Supporting data for the Design and Synthesis of Novel Bismuth-based Materials as Promising Antimicrobials for Tackling Periodontopathogens and Potential Agents for Modulating Oral Ecological Conditions

The following file contains all the data (Folder 01 to Folder 05) generated during this study period, including SEM and TEM images (morphologies and topographies), XRD (crystallinity), BET (porosity and surface area), FTIR & XPS (elemental compositions) of the as-synthesized bismuth-based particles. Additionally, all biological data (antimicrobial activities on pathogens in both planktonic and biofilm modes) and cytotoxicity on host cells were also included in Folder 06 to Folder 09.

Project description
Bismuth drugs, commonly used for treating Helicobacter pylori-associated gastrointestinal infections, have been considerably repositioned to tackle the key oral/periodontal pathogen Porphyromonas gingivalis (Pg). Combining these metallodrugs and classical antibiotics can synergistically eliminate the recalcitrant Pg persisters. However, current bismuth drug formulations exhibit poor water solubility and low bioavailability, and therefore precise delivery of co-administrated drugs is highly challenging.

Essentially, bismuth ions with high affinities towards oxygen, nitrogen and sulfur can be facilely constructed into metal-organic frameworks (MOFs) and other materials by optimizing various synthetic parameters and routes. These resultant particles with antimicrobial effects acquired from the metals act as an adjunct to improve the efficacy of the original drugs. Moreover, they enable the progressively controlled release of drugs and generate synergistic effects after co-administration with antibiotics. Indeed, these materials have emerged as promising therapeutic approaches to tackling current biomedical challenges, such as overcoming the antibiotic resistance crisis for better oral and general healthcare.

In this work, various bismuth-based particles were synthesized, and their morphological and size changes were analyzed with electron microscopy images. Amongst, highly uniformed particles with ellipsoid- (Ellipsoids) and rod-like (Rods) shapes were selected and fully characterized. Specifically, Rods containing a porous structure were confirmed as MOF with an aligned crystallinity of CAU-17. Notably, Rods could be formed within a ‘two-step’ crystallization process by stacking up almond-flake-like intermediates and yet precisely controlled from micro- to nanoscales by varying concentrations of metal ions and their ratio to the ligands. Regarding the biological activities, both particles showed excellent biocompatibility with human gingival fibroblasts and oral epithelial cells and possessed potent antimicrobial effects on the Gram-negative oral pathogens like Aggregatibacter actinomycetemcomitans, Pg and Fusobacterium nucleatum. Particularly, both particles at 50 μg/mL effectively
disrupted the bacterial membranes and eliminated 3-day-old Pg biofilms.

Next, the antimicrobial effects of nanoscale Rods (Bi-MOFsNano) and emodin (an active component of several plants used in Chinese medicine) were evaluated against selected periodontopathogens. Further experiments were undertaken to investigate whether the co-administration of Bi-MOFsNano and emodin could eliminate the noxious intracellular Pg in the host cells. A checkerboard assay was carried out to determine the fractional inhibitory concentration (FIC) index of Bi-MOFsNano and emodin. The co-administration could synergistically suppress the growth of planktonic Pg cells (FIC ≤ 0.5), while both agents at low concentrations exhibited no detectable cytotoxicity of host cells (HGECs) as demonstrated in the cell viability assay. Remarkably, the synergistic pairs of Bi-MOFsNano and emodin could inhibit the intracellular Pg in HGECs.

The present study presents two novel highly efficient and facile approaches to synthesizing bismuth-based particles. Importantly, Bi-MOFs as a bismuth reservoir exhibit potent antimicrobial effects against the keystone periodontopathogen Pg. In synergistic combination with emodin, these particles can serve as an innovative platform to precisely deliver drugs via topical administrations while simultaneously tackling various pathogens and modulating the resultant immunoinflammatory responses. This work may shed light on enriching the administration modalities of metallic drugs for better antibiotic-free oral and general healthcare in the near future.

本文件包含本研究期间生成的所有数据（文件夹01至文件夹05），包括扫描电子显微镜（SEM）和透射电子显微镜（TEM）图像（形态学和表面形貌）、X射线衍射（XRD）（晶体结构）、BET（孔隙率和比表面积）、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）（元素组成）的合成铋基粒子的信息。此外，还包括在浮游和生物膜模式下的病原体中的抗菌活性（针对宿主细胞的细胞毒性）的生物数据（文件夹06至文件夹09）。

项目描述：
铋类药物，常用于治疗幽门螺杆菌相关胃肠道感染，已被重新定位以应对关键的口腔/牙周病原体牙龈卟啉单胞菌（Pg）。将这些金属药物与经典抗生素结合可以协同消除顽强的Pg持久性。然而，目前的铋药物制剂表现出较差的水溶性低生物利用度，因此精确地联合给药药物的递送极具挑战性。

本质上，通过优化各种合成参数和途径，可以轻松地将对氧、氮和硫具有高亲和力的铋离子构建成金属有机框架（MOFs）和其他材料。这些具有抗菌效果的金属衍生的颗粒作为辅助手段，可提高原药的疗效。此外，它们能够实现药物的逐步释放并产生联合给药后的协同效应。实际上，这些材料已成为应对当前生物医学挑战（如克服抗生素耐药性危机，以改善口腔和整体医疗保健）的具有前景的治疗方法。

在本研究中，合成了各种铋基颗粒，并利用电子显微镜图像分析了它们的形态和尺寸变化。其中，选定了高度均匀的椭球形（椭球体）和棒状（棒）形状的颗粒，并对其进行了全面表征。具体而言，具有多孔结构的棒状颗粒被确认为具有对齐的晶体结构CAU-17的MOF。值得注意的是，棒状颗粒可以通过“两步”结晶过程形成，即通过堆积杏仁状中间体，并且可以通过调节金属离子的浓度及其与配体的比例，从微米到纳米尺度进行精确控制。就生物学活性而言，两种颗粒均表现出与人类牙龈成纤维细胞和口腔上皮细胞的良好生物相容性，并对如侵袭性阿克曼氏菌、Pg和牙龈核杆菌等革兰氏阴性口腔病原体具有显著的抗菌作用。特别是，两种颗粒在50 μg/mL的浓度下，可以有效破坏细菌膜并消除3天旧的Pg生物膜。

接下来，对纳米级棒状颗粒（Bi-MOFsNano）和番泻叶苷（一种用于中国传统医学的多种植物的活性成分）对选择的牙周病原体的抗菌效果进行了评估。进一步进行实验，以研究Bi-MOFsNano和番泻叶苷的联合给药是否可以消除宿主细胞中的有害Pg细胞内物质。进行了棋盘实验，以确定Bi-MOFsNano和番泻叶苷的分数抑制浓度（FIC）指数。联合给药可以协同抑制浮游Pg细胞的生长（FIC ≤ 0.5），而细胞活力实验显示，两种制剂在低浓度下对宿主细胞（HGECs）无明显的细胞毒性。值得注意的是，Bi-MOFsNano和番泻叶苷的协同组合可以抑制HGECs中的细胞内Pg。

本研究提出了两种合成铋基颗粒的高效且简便的新方法。重要的是，Bi-MOFs作为铋储备库，对关键的牙周病原体Pg表现出显著的抗菌效果。与番泻叶苷协同结合，这些颗粒可以作为创新的平台，通过局部给药精确递送药物，同时应对各种病原体并调节产生的免疫炎症反应。这项工作可能为丰富金属药物的给药方式，以在未来实现无抗生素的口腔和整体医疗保健提供启示。