Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
NC Oral Health Institute, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Biomed Res Int. 2014;2014:702821. doi: 10.1155/2014/702821. Epub 2014 Mar 25.
Application of biomodification techniques to dentin can improve its biochemical and biomechanical properties. Several collagen cross-linking agents have been reported to strengthen the mechanical properties of dentin. However, the characteristics of collagen that has undergone agent-induced biomodification are not well understood. The objective of this study was to analyze the effects of a natural cross-linking agent, genipin (GE), on dentin discoloration, collagen stability, and changes in amino acid composition and lysyl oxidase mediated natural collagen cross-links. Dentin collagen obtained from extracted bovine teeth was treated with three different concentrations of GE (0.01%, 0.1%, and 0.5%) for several treatment times (0-24 h). Changes in biochemical properties of NaB(3)H4-reduced collagen were characterized by amino acid and cross-link analyses. The treatment of dentin collagen with GE resulted in a concentration- and time-dependent pigmentation and stability against bacterial collagenase. The lysyl oxidase-mediated trivalent mature cross-link, pyridinoline, showed no difference among all groups while the major divalent immature cross-link, dehydro-dihydroxylysinonorleucine/its ketoamine in collagen treated with 0.5% GE for 24 h, significantly decreased compared to control (P < 0.05). The newly formed GE-induced cross-links most likely involve lysine and hydroxylysine residues of collagen in a concentration-dependent manner. Some of these cross-links appear to be reducible and stabilized with NaB(3)H4.
生物修饰技术在牙本质中的应用可以改善其生化和生物力学性能。已经有几种胶原交联剂被报道可以增强牙本质的机械性能。然而，经过试剂诱导的生物修饰后的胶原特性还不是很清楚。本研究的目的是分析天然交联剂京尼平（GE）对牙本质着色、胶原稳定性以及氨基酸组成变化和赖氨酰氧化酶介导的天然胶原交联的影响。从提取的牛牙中获得牙本质胶原，用三种不同浓度的 GE（0.01%、0.1%和 0.5%）处理不同的处理时间（0-24 小时）。用 NaB（3）H4 还原胶原的生化特性通过氨基酸和交联分析来表征。GE 处理牙本质胶原导致浓度和时间依赖性着色和对细菌胶原酶的稳定性。赖氨酰氧化酶介导的三价成熟交联吡啶啉在所有组之间没有差异，而在 0.5%GE 处理 24 小时的胶原中主要的二价未成熟交联去氢-二羟赖氨酰/其酮胺显著低于对照（P<0.05）。新形成的 GE 诱导的交联可能以浓度依赖的方式涉及胶原中的赖氨酸和羟赖氨酸残基。其中一些交联似乎是可还原的，并被 NaB（3）H4 稳定。
