Tissue Engineering Research Group, Department of Anatomy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
School of Mechanical and Design Engineering, Dublin Institute of Technology, Bolton St, Dublin 1, Ireland.
Adv Healthc Mater. 2017 Nov;6(21). doi: 10.1002/adhm.201700598. Epub 2017 Jul 31.
The biofabrication of large natural biomaterial scaffolds into complex 3D shapes which have a controlled microarchitecture remains a major challenge. Freeze-drying (or lyophilization) is a technique used to generate scaffolds in planar 3D geometries. Here we report the development of a new biofabrication process to form a collagen-based scaffold into a large, complex geometry which has a large height to width ratio, and a controlled porous microarchitecture. This biofabrication process is validated through the successful development of a heart valve shaped scaffold, fabricated from a collagen-glycosaminoglycan co-polymer. Notably, despite the significant challenges in using freeze-drying to create such a structure, the resultant scaffold has a uniform, homogenous pore architecture throughout. This is achieved through optimization of the freeze-drying mold and the freezing parameters. We believe this to be the first demonstration of using freeze-drying to create a large, complex scaffold geometry with a controlled, porous architecture for natural biomaterials. This study validates the potential of using freeze-drying for development of organ-specific scaffold geometries for tissue engineering applications, which up until now might not have been considered feasible.
将大型天然生物材料支架生物制造为具有受控微观结构的复杂 3D 形状仍然是一个主要挑战。冷冻干燥（或冻干）是一种用于生成平面 3D 几何形状支架的技术。在这里，我们报告了一种新的生物制造工艺的开发，该工艺可将基于胶原蛋白的支架形成具有大高度与宽度比和受控多孔微观结构的大型复杂几何形状。该生物制造工艺通过成功开发出由胶原蛋白-糖胺聚糖共聚物制成的心脏瓣膜形状支架得到验证。值得注意的是，尽管使用冷冻干燥来创建这种结构存在重大挑战，但所得支架在整个支架中具有均匀、均匀的孔结构。这是通过优化冷冻干燥模具和冷冻参数来实现的。我们相信这是首次使用冷冻干燥来创建具有受控多孔结构的大型复杂支架几何形状的天然生物材料的演示。这项研究验证了冷冻干燥在组织工程应用中开发特定于器官的支架几何形状的潜力，到目前为止，这些应用可能还不可行。
