The process of bone formation onto the bone surface using a hydroxyapatite/collagen bone‐like nanocomposite (HAp/Col) was investigated. Immersion tests were performed to evaluate the impact of pH on the degradation of the specimens in an aqueous environment. The specimens were soaked in aqueous solutions of pH 4.0, 5.0, and 7.0. Using standardized images, the top‐view areas of the specimens were measured. Animal experiments were performed to investigate the bone formation process onto the bone surface. The specimens were placed under the rat calvarial periosteum, and μCT image analysis and histological observation were performed on samples harvested on postoperative Days 3, 5, and 7. In all experiments, β‐tricalciumphosphate (β‐TCP) was adopted as the control. HAp/Col turned to gel in acidic environments below pH 5.0. In contrast to the β‐TCP, the HAp/Col specimens placed under the periosteum expanded and attained a hollow structure with a gel‐filled center, accompanied by larger volume of new bone and appearance of TRAP‐positive multinucleated cells on postoperative Day 5. Therefore, HAp/Col can enhance bone formation onto the bone surface via induction of TRAP‐positive multinucleated cells, and may have clinical applications.

中文翻译：

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使用羟基磷灰石/胶原骨样纳米复合材料增强骨表面的骨形成。

研究了使用羟基磷灰石/胶原骨样纳米复合材料（HAp/Col）在骨表面形成骨的过程。进行浸泡测试以评估 pH 值对水环境中样品降解的影响。将样品浸泡在 pH 值为 4.0、5.0 和 7.0 的水溶液中。使用标准化图像，测量标本的顶视图区域。进行动物实验以研究骨表面上的骨形成过程。将标本置于大鼠颅骨骨膜下，对术后第3、5、7天采集的标本进行μCT图像分析和组织学观察。所有实验均采用β-磷酸三钙（β-TCP）作为对照。HAp/Col 在低于 pH 5.0 的酸性环境中变成凝胶。与 β-TCP 相比，