Electrospinning Academic News

Surface-functionalized electrospun nanofibers for tissue engineering and drug delivery 2021-03-19

Electrospun nanofibers with a high surface area to volume ratio have received much attention because of their potential applications for biomedical devices, tissue engineering scaffolds, and drug delivery carriers. In order to develop electrospun nanofibers as useful nanobiomaterials, surfaces of electrospun nanofibers have been chemically functionalized for achieving sustained delivery through physical adsorption of diverse bioactive molecules. Surface modification of nanofibers includes plasma treatment, wet chemical method, surface graft polymerization, and co-electrospinning of surface active agents and polymers. A variety of bioactive molecules including anti-cancer drugs, enzymes, cytokines, and polysaccharides were entrapped within the interior or physically immobilized on the surface for controlled drug delivery. Surfaces of electrospun nanofibers were also chemically modified with immobilizing cell specific bioactive ligands to enhance cell adhesion, proliferation, and differe

Processing nanoengineered scaffolds through electrospinning and mineralization suitable for biomimetic bone tissue engineering 2021-03-19

Processing scaffolds that mimic the extracellular matrix (ECM) of natural bone in structure and chemical composition is a potential promising option for engineering physiologically functional bone tissue. In this article, we report a novel method, by combining electrospinning and mineralization, to process a series of nano-fibrous scaffolding systems with desirable characteristics suitable for biomimetic bone tissue engineering. We have chosen two types of polymers, namely collagen and poly (lactic-co-glycolic acid) (PLGA), natural and synthetic of its kind, respectively, to electrospin into nano-fibrous scaffolds. The electrospun scaffolds have high surface area, high porosity and well connected open pore network. In order to mimic the chemical composition of native bone ECM, the electrospun scaffolds were subjected to mineralization under optimal conditions. From the experimental results, we observed that the formation of bone-like apatite into collagen was relatively abundant and si

Electrospinning of polymer nanofibers for tissue regeneration 2021-03-19

Repair and regeneration of human tissues and organs using biomaterials, cells, and/or growth factors is a great challenge for tissue engineers and surgeons. The convergence of advanced materials science, nanotechnology, stem cell science, and developmental biology, which we define as Regenerative Engineering, represents the next multidisciplinary paradigm to engineer complex tissues. One of the grand challenges in this field is to mimic closely the hierarchical architecture and properties of the extracellular matrices (ECM) of the native tissues. A bio-inspired approach to creating biomaterials with nanoscale topographical features, micro- and macroscale gradient structures, and biological domains to interact with target growth factors and cells is key to overcoming this challenge for successful tissue regeneration. Furthermore, the healing and repair of diseased musculoskeletal tissues rely on many signaling pathways, involving numerous growth factors and their receptors. Thus, pharma

Fabrication of superhydrophilic surface on copper substrate by electrochemical deposition and sintering process 2021-03-19

Superhydrophilic surfaces were fabricated on copper substrates by an electrochemical deposition and sintering process. Superhydrophobic surfaces were prepared by constructing micro/nano-structure on copper substrates through an electrochemical deposition method. Conversion from superhydrophobic to superhydrophilic was obtained via a suitable sintering process. After reduction sintering, the contact angle of the superhydrophilic surfaces changed from 155° to 0°. The scanning electron microscope (SEM) images show that the morphology of superhydrophobic and superhydrophilic surfaces looks like corals and cells respectively. The chemical composition and crystal structure of these surfaces were examined using energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results show that the main components on superhydrophobic surfaces are Cu, Cu2O and CuO, while the superhydrophilic surfaces are composed of Cu merely. The crystal structure is more inerratic and the grain size becom

Electrospinning of collagen/biopolymers for regenerative medicine and cardiovascular tissue engineering 2021-03-19

The process of electrospinning has seen a resurgence of interest in the last few decades which has led to a rapid increase in the amount of research devoted to its use in tissue engineering applications. Of this research, the area of cardiovascular tissue engineering makes up a large percentage, with substantial resources going towards the creation of bioresorbable vascular grafts composed of electrospun nanofibers of collagen and other biopolymers. These bioresorbable grafts have compositions that allow for the in situ remodeling of the structure, with the eventual replacement of the graft with completely autologous tissue. This review will highlight some of the work done in the field of electrospinning for cardiovascular applications, with an emphasis on the use of biopolymers such as collagens, elastin, gelatin, fibrinogen, and silk fibroin, as well as biopolymers used in combination with resorbable synthetic polymers.

