test, thermogravimetric analysis, nitrogen isotherm adsorption-desorption analysis, mechanical strength test, and water uptake measurement. It is found that the hygroscopic mesoporous SiO2 is contained in a core and the hydrophobic electron-conductive carbon is in a shell that has porous channels. The BET surface area, pore volume, electrical conductivity, mechanical strength, and water uptake of SiO2@C are all superior to that of pure carbon nanofiber. These superior properties make SiO2@C a potential microporous layer (MPL) material, benefitting the water management ability of proton-exchange membrane fuel cells (PEMFCs). The result of the single-cell performance tests shows that under 99.9% or 15% relative humidity (RH) in the temperature range of 50–80 °C, the power densities of the PEMFC fabricated with the SiO2@C-based MPL are all significantly higher than that of the pure carbon nanofiber-based MPL, and 66~302% higher than that of the traditional hydrophobic carbon black powder-based MPL. This study indicates that the as-prepared novel core-shell SiO2@C nanofiber is a promising MPL material for PEMFC.

Fabrication and Characterization of Core-Shell Electrospun Fibrous Mats Containing Medicinal Herbs for Wound Healing and Skin Tissue Engineering.

Nanofibrous structures mimicking the native extracellular matrix have attracted considerable attention for biomedical applications. The present study aims to design and produce drug-eluting core-shell fibrous scaffolds for wound healing and skin tissue engineering. Aloe vera extracts were encapsulated inside polymer fibers containing chitosan, polycaprolactone, and keratin using the co-axial electrospinning technique. Electron microscopic studies show that continuous and uniform fibers with an average diameter of 209 ± 47 nm were successfully fabricated. The fibers have a core-shell structure with a shell thickness of about 90 nm, as confirmed by transmission electron microscopy. By employing Fourier-transform infrared spectroscopy, the characteristic peaks of Aloe vera were detected, which indicate successful incorporation of this natural herb into the polymeric fibers. Tensile testing and hydrophilicity measurements indicated an ultimate strength of 5.3 MPa (elongation of 0.63%) and water contact angle of 89°. In-vitro biological assay revealed increased cellular growth and adhesion with the presence of Aloe vera without any cytotoxic effects. The prepared core-shell fibrous mats containing medical herbs have a great potential for wound healing applications.

Core-shell Nanofibers of Silk Fibroin/Polycaprolactone-Clindamycin: Study on Nanofibers Structure and Controlled Release Behavior

Biocompatible nanofibers with core-shell structures based on natural polymers such as silk fibroin have multiple applications as tissue engineering scaffolds and drug delivery systems. In this study, core-shell nanofibers composed of silk fibroin as shell and blends of clindamycin and polycaprolactone as core was fabricated using coaxial electrospinning technique. The effects of variation in concentration of core and shell polymer solutions, electrical conductivity and viscosity of solutions on the final morphology, average diameter of nanofibers and release behavior of clindamycin were studied. The fabricated nanofibers and their drug release behaviors were evaluated using Fourier transform infrared spectroscopy, ultraviolet spectroscopy, scanning and transmission electron microscope techniques. The results showed that concentration of shell solution have more effect on the final average diameter of core-shell nanofiber in compare to core solution. It is concluded that as the concentration of both polycaprolactone in the core and silk fibroin in the shell increased, the amount of released clindamycin from fabricated core-shell nanofibers showed decreasing trend.

Biomimetic composite scaffold of hydroxyapatite/gelatin-chitosan core-shell nanofibers for bone tissue engineering

