Nature's Raincoats

Anti-biofilm Liquid and Liquid-like Surfaces

Growth of the bacterium S. epidermidis at 2 hours, 2 days and 7 days on three different surfaces.
Growth of S. epidermidis at 2 hours, 2 days and 7 days on three different surfaces. Image adapted from [1].

Biofilms often form and attach to surfaces causing significant societal and economic impacts. A significant concern is biofilm infections associate with medical devices, such as catheter-associated urinary tract infections in hospitals. Anti-biofilm surfaces can use anti-microbial agents, or textured surfaces with nano-spears to rupture the bacterial cell walls and kill bacteria. However, bacteria fight back with antimicrobial resistance and by masking the surface texture.

Another approach is to make the surfaces slippery to bacteria through a liquid or solid lubricant so that the force from shear flow sweeps away the bacteria before a biofilm can be created. The image at the top of the page shows growth of the bacterium S. epidermidis over time on three different surfaces. There is significant growth even after 2 hours on a polydimethylsiloxane (PDMS) surface — which is a material commonly used in medical applications. However, the growth is significantly less on both a slippery omniphobic covalently attached liquid-like (SOCAL) surface and a PDMS surface infused with silicone oil (called S-PDMS).

In other cases, the SOCAL surface performs better than S-PDMS at preventing biomass growth because, unlike with the impregnated oil, it cannot be depleted from the surface [1]. The figure below shows the biomass volume of P. aeruginosa on PDMS, SOCAL and S-PDMS surfaces. This result indicates that making a surface `slippery-to-liquids’ may even be more important than the surface energy and whether the surface is hydrophobic or hydrophilic [2].

Comparison of biomass on different surfaces

Publications

  1. Slippery Liquid-Like Solid Surfaces with Promising Antibiofilm Performance under Both Static and Flow Conditions Y. Zhu, G. McHale, J. Dawson, S. Armstrong, G. Wells, R. Han, H. Liu, W. Vollmer, P. Stoodley, N. Jakubovics and J. Chen, ACS Applied Materials and Interfaces 14 (2022), 6307–6319
  2. Long-Term Antibiofilm Efficacy of Slippery Covalently Attached Liquid-like Surfaces in Dynamic and Static Culture Conditions Y. Zhu, G. McHale, H. Barrio-Zhang, R. Han, G. G. Wells, H. Liu, R. Ledesma-Aguilar, W. Vollmer, N. Jakubovicsand J. Chen, ACS Applied Bio Materials 8 (2025), 5660–5669
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