Superhydrophobic poly(L-lactic acid) surface as potential bacterial colonization substrate

Abstract

Hydrophobicity is a very important surface property and there is a growing interest in the production and characterization of superhydrophobic surfaces. Accordingly, it was recently shown how to obtain a superhydrophobic surface using a simple and cost-effective method on a polymer named poly(L-lactic acid) (PLLA). To evaluate the ability of such material as a substrate for bacterial colonization, this work assessed the capability of different bacteria to colonize a biomimetic rough superhydrophobic (SH) PLLA surface and also a smooth hydrophobic (H) one. The interaction between these surfaces and bacteria with different morphologies and cell walls was studied using one strain of Staphylococcus aureus and one of Pseudomonas aeruginosa. Results showed that both bacterial strains colonized the surfaces tested, although significantly higher numbers of S. aureus cells were found on SH surfaces comparing to H ones. Moreover, scanning electron microscopy images showed an extracellular matrix produced by P. aeruginosa on SH PLLA surfaces, indicating that this bacterium is able to form a biofilm on such substratum. Bacterial removal through lotus leaf effect was also tested, being more efficient on H coupons than on SH PLLA ones. Overall, the results showed that SH PLLA surfaces can be used as a substrate for bacterial colonization and, thus, have an exceptional potential for biotechnology applications.

Tuning the Surface Properties of Polypyrrole Films for Modulating Bacterial Adhesion

“…Figure also reveals that the rougher surfaces were more favorable for adhesion, which is related to the fact that rougher surfaces present more surface area for the bacteria to interact with. In addition to a rougher surface, it has also been observed that the topography of a film affects bacterial adhesion, for example, grooves and scratches in the size range of bacteria increase binding potential between bacterial cells and the surface and therefore facilitates bacterial attachment and colonization . Moreover, in studying the role of polymer chemistry and topography in bacterial adhesion, Epaillard et al highlighted the impact of peak and valley distribution on the same scale as bacterial dimensions on the polymer surface; mechanical adhesion and cell entrapment in the hollow structures adds a further parameter to be taken into consideration for effective polymer film design.…”

Superhydrophobic materials for biomedical applications

“…Dou et al [186] recreated the topology of the rose petal using different polymer mixtures, and reported that the greatest adhesion of Gram-positive bacteria occurred at an intermediate hydrophobicity. Sousa et al [187] showed that bacteria grew better on superhydrophobic PLLA substrates when incubated with S. aureus or P. aeruginosa for 24 hours compared to flat PLLA surfaces (2-log reduction). Fadeeva et al [75] produced Lotus leaf mimics using titanium substrates and laser ablation that produced features of 10-20 μm with dual roughness features of about 200 nm.…”

Antibacterial activity on superhydrophobic titania nanotube arrays

“…[17–20] These surfaces are typically fabricated either by covalently attaching molecules with low surface energies to a roughened surface or by roughening the surface of a material which is already hydrophobic. [7,17,21,22] Such surfaces are of interest for a diverse array of applications. For example, superhydrophobic surfaces have been used to reduce the attachment of marine organisms to ship hulls and reduce the drag forces within pipes.…”