Effect of load-induced local mechanical strain on peri-implant bone cell activity related to bone resorption and formation in mice: An analysis of histology and strain distributions
Effect of load-induced local mechanical strain on peri-implant bone cell activity related to bone resorption and formation in mice: An analysis of histology and strain distributions
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负载引起的局部机械应变对小鼠骨吸收和形成相关的种植体周围骨细胞活性的影响：组织学和应变分布分析
DOI：
10.1016/j.jmbbm.2021.104370
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发表时间：
2021
影响因子：
3.9
通讯作者：
Wakabayashi Noriyuki
中科院分区：
文献类型：
--
作者：
Okawara Hisami;Arai Yuki;Matsuno Hitomi;Marci?n Petr;Bor?k Libor;Aoki Kazuhiro;Wakabayashi Noriyuki
本研究的目的是探讨载荷引起的局部机械应变对小鼠种植体周围骨细胞活性的影响。将钛植入物放置在13周龄雄性C57 BL/6 J小鼠的上颌骨中，并接受间歇性0.15 N、0.3 N或0.6 N载荷，持续6天，每天30分钟。最终加载后2天处死动物。未加载的小鼠用作对照。基于从活体微焦点计算机断层扫描中检索的每只小鼠的形态学数据构建动物特异性三维有限元模型，以计算机械应变分布。应变分布图像覆盖在同一动物相同部位的相应组织学图像上。种植体周围骨的颊颈部区域被预先确定为感兴趣区域（ROI）。将每个ROI分为4个应变强度水平：0-20 με、20-60 με、60-100 με和≥100 με，并通过所有加载样本的每个应变范围的总面积分析骨组织形态计量学参数。在应变强度≥100 μ ε的区域，钙黄绿素标记与钙化前沿的距离作为表征矿化沉积率的参数，显著大于应变强度<100 με的区域，表明较高的机械应变局部增强了成骨细胞的成骨活性。然而，萎缩的骨细胞和空骨细胞陷窝在最高应变区显着降低，这表明破骨细胞生成在高应变区比在低应变区更迟缓。在未加载动物中，组织形态计量学参数未受到几何学影响，表明载荷诱导的机械应变导致组织形态计量学参数差异。我们的研究结果支持这一假设，即骨细胞活性相关的骨吸收和形成是局部应变依赖于种植体负载。
The purpose of this study was to investigate the effect of load-induced local mechanical strain on bone cell activity of peri-implant bone in mice. Titanium implants were placed in the maxillae of 13-week-old male C57BL/6J mice and subjected to intermittent 0.15 N, 0.3 N, or 0.6 N loads for 30 min/day for 6 days. The animals were sacrificed 2 days after the final loading. Unloaded mice were used as controls. An animal-specific three-dimensional finite element model was constructed based on morphological data retrieved fromin vivomicrofocus computed tomography for each mouse to calculate the mechanical strain distribution. Strain distribution images were overlaid on corresponding histological images of the same site in the same animal. The buccal cervical region of the peri-implant bone was predetermined as the region of interest (ROI). Each ROI was divided by four strain intensity levels: 0–20 με, 20–60 με, 60–100 με, and ≥100 με, and the bone histomorphometric parameters were analyzed by the total area of each strain range for all loaded samples. The distance between the calcified front and calcein labeling as a parameter representing the mineral apposition rate was significantly greater in the areas with strain intensity ≥100 με than in the area with strain intensity <100 με, suggesting that the bone formation activity of osteoblasts was locally enhanced by a higher mechanical strain. However, the shrunken osteocytes and the empty osteocyte lacunae were significantly lower in the highest strain area, suggesting that osteoclastogenesis was more retarded in higher strain areas than in lower strain areas. The histomorphometric parameters were not affected geometrically in the unloaded animals, suggesting that the load-induced mechanical strain caused differences in the histomorphometric parameters. Our findings support the hypothesis that bone cell activity related to bone resorption and formation is local strain-dependent on implant loading.