Biofilm Elimination and Caries Prevention using Multifunctional Nanocatalysts

使用多功能纳米催化剂消除生物膜和预防龋齿

基本信息

批准号：
9237531
负责人：
Hyun Koo
金额：
$ 42.69万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-12-09 至 2020-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9237531
关键词：
Acids Affect Anti-Bacterial Agents Apatites Architecture Bacteria Biological Caries prevention Catalysis Cell Line Cell Survival Cells Cessation of life Chemicals Chlorhexidine Clinical Confocal Microscopy Dental Enamel Dental caries Development Dextrans Disease model Effectiveness Ensure Evaluation Exhibits Expenditure Exposure to Extracellular Matrix Face Fluorides Formulation Free Radicals Generations Gingiva Goals Gold Hardness Healthcare High Prevalence Hydrogen Peroxide In Situ In Vitro Infection Iron Lead Lesion Local Anti-Infective Agents Mechanics Medical Device Metals Microbe Microbial Biofilms Minerals Modality Modeling Mouth Diseases Mucous Membrane Oral Oral health Oral mucous membrane structure Organ Outcome Peroxidases Pharmaceutical Preparations Physiological Prevention Preventive Process Production Property Rodent Rodent Model Salts Severity of illness Structure System Testing Therapeutic Time Tissues Topical application Treatment Protocols Virulent Work anticaries antimicrobial antimicrobial drug base biomaterial compatibility biophysical techniques calcium phosphate cariogenic bacteria clinical efficacy clinical translation clinically relevant cohesion cost cytotoxic cytotoxicity demineralization drug efficacy effective therapy efficacy study fascinate improved in vivo iron oxide killings manganese chloride microCT nanomaterials nanoparticle novel strategies prevent product development soft tissue spatiotemporal technology development time use

项目摘要

Despite the high prevalence of biofilm-related oral diseases such as dental caries, there are no clinically effective therapies to disrupt virulent biofilms, resulting in >$40 billion expenditures annually in the US. Effective control of cariogenic biofilms is notoriously challenging because the bacteria are enmeshed in a protective extracellular matrix rich in exopolysaccharides (EPS). Furthermore, EPS-enmeshed bacteria create highly acidic microenvironments that promote acid-dissolution of tooth enamel, leading to the onset of dental caries. Current antimicrobial agents are incapable of disrupting the EPS matrix or affecting the physico- chemical aspects of caries and often fail to efficiently kill the microbes within biofilms, resulting in limited efficacy in vivo. To overcome these remarkable hurdles, we have developed an exciting therapeutic strategy using biocompatible iron oxide nanoparticles (IO-NP) with catalytic activity and pH-responsive properties that display both anti-biofilm and anti-caries actions. IO-NP exhibit peroxidase-like activity at acidic pH values that rapidly activates hydrogen peroxide (H2O2) in situ to simultaneously degrade the protective biofilm EPS-matrix and kill embedded bacteria with exceptional efficacy (>5-log reduction of cell viability) in 5 minutes. Moreover, IO-NP also reduce apatite demineralization in acidic conditions. We hypothesize that IO-NP synergizes with H2O2 to amplify anti-biofilm effects and prevent the onset of dental caries in vivo via nanocatalysis and enhanced in situ production of antibacterial, EPS-degrading and demineralization-blocking agents at acidic pH. The significance of this work is to develop a feasible and superior anti-biofilm and caries preventive approach compared to current chemical modalities. To test our hypothesis, we will optimize the efficacy of IO-NP/H2O2 to further improve anti-biofilm and demineralizing-blocking activities (Aim 1). We will enhance the catalytic activity of IO-NP by inclusion of specific metal salts into the nanoparticles, and explore the effects of various dextran- based coatings to increase IO-NP localization within biofilm structure. Furthermore, we will incorporate calcium-phosphate into IO-NP to enhance its effects on demineralization. Then, we will evaluate the efficacy of enhanced IO-NP/H2O2 for biofilm control in vitro using a mixed-species, cariogenic biofilm model (Aim 2). We will further elucidate the biological actions of IO-NP/H2O2 using time-lapsed confocal and biophysical methods to examine spatiotemporal degradation of EPS-matrix, bacterial killing and cohesiveness within intact biofilms. The effects on enamel demineralization will be assessed using micro-hardness and micro-CT. In Aim 3, we will evaluate the biocompatibility and efficacy of the developed IO-NP/H2O2 therapy in hindering cariogenic biofilms and the onset of carious lesions in vivo using a rodent caries model with a clinically-relevant topical treatment regimen. Successful completion of these aims will provide a framework for further formulation development and clinical efficacy studies. Importantly, IO-NP can be synthesized with low cost at large scale while H2O2 is readily available, which could lead to a feasible new anti-biofilm/anti-caries therapeutic platform for topical use.

尽管龋齿等与生物膜相关的口腔疾病患病率很高，但临床上尚无破坏有毒生物膜的有效疗法，导致美国每年花费超过 400 亿美元。有效控制致龋生物膜是众所周知的挑战，因为细菌陷入了富含胞外多糖（EPS）的保护性细胞外基质。此外，EPS 网状细菌会产生高酸性微环境促进牙釉质酸溶解，导致牙病的发生龋齿。目前的抗菌剂无法破坏 EPS 基质或影响其物理特性。龋齿的化学方面，通常无法有效杀死生物膜内的微生物，导致有限体内功效。为了克服这些显着的障碍，我们制定了令人兴奋的治疗策略使用具有催化活性和 pH 响应特性的生物相容性氧化铁纳米颗粒 (IO-NP) 显示抗生物膜和抗龋齿作用。 IO-NP 在酸性 pH 值下表现出类似过氧化物酶的活性，快速原位激活过氧化氢 (H2O2)，同时降解保护性生物膜 EPS 基质并在 5 分钟内以卓越的功效杀死嵌入的细菌（细胞活力降低 > 5 个对数）。而且， IO-NP 还可减少酸性条件下磷灰石脱矿。我们假设 IO-NP 与 H2O2 通过纳米催化作用增强抗生物膜作用并预防体内龋齿的发生在酸性 pH 值下增强抗菌剂、EPS 降解剂和脱矿质阻断剂的原位生产。这项工作的意义在于开发一种可行且优越的抗生物膜和龋齿预防方法与目前的化学方式相比。为了检验我们的假设，我们将优化 IO-NP/H2O2 的功效进一步提高抗生物膜和脱矿质阻断活性（目标 1）。我们将增强催化活性通过将特定金属盐纳入纳米颗粒中来对 IO-NP 进行修饰，并探索各种葡聚糖的效果基于涂层以增加生物膜结构内 IO-NP 的定位。此外，我们将纳入将磷酸钙转化为 IO-NP 以增强其脱矿作用。然后，我们将评估其功效使用混合物种致龋生物膜模型增强 IO-NP/H2O2 用于体外生物膜控制（目标 2）。我们将使用延时共焦和生物物理方法进一步阐明 IO-NP/H2O2 的生物学作用检查 EPS 基质的时空降解、细菌杀灭和完整生物膜内的粘聚性。将使用显微硬度和显微 CT 评估对牙釉质脱矿的影响。在目标 3 中，我们将评估所开发的 IO-NP/H2O2 疗法在阻碍致龋生物膜方面的生物相容性和功效以及使用啮齿动物龋齿模型和临床相关局部治疗来观察体内龋损的发生养生法。成功完成这些目标将为进一步的制剂开发提供框架和临床疗效研究。重要的是，IO-NP可以低成本大规模合成，而H2O2则容易获得，这可能会导致一种可行的新的局部使用的抗生物膜/抗龋齿治疗平台。