Fabrication of porous beta-tricalcium phosphate with microchannel and customized geometry based on gel-casting and rapid prototyping

State Key Lab for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, ShaanXi, People's Republic of China.
Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine (Impact Factor: 1.33). 03/2011; 225(3):315-23. DOI: 10.1243/09544119JEIM769
Source: PubMed


The tissue engineering scaffolds with three-dimensional porous structure are regarded to be beneficial to facilitate a sufficient supply of nutrients and enable cell ingrowth in bone reconstruction. However, the pores in scaffolds tend to be blocked by the cell ingrowth and result in a restraint of nutrient supply in the further side of the scaffold. An indirect approach of combining the rapid prototyping and gel-casting technique is introduced in this study to fabricate beta-tricalcium phosphate (beta-TCP) scaffolds which not only have interconnected porous structure, but also have a microchannel network inside. The scaffold was designed with customized geometry that matches the defect area, and a double-scale (micropores-microchannel) porous structure inside that is beneficial for cell ingrowth. The scaffolds fabricated have an open, uniform, and interconnected porous architecture with a pore size of 200-400 microm, and posses an internal channel network with a diameter of 600 microm. The porosity was controllable. The compressive yield strength was 4.5 MPa with a porosity of 70 per cent. X-ray diffraction analysis shows that these fabrication processes do not change the crystal structure and chemical composition of beta-TCP. With this technique, it was also possible to fabricate porous scaffolds with desired pore size, porosity, and microchannel, as well as customized geometries by other bioceramics.

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Available from: Xiang Li, Oct 02, 2015
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    • "All artificial ACL grafts were produced from raw silk yarns (Bombyx mori, Grege 20/22, Trudel Limited, Zurich, Switzerland) with thorough removal of the antigenic protein sericin after graft preparation [34]. A TCP component with a diameter of 9.0 mm, length of 11.5 mm and porosity of 45%, was fabricated using techniques combining rapid prototyping and gel-casting methods [36]. The PEEK anchor, which had a hollow cap, was machined to press-fit with the TCP insert, having an outside diameter of 10.4 mm, an inner diameter of 6.0 mm and two arms with anchoring teeth. "
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    Acta Biomaterialia 08/2014; 10(8):3696–3704. DOI:10.1016/j.actbio.2014.05.015 · 6.03 Impact Factor
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    • "The ultimate tensile strength and linear stiffness of the silk ligament scaffold was around 1500 N, and 280 N mm −1 respectively, close to values typical of the native human ACL. The TCP inserts were generated with a porosity of approximately 40% and corresponding compressive strength of approximately 15 MPa [61], with the inserts thus capable of withstanding tensile loads from the silk scaffold of up to 500 N. In vitro tension to failure tests with the assembled silk/TCP/PEEK devices (figure 5) showed that the anchoring system yielded statistically equivalent slippage and graft elongation compared to interference screw fixation (1.65 ± 0.35 mm versus 1.87 ± 0.67, p = 0.49). "
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