介孔钛锆转运前驱体仿生再矿化牙本质胶原的机制研究

Abstract: The poor bonding durability of contemporary dentin adhesive systems is an urgent problem in esthetic restoration. The reason is mainly attributed to the degradation of exposed dentin collagen induced by incomplete infiltration of resin monomers. Biomimetic remineralization of these collagen is an effective way to strengthen the hybrid layer, and to enhance the dentin bonding durability. Our project intends to establish a novel delivery system to transfer mineralizing precursors for intrafibrillar mineralization of dentin collagen. Yolk-shell mesoporous zirconium titanium oxide nanospheres (SiO2@TiZrO2) with stable physicochemical properties will be synthesized as the nanocarrier, while quaternized cellulose-stabilized amorphous calcium phosphate (QC-ACP) will be employed as cationic mineralizing precursors for the first time. QC-ACP@SiO2@TiZrO2 provides sustained release of mineralizing precursors for in-situ remineralization of dentin collagen. The carrier-based delivery system bridges the gap between traditional solution-based biomineralization concepts and clinical practice, and is useful for the improvement of dentin bonding durability.

摘要：牙本质粘接的长期持久性不足是口腔修复领域亟待解决的问题，这主要与粘接界面混合层中牙本质胶原的暴露降解有关，而胶原的仿生再矿化是增强牙本质粘接耐久性的有效方式。本课题拟利用理化性质稳定的蛋黄-蛋壳结构介孔钛锆氧化物（SiO2@TiZrO2）作为纳米载体，并首次使用纤维素季铵盐稳定的无定形磷酸钙（QC-ACP）作为正电荷矿化前驱体负载于介孔钛锆，巧妙构建一种新型的前驱体转运体系（QC-ACP@SiO2@TiZrO2）。该体系改性粘接剂后，旨在不依靠持续外部钙磷供给的条件下，实现矿化前驱体在粘接界面混合层的有效释放，将溶液浸泡的矿化策略革新为更具有临床推广价值的载体矿化策略，并克服传统介孔硅载体易降解形成结构薄弱区的缺点，最终实现脱矿牙本质胶原的仿生再矿化，解决牙本质粘接耐久性不足的问题。

牙本质粘接系统的耐久性不足是口腔修复领域亟待解决的问题，这主要与混合层中牙本质胶原的暴露降解有关，而胶原的仿生再矿化是增强牙本质粘接耐久性的有效方式。本课题利用理化性质稳定的蛋黄-蛋壳结构介孔钛锆氧化物（SiO2@ TiZrO2）作为纳米载体，利用聚烯丙胺稳定的无定形磷酸钙（PAH-ACP）作为正电荷矿化前驱体负载于介孔钛锆，巧妙构建了一种新型的前驱体转运体系（PAH-ACP@SiO2@mTiZrO2）。该体系在不依靠持续外部钙磷供给的条件下，实现了单根牙本质胶原纤维的仿生矿化。在构建的牙本质脱矿模型上，实现牙本质胶原的纤维内原位再矿化，将溶液浸泡的矿化策略革新为更具有临床推广价值的载体矿化策略。这种新策略克服了传统介孔硅载体易降解形成结构薄弱区的缺点，实现了粘接界面脱矿牙本质胶原的仿生再矿化，有望解决牙本质粘接耐久性不足的问题。