Division of Biology, Chemistry and Materials Science, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Office of Medical Products and Tobacco, United States Food and Drug Administration, Silver Spring, Maryland, USA.
Department of Orthopaedic Surgery, Orthopaedic Hospital Research Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA.
J Biomed Mater Res B Appl Biomater. 2022 Aug;110(8):1932-1941. doi: 10.1002/jbm.b.35050. Epub 2022 Mar 30.
Preclinical in vitro and in vivo methods to study bacterial interactions with dermal fillers and infection pathogenesis are lacking. In this work, first in vitro methods to assess protein biofouling and effective pore size of commercial dermal fillers, including degradable hyaluronic acid (HA)-based fillers and other semi-degradable or permanent fillers (non-HA), were developed. The results were then related to Staphylococcus aureus (S. aureus) adhesion rates in vitro. HA fillers had less protein sorption than non-HA fillers and overall had smaller effective pore sizes. The properties correlated with levels of bacterial adhesion, where the control glass surface had the most rapid increase in bacterial cell adhesion, with a slope of 0.29 cm min , three unique non-HA fillers had intermediate adhesion with slopes of 0.11 and 0.06 cm min , and three unique HA fillers had the least adhesion with slopes of 0.02, 0.02, and 0.01 cm min . S. aureus had greater motility on the HA fillers than on non-HA fillers. Next, a mouse model for dermal filler biofilm and infection was developed. Mice were inoculated with a controlled amount of bioluminescent bacteria (Xen36 S. aureus) and polyacrylamide hydrogels of different stiffness were injected. In vivo bioluminescence was monitored longitudinally for 35 days to ensure that lasting colonization was established. The inoculum was optimized to achieve adequate bioluminescent signal, and bacterial bioburden over time and inter-animal variability in bioburden were determined. These in vitro and in vivo approaches can be used for future studies of antimicrobial interventions for dermal fillers.
目前缺乏研究细菌与真皮填充剂相互作用以及感染发病机制的临床前体外和体内方法。在这项工作中，首先开发了评估商业真皮填充剂（包括可降解透明质酸 (HA) 填充剂和其他半降解或永久性填充剂（非 HA））的蛋白质生物污垢和有效孔径的体外方法。然后将结果与金黄色葡萄球菌（S. aureus）的体外粘附率相关联。HA 填充剂的蛋白质吸附量小于非 HA 填充剂，并且总体上具有较小的有效孔径。这些特性与细菌粘附水平相关，其中对照玻璃表面的细菌细胞粘附增加最快，斜率为 0.29 cm min ，三种独特的非 HA 填充剂具有中间粘附性，斜率为 0.11 和 0.06 cm min ，三种独特的 HA 填充剂具有最低的粘附性，斜率为 0.02、0.02 和 0.01 cm min 。金黄色葡萄球菌在 HA 填充剂上的迁移能力强于非 HA 填充剂。接下来，开发了真皮填充剂生物膜和感染的小鼠模型。将一定数量的生物发光细菌（Xen36 S. aureus）接种到小鼠体内，并注射不同硬度的聚丙烯酰胺水凝胶。通过纵向监测体内生物发光长达 35 天，以确保建立持久的定植。优化接种物以获得足够的生物发光信号，并确定随时间推移的细菌生物负荷以及生物负荷的动物间变异性。这些体外和体内方法可用于未来对真皮填充剂的抗菌干预措施的研究。
