Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, D-97070, Würzburg, Germany.
Department of Surgery, Faculty of Medicine, Faculty of Dentistry, McGill University, Montreal, Quebec, H3A 2B2, Canada.
Sci Rep. 2017 Apr 3;7(1):558. doi: 10.1038/s41598-017-00731-6.
Dicalcium phosphate cement preparation requires the addition of setting retarders to meet clinical requirements regarding handling time and processability. Previous studies have focused on the influence of different setting modifiers on material properties such as mechanical performance or injectability, while ignoring their influence on biological cement properties as they are used in low concentrations in the cement pastes and the occurrence of most compounds in human tissues. Here, analyses of both material and biological behavior were carried out on samples with common setting retardants (citric acid, sodium pyrophosphate, sulfuric acid) and novel (phytic acid). Cytocompatibility was evaluated by in vitro tests with osteoblastic (hFOB 1.19) and osteoclastic (RAW 264.7) cells. We found cytocompatibility was better for sodium pyrophosphate and phytic acid with a three-fold cell metabolic activity by WST-1 test, whereas samples set with citric acid showed reduced cell number as well as cell activity. The compressive strength (CS) of cements formed with phytic acid (CS = 13 MPa) were nearly equal to those formed with citric acid (CS = 15 MPa) and approximately threefold higher than for other setting retardants. Due to a proven cytocompatibility and high mechanical strength, phytic acid seems to be a candidate replacement setting retardant for dicalcium phosphate cements.
磷酸氢钙水泥的制备需要添加凝固延缓剂，以满足操作时间和可加工性方面的临床要求。以前的研究主要集中在不同凝固调节剂对材料性能的影响，如机械性能或可注射性，而忽略了它们对生物水泥性能的影响，因为它们在水泥浆中的浓度较低，而且大多数化合物都存在于人体组织中。在这里，对常用凝固延缓剂（柠檬酸、焦磷酸钠、硫酸）和新型凝固延缓剂（植酸）的样品进行了材料和生物学行为的分析。通过体外试验用成骨细胞（hFOB 1.19）和破骨细胞（RAW 264.7）细胞评估细胞相容性。我们发现，焦磷酸钠和植酸的细胞代谢活性提高了三倍，具有更好的细胞相容性，而用柠檬酸凝固的样品则显示细胞数量和细胞活性减少。用植酸形成的水泥的抗压强度（CS）（CS=13 MPa）几乎与用柠檬酸形成的水泥（CS=15 MPa）相等，比其他凝固延缓剂高约三倍。由于具有良好的细胞相容性和较高的机械强度，植酸似乎是磷酸氢钙水泥的候选替代凝固延缓剂。
