Electrospinning Academic News

COAXIAL ELECTROSPINNING 2021-03-15

Electrospinning is a very effective technique for fabricating continuous ultrafifine fifibers with diameters down to the micro/nanometer scale from polymers, ceramics, and composites since it was put forward . Compared with other micro/nanosized object fabrication approaches, electrospinning has outstanding advantages of method simplicity, material versatility, easy large area fabrication, high throughput of continuous fifibers, low cost, etc. In addition, the electrospinning technique is also notable for its facile structural tenability of products. By tuning the materials system, solvent, solution concentration, electrostatic fifield strength, collector confifiguration, environmental humidity and temperature, as well as some other parameters, routine electrospinning can generate micro/nanofifibers with cylindrical, ribbon, spindle, porous, and other complex structures. However, the simple single-nozzle electrospinning setup forms just a single flfluid jet, which can generate only a s

MULTINEEDLE ELECTROSPINNING 2021-03-15

According to the basic principle of conventional electrospinning, the formation of nanofifibers mainly depends on the drafting effect of the electric fifield force. The solution jets split from the Taylor cone are drawn, thinned, and then solidifified into nanofifibers. Multineedle electrospinning technology is based on the traditional single-needle electrospinning method, but it uses a combination of multiple needles that are arranged according to a specifific rule set to complete the electrospinning process. In multineedle electrospinning systems, the use of multiple needles can increase the number of Taylor cones formed during the electrospinning process. The Taylor cones may split into more jets under the electric fifield force and thus signifificantly increase the yield of nanofifibers. The development of multineedle electrospinning technology laid the foundation for the methodology and has provided ideas to improve research on the production of electrospun nanofifibers.

NANOFIBROUS STRUCTURES 2021-03-15

Nature is an intriguing inspiration for designing several artifificial functional structures on the microand nanoscales. The capture silk of the cribellate spider Uloborus walckenaerius has a unique fifiberstructure with periodic spindle-knots separated by nanofifibril joints, facilitating continuous condensation and directional collection of water drops around the spindle-knots. Spider webs are a beautiful inspiration for the textile and composite industry. Some spider webs are made up of short irregular strands of randomly arranged fifibers (cobweb), whereas others are regular (orb web). The side-by-side fifiber structure, which is composed of the orthocortex and paracortex adhering to each other, leads to the self-crimping properties of wool fifibers. Natural fifibrous structures on gecko feet enable them to stick and move on a smooth surface. The anisotropic deformation (actuation) of the cell wall takes place by the absorption and desorption of moisture by the matrix. The orientat

Electrospinning of in situ synthesized silica-based and calcium phosphate bioceramics for applications in bone tissue engineering: A review 2021-03-15

In the present study, we developed a novel approach for functionalization of gelatin nanofibers using the plasma method for tissue engineering applications. For this purpose, tannic acid-crosslinked gelatin nanofibers were fabricated with electrospinning, followed by treatment with argon and argon–oxygen plasmas in a vacuum chamber. Samples were evaluated by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle (CA) and X-ray diffraction (XRD). The biological activity of plasma treated gelatin nanofibers were further investigated by using fibroblasts as cell models. SEM studies showed that the average diameter and the surface morphology of nanofibers did not change after plasma treatment. However, the mean surface roughness (RMS) of samples were increased due to plasma activation. ATR-FTIR spectroscopy demonstrated several new bands on plasma treated fibers related to the pl

Argon and Argon–Oxygen Plasma Surface Modification of Gelatin Nanofibers for Tissue Engineering Applications 2021-03-15

In the present study, we developed a novel approach for functionalization of gelatin nanofibers using the plasma method for tissue engineering applications. For this purpose, tannic acid-crosslinked gelatin nanofibers were fabricated with electrospinning, followed by treatment with argon and argon–oxygen plasmas in a vacuum chamber. Samples were evaluated by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle (CA) and X-ray diffraction (XRD). The biological activity of plasma treated gelatin nanofibers were further investigated by using fibroblasts as cell models. SEM studies showed that the average diameter and the surface morphology of nanofibers did not change after plasma treatment. However, the mean surface roughness (RMS) of samples were increased due to plasma activation. ATR-FTIR spectroscopy demonstrated several new bands on plasma treated fibers related to the pl

Nanostructure, porosity and tensile strength of PVA/Hydroxyapatite composite nanofiber for bone tissue engineering 2021-03-15

Hydroxyapatite [HAp, Ca10(PO4)6(OH)2] was successfully synthesized using natural minerals, precisely limestone from Druju Indonesia. As a bone scaffold compound, HAp has a weakness of low mechanical properties therefore it needs to be mixed with polymeric materials, such as polyvinyl alcohol (PVA) to improve its mechanical properties. The PVA/HAp composites nanofiber have successfully synthesized using the electrospinning method and analyzed including nanostructure, porosity and tensile strength of nanofiber. The diameter of PVA/HAp composites nanofiber in 173 to 234 nm, porosity in 62 to 74%, and tensile strength in 6.96 to 15.85 MPa. Increasing of HAp cocentrasion increase of tensile strength, SEM showed an increase in HAp concentration (0%−20%) causing a decrease in the average diameter of the fiber. The characteristics of PVA/HAp composite nanofiber can be applied as a scaffold in bone tissue engineering.

