Development of Natural Type Hydroxyapatite-Collagen Composite

传统上，羟基磷灰石烧结的目的是通过与骨组织的化学结合来获得坚硬、稳定的磷灰石。然而，烧结型羟基磷灰石与骨的直接结合很容易在严重的重复载荷下破坏，就像金属的骨结合一样，因为彼此的弹性模量不同。因此，开发坚硬、稳定的羟基磷灰石是没有意义的，就像生物惰性金属用于生物力学替代的情况一样。低钙羟基磷灰石的烧结已经被报道，它在缺钙部位结合了水，并在300ﾟC和600 MPa的压力下烧结成完全致密的实体。在水相中有胶原存在的情况下，我们尝试通过磷酸水溶液和氢氧化钙悬浮液的反应来合成羟基磷灰石。将稀释的胶原蛋白溶液与磷酸水溶液混合，缓慢倒入氢氧化钙S…中更多的是悬浮的水相。在形成的母液中没有发现胶原蛋白。溶液中的所有胶原蛋白都聚集在沉淀物中。将500克市售胶原蛋白溶液稀释至8升，并与0.6摩尔的磷酸混合。CaO被碾碎成细粉，并与水混合。将形成的Ca(OH)水悬浮液混合，然后缓慢加入胶原-磷酸混合溶液。沉淀物经过过滤和部分干燥，直到形成合适的水分含量。然后，它被安装在一个金属胶囊中。太空舱被抽空，并通过焊接进行密封。在40ﾟC、200 Mpa条件下保温8小时，得到密度为1.75g/ml、杨氏模量为2 Gpa、抗压强度为6.5 Mpa的磷灰石-胶原复合材料。标本可以用刀切割，并且在水中浸泡是稳定的。这种类型的络合物的物理性质可以根据组成和处理条件的不同而改变。该样本被植入狗(鲨鱼)体内，并进行了组织学评估。利用新开发的生物材料，进行了实验进化研究。成功地进行了鲨鱼和两栖动物之间的异种移植。从这项研究中发现，在原型脊椎动物中，免疫系统就像高等脊椎动物的胚胎一样处于耐受状态。较少

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