三维打印羟基磷灰石晶须增强复合骨修复支架

利用三维打印技术成功制备羟基磷灰石晶须(HAPw)增强的聚己内酯(PCL)复合骨修复支架。通过改变三维打印的挤出速度和挤出气压, 使不同含量HAPw均能在PCL基材中一致排列并均匀分布。PCL支架的机械强度随HAPw含量增加显著提高, 添加33wt%HAPw使PCL支架强度提升了高达3倍。此外, HAPw使PCL支架表面与水的接触角从近100º降低至约50º, 有效改善了细胞表面粘附。经过体外人类骨髓间充质干细胞(hBMSC)在支架上的培养实验, 发现添加HAPw的复合支架具有更好的生物相容性, 能够有效促进hBMSC的增殖生长, 且HAPw-PCL复合支架上细胞具有更高的碱性磷酸酶(ALP)活性和OCN、RUNX2等相关成骨基因表达, 显示出hBMSCs向成骨方向更好的分化及成骨活性。

Hydroxyapatite Whisker-reinforced Composite Scaffolds Through 3D Printing for Bone Repair

Development of bioactive scaffolds with controllable architecture and high osteogenic capability is essential for bone tissue engineering. In this study, hydroxyapatite whiskers (HAPw) were added into polycaprolactone (PCL) matrix materials to fabricate scaffolds through 3D printing technique. The HAPw could distribute homogeneously in PCL and in alignment with 3D printing directions by adjusting squeeze parameters. The mechanical strength of PCL-HAPw composite scaffolds increased along with the increase of HAPw content. Adding 33wt% of HAPw remarkably enhanced the compressive strength of PCL scaffolds to 3 times, which can also lower the surface contact angles from 100° of PCL to 50° and thus enhance the surface hydrophilicity. In vitro culturing experiments of human bone marrow mesenchymal cells (hBMSCs) demonstrated that the incorporation of HAPw promoted their bioactive and osteogenic properties, including better cytocompatibility, cell adhesion, proliferation, alkaline phosphatase (ALP) activity, and bone-related gene expressions (OCN, RUNX2). Therefore, 3D-printed HAPw-PCL composite scaffolds showed improved mechanical strength and osteogenesis properties compared to pure PCL scaffolds, and suggest promising applications in bone regeneration.