Fewer Bacteria Adhere to Softer Hydrogels.
Fewer Bacteria Adhere to Softer Hydrogels.
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DOI：
10.1021/acsami.5b04269
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发表时间：
2015-09-09
影响因子：
9.5
通讯作者：
Schiffman JD
中科院分区：
文献类型：
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作者：
Kolewe KW;Peyton SR;Schiffman JD
临床上，生物膜相关感染通常在血管内导管和其他水凝胶表面形成。过度使用抗生素来治疗这些感染导致了抗生素耐药性的传播，并强调了开发延迟生物膜形成的替代策略的重要性。此前，有报道称，在表面接触过程中，细菌可以通过其马达功能的细微变化来探测表面。然而，聚合物水凝胶的硬度如何影响细菌的初始附着是未知的。系统地，我们研究了聚（乙二醇）二甲基丙烯酸酯（PEGDMA）和琼脂水凝胶，其厚度是细菌细胞附属物累积尺寸的20倍，作为杨氏模量的函数。合成了软（44.05 - 308.5 kPa）、中等（1495 - 2877 kPa）和硬（5152 - 6489 kPa）水凝胶。在2小时和24小时温育期后，使用共聚焦显微镜分析大肠杆菌和金黄色葡萄球菌在水凝胶上的附着。与水凝胶化学性质和孵育时间无关，E. coli和革兰氏阳性菌S.金黄色葡萄球菌的附着与水凝胶硬度的增加正相关。例如，在24小时温育期后，分别减少了52%和82%的E.大肠杆菌对软质PEGDMA水凝胶的粘附性分别高于对中等和硬质PEGDMA水凝胶的粘附性。革兰氏阳性菌S.在软质与中等和硬质PEGDMA水凝胶上温育24小时后出现金黄色葡萄球菌。我们认为，水凝胶硬度是一个易于调节的变量，可能与传统的抗菌策略协同使用，以减少早期细菌粘附，从而减少生物膜相关感染的发生。
Clinically, biofilm-associated infections commonly form on intravascular catheters and other hydrogel surfaces. The overuse of antibiotics to treat these infections has led to the spread of antibiotic resistance and underscores the importance of developing alternative strategies that delay the onset of biofilm formation. Previously, it has been reported that during surface contact, bacteria can detect surfaces through subtle changes in the function of their motors. However, how the stiffness of a polymer hydrogel influences the initial attachment of bacteria is unknown. Systematically, we investigated poly(ethylene glycol) dimethacrylate (PEGDMA) and agar hydrogels that were twenty times thicker than the cumulative size of bacterial cell appendages, as a function of Young’s moduli. Soft (44.05 – 308.5 kPa), intermediate (1495 – 2877 kPa), and stiff (5152 – 6489 kPa) hydrogels were synthesized. Escherichia coli and Staphylococcus aureus attachment onto the hydrogels was analyzed using confocal microscopy after 2 and 24 hr incubation periods. Independent of hydrogel chemistry and incubation time, E. coli and S. aureus attachment correlated positively to increasing hydrogel stiffness. For example, after a 24 hr incubation period, there were 52% and 82% less E. coli adhered to soft PEGDMA hydrogels, than to the intermediate and stiff PEGDMA hydrogels, respectively. A 62% and 79% reduction in the area coverage by the Gram-positive microbe S. aureus occurred after 24 hr incubation on the soft versus intermediate and stiff PEGDMA hydrogels. We suggest that hydrogel stiffness is an easily tunable variable that, potentially, could be used synergistically with traditional antimicrobial strategies to reduce early bacterial adhesion, and therefore the occurrence of biofilm-associated infections.