Laser-Textured Surfaces: A Way to Control Biofilm Formation?

Bacterial biofilms pose serious problems in medical and industrial settings. One of the major societal challenges lies in the increasing resistance of bacteria against biocides used in antimicrobial treatments, e.g., via overabundant use in medicine, industry, and agriculture or cleaning and disinfection in private households. Hence, new efficient bacteria-repellent strategies avoiding the use of biocides are strongly desired. One promising route to achieve bacteria-repellent surfaces lies in the contactless and aseptic large-area laser-processing of technical surfaces. Tailored surface textures, enabled by different laser-processing strategies that result in topographic scales ranging from nanometers to micrometers may provide a solution to this challenge. This article presents a current state-of-the-art review of laser-surface subtractive texturing approaches for controlling the biofilm formation for different bacterial strains and in different environments. Based on specific properties of bacteria and laser-processed surfaces, the challenges of anti-microbial surface designs are discussed, and future directions will be outlined. Laser-texturing appears as a simple and robust strategy for reducing bacterial adhesion of technical surfaces - an approach without chemicals or antibiotics, thus, avoiding bacterial resistances. However, the results reported in the literature are not coherent. This article orders the available literature by first reviewing the different laser-processing approaches and resulting surface textures and then providing a critical assessment of experimental conditions, revealing key bactericidal mechanisms, identifying anti-microbial surface designs, and discussing future directions.image