Design of Bone Scaffolds Structures for Rapid Prototyping with Increased Strength and Osteoconductivity
The geometry of bone scaffolds plays a crucial role in bone tissue regeneration. This architecture, especially pore size and shape, determines the mechanical strength of the scaffold. A number of previous workers have indicated the parameters which are believed to be the main stimulus in the adaptive bone remodelling process. An ideal bone manufacturing system would deliver bone morphogenetic proteins (BMP) and provide adequate mechanical properties. The aim of this study was to design a highly osteoconductive and mechanically strong bone regeneration scaffold which can be successfully manufactured. Three porous architectures of scaffold were designed using Solid EdgeTM 3D solid modelling software. The equivalent trabecular structure model consisted of repeatable unit cells arranged in layers to fill the chosen scaffold volume. The three different unit cell structures examined include cubic, triangular, and hexagonal polyhedral. Designed scaffold’s pores were varied in this study to 120, 340 and 600µm. This range was selected to meet one of the requirements of the scaffold design – the macropores must be at least 100µm in diameter, so the cells can penetrate and proliferate within the structure. The strengths of each scaffold were determined using ANSYSTM finite element software. Trabecular scaffold designs were analysed independently and in connection with simulated cortical bone in order to investigate their stress-strain response. As well as providing useful information on strengths developed from these topologies, the models developed indicated geometric constraints in order to tailor scaffolds to specific patient needs.
M. S. J. Hashmi, B. S. Yilbas and S. Naher
M. Lipowiecki and D. Brabazon, "Design of Bone Scaffolds Structures for Rapid Prototyping with Increased Strength and Osteoconductivity", Advanced Materials Research, Vols. 83-86, pp. 914-922, 2010