Development and characterization of waste equine bone-derived calcium phosphate cements with human alveolar bone-derived mesenchymal stem cells

Calcium phosphate cements (CPCs) are regarded as promising graft substitutes for bone tissue engineering. However, their wide use is limited by the high cost associated with the complex synthetic processes involved in their fabrication. Cheaper xenogeneic calcium phosphate (CaP) materials derived from waste animal bone may solve this problem. Moreover, the surface topography, mechanical strength, and cellular function of CPCs are influenced by the ratio of micro- to nano-sized CaP (M/NCaP) particles. In this study, we developed waste equine bone (EB)-derived CPCs with various M/NCaP particle ratios to examine the potential capacity of EB-CPCs for bone grafting materials. Our study showed that increasing the number of NCaP particles resulted in reductions in roughness and porosity while promoting smoother surfaces of EB-CPCs. Changes in the chemical properties of EB-CPCs by NCaP particles were observed using X-ray diffractometry. The mechanical properties and cohesiveness of the EB-CPCs improved as the NCaP particle content increased. In an in vitro study, EB-CPCs with a greater proportion of MCaP particles showed higher cell adhesion. Alkaline phosphatase activity indicated that osteogenic differentiation by EB-CPCs was promoted with increased NCaP particle content. These results could provide a design criterion for bone substitutes for orthopedic disease, including periodontal bone defects.磷酸钙骨水泥（Calcium phosphate cements, CPCs）被视为骨组织工程领域极具应用潜力的植骨替代材料。但由于其制备工艺复杂、合成成本较高，这一局限限制了该材料的大规模推广应用。源自废弃动物骨骼的低成本异种源磷酸钙（xenogeneic calcium phosphate, CaP）材料，或可有效解决上述问题。此外，磷酸钙骨水泥的表面形貌、力学强度与细胞功能，均受微米/纳米级磷酸钙（micro- to nano-sized CaP, M/NCaP）颗粒的比例影响。本研究制备了一系列不同M/NCaP颗粒比例的废弃马骨（waste equine bone, EB）源磷酸钙骨水泥，以探究EB-CPCs作为植骨材料的应用潜力。研究结果表明：随着纳米级磷酸钙颗粒占比提升，EB-CPCs的表面粗糙度与孔隙率均随之降低，表面愈发平整；通过X射线衍射法（X-ray diffractometry）可观测到，纳米级磷酸钙颗粒会改变EB-CPCs的化学特性；当纳米级磷酸钙颗粒含量增加时，EB-CPCs的力学性能与内聚性均得到优化。体外实验显示，微米级磷酸钙颗粒占比更高的EB-CPCs可促进细胞黏附；碱性磷酸酶活性检测结果证实，纳米级磷酸钙颗粒占比提升可增强EB-CPCs的成骨分化能力。本研究结果可为骨科疾病（包括牙周骨缺损）的植骨替代材料设计提供参考准则。