BME Postdoctoral Recruit Seminar: Daniel Alge, Ph.D.
Development of a 3D Polymer Reinforced Calcium Phosphate Cement Scaffold for Cranial Bone Tissue Engineering
Postdoctoral Recruit to The Therapeutic Biomaterials Laboratory
Department of Biomedical Engineering
Due to the limitations of current approaches to repairing cranial bone defects, there is considerable interest in the development of new strategies. To this end, we have sought to develop a calcium phosphate cement based scaffold for use in cranial bone tissue engineering. Advantages of calcium phosphate cements include osteoconductivity, resorbability, and injectability. This last property of injectability is particularly useful, as it can be leveraged for casting based approaches to scaffold fabrication. Using rapid prototyping technology, it is possible to fabricate calcium phosphate cement scaffolds with precisely controlled architectures. Patient-specific scaffolds can even be designed to give on optimum aesthetic outcome. Nevertheless, the selection of a specific calcium phosphate cement formulation for scaffold fabrication is not trivial.
Furthermore, the inherently poor mechanical properties of calcium phosphate cements represent a critical barrier to scaffold development. To address the first issue, we have rigorously studied the chemistry of dicalcium phosphate dihydrate (DCPD) setting cements, as DCPD is known to have excellent resorbability. To improve cement mechanical properties, we have developed a novel method for polymer reinforcement of calcium phosphate cements, which we have termed polymer infiltration and in situ curing. This method was used to fabricate resorbable 3D poly(propylene fumarate) (PPF) reinforced DCPD cement scaffolds, which were subsequently seeded with mesenchymal stem cells and evaluated in a rabbit calvarial defect model. Our results suggest that 3D PPF reinforced DCPD cement scaffolds are a promising platform for cranial bone tissue engineering.