Department of Orthopedic Surgery, School of Medicine, Stanford University, 240 Pasteur Drive, BMI 258, Stanford, CA, 94304, USA.
Department of Material Science and Engineering, Stanford University, Stanford, USA.
Sci Rep. 2021 Mar 23;11(1):6704. doi: 10.1038/s41598-021-86210-5.
Autologous bone grafts are considered the gold standard grafting material for the treatment of nonunion, but in very large bone defects, traditional autograft alone is insufficient to induce repair. Recombinant human bone morphogenetic protein 2 (rhBMP-2) can stimulate bone regeneration and enhance the healing efficacy of bone grafts. The delivery of rhBMP-2 may even enable engineered synthetic scaffolds to be used in place of autologous bone grafts for the treatment of critical size defects, eliminating risks associated with autologous tissue harvest. We here demonstrate that an osteoinductive scaffold, fabricated by combining a 3D printed rigid polymer/ceramic composite scaffold with an rhBMP-2-eluting collagen sponge can treat extremely large-scale segmental defects in a pilot feasibility study using a new sheep metatarsus fracture model stabilized with an intramedullary nail. Bone regeneration after 24 weeks was evaluated by micro-computed tomography, mechanical testing, and histological characterization. Load-bearing cortical bridging was achieved in all animals, with increased bone volume observed in sheep that received osteoinductive scaffolds compared to sheep that received an rhBMP-2-eluting collagen sponge alone.
自体骨移植物被认为是治疗骨不连的金标准移植物材料，但在非常大的骨缺损中，单独使用传统的自体骨不足以诱导修复。重组人骨形态发生蛋白 2（rhBMP-2）可刺激骨再生并增强移植物的愈合效果。rhBMP-2 的递送甚至可以使工程合成支架替代自体骨移植物用于治疗临界尺寸缺陷，从而消除与自体组织采集相关的风险。我们在此证明，一种由 3D 打印刚性聚合物/陶瓷复合支架与 rhBMP-2 洗脱胶原海绵组合而成的诱导成骨支架，可通过使用髓内钉稳定的新型绵羊跖骨骨折模型在初步可行性研究中治疗非常大规模的节段性缺损。通过 micro-CT、力学测试和组织学特征评估 24 周后的骨再生情况。所有动物均实现了承重皮质桥接，与单独接受 rhBMP-2 洗脱胶原海绵的绵羊相比，接受诱导成骨支架的绵羊观察到的骨体积增加。
