Depletion forces drive reversible capture of live bacteria on non-adhesive surfaces
Depletion forces drive reversible capture of live bacteria on non-adhesive surfaces
复制标题
消耗力驱动非粘性表面上活细菌的可逆捕获
DOI：
10.1039/d1sm00631b
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
Santore, Maria M.
中科院分区：
文献类型：
--
作者：
Niu, Wuqi Amy;Rivera, Sylvia L.;Siegrist, M. Sloan;Santore, Maria M.
由于细菌与表面的黏附与感染和生物膜的生长有关，因此开发能够最大限度地减少生物分子吸附并消除细菌黏附的涂层一直是人们的目标。我们证明，即使在精心设计的非生物粘附性涂层(如聚乙二醇层)上，防止生物分子吸附和细胞粘连的涂层，溶液中非吸附聚合物(如10K聚乙二醇酯或100K聚氧乙烯醚)的耗尽相互作用也会导致大肠杆菌细胞的粘连和滞留，从而破坏涂层的防污染功能。这些细胞是固定的，并在研究的时间范围内保持存活，至少长达45分钟。当聚合物溶液被缓冲液取代时，细胞迅速从表面逃逸，这与耗尽吸引的可逆性的预期一致。此外，溶解的聚合物还导致细胞在溶液中聚集，并在缓冲液中稀释10倍时迅速解离为单线态，这也与耗尽一致。在单细胞通过耗尽而粘连的条件下，流体动力可以显著降低聚集体在表面上的粘附性。这里报道的发现表明，由于细菌在体内和原位富含聚合物的环境中茁壮成长，耗尽相互作用可能使其无法避免细菌滞留在表面。
Because bacterial adhesion to surfaces is associated with infections and biofilm growth, it has been a longstanding goal to develop coatings that minimize biomolecular adsorption and eliminate bacteria adhesion. We demonstrate that, even on carefully-engineered non-bioadhesive coatings such as polyethylene glycol (PEG) layers that prevent biomolecule adsorption and cell adhesion, depletion interactions from non-adsorbing polymer in solution (such as 10 K PEG or 100 K PEO) can cause adhesion and retention of Escherichia coli cells, defeating the antifouling functionality of the coating. The cells are immobilized and remain viable on the timescale of the study, at least up to 45 minutes. When the polymer solution is replaced by buffer, cells rapidly escape from the surface, consistent with expectations for the reversibility of depletion attractions. The dissolved polymer additionally causes cells to aggregate in solution and aggregates rapidly dissociate to singlets upon tenfold dilution in buffer, also consistent with depletion. Hydrodynamic forces can substantially reduce the adhesion of aggregates on surfaces in conditions where single cells adhere via depletion. The findings reported here suggest that because bacteria thrive in polymer-rich environments both in vivo and in situ, depletion interactions may make it impossible to avoid bacterial retention on surfaces.