Biomimetic Growth of Enamel-like Hierarchical Structures

描述（由申请人提供）：提出的研究旨在证明，在特定分子的存在下，使用焦磷酸盐（PPi）稳定的高度过饱和溶液，可以生成酸蚀人类牙釉质的高度定向搪瓷类纳米和微观结构，这些分子表现出引导成熟牙釉质晶体外延生长的能力。这项研究是在PI实验室最新进展的指导下进行的，这些进展为釉质基质蛋白调节釉质形成的机制提供了独特的见解，并提供了强有力的初步数据，支持所提出的牙釉质再生仿生方法的可行性。尽管在促进口腔卫生和氟化方面做出了巨大的努力，但需要进一步研究以实现易于应用，快速生长的类搪瓷生物陶瓷用于仿生修复。因此，迫切需要开发有效的方法来再生牙齿结构。其核心假设是通过调节矿物离子的可用性、晶体生长动力学和晶体取向来实现牙釉质结构和功能的恢复。从长远来看，更好地了解牙釉质矿物形成的机制将有助于开发用于牙釉质再生的新型仿生和生物相容性修复材料，例如早期龋齿的治疗。类淀粉原蛋白材料，特别是在商业合成的富含亮氨酸的淀粉原蛋白肽（LRAP）中保留的淀粉原蛋白关键功能序列，有可能用于牙釉质结构和性能的再生。本建议的目标将通过完成以下两个具体目标来实现：目标1。确定LRAP和非磷酸化全长淀粉原蛋白在焦磷酸（PPi）稳定的过饱和磷酸钙溶液中引导体外牙釉质结构再生的机制和有效性。酸蚀人牙釉质的矿化动力学和外延生长受PPi矿化抑制剂的水解作用(1)牙釉质表面本身和2)碱性磷酸酶（AP）的调控。目标2。确定高过饱和磷酸钙溶液的机制和有效性，磷酸钙溶液由磷酸化的天然和合成淀粉原蛋白稳定，使用AP触发体外牙釉质结构的再生。全长天然（磷酸化）猪淀粉原蛋白和LRAP（+P）是过饱和磷酸钙溶液的有效稳定剂，将作为PPi的替代品进行研究，并研究它们在添加AP去磷酸化后指导酸蚀珐琅质矿物结构再生的额外潜力。形成的矿物的范围、性质和取向将通过SEM、EDX、FT-IR和掠射x射线衍射进行评估。修复和/或改善基本牙釉质性能将根据机械性能、物理-化学性能和矿物附着强度进行评估。

DESCRIPTION (provided by applicant): The proposed study is designed to prove that highly oriented enamel-like nano- and micro-structures of acid-etched human enamel can be generated using pyrophosphate (PPi)-stabilized highly supersaturated solutions in the presence of specific molecules that exhibit the capacity to guide the epitaxial growth of mature enamel crystals. This study is guided by recent advances in the PI's laboratory that have provided unique insight into the mechanism by which enamel matrix proteins regulate enamel formation and strong preliminary data that support the feasibility of proposed biomimetic approaches for enamel regeneration. Despite tremendous efforts in promoting oral hygiene and fluoridation, further research is needed to achieve an easy-to-apply, fast growing enamel-like bioceramic for biomimetic repair. Thus, there is a great need to develop effective means to regenerate tooth structures. The central hypothesis is that the restoration of proper enamel structure and function can be achieved through the regulation of mineral ion availability, crystal growth kinetics, and crystal orientation. Long-term, a better understanding of the mechanism of enamel mineral formation will aid in the development of novel biomimetic and biocompatible restorative materials for enamel regeneration and, for example, the treatment of early dental caries. Amelogenin-like materials, especially key functional sequences of amelogenin retained within commercially synthesized leucine-rich amelogenin peptide (LRAP) can potentially be used in the regeneration of tooth enamel structure and properties. The goals of this proposal will be achieved through the completion of the following two Specific Aims: Aim 1. To determine the mechanism and effectiveness of LRAP and non-phosphorylated full-length amelogenin to guide the regeneration of enamel structure in vitro using pyrophosphate (PPi)-stabilized supersaturated calcium phosphate solutions. Mineralization kinetics and epitaxial growth of acid-etched human enamel will be regulated by the hydrolysis of the PPi mineralization inhibitor by 1) the enamel surface itself and 2) alkaline phosphatase (AP). Aim 2. To determine the mechanism and effectiveness of highly supersaturated calcium phosphate solutions that are stabilized by phosphorylated native and synthetic amelogenins using AP to trigger the regeneration of the enamel structure in vitro. Full-length native (phosphorylated) porcine amelogenin and LRAP(+P), potent stabilizers of supersaturated calcium phosphate solutions, will be studied as substitutes for PPi and examined also for their additional potential to guide th regeneration of the acid-etched enamel mineral structure upon dephosphorylation by added AP. The extent, nature, and orientation of formed mineral will be assessed using SEM, EDX, FT-IR and grazing incidence X-ray diffraction. The restoration and/or improvement of base-line enamel properties will be assessed with respect to mechanical properties, physico- chemical properties, and strength of mineral attachment.