Good biocompatibility and osteogenesis of three-dimensional porous scaffolds are critical for bone tissue engineering. In this work, biomimetic hydroxyapatite/gelatin-chitosan core-shell nanofibers composite scaffolds have been fabricated to mimic both the specific structure and the chemical composition of natural bone. The coaxial electrospinning technique was introduced to prepare gelatin-chitosan core-shell structured nanofibers mat which formed three-dimensional porous structure for promoting cells growth. The gelatin-chitosan core-shell nanofibers formed Arginine-Glycine-Aspartic acid (RGD)-like structure to mimic the organic component of natural bone extracellular matrix. Hydroxyapatite (Ca10(PO4)6(OH)2, HAP), as the major mineral constituent of native bone, was then deposited onto the surface of gelatin-chitosan core-shell structured nanofibers by a wet chemical method. Compared with chitosan nanofibers, gelatin nanofibers and chitosan-gelatin composite nanofibers, gelatin-chitosan core-shell structured nanofibers improved the mineralization efficiency of hydroxyapatite and formed a homogeneous HAP deposit. When Human osteoblast like cell line (MG-63) were cultured on the materials, the results showed that hydroxyapatite deposited on the gelatin-chitosan core-shell structured nanofibers could further enhance osteoblast cell proliferation. The biomimetic composite scaffolds could be suggested as a promising material to promote osteoblast cell growth in bone tissue engineering.

Coconut oil-cellulose beaded microfibers by coaxial electrospinning: An eco-model system to study thermoregulation of confined phase change materials

Coconut oil was used to produce biomass microfibers with a coconut oil core and a cellulose shell by a co-axial electrospinning technique. This novel material was developed as a model system to determine the effect of confining a phase changing material within an axial micropore of a coaxial fiber. The morphology of these composite fibers was determined by scanning electron microscopy and transmission electron microscopy, which revealed a unique beaded necklace morphology with sub-micron scale pockets of confined coconut oil. Thermogravimetric analysis and differential scanning calorimetry were employed to study the thermal behavior of the composite fibers. A significant increase of the specific heat capacity (+ 98%) was observed when the coconut oil was confined within the micropore of the composite fiber compared to the bulk. There was also a notable increase (+ 41%) of the specific heat of melting for the micropore confined coconut oil. Thus, coconut oil isolated in the axial micropore core of these cellulose composite fibers showed excellent potential for temperature regulation in the range of 7 to 22 °C, which includes 21 °C, the temperature which most humans find comfortable. The results of the studied model system can be used to tailor the properties of phase change materials in confined micropores, in both electrospun fibers and other mesoscale structures.

Time-dependently slow-released multiple-drug eluting external sheath for efficient long-term inhibition of saphenous vein graft failure

Coronary artery bypass graft surgery (CABG) is an effective therapeutic method for coronary artery disease. Great saphenous vein is the predominant graft due to the accessibility, sufficient length and suitable size matching with coronary artery. However, saphenous vein graft failure (SVGF) always restrict the long-term success of CABG. In this study, a complex external sheath was prepared using multi-channel and coaxial electrospinning techniques. The sheath can slowly release fasudil dihydrochloride (100% at 63 days), everolimus (100% at 84 days) and simvastatin (31.87 ± 1.55% at 20 weeks) to match the time-dependent pathological changes of SVGF through a cocktail pattern. In 16 weeks animal experiments, drug loaded sheath exhibited significantly greater efficacy in inhibiting neointima formation and ensuring graft patency than bare vein graft and empty sheath. Under the joint action of mechanical restriction of the sheath and the synergistic effect of loaded fasudil dihydrochloride and everolimus, the endothelium damage and the proliferation/migration of smooth muscle cells, which were thought to be the early cause of graft failure, could be efficiently alleviated. Moreover, the long-term patency could be expected due to the inhibition of atherosclerosis by the sustained released simvastatin.

