A large variety of approaches has been used to treat large and irregular shaped bone defects with less than optimal success due to material or design issues. In the recent years patient specific constructs prepared by additive manufacturing provided a solution to the need for shaping implants to fit irregular defects in the surgery theater. In this study, cylindrical disks of poly(ε-caprolactone) (PCL) was printed by fused deposition modeling and modified with nanohydroxyapatite (HAp) and poly(propylene fumarate) (PPF) to create a mechanically strong implant with well-defined pore size and porosity, controllable surface hydrophilicity (with PPF) and osteoconductivity (with HAp). Cytotoxicity, irritation and inflammation tests demonstrated that the scaffolds were biocompatible. PCL/HAp and PCL/HAp/PPF scaffolds were implanted in the femurs of rabbits with and without seeding with Rabbit Bone Marrow Stem Cells (BMSC) and examined after 4 and 8 weeks with micro-CT, mechanically and histologically. BMSC seeded PCL/HAp/PPF scaffolds showed improved tissue regeneration as determined by bone mineral density and micro-CT. Compressive and tension stiffness values (394 and 463 N/mm) were significantly higher than that of the healthy rabbit femur (316 and 392 N/mm, respectively) after 8 weeks of implantation. These 3D implants have great potential for patient-specific bone defect treatments.

中文翻译：

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羟基磷灰石和聚富马酸丙二酯修饰的3D打印聚（ε-己内酯）支架及其对兔股骨缺损愈合的影响

由于材料或设计问题，已经使用了各种各样的方法来治疗大型和不规则形状的骨缺损，但收效并不理想。近年来，通过增材制造制备的针对患者的特定构造提供了一种解决方案，可用于对植入物进行整形以适合手术室中的不规则缺陷。在这项研究中，通过熔融沉积模型印刷了聚（ε-己内酯）（PCL）的圆柱盘，并用纳米羟基磷灰石（HAp）和聚（富马酸丙二酯）（PPF）进行了改性，以制造出机械强度高，具有明确孔径的植入物孔隙率，可控制的表面亲水性（使用PPF）和骨传导性（使用HAp）。细胞毒性，刺激性和炎症测试表明该支架具有生物相容性。将PCL / HAp和PCL / HAp / PPF支架植入有或没有接种兔骨髓干细胞（BMSC）的兔股骨中，并在4和8周后用微型CT进行机械和组织学检查。BMSC接种的PCL / HAp / PPF支架通过骨矿物质密度和微CT的测定显示改善的组织再生。植入8周后，抗压和抗拉刚度值（394和463 N / mm）显着高于健康兔股骨（分别为316和392 N / mm）。这些3D植入物具有针对患者特定的骨缺损治疗的巨大潜力。BMSC接种的PCL / HAp / PPF支架通过骨矿物质密度和微CT的测定显示改善的组织再生。植入8周后，抗压和抗拉刚度值（394和463 N / mm）显着高于健康兔股骨（分别为316和392 N / mm）。这些3D植入物具有针对患者特定的骨缺损治疗的巨大潜力。BMSC接种的PCL / HAp / PPF支架通过骨矿物质密度和微CT的测定显示改善的组织再生。植入8周后，抗压和抗拉刚度值（394和463 N / mm）显着高于健康兔股骨（分别为316和392 N / mm）。这些3D植入物具有针对患者特定的骨缺损治疗的巨大潜力。