Biopolymers

The main aim of this research study was to create a double-layered cryogel with enhanced mechanical properties and biocompatibility for biomedical applications. To this end, this work focussed on the creation of polyvinyl acohol(PVA) based polymer composites with two known biocompatible ceramics, namely, α-tricalcium phosphate (α-TCP) and titanium dioxide (TiO2). In brief, using the freeze/thaw methods a layered composite structure was built with a PVA boundary as a layer. Subsequently, the swelling characteristics, together with the chemical,physical and rheological properties of the composites were examined. Upon optimisation of the structure and composition, cell metabolic activity, ell attachment and controlled release of theophylline were investigated. Using scanning electron microscopy, a well integrated multi-layered structure was observed. Moreover, FTIR spectroscopy revealed that the chemical composition was homogenous throughout the layers. Swelling studies in buffered solution at pH 7.4 revealed that the control PVA multilayered gels had a 200 % higher degree of swelling and 9 % lower mechanical properties compared to the double-layered systems containing bioceramics. These results indicate an increase in intramolecular bonding based on the amount of the ceramics added on cryogels. Furthermore, there was no evidence of an adverse affect on cell metabolica activity, when MC3T3 cells were grown in the presence of the composites for 72 hours. In addition, controlled release of theophylline was observed over a x hour period. Taken together, these results indicate that the novel multilayered composite fabricated in this work have potential for bone repair applications.