Electrospinning nanofiber scaffolds for soft and hard tissue regeneration 2021-03-18

Tissue engineering is an interdisciplinary field that integrates medical, biological, and engineering expertise to restore or regenerate the functionality of healthy tissues and organs. The three fundamental pillars of tissue engineering are scaffolds, cells, and biomolecules. Electrospun nanofibers have been successfully used as scaffolds for a variety of tissue engineering applications because they are biomimetic of the natural, fibrous extracellular matrix (ECM) and contain a three-dimensional (3D) network of interconnected pores. In this review, we provide an overview of the electrospinning process, its principles, and the application of the resultant electrospun nanofibers for tissue engineering. We first briefly introduce the electrospinning process and then cover its principles and standard equipment for biomaterial fabrication. Next, we highlight the most important and recent advances related to the applications of electrospun nanofibers in tissue engineering, including skin, b

Electrospinning for tissue engineering applications 2021-03-18

Tissue engineering makes use of the principles of medicine, biology and engineering and integrates them into the design of biological substitutes to restore, maintain and improve the functions of tissue. To fabricate a functional tissue, the engineered structures have to be able to mimic the extracellular matrix (ECM), provide the tissue with oxygen and nutrient circulation as well as remove metabolic wastes in the period of tissue regeneration. Continued efforts have been made in order to fabricate advanced functional three-dimensional scaffolds for tissue engineering. Electrospinning has been recognized and served as one of the most useful techniques based on the resemblance between electrospun fibers and the native tissues. Over the past few decades, a bewildering variety of nanofibrous scaffolds have been developed for various biomedical applications, such as tissue regeneration and therapeutic agent delivery. The present review aims to provide with researchers an in-depth understa

Design of scaffolds for blood vessel tissue engineering using a multi-layering electrospinning technique 2021-03-18

Aiming to develop a scaffold architecture mimicking morphological and mechanically that of a blood vessel, a sequential multi-layering electrospinning (ME) was performed on a rotating mandrel-type collector. A bi-layered tubular scaffold composed of a stiff and oriented PLA outside fibrous layer and a pliable and randomly oriented PCL fibrous inner layer (PLA/PCL) was fabricated. Control over the level of fibre orientation of the different layers was achieved through the rotation speed of the collector. The structural and mechanical properties of the scaffolds were examined using scanning electron microscopy (SEM) and tensile testing. To assess their capability to support cell attachment, proliferation and migration, 3T3 mouse fibroblasts and later human venous myofibroblasts (HVS) were cultured, expanded and seeded on the scaffolds. In both cases, the cell-polymer constructs were cultured under static conditions for up to 4 weeks. Environmental-scanning electron microscopy (SEM), conf

Electrospinning: A fascinating fiber fabrication technique 2021-03-18

With the emergence of nanotechnology, researchers become more interested in studying the unique properties of nanoscale materials. Electrospinning, an electrostatic fiber fabrication technique has evinced more interest and attention in recent years due to its versatility and potential for applications in diverse fields. The notable applications include in tissue engineering, biosensors, filtration, wound dressings, drug delivery, and enzyme immobilization. The nanoscale fibers are generated by the application of strong electric field on polymer solution or melt. The non-wovens nanofibrous mats produced by this technique mimics extracellular matrix components much closely as compared to the conventional techniques. The sub-micron range spun fibers produced by this process, offer various advantages like high surface area to volume ratio, tunable porosity and the ability to manipulate nanofiber composition in order to get desired properties and function. Over the years, more than 200 poly

Electrospinning in water and in situ crosslinking of hyaluronic acid / cyclodextrin nanofibers: Towards wound dressing with controlled drug release 2021-03-18

Hyaluronic acid (HA) is widely investigated due to its high potential for wound dressing applications. The fabrication of biomimetic HA-based scaffolds by electrospinning is thus extensively studied. However, HA is often dissolved in toxic organic solvents to allow the efficient production of electrospun nanofibers. Indeed, although HA is soluble in water, its ionic nature leading to long-range electrostatic interactions and the presence of counter ions induce a dramatic increase of the viscosity of aqueous HA solutions without insuring enough chain entanglements necessary for a stable and efficient electrospinning. In this study, biocompatible insoluble HA-based nanofibers were fabricated by electrospinning in pure water. To this end, poly(vinyl alcohol) (PVA) was added as a carrier polymer and it was found that the addition of hydroxypropyl-βcyclodextrin (HPβCD) stabilized the process of electrospinning and led to the efficient formation of uniform nanofibrous scaffolds. An in situ c

Electrospun nanofibrous polymeric scaffold with targeted drug release profiles for potential application as wound dressing 2021-03-18

We have successfully fabricated a dual drug release electrospun scaffold containing an anesthetic, lidocaine, and an antibiotic, mupirocin. Two drugs with different lipophilicities were electrospun from a poly-l-lactic acid (PLLA) solution with a dual spinneret electrospinning apparatus into a single scaffold. The release of the drugs from the scaffold showed different profiles for the two drugs. Lidocaine hydrochloride exhibited an initial burst release (80% release within an hour) followed by a plateau after the first few hours. Mupirocin exhibited only a 5% release in the first hour before experiencing a more sustained release to provide antibacterial action for over 72 h. For comparative purposes, both drugs were spun from a single spinneret and evaluated to determine their release profiles. The scaffold maintained its antibiotic activity throughout the processes of electrospinning and gas sterilization and supported cell viability. It has been reported in the literature that inter

Electrospinning of gelatin and gelatin/poly(l-lactide) blend and its characteristics for wound dressing 2021-03-18

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.

Academic News