Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, Germany.
Biomed Mater. 2012 Feb;7(1):015005. doi: 10.1088/1748-6041/7/1/015005. Epub 2012 Jan 27.
Bone substitute material properties such as granule size, macroporosity, microporosity and shape have been shown to influence the cellular inflammatory response to a bone substitute material. Keeping these parameters constant, the present study analyzed the in vivo tissue reaction to three bone substitute materials (granules) with different chemical compositions (hydroxyapatite (HA), beta-tricalcium phosphate (TCP) and a mixture of both with a HA/TCP ratio of 60/40 wt%). Using a subcutaneous implantation model in Wistar rats for up to 30 days, tissue reactions, including the induction of multinucleated giant cells and the extent of implantation bed vascularization, were assessed using histological and histomorphometrical analyses. The results showed that the chemical composition of the bone substitute material significantly influenced the cellular response. When compared to HA, TCP attracted significantly greater multinucleated giant cell formations within the implantation bed. Furthermore, the vascularization of the implantation bed of TCP was significantly higher than that of HA implantation beds. The biphasic bone substitute group combined the properties of both groups. Within the first 15 days, high giant cell formation and vascularization rates were observed, which were comparable to the TCP-group. However, after 15 days, the tissue reaction, i.e. the extent of multinucleated giant cell formation and vascularization, was comparable to the HA-group. In conclusion, the combination of both compounds HA and TCP may be a useful combination for generating a scaffold for rapid vascularization and integration during the early time points after implantation and for setting up a relatively slow degradation. Both of these factors are necessary for successful bone tissue regeneration.
骨替代材料的性质，如颗粒大小、大孔率、微孔率和形状，已被证明会影响细胞对骨替代材料的炎症反应。在保持这些参数不变的情况下，本研究分析了三种具有不同化学成分的骨替代材料（颗粒）的体内组织反应（羟基磷灰石（HA）、β-磷酸三钙（TCP）和两者的混合物，HA/TCP 比例为 60/40wt%）。在 Wistar 大鼠的皮下植入模型中，最长达 30 天，通过组织学和组织形态计量学分析评估了组织反应，包括多核巨细胞的诱导和植入床血管化的程度。结果表明，骨替代材料的化学成分显著影响细胞反应。与 HA 相比，TCP 在植入床内吸引了更多的多核巨细胞形成。此外，TCP 植入床的血管化程度明显高于 HA 植入床。双相骨替代物组结合了两组的特性。在最初的 15 天内，观察到高巨细胞形成和血管化率，与 TCP 组相当。然而，15 天后，组织反应，即多核巨细胞形成和血管化的程度，与 HA 组相当。总之，HA 和 TCP 两种化合物的组合可能是一种有用的组合，可以在植入后早期产生快速血管化和整合的支架，并建立相对较慢的降解速度。这两个因素对于成功的骨组织再生都是必要的。
