Biomimetic PMMA coating surface and its application on inhibition of bacterial attachment and anti-biofilm performance

In this study, poly(methyl methacrylate) (PMMA) coating with biomimetic hydrophobic surface was fabricated through the nano-casting technique to transfer the surface of natural Xanthosoma sagittifolium leaf (XSL) to polymer surface and apply it in the inhibition of bacterial attachment and the anti-biofilm performance. First, poly(dimethyl siloxane) (PDMS) was used as a negative template to transfer the pattern of natural XSL surface. Subsequently, the commercial PMMA powder was dissolved in toluene and then dropped onto the PDMS template, resulting in the successful pattern transfer of natural XSL surface in producing an artificial biomimetic PMMA coating surface. Next, the surface morphology of biomimetic coating, denoted by Bio-PMMA, was investigated by SEM, containing micron-sized papillae decorated with many nano-scaled creases. Compared with that of non-Bio-PMMA coating, the contact angle(CA) of Bio-PMMA coating was found to increase significantly (increased from 68°±0.8° to 121°±0.6°), reflecting an increase of 53°±0.8° in CA, indicating that the original hydrophilic surface of PMMA can be converted to a hydrophobic surface when replicating the XSL template. In the research of anti-biofilm applications on artificial biomimetic PMMA coating, three types of bacteria (i.e., Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) were observed to study short-term anti-bacterial attachment and conducted long-term anti-biofilm test via SEM. Crystal violet and a Microplate reader were used for bacterial qualitative and quantitative analysis, respectively. The results showed that Bio-PMMA coating surface with micro papillae and folded micro-nanostructures inhibited the growth of bacteria and effectively delayed the formation of biofilm, and the hydrophobicity of the surface also helped to prevent the adhesion of bacteria, thus inhibiting the adhesion of bacteria with good long-term anti-biofilm performance.