School of Engineering and Materials Science
Research Student Awards
PhD Thesis: In vitro characterisation of novel biodegradable polymeric films for the prevention of post operative adhesion
Author: THOMAS, Paul
Supervisor(s): Ray Smith
`Adhesions' frequently occur as a sequel to internal disease or surgery, leading to chronic pain, ischaemia and obstruction of hollow viscera. A large percentage of such adhesions may be prevented by the incorporation of a suitable temporary blocking agent during surgery. The blocking agent should have adequate biocompatibility, the ability to completely degrade over a period of time, suitable mechanical properties and ideally, one treated non adhesive surface. The present study concerns the development and in vitro characterization of potential degradable polymeric film samples for use in such cases.
The properties of several degradable polymers were reviewed to assess their potential as appropriate barrier films. High molecular weight polylactic acid, various segmented polyester-urethanes and polydimethylsiloxane modified segmented polyester-urethanes were chosen as candidate materials. Suitable casting techiques for the production of films from these materials were developed. Initial characterization of the candidate films was carried out using Fourier transform infrared spectroscopy, differential scanning calorimetry, gel permeation chromatography, scanning electron microscopy, and mechanical testing. Adhesion properties of films were examined using an in vitro model gelatin based peel test.
Assessment of candidate film degradation properties was investigated using in vitro techniques consisting of film immersion in buffer and buffered enzyme solutions at 37oC for set time periods followed by film characterization. Characterization techniques of mass loss analysis, tensile testing, differential scanning calorimetry, gel permeation chromatography, Fourier transform infrared spectroscopy, scanning electron microscopy and qualitative analysis of collected solutions were employed.
A polydimethylsiloxane modified polyester-urethane was found to exhibit the desired properties to potentially fulfil the role as a temporary blocking agent.