Fabrication and assessment of chondroitin sulfate-modified collagen nanofibers for small-diameter vascular tissue engineering applications 2021-03-15

Chondroitin sulfate (ChS) has shown promising results in promoting cell proliferation and antithrombogenic activity. To engineered develop a dual-function vascular scaffold with antithrombosis and endothelialization, ChS was tethered to collagen to accelerate the growth of endothelial cells and prevent platelet activation. First, ChS was used to conjugate with collagen to generate glycosylated products (ChS-COL) via reductive amination. Then, the fabricated ChS-COL conjugates were electrospun into nanofibers and their morphologies and physicochemical characteristics, cell-scaffold responses and platelet behaviors upon ChS-COL nanofibers were comprehensively characterized to evaluate their potential use for small-diameter vascular tissue-engineered scaffolds. The experimental results demonstrated that the ChS modified collagen electrospun nanofibers were stimulatory of endothelial cell behavior, alleviated thrombocyte activation and maintained an antithrombotic effect in vivo in 10-day

Scaffold Fabrication Technologies and Structure/Function Properties in Bone Tissue Engineering 2021-03-13

Bone tissue engineering (BTE) is a rapidly growing field aiming to create a biofunctional tissue that can integrate and degrade in vivo to treat diseased or damaged tissue. It has become evident that scaffold fabrication techniques are very important in dictating the final structural, mechanical properties, and biological response of the implanted biomaterials. A comprehensive review of the current accomplishments on scaffold fabrication techniques, their structure, and function properties for BTE is provided herein. Different types of biomaterials ranging from inorganic biomaterials to natural and synthetic polymers and related composites for scaffold processing are presented. Emergent scaffolding techniques such as electrospinning, freeze‐drying, bioprinting, and decellularization are also discussed. Strategies to improve vascularization potential and immunomodulation, which is considered a grand challenge in BTE scaffolding, are also presented.

Electrospinning new book recommendation：Electrospun Polymers and Composites：Ultrafine Materials, High Performance Fibres and Wearables 2021-03-11

This book reviews the latest technological developments and innovations in electrospun polymers and composites, highlighting the multifunctionality of these ultrafine materials as high performance fibers. The book's chapters investigate a wide range of different electrospinning applications, including drug delivery, tissue scaffolding, fiber reinforcement and nanofiltration, with a particular focus on shape memory effect and the wearable characteristics of electrospun polymers and composites.

Hydrogel Complex Electrospun Scaffolds and Their Multiple Functions in In Situ Vascular Tissue Engineering 2021-03-11

There has been substantial progress in tissue engineering of biological substitutes for medical applications. One of the major challenges in development of complex tissues is the difficulty of creating vascular networks for engineered constructs. The diameter of current artificial vascular channels is usually at millimeter or submillimeter level, while human capillaries are about 5 to 10 µm in diameter. In this paper, a novel core-sheath electrospinning process was adopted to fabricate nanoporous microtubes to mimic the structure of fenestrated capillary vessels. A mixture of polylactic acid (PLA) and polyethylene glycol (PEO) was used as the sheath solution and PEO was used as the core solution. The microtubes were observed under a scanning electron microscope and the images were analyzed by ImageJ. The diameter of the microtubes ranged from 1–8 microns. The diameter of the nanopores ranged from 100 to 800 nm. The statistical analysis showed that the microtube diameter was significant

Fabrication of Nanopores Polylactic Acid Microtubes by Core-Sheath Electrospinning for Capillary Vascularization 2021-03-11

There has been substantial progress in tissue engineering of biological substitutes for medical applications. One of the major challenges in development of complex tissues is the difficulty of creating vascular networks for engineered constructs. The diameter of current artificial vascular channels is usually at millimeter or submillimeter level, while human capillaries are about 5 to 10 µm in diameter. In this paper, a novel core-sheath electrospinning process was adopted to fabricate nanoporous microtubes to mimic the structure of fenestrated capillary vessels. A mixture of polylactic acid (PLA) and polyethylene glycol (PEO) was used as the sheath solution and PEO was used as the core solution. The microtubes were observed under a scanning electron microscope and the images were analyzed by ImageJ. The diameter of the microtubes ranged from 1–8 microns. The diameter of the nanopores ranged from 100 to 800 nm. The statistical analysis showed that the microtube diameter was significant

Controlled drug release from electrospun PCL nonwoven scaffolds 2021-03-11

Currently, electrospun synthetic bioresorbable polymer scaffolds are applied in regenerative medicine and tissue engineering as targeted drug delivery devices because of their mechanical and physico-chemical properties. To control the rate of polymer degradation and drug release from polymer scaffolds, surface modification techniques are widely used. In this study, paracetamol-loaded poly (ε-caprolactone) electrospun fibrous scaffolds were treated by the pulsed electron beam irradiation. Pure control PCL scaffold, as well as scaffolds with four paracetamol concentrations (2 wt./wt. %, 8 wt./wt. %, 16 wt./wt. %, and 32 wt./wt.%) were modified. The mechanical and chemical properties and morphology of modified materials were examined. The sustained release of the model drug over a period of one hour for both non-treated and treated samples was demonstrated. It was shown that treatment leads to an increase in drug release rate and does not change surface morphology of scaffolds and fibers

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