There remains a need to develop synthetic bone substitutes with desirable architectures and properties to repair lost bone tissue. Three-dimensional printing (3DP) has been increasingly recognised as a promising technology for the fabrication of tissue-engineering scaffolds with the advantages of fully controlled geometries. However, the development of 3DP scaffolds with ideal printability, mechanical stability and resorption behaviour is still a challenge. The aim of this research was to design and develop bioceramic-based scaffold using 3DP technology. It started with the investigation of scaffold manufacture from the commercial calcium sulphate(CaS04) powder. Poly(ε-caprolactone) (PCL) coating was used to overcome the limitations of 3DP scaffolds. It was deeply infiltrated into inter-particle spaces, thus increasing the compressive properties of scaffolds to the level of cancellous bone and prolonging the complete resorption period from less than 7 days to more than 56 days. A dynamic flow system was designed to assess effects of flow condition on scaffold resorption. This research also developed a hydroxyapatite-calcium sulphate (HA-CaS04) formulation for a reliable and consistent 3DP process. A fundamental study was conducted to quantitatively assess effects of particle size on the key 3DP process parameters, such as powder bed packing and drop penetration behaviour. Based on the results, HA-CaS04 scaffolds were manufactured via 3DP followed by coated with PCL. Same characterisations were performed on the HA-CaS04 scaffolds to evaluate their compressive properties and in vitro resorption. The feasibility of printing HA-based scaffolds by incorporating different binding additives, such as maltodextrin and polyvinyl alcohol (PVOH), into HA powder was also investigated. Scaffolds with high geometrical accuracy and excellent green compressive strength were obtained when the PVOH (high viscosity) was used as the binding additive for HA.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:676500 |
| Date | January 2015 |
| Creators | Zhou, Zuoxin |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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