Growing demand in bone tissue replacement has shifted treatment strategy from pursuing traditional bone-bone grafting to tissue replacement with bioactive biomaterials. Constructs that exhibit the ability to support the bone structure while encouraging tissue regeneration, integration, and replacement represent the future of bone tissue engineering. The present study aimed to understand the osteogenic and mechanical effects of binder-jet 3D printed, porous β-tricalcium phosphate scaffolds modified with a natural polymer/drug coating of polydopamine and Cissus Quadrangularis extract. Compression testing was used to determine the effect the polydopamine coating process had on the mechanical strength of the scaffolds. 3D printed scaffolds without and with polydopamine coatings fractured at 3.84 ± 1.01 MPa and 3.88 ± 0.51 MPa, respectively, suggesting no detrimental effect on strength due to the coating process. The osteogenic potential of the extract-loaded coating was tested in vitro, under static and dynamic flow conditions, and in vivo in a rat distal femur model. Osteoblast cell cultures showed polydopamine resulted in increased proliferation and alkaline phosphatase expression under dynamic flow, which was further enhanced by the addition of Cissus Quadrangularis extract. Histological analysis of implanted scaffolds showed significantly more new bone growth throughout the implant pores at 4 weeks post-op in polydopamine and extract-loaded implants compared to pure β-tricalcium phosphate. These results indicate that implants modified with polydopamine and Cissus Quadrangularis extract considerably outperform pure β-tricalcium phosphate scaffolds in facilitating early bone formation and ingrowth.

骨组织替代的需求不断增长，已经将治疗策略从传统的骨-骨移植转变为使用生物活性生物材料进行组织替代。具有支撑骨结构同时促进组织再生、整合和替换能力的结构代表了骨组织工程的未来。本研究旨在了解用聚多巴胺和白粉藤提取物的天然聚合物/药物涂层修饰的粘合剂喷射 3D 打印多孔 β-磷酸三钙支架的成骨和机械效应。压缩测试用于确定聚多巴胺涂层工艺对支架机械强度的影响。没有和有聚多巴胺涂层的 3D 打印支架分别在 3.84 ± 1.01 MPa 和 3.88 ± 0.51 MPa 下断裂，表明涂层过程不会对强度产生不利影响。在静态和动态流动条件下的体外以及大鼠股骨远端模型的体内测试了负载提取物的涂层的成骨潜力。成骨细胞培养物显示，聚多巴胺在动态流动下导致增殖和碱性磷酸酶表达增加，添加白粉藤提取物进一步增强了增殖和碱性磷酸酶表达。植入支架的组织学分析显示，与纯 β-磷酸三钙相比，术后 4 周，聚多巴胺和提取物负载的植入物在整个植入物孔中的新骨生长明显更多。这些结果表明，用聚多巴胺和白粉藤提取物修饰的植入物在促进早期骨形成和向内生长方面明显优于纯β-磷酸三钙支架。