A high-strength PPESK/PVDF fibrous membrane prepared by coaxial electrospinning for lithium-ion battery separator

Electrospinning fibrous membranes have attracted a great deal of attention because of their advantages, including uniform pore size, large ratio surface area, and high porosity. For extended application in lithium-ion battery, it is essential to further improve their electrochemical, mechanical, and thermal properties. In this work, a new poly (phthalazine ether sulfone ketone) (PPESK)/polyvinyli-denefluoride (PVDF) core/shell fibrous membrane was fabricated via the coaxial electrospinning technique, followed by hot press. The PPESK/PVDF membrane hot pressed at 160°C exhibits excellent comprehensive performance, including large porosity (80%), high electrolyte uptake (805%), and excellent thermal stability (at 200°C). Moreover, due to the improved bonding effect derived from the solidification of the PVDF shell layer after the hot press, the mechanical property of the membrane is effectively enhanced. The electrochemical tests also indicate that the PPESK/PVDF membrane shows larger ionic conductivity and lower interfacial resistance when compared with commercial microporous polypropylene separator. In addition, simulated cells assembled with the PPESK/PVDF membrane present superior discharge capacity, stable cycle performance, and excellent rate capability. Therefore, the hot-pressed coaxial PPESK/PVDF fibrous membrane has the potential to be a promising candidate as the separator for high-performance lithium-ion battery.

Biodegradable core-shell electrospun nanofibers containing bevacizumab to treat age-related macular degeneration.

Age-related macular degeneration (AMD) is a degenerative ocular disease that affects the central retina. It is considered the main cause of blindness and loss of vision worldwide. Angiogenic factors are associated with AMD, which has led to the use of antiangiogenic drugs, such as bevacizumab, to treat the disease using frequent intravitreal injections. In the present study, biodegradable core shell nanofibers containing bevacizumab were prepared by the coaxial electrospinning technique. It is thought that the shell could control the release of the drug, while the core would protect and store the drug. Poly(caprolactone) (PCL) and gelatin were used to form the shell of the nanofibers, while poly(vinyl alcohol) (PVA) and bevacizumab comprised the core. The nanofibers were characterized using microscopy techniques, thermal analysis, and FTIR. The results showed that core-shell nanofibers were produced as designed. Bevacizumab activity was evaluated using a chicken embryo chorioallantoic membrane (CAM) assay. An enzyme-linked immunosorbent assay was used to quantify the amount of the drug released from the different nanofibers in vitro. The toxicity of the nanofibers was evaluated in human retinal pigment epithelial (ARPE) cells. The CAM results demonstrated that bevacizumab maintained its antiangiogenic activity when incorporated into the nanofibers. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests revealed that the nanofibers showed no cellular toxicity, even in the presence of bevacizumab. The core-shell structure of the nanofibers reduced the release rate of bevacizumab compared with PVA nanofibers. The bevacizumab-loaded biodegradable nanofibers presented interesting properties that would potentially constitute an alternative therapy to intravitreal injections to treat AMD.

Production of core-shell nanofibers from zein and tragacanth for encapsulation of saffron extract

In this study, encapsulation of aqueous saffron extract (ASE) was studied using a core-shell nanofiber structure (zein-tragacanth) via coaxial electrospinning technique. Morphological features of nanofibers were investigated under different processing conditions (polymer concentration and applied voltage). The nanofibers produced under optimum criteria had diameter in a range of 95 to 271 nm. Concentration of zein and percentage of ASE were found to be critical factors affecting loading capacity (LC) and encapsulation efficiency (EE). The range of LC and EE were 3.57–9.52% and 60.89–91.55%, respectively. FTIR and differential scanning calorimetry (DSC) characterizations demonstrated that ASE was appropriately encapsulated in the nanofibers matrix with high thermal stability. TEM images showed a core-shell structure. Release values of 21.66, 27.75, 43.88 and 16.12% of saffron extract were observed in saliva, hot water, gastric and intestinal media, respectively. Mechanism of safranal release from fibers for saliva, water, gastric and intestinal were well demonstrated by Kopcha, Peppas-Sahlin, Peppas-Sahlin and Ritger-Peppas models, respectively. Finally, the results of this research indicated that produced thermostable core-shell nanofibers can be used in various food industries such as chewing gum and tea bag development.

