Electrostatic spinning of scaffolds for tissue engineering applications
The field of tissue engineering is constantly seeking fabrication techniques for the
optimum, application-specific production of scaffolds suitable for generating
functioning cellular structures. The electrostatic spinning technique was investigated
as such a technique.
The aims of this research were to establish the potential of this technique with regard
to: the ability to produce a range of reproducible scaffolds with a variety of structures
and properties, related to the original fabrication conditions; the suitability of the
produced scaffolds for cell-seeding and their potential to induce varying cellular
behaviour; the ability to produce scaffolds with controlled variable properties; the
potential to alter the scaffolds during or after production, inadvertently or through
deliberate further modification; the ability of the modified scaffolds to alter the
A range of 12.5% Tecoflex® polyurethane electrostatically spun scaffolds was
produced,t hrought he systematicv ariation of the spinningp arametersT. he scaffold
inter-fibre separation and fibre diameters were characterized using SEM. The
scaffolds were seeded with 5x 104 L929 and human embryonic lung fibroblasts and
cultured for 1 day, 1,4,8 and 12 weeks. Cell coverage, number, spreading,
orientation and cytoskeletal involvement were investigated using SEM, image
analysis and confocal microscopy. Cellular matrix and adhesion molecules were
examined by immunostaining for collagen I, elastin, CD54 and CD106. Scaffold
properties of Young's Modulus, surface roughness, contact angle and porosity were
determined, using tensile testing, AFM, DCA and mercury porosimetry, and related
to the original scaffold structures. Scaffold modification through scaffold
sterilisation, ageing, surface modification with RGD sequences and the addition of metallic particulate to the spinning solution was tested. The resultant effect on the
inter-fibre separation, fibre diameter and surface roughness was examined using
SEM andA FM, andt he subsequenetf fectso n the cell coveragein vestigated.
The electrostatic spinning technique was capable of fabricating fibrous scaffolds,
with variable inter-fibre separation and fibre diameter. The alteration of the spinning
parameters changed the mechanisms of spray jet manipulation around the
electrostatic zone and fibre deposition, as did temperature, relative humidity and the
mandrel coating. Scaffold thickness was varied by the flow rate and the duration of
the spinning process.
The scaffolds were capable of supporting cellular growth and adhesion, with
significant differences present between scaffolds and cell types. Cell coverage,
number, spreading, orientation and cytoskeletal involvement were altered between
scaffolds through differences in the cellular growth methodologies.
Scaffolds had different properties, showing some correlation to scaffold structure.
Cell matrix anda dhesionm oleculesw ereu pregulateda crosst he scaffolds.
The scaffolds were modified, with the structure and surface being altered, producing
varying cellular results, dependent on the modification technique. It was feasible to
add metallic particulate into the scaffolds during production.
The electrostatic spinning technique showed potential for the use in the field of tissue
engineering, with the capability of developing optimum, application-specific