Department of Biomaterials, Faculty of Dental Science, Kyushu University 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Department of Biomaterials, Faculty of Dental Science, Kyushu University 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Biomater Adv. 2025 Jan;166:214026. doi: 10.1016/j.bioadv.2024.214026. Epub 2024 Sep 7.
To restore functions of long bones and avoid reconstruction failure, segmental defects should be quickly repaired using abundant amounts of regenerated bone with high mechanical strength and orientation along the bone axis. Although both bone volume and bone matrix orientation are important for faster restoration of long bones with segmental defects, researchers have primarily focused on the former. Artificial bone scaffolds with uniaxial channels, (e.g., honeycomb (HC) scaffolds), are considered adequate for regenerating bone oriented along the bone axis. The channel size may affect the orientation, amount, and strength of the regenerated bone. In this study, we investigated the effects of channel size in carbonate apatite HC scaffolds on the orientation of bones regenerated in segmental bone defects and determined the adequate channel size. Carbonate apatite HC scaffolds, with different channel sizes (350, 550, 730, and 890 μm in length on the side of the square aperture), were fabricated by extrusion molding of a mixture of calcium carbonate and organic binder, debinding, and subsequent phosphatization to convert the composition from calcium carbonate to carbonate apatite. No significant difference in the amounts of regenerated bones was observed for different channel sizes. However, bone along the bone axis was formed in the channels ≤550 μm in size but not in channels ≥730 μm. The HC scaffolds with a channel size of 350 μm regenerated bone with higher bending strength than those with a channel size of 890 μm. However, bone regenerated with the HC scaffolds having channel sizes of 350, 550, and 730 μm showed equal bending strength. Thus, the adequate channel size for fast regeneration of high-strength bone, oriented to the bone axis, is ≤730 μm. To the best of our knowledge, this is the first study to report the effect of channel size on bone orientation and strength. The findings of this study are relevant to the fast repair of segmental bone defects.
为了恢复长骨的功能并避免重建失败，应使用大量具有高强度和沿骨轴方向取向的再生骨来快速修复节段性缺损。尽管骨体积和骨基质取向都对更快地恢复节段性骨缺损很重要，但研究人员主要关注前者。具有单轴通道的人工骨支架（例如，蜂窝（HC）支架）被认为足以沿骨轴再生骨。通道尺寸可能会影响再生骨的取向、数量和强度。在这项研究中，我们研究了 HC 支架中海盐基磷灰石通道的大小对节段性骨缺损中再生骨的取向的影响，并确定了合适的通道大小。通过碳酸钙和有机粘合剂混合物的挤压成型、脱粘和随后的磷化，制造出具有不同通道尺寸（边长为 350、550、730 和 890 μm 的方孔）的碳酸盐磷灰石 HC 支架，以将组成从碳酸钙转换为碳酸盐磷灰石。不同通道尺寸之间的再生骨量没有显著差异。然而，在尺寸≤550μm 的通道中形成了沿骨轴的骨，而在尺寸≥730μm 的通道中则没有。通道尺寸为 350μm 的 HC 支架再生的骨具有比通道尺寸为 890μm 的骨更高的弯曲强度。然而，具有通道尺寸为 350、550 和 730μm 的 HC 支架再生的骨具有相等的弯曲强度。因此，快速再生高强度、沿骨轴取向的骨的合适通道尺寸≤730μm。据我们所知，这是第一项研究通道尺寸对骨取向和强度影响的研究。本研究的结果与节段性骨缺损的快速修复有关。
