Studies on the tissue response to fast-setting calcium phosphate cement

虽然传统的磷酸钙骨水泥(c-CPC)被认为是修复骨缺损的理想生物材料之一，但其固化时间较长(30-60min)，严重制约了其在外科手术中的应用。我们提出了快速固化CPC(FSCPC)，它可以在大约5分钟内固化，从而从最初阶段显示出更高的机械强度。本研究旨在以c-CPC为对照评价FSCPC的组织反应。将FSCPC和c-CPC植入实验动物的骨缺损区和皮下。FSCPC和c-CPC在组织对硬组织的反应和骨传导性方面没有差异。两种CPC均表现出良好的硬组织反应和良好的骨传导性。然而，他们对软组织的组织反应有显著差异。当将这些糊剂植入实验动物的皮下时，发现c-CPC碎裂，并引起严重的炎症反应。相比之下，FSCPC组在植入时保持了形状，并表现出良好的组织反应。软组织的炎症反应被认为是由于c-CP的机械强度较低以及由此产生的粉碎性能引起的。尽管FSCPC在本研究中使用的植入条件下表现出良好的组织反应，但如果FSCPC崩溃，可能会引起炎症反应。当FSCPC在凝结反应之前面临大量体液时，它可能会崩溃。根据本研究的结果，对不同病例的FSCPC的进一步评估尚待进行。

Although conventional calcium phosphate cement (c-CPC) is thought as one of the ideal biomaterials that can be used for the reconstruction of bony defects, its long setting time, 30 - 60 min, was a serious shortcoming for its application in the surgical procedure. We have proposed fast-setting CPC (FSCPC) which can set within approximately 5 min and thus shows higher mechanical strength from the initial period. This study aimed to evaluate the tissue response of FSCPC using c-CPC as a control. FSCPC and c-CPC were implanted in the bony defect and subcutaneously in experimental animals. No difference was observed between FSCPC and c-CPC with respect to their tissue response to hard tissue and their osteoconductivity. Both CPCs showed excellent hard tissue response and good osteoconductivity. However, there was a significant difference in their tissue response to soft tissue. When, the pastes were implanted subcutaneously in experimental animals, c-CPC was found crumbled and caused severe inflammatory response. In contrast, FSCPC set keeping the shape at implantation and showed excellent tissue response. It was assumed that the inflammatory response to soft tissue was caused due to the lower mechanical strength and the resulting crumbing properties of the c-CPC.Although FSCPC showed excellent tissue response regardless of the implantation condition used in this study, there could be a case that FSCPC cause inflammatory response if it crumbled. FSCPC could be crumbled when it faces plenty of body fluid before its setting reaction. Further evaluation of FSCPC for various case is awaited based on the findings obtained in this study.