Apatite-collagen complex as a possible bone substitute

在pH 8.50的β-甘油磷酸钙溶液中制备了一种新的磷灰石-胶原复合物。在一种制备中，在碱性磷酸酶的存在下，通过使用二甲基辛二酰亚胺酸交联剂，将重构的I型胶原蛋白与葡甘露聚糖交联。在每天更新的β-甘油磷酸钙溶液中浸泡两周后，磷灰石沉积在胶原纤维上。由此制备的磷灰石-胶原复合物含有约两倍于改性胶原重量的磷灰石。当在扫描电子显微镜下观察时，针状晶体密集地沉淀在胶原原纤维上。然而，在络合物的某些部分中，也观察到点状沉淀。X射线衍射和红外光谱分析表明，胶原纤维上沉淀的磷灰石在结晶度和碳酸盐含量两个方面与骨矿物质非常相似。当植入一个月作为骨替代物在狗颌骨后牙w ...更多信息 在提取之前，发现复合物被再吸收，没有实质性的异物反应。植入复合体的部位充满了新形成的骨。在第二种制备中，将沉积有磷灰石的去端胶原片（MEIPAK）在由Te-CP和DCPD的等体积混合物组成的磷灰石水泥中在600 MPa的等静压下层压，随后将其浸入37 ℃的蒸馏水中7天，以将该水泥部分完全转化为磷灰石。对由此获得的片-胶原层压磷灰石块进行四点弯曲测试，其中加载方向垂直于块内的片。将载荷绘制为块试样纵向位移的函数。从具有和不具有胶原蛋白片的块试样获得的数据的比较表明，胶原蛋白片的存在未能增加弯曲强度，但增加了对试样所做的功。还尝试将未处理的胶原片层压在磷灰石中。然而，实际上不可能制备压实块。这一发现表明，磷灰石晶体在胶原蛋白片上的预沉积是成功地将联合收割机胶原蛋白和磷灰石结合的关键步骤，表明沉积在胶原蛋白片上的磷灰石充当了用于硬化过程的晶种。少

A new apatite-collagen complex was prepared in calcium beta-glycerophosphate solutions at pH 8.50. In one preparation, reconstituted type I collagen was cross-linked with phosvitin in the presence of alkaline phosphatase by the use of cross-linking agent of dimethyl subrimidate. After two weeks of immersion in daily-renewed solution of calcium beta-glycerophosphate, apatite deposited on the collagen fibrils. The apatitte-collagen complex thus prepared contained apatite approximately two times the modified collagen in weight. When viewed under a scanning electron microscope, needle-like crystals precipitated densely on the collagen fibrils. In some portion of the complex, however, dotlike precipitate was observed as well. X-ray diffraction and IR analyses of the complex suggested that apatite precipitated on the collagen fibrils was very similar to bone mineral in two aspects, crystallinity and carbonate content. When implanted for one month as a bone substitute in dog jaw after teeth w … More ere extracted, the complex was found resorbed without no substantial foreign body response. The site where the complex was implanted was filled with newly formed bone. This finding may suggest that the apatite-collagen, -complex prepared here is biodegrable and osteogeneiic as well.In the second preparation, atelocollagen sheets (MEIPAK) with apatite deposited on were laminated in apatite cement consisting of an equisolar mixture of Te-CP and DCPD under isostatic pressure of 600 MPa, which was later immersed in distilled water at 37ﾟC for 7 days to completely transform the sement portion into apatite. The sheet-collagen laminated apatite blocks thus obtained were subjected to four points bending test with a loading direction perpendicular to the sheets inside the block. The load was plotted as a function of longitudinal displacement of the block specimen. Comparison of data obtained from the block specimens with and without the collagen sheets showed that presence of the collagen sheet failed to increase the bending strength but increased the work done on the specimen. Non-treated collagen sheet was also tried to laminate in apatite. However, it was practically impossible to prepare compacted blocks. This finding suggests that predeposition of apatite crystals on collagen sheet is a key step to successfully combine collagen and apatite, indicating that apatite deposited on collagen sheet acts as seed crystal for the sement setting process. Less