聚酰胺-胺/纳米羟基磷灰石的合成、表征以及对牙本质小管的封闭作用

Synthesis and Characterization of Polyamidoamine Dendrimers/Nano-hydroxyapatite and Its Role in Dentin Tubule Occlusion

目的合成并表征同时具有有机、无机材料特性的纳米复合生物材料聚酰胺-胺/纳米羟基磷灰石(PAMAM/n-HAP),并观察其对牙本质小管的封闭作用。方法采用Pramanik水化学反应的方法制备PAMAM/n-HAP,并通过透射电子显微镜、傅里叶变换红外光谱仪对其表征和验证。最终应用PAMAM/n-HAP封闭脱矿的牙本质小管,并应用扫描电子显微镜对其修复牙本质小管的效果进行评价。结果傅里叶变换红外光谱仪显示1244 cm^(-1)和1650 cm^(-1)出现了PAMAM所特有的强振动峰,同时透射电子显微镜显示n-HAP的表面出现10 nm厚的低衬度包裹层,证实了PAMAM/n-HAP的成功合成。扫描电子显微镜显示应用PAMAM/n-HAP能够有效地降低牙本质小管的直径,填充空虚的牙本质小管,封闭牙本质小管。结论 PAMAM/n-HAP作为一种新型的纳米复合生物材料具有良好的生物活性,能够借助表面的羧基与暴露的胶原纤维发生特异性结合,从而能够在较深的位置稳定封闭牙本质小管,提示PAMAM/n-HAP可能成为一种新型的脱敏材料应用于临床。

Objective To synthesis and characterization nano-composite biomaterials-polyamidoamine dendrimers/nano-hydroxyapatite（ PAMAM/n-HAP）, which has the properties of both organic and inorganic materials,and then evaluate its role in dentin tubule occlusion. Methods PAMAM/n-HAP was characterized and validated by Fourier transform infrared spectrometry and transmission electron microscopy after its preparation via the Pramanik aqueous-based chemical method. Scanning electron microscope was used to evaluate its role in dentin tublule occlusion. Results The peak absorption bands were found at 1244 cm^-1and 1650 cm^-1in Fourier transform infrared spectroscopy. A relatively low-density coating（ about 10 nm） appeared on the nHAP. The results of Fourier transform infrared spectrometry and transmission electron microscopy confirmed the successful synthesis of PAMAM/n-HAP. The scanning electron microscope showed that PAMAM/n-HAP could effectively reduce the diameter of the dentin tubule and close dentin tubule. Conclusions PAMAM/n-HAP,as a newly synthesized biomaterial,has a good binding capacity with collagen fibers with the help of superficial car-boxyl. It can induce effective dentinal tubule occlusion,indicating that PAMAM/n-HAP have great potential in clinical practice for dentin hypersensitivity.