ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, University Complutense, Madrid, Spain.
Biomaterials in Dentistry Research Group, University of Granada, Spain.
Dent Mater. 2020 Dec;36(12):1566-1577. doi: 10.1016/j.dental.2020.09.011. Epub 2020 Sep 30.
The purpose of this in vitro study was to evaluate the antibacterial effect of a novel non-resorbable, bioactive polymeric nanostructured membrane (NMs), when doped with zinc, calcium and doxycycline.
A validated in vitro subgingival biofilm model with six bacterial species (Streptococcus oralis, Actinomyces naeslundii, Veillonela parvula, Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans) was used. The experimental NMs, with and without being doped with doxycycline, calcium and zinc, were placed on hydroxyapatite (HA) discs. As positive control membranes, commercially available dense polytetrafluoroethylene (d-PTFE) membranes were used and, as negative controls, the HA discs without any membrane. The experimental, positive and negative control discs were exposed to a mixed bacterial suspension, at 37 °C under anaerobic conditions, during 12, 24, 48 and 72 h. The resulting biofilms were analyzed through scanning electron microscopy (SEM), to study their structure, and by quantitative polymerase chain reaction (qPCR), to assess the bacterial load, expressed as colony forming units (CFU) per mL. Differences between experimental and control groups were evaluated with the general linear model and the Bonferroni adjustment.
As shown by SEM, all membrane groups, except the NMs with doxycycline, resulted in structured biofilms from 12-72 hours. Similarly, only the membranes loaded with doxycycline demonstrated a significant reduction in bacterial load during biofilm development, when compared with the control groups (p < 0.001).
Doxycycline-doped nanostructured membranes have an impact on biofilm growth dynamics by significant reducing the bacterial load.
本体外研究旨在评估新型不可吸收的生物活性聚合纳米结构膜（NMs）在掺杂锌、钙和强力霉素时的抗菌效果。
采用已验证的六菌（口腔链球菌、奈瑟氏放线菌、小韦荣球菌、核梭杆菌、牙龈卟啉单胞菌和伴放线放线杆菌）龈下生物膜体外模型。将载有或不载有强力霉素、钙和锌的实验性 NMs 放置在羟磷灰石（HA）圆盘上。作为阳性对照膜，使用市售的致密聚四氟乙烯（d-PTFE）膜，作为阴性对照，HA 圆盘上不放置任何膜。在 37°C 厌氧条件下，将实验、阳性和阴性对照盘暴露于混合细菌悬浮液中 12、24、48 和 72 小时。通过扫描电子显微镜（SEM）分析生物膜的结构，通过定量聚合酶链反应（qPCR）评估细菌负荷，以每毫升形成的菌落数（CFU）表示。用一般线性模型和 Bonferroni 调整评估实验组和对照组之间的差异。
SEM 显示，除载有强力霉素的 NMs 外，所有膜组在 12-72 小时内均形成结构生物膜。同样，只有载有强力霉素的膜在生物膜形成过程中表现出细菌负荷的显著降低，与对照组相比（p < 0.001）。
强力霉素掺杂的纳米结构膜通过显著降低细菌负荷对生物膜生长动态产生影响。
