Mechanical properties and failure of Streptococcus mutans biofilms, studied using a microindentation device
Mechanical properties and failure of Streptococcus mutans biofilms, studied using a microindentation device
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DOI：
10.1016/j.mimet.2006.04.023
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发表时间：
2006-12-01
影响因子：
2.2
通讯作者：
van Dongen, M. E. H.
中科院分区：
文献类型：
--
作者：
Cense, A. W.;Peeters, E. A. G.;van Dongen, M. E. H.
为了确定生物膜对机械应力的反应，需要了解生物膜的机械特性和破坏机制。现有的方法不能用于小规模、高精度地测定生物膜的机械性能。采用一种新型微压痕仪与共聚焦显微镜相结合的方法，测定了变形链球菌生物膜的粘弹性。该装置包括一个小的玻璃压痕和一个高灵敏度的力传感器。结果表明，在静止条件下生长的生物膜为粘弹性固体，在应变为10%时，其储能模数为1-8kpa，损耗模数为5-10kpa。通过拖动压头穿过生物膜，通过共聚焦显微镜直观地观察生物膜的破坏情况。结果表明，生物膜的抗张强度主要由胞外多糖基质的抗张强度决定。微压痕和共聚焦显微镜的结合是微生物学各个领域中确定和表征软材料力学性能的一种很有前途的技术。(C)2006年，爱思唯尔出版。
Knowledge of mechanical properties and failure mechanisms of biofilms is needed to determine how biofilms react on mechanical stress. Methods currently available cannot be used to determine mechanical properties of biofilms on a small scale with high accuracy. A novel microindentation apparatus in combination with a confocal microscope was used to determine the viscoelastic properties of Streptococcus mutans biofilms. The apparatus comprises a small glass indenter and a highly sensitive force transducer. It was shown that the present biofilm, grown under still conditions, behaves as a viscoelastic solid with a storage modulus of 1-8 kPa and a loss modulus of 5-10 kPa at a strain of 10%. Biofilm failure was investigated visually through a confocal microscope by dragging the indenter through the biofilm. It was shown that the tensile strength of the biofilm is predominantly determined by the tensile strength of the extracellular polysaccharide matrix. The combination of microindentation and confocal microscopy is a promising technique to determine and characterize the mechanical properties of soft materials in various fields of microbiology. (c) 2006 Published by Elsevier B.V.