Investigation of the antibiofilm capacity of peptide-modified stainless steel

Abstract

Biofilm formation on surfaces is an important research topic in ship tribology and medical implants. In this study, dopamine and two types of synthetic peptides were designed and attached to 304 stainless steel surfaces, aiming to inhibit the formation of biofilms. A combinatory surface modification procedure was applied in which dopamine was used as a coupling agent, allowing a strong binding ability with the two peptides. X-ray photoelectron spectroscopy (XPS), elemental analysis, contact angle measurement and surface roughness test were used to evaluate the efficiency of the peptide modification. An antibiofilm assay against Staphylococcus aureus was conducted to validate the antibiofilm capacity of the peptide-modified stainless steel samples. XPS analysis confirmed that the optimal dopamine concentration was 40 µg ml−1 in the coupling reaction. Element analysis showed that dopamine and the peptides had bound to the steel surfaces. The robustness assay of the modified surface demonstrated that most peptide molecules had bound on the surface of the stainless steel firmly. The contact angle of the modified surfaces was significantly changed. Modified steel samples exhibited improved antibiofilm properties in comparison to untreated and dopamine-only counterpart, with the peptide 1 modification displaying the best antibiofilm effect. The modified surfaces showed antibacterial capacity. The antibiofilm capacity of the modified surfaces was also surface topography sensitive. The steel sample surfaces polished with 600# sandpaper exhibited stronger antibiofilm capacity than those polished with other types of sandpapers after peptide modification. These findings present valuable information for future antifouling material research.

Stainless steel coated by Cu NPs via dopamine coupling for antifouling application

“…The procedure of antibacterial assays followed our previously published protocol (plate counting) . Briefly, E .…”

“…Biofouling occurred in most of surfaces in aquatic environment, such as shipbuilding, food packaging, aquaculture cages, and medical implants . Biofouling of hull surfaces was ascribed to marine microorganisms colonization, which caused severe problems such as increased operating costs, fuel consumption, and CO 2 emission . Many methods have been utilized to prevent the occurring of biofouling, but it is still a challenge to develop the new antifouling method with high efficiency and broad spectrum because of the complexity of the marine environment and diversity of the fouling organisms .…”

“…The procedure of antibacterial assays followed our previously published protocol (plate counting). 4,30 Briefly, E. coli and S. aureus suspensions with a concentration of 10 7 CFU/mL were centrifuged at 5000 rpm for 20 minutes, and the centrifugal products were resuspended in PBS solution (pH 7.4) separately. Sample surfaces were then treated with 100 μL of bacterial solutions, covered by a plastic wrap, and incubated at 37°C for 3 hours.…”

Peptide‐modified stainless steel with resistance capacity of Staphylococcus aureus biofilm formation

“…Staphylococcus aureus ( S. aureus , CMCC (B) 44102) was chosen to conduct antibiofilm and bacterial resistance ability tests as the previous work . The metal discs (untreated, and peptide treated) were put into 24‐well suspension culture plates (one sample per well).…”

“…The S. aureus resistance ability of peptide‐modified surfaces was tested using plate counting method as our previous work . The treated and untreated samples were placed into 24‐well plate (one sample per well), and the surfaces of samples were deposited evenly by S. aureus solution with concentration of 10 6 CFU/mL (100 μL/disc).…”