Bacterial Colonization of Low‐Wettable Surfaces is Driven by Culture Conditions and Topography

Abstract

or food industry materials. [2-6] The initial events of biofilm formation include bacterial attachment to surface. This attachment depends on the environmental conditions (bacterial species, medium, temperature, etc) and on the material surface properties. Chemical composition, topography, mechanical properties as well as wettability (hydrophobicity and hydrophilicity), surface energy, and charge are the surface-related factors known to influence bacterial adhesion and biofilm development. [7,8] Some of them are specially examined for their great potential to create antibiofilm surfaces. [9] Surface energy is one of the factors involved in bacterial attachment. [10-13] More particularly, low-wettable especially superhydrophobic surfaces demonstrated some promising potential to reduce surface colonization by bacteria. [14-19] This prevention may be the result of reduced protein adsorption and entrapped air layer between the bacterial suspension and the surface [14,20-22] However, contradictory results are reported. [23,24] Aside from high differences in nature and wettability of the surfaces used in these studies, a serious reason is the common confusion regarding the distinction between bacterial retention and adhesion. Indeed, in Effect of surface low-wettability on bacterial colonization has become a prominent subject for the development of antibacterial coatings. However, bacteria's fate on such surfaces immersed in liquid as well as causal factors is poorly understood. This question is addressed by using a range of coatings with increasing hydrophobicity, to superhydrophobic, obtained by an atmospheric plasma polymer method allowing series production. Chemistry, wettability, and topography are thoroughly described, as well as bacterial colonization by in situ live imaging up to 24 h culture time in different liquid media. In the extreme case of superhydrophobic coating, substrates are significantly less colonized in biomolecule-poor liquids and for short-term culture only. Complex statistical analysis demonstrates that bacterial colonization on these low-wettable substrates is predominantly controlled by the culture conditions and only secondary by topographic coating's properties (variation in surface structuration with almost constant mean height). Wettability is less responsible for bacterial colonization reduction in these conditions, but allows the coatings to preserve colonization-prevention properties in nutritive media when topography is masked by fouling. Even after long-term culture in rich medium, many large places of the superhydrophobic coating are completely free of bacteria in relation to their capacity to preserve air trapping.

Bacteriostatic Poly Ethylene Glycol Plasma Coatings for Orthodontic Titanium Mini-Implants

“…Marguier et al [ 50 ] showed that the hydrophobic surface presents a clear decrease in bacterial adhesion and colonization, with areas completely free of bacteria regardless of the surrounding media, even after static long time culture or under hydrodynamic flow conditions. This fact may justify how superhydrophilic surfaces show poor bacterial behavior, as can be observed for argon-treated samples.…”

Biofilm Adhesion to Surfaces is Modulated by Biofilm Wettability and Stiffness

“…Bacteria form slimy substances, so-called biofilms; this allows them to settle permanently on surfaces [1][2][3][4] and to protect themselves from external challenges, such as temperature differences, toxic substances or shear loads. [5][6][7][8][9] Biofilms are able to adhere to nearly any surface in a wet environment; examples behavior of biofilms by removing them from their substrate with a spatula and measuring the lateral force occurring during this scraping process.…”

Combining Topography and Chemistry to Produce Antibiofouling Surfaces: A Review

“…An atmospheric plasma polymer coating was used to treat silicon wafers and produced a microstructured topography while also imparting hydrophobic and superhydrophobic properties to the surface, that prevent bacterial adhesion. 56 A mixture of docecyl acrylate and the 1H,1H,2H,2H-perfluorodecyl acrylate precursor was used. AFM imaging revealed a heterogeneous globular grain structure.…”