Gashti Mazeyar Parvinzadeh, Bourquin Marc, Stir Manuela, Hulliger Jürg
Department of Chemistry & Biochemistry, University of Berne, Freiestrasse 3 CH-3012, Berne, Switzerland.
J Mater Chem B. 2013 Mar 14;1(10):1501-1508. doi: 10.1039/c3tb00088e. Epub 2013 Jan 28.
Brushite is a well known precursor of calcium oxalate monohydrate, the main mineral found in kidney stones having a monoclinic crystal structure. Here, we present a new method for biomimicking brushite using a single tube diffusion technique for gel growth. Brushite crystals were grown by precipitation of calcium hydrogen phosphate hydrate in a gelatin/glutamic acid network. They are compared with those produced in gel in the presence of urea. The aggregates were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (IR) and thermal gravimetric analysis (TGA). SEM revealed a change of morphology by glutamic acid from spherulitic growth to plate-shaped and mushroom-like forms consisting of crystal plates and highly ordered prismatic needles, respectively. Furthermore, brushite crystals grown in a gelatin/glutamic acid/urea network showed needle-shaped morphology being different from other brushite growth forms. The XRD method showed that cell parameters for brushite specimens were slightly larger than those of the American Mineral Society reference structure. The mushroom-like biomimetic composite bears a strong resemblance to the brushite kidney stones which may open up new future treatment options for crystal deposition diseases. Hence, suitable diets from glutamic acid rich foods could be recommended to inhibit and control brushite kidney stones.
透钙磷石是一水草酸钙的一种著名前驱体，一水草酸钙是肾结石中发现的主要矿物质，具有单斜晶体结构。在此，我们提出一种利用单管扩散技术进行凝胶生长来仿生合成透钙磷石的新方法。透钙磷石晶体通过磷酸氢钙水合物在明胶/谷氨酸网络中的沉淀生长而成。将它们与在有尿素存在的凝胶中生成的晶体进行比较。通过扫描电子显微镜（SEM）、X射线衍射（XRD）、红外光谱（IR）和热重分析（TGA）对聚集体进行分析。SEM显示，谷氨酸使形态发生了变化，从球状生长变为分别由晶板和高度有序的棱柱形针组成的板状和蘑菇状形态。此外，在明胶/谷氨酸/尿素网络中生长的透钙磷石晶体呈现出针状形态，与其他透钙磷石生长形态不同。XRD方法表明，透钙磷石样品的晶胞参数略大于美国矿物学会参考结构的晶胞参数。这种蘑菇状仿生复合材料与透钙磷石肾结石非常相似，这可能为晶体沉积疾病开辟新的未来治疗选择。因此，可以推荐食用富含谷氨酸的食物组成的适宜饮食，以抑制和控制透钙磷石肾结石。
