Novel Ceramic Based Scaffolds with Improved Mechanical and Biological Properties for Bone Tissue Regeneration

In the case of repairing large and critical-size bone defects, the currently available synthetic materials fall short of meeting the combined requirements for high porosity and interconnectivity while maintaining adequate mechanical properties. The aim of this thesis is to develop the novel synthetic bioactive scaffolds for the repair and regeneration of large bone defects in load-bearing applications. Major advances have been achieved in this thesis through the development of materials with the right balance between material properties, implant architecture and bioactivity to satisfy the functional and regenerative requirements of bone. Using new microstructural design strategies we were able to turn brittle, weak and highly porous ceramics (Biphasic calcium phosphate(BCP) and Baghdadite (Ca3ZrSi2O9)) into tough and strong scaffolds by coating their surfaces using multilayers of silk and polycaprolactone (PCL) or by using a nanocomposite layer of PCL as the matrix and bioactive glass (BG) or HA nanoparticles as fillers. Moreover, a new bioactive multi-component ceramic was developed; strontium-doped Hardystonite (Ca2ZnSi2O7) (85 wt. %) and Gahnite (ZnAl2O4) (15 wt. %), called Sr-HT Gahnite. The ceramic was designed with the aim of developing a highly bioactive, mechanically strong and tough material with mechanical properties approaching those of bone for use as a highly porous scaffold for regeneration of large bone defects. In conclusion, the approach adapted in this thesis is the rational combination of many validated individual elements, which act synergistically to produce for the very first time biomaterials which can substitute for lost bone, both by allowing bone formation and in the meantime withstanding load. These newly developed ceramics have the potential to have a significant contribution in existing therapies to provide a promising clinical result