Bertassoni Luiz E, Kury Matheus, Rathsam Catherine, Little Christopher B, Swain Michael V
Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, 2730 Moody Avenue, Collaborative Life Sciences Building, Level 6 N6005, Portland, 97201 OR, USA; Center for Regenerative Medicine, Oregon Health and Science University, Portland, OR, USA; Bioengineering Laboratory, Faculty of Dentistry, University of Sydney, Sydney, NSW, Australia.
Bioengineering Laboratory, Faculty of Dentistry, University of Sydney, Sydney, NSW, Australia.
J Mech Behav Biomed Mater. 2015 Mar;55:264-270. doi: 10.1016/j.jmbbm.2015.10.018. Epub 2015 Nov 10.
Attempts to understand the mechanical behavior of dentin and other mineralized tissues have been primarily focused on the role of their more abundant matrix components, such as collagen and hydroxyapatite. The structural mechanisms endowing these biological materials with outstanding load bearing properties, however, remain elusive to date. Furthermore, while their response to deformation has been extensively studied, mechanisms contributing to their recovery from induced deformation remain poorly described in the literature. Here, we offer novel insights into the participation of proteoglycans (PG) and glycosaminoglycans (GAG) in regulating the nanoindentation creep deformation and recovery of mineralized and demineralized dentin. Accordingly, after the enzymatic digestion of either PGs and associated GAGs or only GAGs, the nanoindentation creep deformation of dentin increased significantly, while the relative recovery of both the mineralized and demineralized dentin dropped by 40-70%. In summary, our results suggest that PGs and GAGs may participate in a nanoscale mechanism that contributes significantly to the outstanding durability of dentin and possibly other mineralized tissues of similar composition.
人们对牙本质及其他矿化组织力学行为的研究主要集中在其含量更为丰富的基质成分，如胶原蛋白和羟基磷灰石的作用上。然而，赋予这些生物材料卓越承载性能的结构机制至今仍不清楚。此外，虽然它们对变形的响应已得到广泛研究，但文献中对其从诱导变形中恢复的机制描述甚少。在此，我们对蛋白聚糖（PG）和糖胺聚糖（GAG）在调节矿化和脱矿牙本质的纳米压痕蠕变变形及恢复过程中的作用提供了新的见解。相应地，在对PG及其相关GAG或仅对GAG进行酶消化后，牙本质的纳米压痕蠕变变形显著增加，而矿化和脱矿牙本质的相对恢复率下降了40 - 70%。总之，我们的结果表明，PG和GAG可能参与了一种纳米级机制，该机制对牙本质以及可能其他成分相似的矿化组织的卓越耐久性有显著贡献。
