Zhang Bin, Yin Xiaohong, Zhang Feng, Hong Yirong, Qiu Yuesheng, Yang Xianyan, Li Yifan, Zhong Cheng, Yang Huayong, Gou Zhongru
State Key Laboratory of Fluid Power & Mechatronic Systems, Zhejiang University, Hangzhou 310058, China.
School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, China.
Regen Biomater. 2023 Jun 7;10:rbad057. doi: 10.1093/rb/rbad057. eCollection 2023.
Large-size mandible graft has huge needs in clinic caused by infection, tumor, congenital deformity, bone trauma and so on. However, the reconstruction of large-size mandible defect is challenged due to its complex anatomical structure and large-range bone injury. The design and fabrication of porous implants with large segments and specific shapes matching the native mandible remain a considerable challenge. Herein, the 6% Mg-doped calcium silicate (CSi-Mg6) and β- and α-tricalcium phosphate (β-TCP, α-TCP) bioceramics were fabricated by digital light processing as the porous scaffolds of over 50% in porosity, while the titanium mesh was fabricated by selective laser melting. The mechanical tests showed that the initial flexible/compressive resistance of CSi-Mg6 scaffolds was markedly higher than that of β-TCP and α-TCP scaffolds. Cell experiments showed that these materials all had good biocompatibility, while CSi-Mg6 significantly promoted cell proliferation. In the rabbit critically sized mandible bone defects (∼13 mm in length) filled with porous bioceramic scaffolds, the titanium meshes and titanium nails were acted as fixation and load bearing. The results showed that the defects were kept during the observation period in the blank (control) group; in contrast, the osteogenic capability was significantly enhanced in the CSi-Mg6 and α-TCP groups in comparison with the β-TCP group, and these two groups not only had significantly increased new bone formation but also had thicker trabecular and smaller trabecular spacing. Besides, the CSi-Mg6 and α-TCP groups showed appreciable material biodegradation in the later stage (from 8 to 12 weeks) in comparison with the β-TCP scaffolds while the CSi-Mg6 group showed much outstanding mechanical capacity in the early stage compared to the β-TCP and α-TCP groups. Totally, these findings suggest that the combination of customized strength-strong bioactive CSi-Mg6 scaffolds together with titanium meshes is a promising way for repairing the large-size load-bearing mandible defects.
由于感染、肿瘤、先天性畸形、骨创伤等原因，临床上对大尺寸下颌骨移植物有巨大需求。然而，大尺寸下颌骨缺损的重建因其复杂的解剖结构和大范围的骨损伤而面临挑战。设计和制造具有大段且特定形状与天然下颌骨匹配的多孔植入物仍然是一项重大挑战。在此，通过数字光处理制备了6%镁掺杂硅酸钙（CSi-Mg6）以及β-和α-磷酸三钙（β-TCP、α-TCP）生物陶瓷作为孔隙率超过50%的多孔支架，同时通过选择性激光熔化制备了钛网。力学测试表明，CSi-Mg6支架的初始挠曲/抗压阻力明显高于β-TCP和α-TCP支架。细胞实验表明，这些材料均具有良好的生物相容性，而CSi-Mg6显著促进细胞增殖。在填充有多孔生物陶瓷支架的兔临界尺寸下颌骨骨缺损（长度约13毫米）中，钛网和钛钉起到固定和承重作用。结果显示，空白（对照）组在观察期内缺损持续存在；相比之下，与β-TCP组相比，CSi-Mg6组和α-TCP组的成骨能力显著增强，这两组不仅新骨形成明显增加，而且小梁更厚且小梁间距更小。此外，与β-TCP支架相比，CSi-Mg6组和α-TCP组在后期（8至12周）显示出明显的材料生物降解，而与β-TCP组和α-TCP组相比，CSi-Mg6组在早期显示出更出色的力学性能。总的来说，这些发现表明定制强度高的生物活性CSi-Mg6支架与钛网相结合是修复大尺寸承重下颌骨缺损的一种有前景的方法。
