Electrospun nanomaterials for health and energy applications

Electrospinning is the only technique that allows the fabrication of continuous fibers with diameters varying from 3 nm to 8 µm. This is a simple and inexpensive technique, and is already used by industry for mass production of nanomaterials. Due to their high surface area, electrospun fibers have potential applications in filtration, sensing, catalysis, energy, drug delivery and tissue engineering (Figure 1).
Electrospun nanofibers can be easily carbonized, and applied in air filtration, or can be used for water treatment even without the carbonization process.
This technique can also improve catalytic activity, and be used for energy by making e.g. nano-sized electrolyte for solid-state batteries or fuel cells.
These nanofibers can be also used as ultra-sensitive sensors, and are already utilized as biosensors for detecting several different diseases.
Electrospun fibers have been investigated as promising tissue engineering scaffolds since they mimic the nanoscale properties of native extracellular matrix. These scaffolds can be made from either natural or synthetic biodegradable polymers to simulate the cellular microenvironment.
An increasingly growing trend is the production and deliberate manipulation of nanoscale three-dimensional (3D) architectures, as 3D structures are more desirable than a 2D mats for many applications. Our group has developed a novel 3D electrospinner, a device that combines the simplicity of electrospinning with the manoeuvrability of extrusion-based 3D printing. With this technology, it is possible to assemble 3D macrostructures with internal nano/microfibrous features.
For energy application, an engineered 3D electrode can provide increased area for reactions, and increased mass transport. This can be used for batteries, fuel cells or supercapacitors.
In tissue engineering, 3D architectures can be used to control cell function. Nanofibrous scaffolds are ideal for this purpose because their dimensions are similar to components in the extracellular matrix (ECM) and mimic its fibrillar structure, providing essential cues for cellular organization, survival and function. Furthermore, the inherently high surface to volume ratio of electrospun scaffolds can enhance cell attachment, drug loading, and mass transfer properties. Electrospun fibers can be oriented or arranged randomly, giving control over both the bulk mechanical properties and the biological response to the scaffold. Drugs ranging from antibiotics and anticancer agents to proteins, DNA, and RNA can be incorporated and immobilized into electrospun scaffolds. Suspensions containing living cells have even been electrospun successfully. Thus, the applications of (3D) electrospinning in energy device fabrication, tissue engineering and drug delivery are nearly limitless.