| Three-dimensional scaffolds play important roles in scaffold guided tissue engineering because they provide critical functions as extra-cellular matrices onto which cells can attach, grow, and form new tissues. To design scaffolds for load bearing tissue replacement, researchers often needs to address multiple biological, mechanical and geometrical design constraints. Therefore a novel fabrication system, Precision Extrusion Deposition (PED), has been developed allowing for the precise control of the scaffold external and internal geometry, porosity, pore size and interconnectivity. The system consists of a screw driven heated mini-extruder mounted on a 3-axis positioning system. This allows for bulk agglomerates of thermoplastic material to be fabricated into structures of a specified geometry.;A computer-aided tissue engineering approach (CATE), combined with the PED process, Polycaprolactone and composite Polycaprolactone/Hydroxyapatite scaffolds for bone tissue engineering applications were fabricated. Characterizations through SEM, Micro-CT and mechanical testing demonstrate the viability of the PED process. The results show good mechanical property, structural integrity, controlled pore size, and pore interconnectivity. The biological compatibility of the fabricated scaffolds was proved through both In-vitro cell culture and In-vivo nude mice studies.;This major accomplishments reported in this thesis are: (1) The development of a novel fabrication technology to manufacture load bearing tissue scaffolds with controlled and reproducible micro-architecture; (2) Demonstrated the compatibility of the structures, through a variety of characterization techniques, with biological systems and the potential in Tissue Engineering applications.;The PED technique offers a unique opportunity to study the influence of the micro-architecture upon cell proliferation and ECM generation allowing for the needed structural integrity, strength, and transport properties, for and an ideal micro-environment for cell and tissue in-growth and healing. |