Electrospun ZnO Nanoparticles Doped Core–Sheath Nanofibers: Characterization and Antimicrobial Properties

Coaxial electrospinning technique was used to fabricate the core–sheath composite nanofibers of ZnO nanoparticle (Nps) (10%, 20% w/w) doped polymethyl methacrylate (PMMA) (as sheath) and polyvinyl alcohol (PVA) (as core). Fourier transform infrared (FT-IR) spectra were confirmed the weak forces arise between ZnO Nps, PMMA and PVA matrixes. The hexagonal (wurtzite) structure of ZnO Nps with ~ 30.8 nm of diameter was confirmed from the X-ray diffraction pattern. The morphology and microstructure of core–sheath composite nanofibers were confirmed from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is clearly seen from the TEM images that the PMMA encapsulate the PVA core. Core–sheath composite nanofibers were assessed against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) bacteria through quantitative, disk diffusion and viable cell count methods. It was found that ZnO Nps doped core–sheath nanofibers were effectively inhibit the growth of gram positive bacteria, B. subtilis.

Novel smart textile with phase change materials encapsulated core-sheath structure fabricated by coaxial electrospinning

The development of rational material structure design for thermo-regulated smart textiles based on phase change materials (PCMs) paraffin wax (PW) is paramount for effectively solving leakage issue in the process of phase change. Here, a material structure with high-performance in overcoming leakage of PW is achieved by coaxial electrospinning technique resulting from core-sheath structured smart textiles with PW as core layer and polyacrylonitrile (PAN) as sheath layer. Additionally, to improve the heat utilization efficiency of solar energy, the hexagonal cesium tungsten bronze (Cs0.32WO3) with excellent near-infrared region (NIR) absorbing ability is incorporated in the textiles. It is noteworthy that the smart textile possesses the high encapsulation efficiency of 54.3% (latent heat of 60.31 J/g) and shows good stability because of almost no change of latent heat for the smart textiles after 500 heating-cooling cycles. Hence, this work provides a meaningful guidance for smart textiles and opens up some opportunities for comfortable wearing.

Antibiofilm activity of synthesized electrospun core-shell nanofiber composites of PLA and PVA with silver nanoparticles

In recent work, we have demonstrated the significant enhancements in the mechanical, surface wetting, and cytocompatibility properties of core–shell nanofiber composites of Poly (lactic acid) (PLA) and Poly (vinyl alcohol) (PVA). This core/shell-structured PLA/PVA nanofibers combined the hydrophilic benefits of PVA and the attractive biological properties of PLA. In this paper, we expound the antibiofilm activity of this promising coaxial nanofiber composites by incorporating silver nanoparticles on the shell layer using coaxial electrospinning technique. The morphological analysis of the coaxial nanofiber mats was carried out using scanning and transmission electron microscopy. The presence of silver nanoparticles was confirmed using x-ray diffraction (XRD) analysis. The antibiofilm activity of the synthesized core–shell nanofiber membranes loaded with silver nanoparticles were investigated against two prokaryotes, namely Pseudomonas aeruginosa (Gram negative), and Staphylococcus aureus (Gram positive) and a eukaryote (Candida albicans). The results presented in this study revealed substantial improvements in the antibiofilm activity of synthesized core–shell membranes of PLA and PVA incorporated with silver nanoparticles compared to those coaxial membranes without silver nanoparticles.

Custom-built electrostatics and supplementary bonding in the design of reinforced Collagen-g-P(methyl methacrylate-co-ethyl acrylate)/ nylon 66 core-shell fibers.

In this study, Acid Soluble Collagen-g-P(methyl methacrylate-co-ethyl acrylate) (CME) was synthesized to take advantage of the flexibility of the resulted branched polymer chains and the high density of their chain entanglement. The coaxial electrospinning technique was applied to study the effect of electrically and structurally varied materials on fiber formation and fiber morphology when CME and Nylon 66 were electrospun as core and shell respectively. By tailoring the electrostatic field, different fiber content was achieved. The effect of chain orientation and intermolecular forces between the polymeric chains was investigated in the formed fibers by measuring thermal and mechanical properties, hydration degree and degradability. This approach to in situ fiber formation is not restricted to biomedical but has potential end-uses in a variety of multi-functional applications.