Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine.

Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID).

在脱矿牙釉质表面实现定向有序的再矿化，从而恢复接近健康牙釉质的良好机械性能，对牙医来说仍然是一个挑战。为了模拟牙釉质再矿化的天然生物矿化方法，本研究模拟了牙釉质发育蛋白（如釉原蛋白）的生物过程。在这项工作中，应用与阿仑膦酸盐（ALN）共轭的羧甲基壳聚糖（CMC）来稳定无定形磷酸钙（ACP），以形成CMC/ACP纳米粒子。次氯酸钠（NaClO）作为在体内分解釉原蛋白的蛋白酶，用于降解CMC - ALN基质并生成羟基磷灰石@无定形磷酸钙（HAP@ACP）核 - 壳纳米粒子。最后，在10 mM甘氨酸（Gly）的引导下，HAP@ACP纳米粒子能够有序排列，并随后从无定形相转变为排列良好的棒状磷灰石晶体，从而在酸蚀牙釉质表面实现定向有序的仿生再矿化。这种仿生再矿化过程是基于非经典结晶理论通过纳米粒子的定向附着（OA）实现的。这些结果表明，通过天然大分子聚合物寻找和开发参与生物矿化的天然蛋白质（如釉原蛋白）的类似物，并模拟生物矿化过程，将是牙釉质再矿化的一种有效策略。此外，这种方法是微创牙科（MID）中早期龋齿治疗的一种有前景的方法。