Nanofibres have potential in biomedical and pharmaceutical applications including tissue engineering and drug release, which demand specific material properties to perform the required function without toxic side-effects, and preferably with minimal adverse ecological impact. Electrospinning is a promising technique for generating fibres with specific requirements and properties from organic, replaceable, non-toxic materials. Aqueous gelatin solution was chosen for its ability to react to changes in temperature. This work, including development of enhanced temperature control, demonstrated nanofibres of gelatin electrospun from aqueous solution with appropriate production conditions, which was previously unreported. To characterise the effects of the gelation mechanism caused by the partial reformation of the triple helix with aqueous gelatin solutions, electrospinning was attempted over a wide range of concentrations and temperatures. The study included measurements of the surface tension, viscosity and conductivity for the solutions, Scanning Electron Microscopy for size and form of product, and Wide Angle X•ray Scattering to ascertain the development of the structures from the solution to the fibre, determining the presence of the triple helix structure, and ThermoGravimetric Analysis to determine fibre water content. To provide comparison and continuity with previous studies, solutions of gelatin dissolved in glacial acetic acid, and polystyrene dissolved in MEK and DMF was electrospun and the products characterised in a similar manner to aqueous gelatin. Polystyrene solutions were chosen as examples of non-gelling solutions, thereby providing a contrast to the aqueous gelatin solutions. A potential area for nanofibres is in drug delivery. Aspirin (acetylsalicylic acid) was considered as an example, but its solubility in water is insufficient to incorporate into electrospun nanofibres for this purpose. Hence, the soluble salt, sodium acetylsalicylate, which shares some of the same medicinal properties as aspirin, was chosen. Nanofibres were electrospun from a solution of gelatin and sodium acetylsalicylate dissolved in water, but then 'disappeared', presumed to have dissolved in air moisture. This demonstrated that gelatin nanofibres could be considered for drug delivery, but further studies would be required to determine methods to stabilise the fibres. Gelatin was dissolved in a suspension of cellulose nanofibres derived from carrots and the resulting liquid was successfully electrospun to produce nanofibres. The nanofibres did not exhibit the expected properties of the gelatin triple helix structure. Attempts to silver coat gelatin nanofibres for medical applications, using Tollens' reagent showed the fibres must be made less soluble by polymer cross-linking or otherwise. A limited study of incorporating gold nanoparticles within the nanofibres to increase their electrical conductivity was inconclusive as the elemental analysis equipment was unable to detect the gold.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:590136 |
| Date | January 2013 |
| Creators | Elliott, Delyth Elin |
| Publisher | University of Reading |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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