Manipulation of Bacterial Metabolism: A New Approach to Develop Smart Dental Composites

建议书摘要 在口腔中，细菌产生的代谢性乳酸和相关的pH变化是可疑的。 在牙科复合修复体的寿命和完整性方面发挥关键作用。我们提议召集 关于牙科细菌代谢产物所产生的化学微环境的基础知识 设计下一代牙科复合材料的材料界面。我们的中心假设是金属离子(钙， 释放镁的复合材料可以被设计成影响细菌的新陈代谢和操纵化学物质 抑制牙齿脱矿的微环境。为了量化这些细菌的化学微环境，我们 将应用我们最新开发的独特的电化学传感器(pH、乳酸、过氧化氢、金属离子)来测量 主要细菌代谢物，如乳酸和过氧化氢的实时监测。目标1：确定金属离子对金属离子的影响 细菌代谢和化学微环境。我们将确定金属离子对金属离子的影响 细菌代谢与牙菌斑衍生的微宇宙生物膜，使局部pH值为5.5或更高。至 创建一个基因可修改和可复制的生物膜模型，我们将扩展我们的研究以复制当地的pH， 乳酸和过氧化氢浓度与三种模式生物的不同比例：变形链球菌(乳酸 产酸菌(产酸、降低pH值)、细小韦罗氏菌(消耗乳酸盐)和戈登链球菌(产过氧化氢)。 我们将使用pH、乳酸和过氧化氢微传感器作为扫描电化学显微镜(SECM)探针 测定乳酸盐和过氧化氢产生的局部速率以及相应的局部pH值变化 在金属离子存在的情况下实时生物膜。目的2：量化细菌生物膜上方的局部pH值 生长在金属离子释放袋复合材料上。我们将使用SECM在牙齿上方20微米处测量PH值 菌斑微观区及以上三种生物膜(Sm/Sg/Vp)在不同金属离子释放上的生长 复合体(浓度范围与目标1相似)。这将帮助我们确定金属离子是否释放 来自袋子的复合材料会影响细菌的新陈代谢，以至于局部的pH值为&gt；5.5。我们还将使用钙- 和镁敏感的SECM探针，以量化从袋子中释放的金属离子的局部浓度 复合体以确定细菌在这些材料上生长时暴露的离子浓度 复合材料。目的3：实时测量生物膜-复合体界面的pH值和过氧化氢。创新灵活 金属丝传感器(pH、H_2O_2、金属离子)将放置在高度动态的材料-生物膜界面上进行监测 并回答一个关键问题：细菌代谢物如何影响生物材料的完整性，金属如何 生物材料释放的离子会影响细菌的代谢物吗？拟议的研究提供了重要的一步 朝着识别下一代可控制生物膜成分的智能牙科复合材料的方向发展 局部PH值5.5或更高，从而抑制邻近牙齿的脱矿，延长牙齿的使用寿命 复合修复体。

Proposal Summary In the oral cavity, metabolic lactic acid production by bacteria and the associated change in pH are suspected to play a key role in the longevity and integrity of dental composite restorations. We propose gathering fundamental knowledge about the chemical microenvironment created by bacterial metabolites at the dental material interface to design next-generation dental composites. Our central hypothesis is that metal ion (Ca2+, Mg2+)-releasing composites can be engineered to influence bacterial metabolism and manipulate the chemical microenvironment to inhibit tooth demineralization. To quantify these bacterial chemical microenvironments, we will apply our newly developed unique electrochemical sensors (pH, lactate, H2O2, metal ions) to measure major bacterial metabolites such as lactate and H2O2 in real time. Aim 1: Determine the effects of metal ions on bacterial metabolism and the chemical microenvironment. We will determine the effects of metal ions on bacterial metabolism with dental plaque-derived microcosm biofilms such that the local pH is 5.5 or higher. To create a genetically amendable and reproducible biofilm model, we will extend our study to replicate local pH, lactate, and H2O2 concentrations with different ratios of three model organisms: Streptococcus mutans (lactate producing, pH lowering), Veillonella parvula (lactate consuming), and Streptococcus gordonii (H2O2 producing). We will use pH, lactate, and H2O2 microsensors as scanning electrochemical microscope (SECM) probes to determine the local rate of lactate and H2O2 production and the corresponding local pH change above the biofilms in real time in the presence of metal ions. Aim 2: Quantify the local pH above the bacterial biofilms grown on metal ion-releasing BAG composites. We will use SECM to measure pH at 20 µm above the dental plaque microcosm and above three-species biofilm (Sm/Sg/Vp) grown on different metal ion-releasing composites (similar concentration ranges as in Aim 1). This will help us determine whether metal ions released from BAG composites can influence bacterial metabolism such that the local pH is >5.5. We will also use Ca2+- and Mg2+-sensing SECM probes to quantify the local concentration of metal ions released from BAG composites to determine the ion concentration to which bacteria will be exposed while growing on these composites. Aim 3: Measure pH and H2O2 at the biofilm–composite interface in real time. Innovative flexible wire sensors (pH, H2O2, metal ions) will be placed at the highly dynamic material–biofilm interface to monitor it and answer a crucial question: How do bacterial metabolites influence biomaterial integrity and how do metal ions released from biomaterials affect bacterial metabolites? The proposed research provides a significant step towards identifying next-generation “smart” dental composites that can control biofilm composition to maintain a local pH of 5.5 or higher, thus inhibiting adjacent tooth demineralization and extending the lifespan of dental composite restorations.