The aim of this study is to investigate a robust and stable calcium-phosphorus system to remineralize human early enamel caries lesions with nanocomplexes of carboxymethyl chitosan/L-serine/amorphous calcium phosphate (CMC-Ser-ACP) to develop an effective method for mimicking the amelogenin (AMEL) mineralization pattern through ACP assembly. A CMC-Ser-ACP nanocomplex solution was first synthesized by a chemical precipitation method, and then 1% sodium hypochlorite (NaClO) was added to induce ACP phase formation. The morphologies of the nanocomplexes were characterized by transmission electron microscopy (TEM), and zeta potential analysis and Fourier transform infrared spectroscopy (FTIR) were performed to detect surface charge and functional group changes. The subtle changes of the demineralized enamel models induced by the remineralization effect were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The CMC-Ser-ACP nanocomplex solution could be preserved without any precipitation for 45 days. After the application of NaClO and through the guidance of Ser, ACP nanoparticles transformed into relatively orderly arranged hydroxyapatite (HAP) crystals, generating an aprismatic enamel-like layer closely integrated with the demineralized enamel, which resulted in enhanced mechanical properties for the treatment of early enamel caries lesions. The CMC-Ser-ACP nanocomplex solution is a remineralization system with great solution stability, and when NaClO is added, it can rapidly regenerate an aprismatic enamel-like layer in situ on the demineralized enamel surface. This novel remineralization system has stable chemical properties and can greatly increase the therapeutic effects against early enamel caries.

Graphical Abstract

中文翻译：

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L-丝氨酸与羧甲基壳聚糖结合引导无定形磷酸钙使牙釉质再矿化

本研究的目的是研究一种强大而稳定的钙磷系统，用羧甲基壳聚糖/L-丝氨酸/无定形磷酸钙（CMC-Ser-ACP）纳米复合物对人类早期牙釉质龋齿病变进行再矿化，以开发一种有效的模拟方法通过 ACP 组装的釉原蛋白 (AMEL) 矿化模式。首先通过化学沉淀法合成CMC-Ser-ACP纳米复合物溶液，然后添加1%次氯酸钠（NaClO）诱导ACP相形成。通过透射电子显微镜（TEM）对纳米复合物的形貌进行表征，并进行zeta电位分析和傅里叶变换红外光谱（FTIR）来检测表面电荷和官能团的变化。通过扫描电子显微镜（SEM）和X射线衍射（XRD）观察再矿化效应引起的脱矿牙釉质模型的细微变化。CMC-Ser-ACP纳米复合物溶液可保存45天无沉淀。使用 NaClO 后，在 Ser 的引导下，ACP 纳米粒子转化为排列相对有序的羟基磷灰石（HAP）晶体，生成与脱矿牙釉质紧密结合的棱柱状牙釉质层，从而增强了机械性能，可用于治疗早期牙釉质。牙釉质龋损。CMC-Ser-ACP纳米复合物溶液是一种具有良好溶液稳定性的再矿化体系，当添加NaClO时，可以在脱矿牙釉质表面快速原位再生出棱形牙釉质层。这种新型的再矿化系统具有稳定的化学性质，可以大大提高针对早期牙釉质龋齿的治疗效果。

图形概要