Department of Orthopedics , Guangdong General Hospital, Guangdong Academy of Medical Sciences , Guangzhou , Guangdong 510080 , PR China.
School of Materials Science and Engineering , South China University of Technology , Guangzhou , 510641 , PR China.
ACS Appl Mater Interfaces. 2018 Dec 12;10(49):42146-42154. doi: 10.1021/acsami.8b17495. Epub 2018 Dec 3.
Titanium (Ti) alloy implants can repair bone defects at load-bearing sites. However, they mechanically mismatch with the natural bone and lack customized adaption with the irregularly major-sized load-bearing bone defects, resulting in the failure of implant fixation. Mineralized collagen (MC), a building block in bone, can induce angiogenesis and osteogenesis, and 3D printing technology can be employed to prepare scaffolds with an overall shape customized to the bone defect. Hence, we induced the formation of MC, made of hydroxyapatite (HAp) nanocrystals and collagen fibers, in 3D-printed porous TiAlV (PT) scaffolds through in situ biomimetic mineralization. The resultant MC/PT scaffolds exhibited a bone-like Young's modulus and were customized to the anatomical contour of actual bone defects of rabbit model. We found that the biocompatibility and osteogenic differentiation are best when the mass ratio between HAp nanocrystals and collagen fibers is 1 in MC. We then implanted the MC/PT scaffolds into the customized radius defect rabbit model and found that the MC/PT scaffolds significantly improved the vascularized bone tissue formation and integration between new bone and the implants. Therefore, a combination of 3D printing and biomimetic mineralization could lead to customized 3D PT scaffolds for enhanced angiogenesis, osteogenesis, and osteointegration. Such scaffolds represent novel patient-specific implants for precisely repairing irregular major-sized load-bearing bone defects.
钛（Ti）合金植入物可修复承重部位的骨缺损。然而，它们与天然骨在机械性能上不匹配，并且缺乏对不规则大尺寸承重骨缺损的定制适应性，导致植入物固定失败。矿化胶原（MC）是骨的组成部分，可诱导血管生成和骨生成，并且可以使用 3D 打印技术来制备与骨缺损整体形状相匹配的支架。因此，我们通过原位仿生矿化在 3D 打印多孔 TiAlV（PT）支架中诱导形成由羟基磷灰石（HAp）纳米晶体和胶原纤维组成的 MC。所得的 MC/PT 支架具有类似骨的杨氏模量，并可定制为兔模型实际骨缺损的解剖轮廓。我们发现，当 MC 中 HAp 纳米晶体和胶原纤维的质量比为 1 时，生物相容性和成骨分化最佳。然后，我们将 MC/PT 支架植入定制的桡骨缺损兔模型中，发现 MC/PT 支架可显著促进血管化骨组织形成以及新骨与植入物之间的整合。因此，3D 打印和仿生矿化的结合可以产生定制的 3D PT 支架，以增强血管生成、成骨和骨整合。这种支架代表了用于精确修复不规则大尺寸承重骨缺损的新型患者特异性植入物。
