Electrospinning: a fascinating fiber fabrication technique.

Electrospinning is a highly versatile method to process solutions or melts, mainly of polymers, into continuous fibers with diameters ranging from a few micrometers to a few nanometers. This technique is applicable to virtually every soluble or fusible polymer. The polymers can be chemically modified and can also be tailored with additives ranging from simple carbon-black particles to complex species such as enzymes, viruses, and bacteria. Electrospinning appears to be straightforward, but is a rather intricate process that depends on a multitude of molecular, process, and technical parameters. The method provides access to entirely new materials, which may have complex chemical structures. Electrospinning is not only a focus of intense academic investigation; the technique is already being applied in many technological areas.

Electrospinning: A Fascinating Method for the Preparation of Ultrathin Fibers

Carbon nanotube–polymer composites: Chemistry, processing, mechanical and electrical properties

Interest in electrospinning has recently escalated due to the ability to produce materials with nanoscale properties. Electrospun fibers have been investigated as promising tissue engineering scaffolds since they mimic the nanoscale properties of native extracellular matrix. In this review, we examine electrospinning by providing a brief description of the theory behind the process, examining the effect of changing the process parameters on fiber morphology, and discussing the potential applications and impacts of electrospinning on the field of tissue engineering.

Electrospinning of polymeric nanofibers for tissue engineering applications: a review.

Although there are many methods of fabricating nanofibres, electrospinning is perhaps the most versatile process. Materials such as polymer, composites, ceramic and metal nanofibres have been fabricated using electrospinning directly or through post-spinning processes. However, what makes electrospinning different from other nanofibre fabrication processes is its ability to form various fibre assemblies. This will certainly enhance the performance of products made from nanofibres and allow application specific modifications. It is therefore vital for us to understand the various parameters and processes that allow us to fabricate the desired fibre assemblies. Fibre assemblies that can be fabricated include nonwoven fibre mesh, aligned fibre mesh, patterned fibre mesh, random three-dimensional structures and sub-micron spring and convoluted fibres. Nevertheless, more studies are required to understand and precisely control the actual mechanics in the formation of various electrospun fibrous assemblies.

https://iopscience.iop.org/article/10.1088/0957-4484/17/14/R01/pdf

A review on electrospinning design and nanofibre assemblies.

Electrospinning is a technique employed for preparing polymer fibers having diameters in the range of 10 μm–10 nm using high electrostatic field. In this letter, we report the formation of aligned polymer fibers, several centimeters in length, with separation between the fibers in the range of 5–100 μm. Achieving alignment is an important step toward the exploitation of these fibers in applications. We have employed about 4500 V and a separation distance of about 1–3 cm between the electrodes. Smaller distance between electrodes, we believe, provides better control on the formation of the fibers.

Electrospinning of continuous aligned polymer fibers

Electrospinning produces polymeric fibers with diameters in the range of 10μm–10nm by accelerating a charged polymer jet under a high electric field. We report the preparation of conducting nanocomposite fibers of poly(methyl methacrylate) (PMMA) and multiwalled carbon nanotubes (MWCNTs) by electrospinning. The fibers obtained are long and well aligned. The carbon nanotubes are found to be oriented along the fiber axis. The room temperature dc electrical conductivity of a single fiber with MWCNT (0.05% w/w) shows about a ten orders of magnitude improvement from the pure PMMA. The conductivity increases with MWCNT concentration.

Electrical conductivity of a single electrospun fiber of poly(methyl methacrylate) and multiwalled carbon nanotube nanocomposite

Highly conducting electrospun polyaniline-polyethylene oxide nanofibrous membranes filled with single-walled carbon nanotubes

Electrospinning is a versatile method of preparing polymer nanocmposite fibers. Electrospun nanocomposite fibers of poly(methyl methacrylate) and single walled carbon nanotubes were prepared. The f...

https://journals.sagepub.com/doi/pdf/10.1177/155892500800300405

Preparation and Characterization of Electrospun Fibers of Poly(methyl methacrylate) - Single Walled Carbon Nanotube Nanocomposites

Concentration gradient of diffusible bioactive chemicals assumes many important roles in regulating cellular behavior. Among the many factors influencing functional recovery after nerve injury, such as topographical and biochemical signals, concentration gradients of neurotrophic factors provide chemotactic cues for neurite outgrowth and targeted renervation. In this study, a concentration gradient of nerve growth factor (NGF, 0–250 μg/ml) was incorporated throughout the thickness of poly(e-caprolactone)–poly(ethylene glycol) coaxial electrospun nanofibrous scaffolds (∼700 μm thick with ∼800 nm average fiber diameter). The existence of the protein gradient upon protein release was demonstrated using a customized under-agarose–PC12 neurite outgrowth assay. When exposed to scaffolds endowed with NGF concentration gradient (NGF-CG), a significant difference in the percentage of cells bearing neurite outgrowth was observed (7.1 ± 1.9% vs. 0.8 ± 0.3% for cells exposed to high vs. low concentration surface, respectively; p < 0.05). In contrast, no significant difference was observed when cells were exposed to scaffolds that encapsulated a fixed concentration of NGF. Direct culture of PC12 cells on the substrates demonstrated the cytocompatibility and the effect of diffusible NGF gradient on neurite outgrowth. A significant difference in the percentage of cells with neurite extensions was observed when PC12 cells were seeded on NGF-CG scaffolds (21.2 ± 3.6% vs. 10.4 ± 1.3% on high vs. low concentration surface, respectively; p < 0.05). Furthermore, Z-stack confocal microscopy tracking of neurite extensions revealed the chemotatic guidance effect of NGF concentration gradient. Directed and enhanced neurite penetration into the scaffolds towards increasing NGF concentration was observed. In vitro release study indicated that the encapsulated NGF was released in a sustained manner for at least 30 days (80.4 ± 3.6% released). Taken together, this study demonstrates the feasibility of incorporating concentration gradient of diffusible bioactive chemicals in nanofibrous scaffolds via the coaxial electrospinning technique.

Bibekananda Sundaray

Papers

Electrospinning of continuous aligned polymer fibers

Electrical conductivity of a single electrospun fiber of poly(methyl methacrylate) and multiwalled carbon nanotube nanocomposite

Highly conducting electrospun polyaniline-polyethylene oxide nanofibrous membranes filled with single-walled carbon nanotubes

Preparation and Characterization of Electrospun Fibers of Poly(methyl methacrylate) - Single Walled Carbon Nanotube Nanocomposites

Nanofibrous scaffold with incorporated protein gradient for directing neurite outgrowth