Background

/Objective: The treatment of bone defect has always been a difficult problem in orthopedic clinic. The search for alternative biodegradable implants is a hot topic. The development of biodegradable magnesium scaffolds for the treatment of bone defects has long been a goal of the public.

Methods

In this study, we proposed a porous magnesium scaffold prepared by 3D gel printing and surface modification with an additional calcium phosphate coating and use of its strength, degradability and slow degradation rate in a bone graft substitute material. The porous magnesium granular scaffold was prepared by 3D gel printing technology and modified by DCPD (Dibasic Calcium Phosphate Dihydrate) coating. The biocompatibility, degradation rate, and osteogenic ability of the scaffold were evaluated in vitro and in vivo.

Results

The biocompatibility, in vivo degradation and bone defect healing response of the implants were investigated. Porous magnesium scaffolds were successfully prepared, and the strength of sintered scaffolds reached 5.38 ​MPa. The degradation rates of scaffolds were significantly reduced after coating with DCPD. The cell compatibility evaluation showed that DCPD-coated Mg scaffold was suitable for cell proliferation. In vivo biosafety monitoring showed that scaffold implantation did not cause an increase in Mg ion concentration in vivo, and no toxic damage was detected in the liver or kidney. Micro-CT and pathological results showed that a large amount of new bone was formed at 6 weeks. At 12 weeks, approximately 52% of the scaffold volume remained. At 24 weeks, osteogenesis, which was stimulated by some residual scaffold, still can be observed. In summary, this study suggests that 3D gel-printed DCPD-coated porous magnesium scaffolds have great potential as bone graft alternatives.

Conclusion

In summary, this study suggests that 3D gel-printed DCPD-coated porous magnesium scaffolds have great potential as bone graft alternatives.

The Translational potential of this article

The translational potential of this article is to make use of the advantages of 3D gel printing technology with higher efficiency and lower cost compared with SLM and SLS technologies, and use pure magnesium powder as raw material to prepare degradable porous magnesium metal scaffolds, opening up a new technical route for the preparation of degradable porous magnesium scaffolds which are made for bone defect regeneration in the future.

中文翻译：

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涂有二水合磷酸氢钙的 3D 凝胶打印多孔镁支架用于体内骨修复

背景

/目的：骨缺损的治疗一直是骨科临床的难题。寻找可替代的可生物降解植入物是一个热门话题。长期以来，开发用于治疗骨缺损的可生物降解镁支架一直是公众的目标。

方法

在这项研究中，我们提出了一种通过 3D 凝胶打印和表面改性制备的多孔镁支架，并带有额外的磷酸钙涂层，并将其强度、可降解性和慢降解速率用于骨移植替代材料。多孔镁颗粒支架采用 3D 凝胶打印技术制备，并通过 DCPD（二水合磷酸氢钙）涂层进行改性。在体外和体内评估了支架的生物相容性、降解率和成骨能力。

结果

研究了植入物的生物相容性、体内降解和骨缺损愈合反应。成功制备了多孔镁支架，烧结支架强度达到5.38 MPa。DCPD涂层后支架的降解率显着降低。细胞相容性评估表明，DCPD包被的Mg支架适合细胞增殖。体内生物安全监测表明，支架植入并未导致体内镁离子浓度增加，肝脏或肾脏未检测到毒性损伤。显微CT和病理结果显示，6周时有大量新骨形成。在 12 周时，大约 52% 的支架体积仍然存在。在 24 周时，仍然可以观察到由一些残留支架刺激的成骨。

结论

总之，这项研究表明，3D 凝胶打印的 DCPD 涂层多孔镁支架具有作为骨移植替代品的巨大潜力。

本文的转化潜力

本文的转化潜力在于利用3D凝胶打印技术相比SLM和SLS技术效率更高、成本更低的优势，以纯镁粉为原料制备可降解多孔镁金属支架，开辟了一种新型的可降解多孔镁金属支架。未来可降解多孔镁支架制备用于骨缺损再生的新技术路线。