Biomaterials and Tissue Engineering Research Unit, School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, NSW, 2006, Australia.
Raymond Purves Bone and Joint Research Laboratories, Institute of Bone and Joint Research, Kolling Institute, Northern Sydney Local Health District, Faculty of Medicine and Health, University of Sydney, St Leonards, NSW, 2065, Australia.
Adv Healthc Mater. 2019 Apr;8(8):e1801298. doi: 10.1002/adhm.201801298. Epub 2019 Feb 18.
Achieving adequate healing in large or load-bearing bone defects is highly challenging even with surgical intervention. The clinical standard of repairing bone defects using autografts or allografts has many drawbacks. A bioactive ceramic scaffold, strontium-hardystonite-gahnite or "Sr-HT-Gahnite" (a multi-component, calcium silicate-based ceramic) is developed, which when 3D-printed combines high strength with outstanding bone regeneration ability. In this study, the performance of purely synthetic, 3D-printed Sr-HT-Gahnite scaffolds is assessed in repairing large and load-bearing bone defects. The scaffolds are implanted into critical-sized segmental defects in sheep tibia for 3 and 12 months, with bone autografts used for comparison. The scaffolds induce substantial bone formation and defect bridging after 12 months, as indicated by X-ray, micro-computed tomography, and histological and biomechanical analyses. Detailed analysis of the bone-scaffold interface using focused ion beam scanning electron microscopy and multiphoton microscopy shows scaffold degradation and maturation of the newly formed bone. In silico modeling of strain energy distribution in the scaffolds reveal the importance of surgical fixation and mechanical loading on long-term bone regeneration. The clinical application of 3D-printed Sr-HT-Gahnite scaffolds as a synthetic bone substitute can potentially improve the repair of challenging bone defects and overcome the limitations of bone graft transplantation.
即使通过手术干预，实现大的或承重骨缺损的充分愈合仍然极具挑战性。使用自体移植物或同种异体移植物修复骨缺损的临床标准存在许多缺点。开发了一种生物活性陶瓷支架，锶硬硅钙石-锌尖晶石或“Sr-HT-Gahnite”（一种多组分、基于硅酸钙的陶瓷），当 3D 打印时，它结合了高强度和出色的骨再生能力。在这项研究中，评估了纯合成的、3D 打印的 Sr-HT-Gahnite 支架在修复大的承重骨缺损中的性能。将支架植入绵羊胫骨的临界尺寸节段性缺损中 3 个月和 12 个月，并用骨自体移植物进行比较。X 射线、微计算机断层扫描以及组织学和生物力学分析表明，支架在 12 个月后诱导了大量的骨形成和缺损桥接。使用聚焦离子束扫描电子显微镜和多光子显微镜对骨-支架界面进行的详细分析表明，支架降解和新形成骨的成熟。支架中应变能分布的计算机模拟表明手术固定和机械加载对长期骨再生的重要性。3D 打印 Sr-HT-Gahnite 支架作为合成骨替代品的临床应用有可能改善挑战性骨缺损的修复，并克服骨移植物移植的局限性。
