Design and Fabrication of Complex Scaffolds for Bone Defect Healing: Combined 3D Plotting of a Calcium Phosphate Cement and a Growth Factor-Loaded Hydrogel
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- 作者：Tilman Ahlfeld ; Ashwini Rahul Akkineni ; Yvonne Förster…
- 关键词：3D printing ; Additive manufacturing ; Rapid prototyping ; Alginate ; Gellan gum ; Calcium phosphate ; Biphasic scaffolds ; Drug delivery
- 刊名：Annals of Biomedical Engineering
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：45
- 期：1
- 页码：224-236
- 全文大小：
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Biomedicine, general; Biomedical Engineering; Biological and Medical Physics, Biophysics; Classical Mechanics; Biochemistry, general;
- 出版者：Springer US
- ISSN：1573-9686
- 卷排序：45
文摘
Additive manufacturing enables the fabrication of scaffolds with defined architecture. Versatile printing technologies such as extrusion-based 3D plotting allow in addition the incorporation of biological components increasing the capability to restore functional tissues. We have recently described the fabrication of calcium phosphate cement (CPC) scaffolds by 3D plotting of an oil-based CPC paste under mild conditions. In the present study, we have developed a strategy for growth factor loading based on multichannel plotting: a biphasic scaffold design was realised combining CPC with VEGF-laden, highly concentrated hydrogel strands. As hydrogel component, alginate and an alginate–gellan gum blend were evaluated; the blend exhibited a more favourable VEGF release profile and was chosen for biphasic scaffold fabrication. After plotting, two-step post-processing was performed for both, hydrogel crosslinking and CPC setting, which was shown to be compatible with both materials. Finally, a scaffold was designed and fabricated which can be applied for testing in a rat critical size femur defect. Optimization of CPC plotting enabled the fabrication of highly resolved structures with strand diameters of only 200 µm. Micro-computed tomography revealed a precise strand arrangement and an interconnected pore space within the biphasic scaffold even in swollen state of the hydrogel strands.