Bigi A, Panzavolta S, Roveri N
Department of Chemistry G. Ciamician, University of Bologna, Italy.
Biomaterials. 1998 Apr-May;19(7-9):739-44. doi: 10.1016/s0142-9612(97)00194-4.
Composite films of gelatin and hydroxyapatite were prepared and characterized by mechanical tests, scanning electron microscopy and X-ray diffraction investigation. The mechanical properties of the films are greatly affected by the presence of hydroxyapatite and change as a function of inorganic phase content. On stretching, the long axis of the collagen molecular portions align parallel to the direction of deformation and the gelatin coarse layered structure becomes more evident and ordered. Furthermore, under deformation the inorganic crystals, which are embedded in the gelatin layers, seem to squeeze out in the interlayer spaces and assume a preferential orientation parallel to the force trajectories. Thus, as the inorganic phase stiffens the gelatin films, the macromolecular matrix distributes the stress promoting the preferential orientation of the apatitic crystals. The results indicate that this experimental approach can be used to prepare composites with anisotropic properties, which can be modulated through variation in composition and mechanical deformation in order to get biomaterials suitable to fulfill specific mechanical functions.
制备了明胶和羟基磷灰石复合膜,并通过力学测试、扫描电子显微镜和X射线衍射研究对其进行了表征。羟基磷灰石的存在对膜的力学性能有很大影响,并随无机相含量的变化而变化。在拉伸时,胶原分子部分的长轴与变形方向平行排列,明胶的粗层状结构变得更加明显和有序。此外,在变形过程中,嵌入明胶层中的无机晶体似乎被挤出到层间空间,并呈现出与力轨迹平行的优先取向。因此,随着无机相使明胶膜变硬,大分子基质分散应力,促进磷灰石晶体的优先取向。结果表明,这种实验方法可用于制备具有各向异性性能的复合材料,通过改变组成和机械变形可以对其进行调控,从而获得适合实现特定机械功能的生物材料。