Zhao Luyi, Sun Jian, Zhang Ce, Chen Chaoqun, Chen Yi, Zheng Bo, Pan Haihua, Shao Changyu, Jin Biao, Tang Ruikang, Gu Xinhua
The Affiliated Hospital of Stomatology, School of Stomatology, Zhejiang University School of Medicine, and Key Laboratory of Oral Biomedical Research of Zhejiang Province, Hangzhou, Zhejiang, 310006, China.
Department of Stomatology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, PR China.
J Mech Behav Biomed Mater. 2021 Mar;115:104226. doi: 10.1016/j.jmbbm.2020.104226. Epub 2020 Dec 5.
Type I collagen and non-collagen proteins are the main organic components of dentin. This study aimed to investigate the biomimetic remineralization of demineralized dentin by aspartic acid (Asp), which is abundant in non-collagenous proteins (NCPs). Asp was added to a mineralizing solution containing polyacrylic acid (PAA) to explore the mechanism of Asp regulating the pure amorphous calcium phosphate (ACP) phase transition process. The remineralization process and superstructure of the remineralized layer of demineralized dentin were evaluated and analyzed by transmission electron microscope (TEM) and scanning electron microscope (SEM), and the biological stability of the remineralized layer was investigated by collagenase degradation experiment. It demonstrated that Asp promoted the crystallization kinetics of PAA-stabilized amorphous calcium phosphate to hydroxyapatite (HAP), and shortened the remineralization time of demineralized dentin from 7 days to 2 days. The newly formed remineralized dentin had similar morphology and biological stability to the natural dentin layer. The presence of a large number of Asp residues in NCPs promoted the phase transformation of ACP, and further revealed the mechanism of action of NCPs in dentin biomineralization. This experiment also showed that Asp promoted the biomimetic remineralization of dentin; the morphology and hierarchical structure of remineralized layer was similar to that of natural teeth, and had good biological properties.
I型胶原蛋白和非胶原蛋白是牙本质的主要有机成分。本研究旨在探讨天冬氨酸（Asp）对脱矿牙本质的仿生再矿化作用，天冬氨酸在非胶原蛋白（NCPs）中含量丰富。将天冬氨酸添加到含有聚丙烯酸（PAA）的矿化溶液中，以探究天冬氨酸调节纯无定形磷酸钙（ACP）相变过程的机制。通过透射电子显微镜（TEM）和扫描电子显微镜（SEM）对脱矿牙本质再矿化层的再矿化过程和超微结构进行评估和分析，并通过胶原酶降解实验研究再矿化层的生物稳定性。结果表明，天冬氨酸促进了PAA稳定的无定形磷酸钙向羟基磷灰石（HAP）的结晶动力学，将脱矿牙本质的再矿化时间从7天缩短至2天。新形成的再矿化牙本质在形态和生物稳定性方面与天然牙本质层相似。NCPs中大量天冬氨酸残基的存在促进了ACP的相变，进一步揭示了NCPs在牙本质生物矿化中的作用机制。本实验还表明，天冬氨酸促进了牙本质的仿生再矿化；再矿化层的形态和层次结构与天然牙齿相似，具有良好的生物学特性。
