Organo-chemical modification of titanium alloy and zirconia surfaces to achieve tight gingival adhesion (GingiSeal)

钛合金和氧化锆表面的有机化学改性以实现紧密的牙龈粘附（GingiSeal）

• 批准号: 418670251
• 负责人: Professor Dr.-Ing. Horst Fischer
• 金额: --
• 依托单位: Klinik für Zahnärztliche Prothetik und Biomaterialien, Zentrum für Implantologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/418670251?language=en
• 关键词: Organo; chemical; modification; titanium; alloy

Oral rehabilitation using dental implants provides several options for treating patients with tooth loss, thereby offering them better quality of life. In addition to the integration of the implant into the alveolar bone, the attachment of the surrounding soft tissue to the material surface of the implant's supraconstruction (abutment) plays an essential role. However, the peri-implant mucosa exhibits significant differences compared to that of a natural tooth. The natural ”seal” at the interface between mucosa and tooth, which is ensured by the so-called junctional epithelium, is missing in an implant-supported restoration. Thus, bacteria can easier penetrate into the interface and can subsequently provoke pathological processes at the interface between implant and alveolar bone. In the first phase of the research project GingiSeal, the abutment materials zirconia (Y-TZP) and the established titanium alloy (Ti6Al4V) were modified by self-assembled monolayers (SAM) and further functionalized with proteins of the extracellular matrix (ECM) with the help of a suitable cross linker. In-vitro experiments with human gingival fibroblasts have shown significantly enhanced cell adhesion, cell proliferation, cell spreading, and integrin expression on the organo-chemically modified surfaces compared to untreated surfaces. In addition to the mimicry of oral conditions in-vitro, which are tasks still to be completed within the first phase of the project, important further questions have arisen. In the second phase of the project, the exact adhesion mechanisms between the functionalized abutment surfaces and gingival epithelial cells is of importance. Furthermore, mass spectrometry will be used to determine how the crosslinker interacts with the proteins of the ECM. Furthermore, the bacterial DNA content on the differently modified surfaces will be determined via qPCR. In addition, a three-dimensional in vitro model of a gingival mucosa will be fabricated using bioprinting technology. A biofilm consisting of various bacteria strains is then applied to the interface between the modified/unmodified abutment material and the bioprinted mucosa substitute. The 3D model will be used to determine whether increased adhesion of the printed soft tissue to the modified abutment materials is impermeable to bacteria. For this purpose, live-dead staining will be performed, cytokine release from the printed gingival mucosa will be investigated by ELISA, and biofilm-induced cytotoxicity will be analyzed using a lactate dehydrogenase (LDH) assay. If the project progresses positively, the findings from the experiments with the bioprinted in vitro 3D model will form the foundation for a clinical pilot study envisaged after the two years.

使用牙科植入物的口腔康复为治疗牙齿缺失的患者提供了几种选择，从而为他们提供更好的生活质量。除了将种植体整合到牙槽骨中之外，周围软组织与种植体上部结构（基台）材料表面的附着也起着重要作用。然而，种植体周围粘膜与天然牙齿相比表现出显著差异。在种植体支持的修复体中，粘膜和牙齿之间的界面处的天然“密封”（由所谓的结合上皮确保）缺失。因此，细菌可以更容易地渗透到界面中，并且可以随后在种植体和牙槽骨之间的界面处引起病理过程。在研究项目GingiSeal的第一阶段，基台材料氧化锆（Y-TZP）和已建立的钛合金（Ti6 Al 4V）通过自组装单分子层（SAM）进行了改性，并在合适的交联剂的帮助下进一步与细胞外基质（ECM）的蛋白质功能化。人牙龈成纤维细胞的体外实验表明，与未经处理的表面相比，有机化学修饰的表面上的细胞粘附、细胞增殖、细胞扩散和整合素表达显著增强。除了在体外模拟口腔条件外，这是该项目第一阶段仍需完成的任务，还出现了重要的进一步问题。在项目的第二阶段，功能化基台表面和牙龈上皮细胞之间的确切粘附机制是重要的。此外，质谱法将用于确定交联剂如何与ECM的蛋白质相互作用。此外，将通过qPCR测定不同改性表面上的细菌DNA含量。此外，将使用生物打印技术制造牙龈粘膜的三维体外模型。然后将由各种细菌菌株组成的生物膜施加到改性/未改性基台材料和生物打印的粘膜替代物之间的界面。3D模型将用于确定打印的软组织与改良基台材料的粘附性是否增加，是否对细菌具有不可渗透性。为此，将进行活-死染色，通过ELISA研究印刷牙龈粘膜的细胞因子释放，并使用乳酸脱氢酶（LDH）测定分析生物膜诱导的细胞毒性。如果该项目进展顺利，生物打印体外3D模型的实验结果将为两年后设想的临床试点研究奠定基础。