Tokyo Metropolitan Industrial Technology Research Institute, Setagaya-ku, Japan.
Biomed Mater. 2011 Feb;6(1):015012. doi: 10.1088/1748-6041/6/1/015012. Epub 2011 Jan 18.
The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm⁻³ and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 ± 0.48 and 0.651 ± 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.
本研究旨在评估增加胶原基质密度对多孔羟基磷灰石（HAp）-胶原复合材料作为人工骨材料的机械性能和体内可吸收性的影响。从 HAp 纳米晶体和致密胶原原纤维制备了七种类型的多孔 HAp-胶原复合材料。它们的密度和 HAp/胶原重量比分别在 122 至 331mg/cm³和 20/80 至 80/20 范围内变化。随着密度的增加，弯曲模量和强度增加，分别达到 2.46±0.48 和 0.651±0.103MPa。具有较高胶原基质密度的多孔复合材料在相同密度下表现出更高的机械性能，表明增加胶原基质密度是提高机械性能的有效方法。此外，除了胶原基质密度之外，还需要其他结构因素来实现类似骨骼的机械性能。在兔股骨骨缺损中研究了复合材料的体内可吸收性，结果表明，随着复合材料密度的增加，吸收率降低。作为人工骨，密度的过度增加可能受到可吸收性降低的限制。
