Bioceramics Group, Biomaterials Field, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan.
Department of Applied Chemistry, Graduate School of Science and Technology, Meiji University, Kawasaki, Kanagawa, Japan.
J Biomed Mater Res B Appl Biomater. 2024 Aug;112(8):e35451. doi: 10.1002/jbm.b.35451.
We have previously reported that a novel bioresorbable self-setting injectable bone paste composed of hydroxyapatite/collagen bone-like nanocomposite (HAp/Col) and (3-glycidoxypropyl)trimethoxysilane (GPTMS) was successfully prepared and was replaced with new bone within 3 months of implantation in defects created in porcine tibia. In this study, the HAp/Col-GPTMS paste was implanted into bone defects in rat tibiae to investigate the initial kinetics and bone tissue response. Even though more than 35% of GPTMS molecules should be eluted rapidly from directly injected pastes according to previously reported cell culture tests, in this study, energy-dispersive X-ray spectrometry did not detect Si (GPTMS) deposition in tissues surrounding the paste at 1 day postimplantation. Further, no abnormal inflammatory responses were observed in the surrounding tissues over the test period for both directly injected and prehardened pastes. Companying these observations with the results of the previous animal test (in which the paste was fully resorbed and was substituted with new bone), the eluted GPTMS resolved in no harm in vivo from the initial to final (completely resorbed) stages. Material resorption rates calculated from X-ray microcomputed tomography (μ-CT) images decreased with increasing in GPTMS concentration. Histological observations indicated that tartrate-resistant acid phosphatase (TRAP) active cells, (assumed to be osteoclasts), exist on the periphery of pastes. This result suggested that the paste was resorbed by osteoclasts in the same way as the HAp/Col. Since a good correlation was observed between TRAP active areas in histological sections and material resorption rate calculated from μ-CT, the TRAP activity coverage ratio offers the possibility to estimate the osteoclastic resorption ratio of materials, which are replaced with bone via bone remodeling process.
我们之前曾报道过，一种新型的可生物吸收的自凝固注射型骨糊，由羟基磷灰石/胶原骨样纳米复合材料（HAp/Col）和（3-缩水甘油丙基）三甲氧基硅烷（GPTMS）组成，在植入猪胫骨缺损 3 个月内成功地被新骨所取代。在这项研究中，将 HAp/Col-GPTMS 糊剂植入大鼠胫骨骨缺损中，以研究其初始动力学和骨组织反应。尽管根据之前的细胞培养试验，超过 35%的 GPTMS 分子应该从直接注射的糊剂中迅速洗脱出来，但在这项研究中，能量色散 X 射线光谱法在植入后 1 天未检测到组织中存在硅（GPTMS）沉积在糊剂周围。此外，在试验期间，直接注射和预固化糊剂的周围组织均未观察到异常的炎症反应。这些观察结果与之前的动物试验结果（糊剂完全吸收并被新骨取代）一致，即从初始到最终（完全吸收）阶段，洗脱的 GPTMS 在体内不会造成任何伤害。从 X 射线微计算机断层扫描（μ-CT）图像计算得出的材料吸收率随着 GPTMS 浓度的增加而降低。组织学观察表明，抗酒石酸酸性磷酸酶（TRAP）活性细胞（假定为破骨细胞）存在于糊剂的外围。这一结果表明，糊剂被破骨细胞以与 HAp/Col 相同的方式吸收。由于在组织学切片中观察到的 TRAP 活性区域与从 μ-CT 计算得出的材料吸收率之间存在良好的相关性，因此 TRAP 活性覆盖比提供了一种可能性，可以估计通过骨重塑过程被新骨取代的材料的破骨细胞吸收比。
