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Development of Natural Type Hydroxyapatite-Collagen Composite

天然型羟基磷灰石-胶原蛋白复合物的研制

基本信息

批准号：
06558119
负责人：
NISHIHARA Katsunari
金额：
$ 1.66万
依托单位：
UNIVERSITY of TOKYO
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

Conventionally, hydroxyapatite sintering has been aimed at stiff, stable apatite due to chemical bonding with osseous tissue. However, direct bonding of sintered hydroxyapatite with bone may easily be destroyed under severe repeated loading just like osseointegration of metal because of differences in elastic moduli from each other. Therefore, development of stiff, stable hydroxyapatite makes no sense just as in the case of bioinert metal for biomechanical substitution.Sintering of calcium-deficient hydroxyapatite has already been reported, which bonded water at the calcium-deficient site, and was sintered up to fully dense bodies at 300ﾟC under a pressure of 600MPa. In the presence of collagen in an aqueous phase, we tried tosynthesize the hydroxyapatite by means of reaction between an aqueous solution of phosphoric acid and a calcium-hydroxide suspension. A diluted collagen solution was mixed with an aqueous solution of phosphoric acid and was poured slowly into a calcium-hydroxide s … More uspended aqueous phase. No collagen was found in the mother liquid thus formed. All collagen in the solution was found to be collecting in the precipitate. Five hundred grams of commercially available collagen solution was diluted up to 8 liters and mixed with 0.6mole of phosphoric acid. The CaO was crushed into fine powder and mixed with water. The Ca (OH) aqueous suspension thus formed was mixed, and the collagen-phosphoric acid mixed solution was added slowly. The precipitate was filtered and partly dried until suitable water content formed. Then, it was mounted in a metal capsule. The capsule was evacuated and sealed by welding. It was thin kept for 8 hrs at 200 MPa at 40ﾟC.The resulting apatite-collagen composite was 1.75g/ml in density, 2GPa in Young's modulus, and 6.5MPa in compression strength. The specimen could be cut by a knife, and was stable against immersion in water. The physical property of this type of complex may change according to composition and treating conditions. The sample was implanted in dogs chandrichthies (shark) and histologically evalutated. Using newly development biomaterials, experimental evolutionary study is carried out. Xenotransplantations between shark and amphibian are successfully carried out. From this research implant fact is discovered that in archetype vertebrates immune system is in tolerance just like embryo of higher vertebrates. Less

传统上，羟基磷灰石烧结是针对坚硬、稳定的磷灰石，由于与骨组织的化学结合。然而，由于不同的弹性模量，烧结羟基磷灰石与骨的直接结合在剧烈的反复载荷下容易像金属的骨整合一样被破坏。因此，发展坚硬、稳定的羟基磷灰石就像生物惰性金属用于生物力学替代一样没有意义。羟基磷灰石在600MPa压力下，在300℃的温度下烧结成致密体。在水相中存在胶原蛋白的情况下，我们尝试用磷酸水溶液与氢氧化钙悬浮液反应的方法合成羟基磷灰石。将稀释后的胶原蛋白溶液与磷酸水溶液混合，慢慢倒入氢氧化钙溶液中。在这样形成的母液中没有发现胶原蛋白。发现溶液中的所有胶原蛋白都在沉淀中聚集。500克市售胶原蛋白溶液稀释至8升，与0.6摩尔磷酸混合。CaO被粉碎成细粉，与水混合。将由此形成的Ca （OH）水悬浮液混合，缓慢加入胶原-磷酸混合溶液。沉淀物经过过滤和部分干燥，直到形成合适的含水量。然后，它被安装在一个金属胶囊中。胶囊被抽真空并焊接密封。在40ºC， 200mpa下保存8小时。所得磷灰石-胶原复合材料的密度为1.75g/ml，杨氏模量为2GPa，抗压强度为6.5MPa。这种标本可以用刀切开，而且不浸在水中也很稳定。这类配合物的物理性质可根据组成和处理条件而改变。该样本被植入狗chandrichthies（鲨鱼）并进行组织学评估。利用新开发的生物材料，进行了实验进化研究。在鲨鱼和两栖动物之间成功地进行了异种移植。由此研究发现，原始脊椎动物的免疫系统与高等脊椎动物的胚胎一样处于耐受状态。少