The regeneration of mineral crystals under physiological conditions is an efficient way to repair defects in hard tissues. To achieve robust mineralization on surfaces such as the tooth enamel, an inducer requires strong affinity with the substrates and should be able to induce mineralization. Thus far, most studies used a single molecule containing two components to realize the above functions separately, which might be troublesome to synthesize and purify. In this work, inspired by the statherin in the salivary acquired pellicle, we designed a simple peptide sequence, Asp–Asp–Asp–Glu–Glu–Lys–Cys (peptide-7), to accomplish the dual tasks of adsorption and mineralization on enamel surfaces. We speculate the calcium binding ability of the negatively charged carboxylic acid groups in the peptide itself contributes to the dual functions of peptide-7. In vitro and in vivo experiments demonstrated its excellent repair effect on enamel as compared to fluoride. More importantly, due to the strong affinity between peptides and hydroxyapatite, a compact mineralized crystal layer and a strong adhesion between the regenerated minerals and the bottom substrates were observed, similar to the effect induced by fluoride. This work sheds light on the interaction mechanism between peptide-7 and minerals. In addition, since it is safer than fluoride, peptide-7 may have potential applications in the repair of other hard tissues and the functionalization of biomaterials.

中文翻译：

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生物启发的七肽作为功能化矿化诱导剂，具有增强的羟磷灰石亲和力†

在生理条件下再生矿物晶体是修复硬组织缺陷的有效方法。为了在诸如牙釉质的表面上实现坚固的矿化作用，诱导剂需要与底物具有很强的亲和力，并且应该能够诱导矿化。迄今为止，大多数研究使用包含两个组分的单个分子来分别实现上述功能，这可能难以合成和纯化。在这项工作中，受唾液腺获得性表膜中的statherin的启发，我们设计了一个简单的肽序列，即Asp–Asp–Asp–Glu–Glu–Lys–Cys（peptide-7），以完成吸附和矿化的双重任务搪瓷表面。我们推测肽本身中带负电荷的羧酸基团的钙结合能力有助于肽7的双重功能。体外和体内实验表明，与氟化物相比，它对牙釉质具有出色的修复作用。更重要的是，由于肽和羟基磷灰石之间的强亲和力，观察到致密的矿化晶体层以及再生矿物质和底部基质之间的强粘附性，类似于氟化物诱导的效果。这项工作阐明了7肽与矿物质之间的相互作用机理。此外，由于肽7比氟化物更安全，因此在其他硬组织的修复和生物材料功能化方面可能具有潜在的应用。