Chen Liang, Yuan He, Tang Bei, Liang Kunneng, Li Jiyao
College of Stomatology, Chongqing Medical University, Chongqing, PR China.
Caries Res. 2015;49(3):282-90. doi: 10.1159/000375376. Epub 2015 Apr 28.
Poly(amidoamine) (PAMAM) dendrimers, known as artificial proteins, have unique and well-defined molecular size and structure. It has previously been used to mimic protein-crystal interaction during biomineralization. In this study, generation 4.5 (4.5G) PAMAM with carboxylic acid (PAMAM-COOH) was synthesized and utilized to remineralize the surface of etched enamel in vitro. Using confocal laser scanning microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy we observed that 4.5G PAMAM-COOH can be absorbed on the etched enamel surface and that it can induce the formation of hydroxyapatite crystals with the same orientation as that of the enamel prisms on longitudinal and transversal enamel surfaces. The self-assembly behavior of PAMAM in the mineralization solution was also investigated and the result showed that 4.5G PAMAM can assemble to microribbon structure similar to the behavior of amelogenins. Therefore, we concluded that 4.5G PAMAM-COOH assemblies can act as the organic template on enamel surface and in mineralization solution to control the nucleation site and morphology of new-grown crystals to form the biomimetic structure of human enamel, which may open a new way for repairing damaged enamel.
聚（酰胺胺）（PAMAM）树枝状大分子，被称为人工蛋白质，具有独特且明确的分子大小和结构。它此前已被用于模拟生物矿化过程中的蛋白质-晶体相互作用。在本研究中，合成了带有羧酸的第4.5代（4.5G）PAMAM（PAMAM-COOH），并用于体外再矿化蚀刻釉质的表面。使用共聚焦激光扫描显微镜、傅里叶变换红外光谱、X射线衍射分析和扫描电子显微镜，我们观察到4.5G PAMAM-COOH可以吸附在蚀刻釉质表面，并且它可以诱导在纵向和横向釉质表面形成与釉柱取向相同的羟基磷灰石晶体。还研究了PAMAM在矿化溶液中的自组装行为，结果表明4.5G PAMAM可以组装成类似于釉原蛋白行为的微带结构。因此，我们得出结论，4.5G PAMAM-COOH组装体可以作为釉质表面和矿化溶液中的有机模板，以控制新生长晶体的成核位点和形态，从而形成人牙釉质的仿生结构，这可能为修复受损牙釉质开辟一条新途径。
