Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook

Full text: It has been well known that calcium phosphates, specifically hydroxyapatites, are bioactive minerals which can promote cell proliferation and production of an extracellular matrix. Because hydrogels have unique properties as 3D hydrophilic polymer networks with high water content and an elasticity which mimics the natural tissue, they have been especially attractive matrices for tissue engineering of bone and dentine, and as scaffolds to promote the formation of complex tissue microstructure. The only drawback is that the synthetic hydrogels without modification have poor cellular compatibility; hence they are not readily used for tissue engineering. In this preliminary work, the PVA/PVP hydrogels prepared by γ-irradiation of the PVA/PVP aqueous solutions have been subjected to a simulated body fluid to induce the deposition of calcium phosphates in the hydrogel. Series of analyses reveal that calcium phosphates are formed not only on the surface but throughout the interior part of the hydrogel networks. These calcification patterns are beneficial for their application as scaffolds for tissue engineering. On the basis of X-ray microanalysis, it was found that most of the calcium phosphates were formed after three weeks of calcification time. The types of calcium phosphates identified were of mainly Ca2+ and OH- deficient hydroxyapatite with Cl- as the most likely substituting species at the OH- site. It is hoped that with this modification, PVA/PVP hydrogel/calcium phosphate composites will eventually lead to the development of medically applicable tissue engineering scaffolds