Nickel, molybdenum, and tungsten nanoparticle-dispersed alkylalkoxysilane polymer for biomaterial coating: evaluation of effects on bacterial biofilm formation and biosafety

Abstract

Biofilm formation on the surfaces of biomaterials can cause severe infectious diseases due to of inefficiency of antibiotics against biofilm-protected pathogens. On one hand, the prevention of biofilm formation is a critical issue in the development of biomaterials. On the other hand, biomaterials require biological compatibility. To achieve these two goals without compromising the original features of the biomaterial, we proposed metal nanoparticle (NP)-dispersed alkylalkoxysilane (AAS) coatings. Here, we chose nickel, molybdenum, and tungsten, components of stainless steel and other alloys for biomaterials, as prospective metals that could regulate biofilm formation without harming human health. To the best of our knowledge, this is the first report to describe the effect of tungsten on biofilm formation. We performed a biofilm formation test using an open laboratory biofilm reactor that utilizes tap water and environmental bacteria from the laboratory air, and we also performed a cytotoxicity test on the human monocyte-derived U937 cell line. Compared with the AAS polymer alone, nickel NP-dispersed AAS polymer exhibited an inhibitory activity against biofilm formation whereas tungsten and molybdenum NP-dispersed AAS polymers facilitated biofilm formation. The effect of tungsten was dose-dependent. At a low metal concentration (0.1 mol%), the NP-dispersed AAS polymers did not affect cell survival. These results showed that for nickel, molybdenum, and tungsten, the NP-dispersed AAS polymers exhibited biosafety and that the nickel NP-dispersed AAS polymer is suitable for inhibiting biofilm formation. To determine whether molybdenum (or tungsten) NP-dispersed AAS polymer is suitable for biomaterial application, further evaluation in an environment that mimics the human body with clinically relevant pathogens is necessary.

Biofilm Formation of a Polymer Brush Coating with Ionic Liquids Compared to a Polymer Brush Coating with a Non-Ionic Liquid

“…It suggests nitrile compounds or alkyne molecules would exist. Both might be formed through some components derived from biofilms, since the broad peaks were sometimes found in the past by us [79]. However, in this case, we used acetonitrile to swell the brush coating.…”

“…All of the specimens were subjected to Raman spectroscopy and the results were analyzed to confirm the presence of biofilm by "finger print method" (Identification by comparing the data with those in the previous papers [71][72][73][74][75][76][77][78][79][80][81]). For each case, the same measurements were repeated three times for three specimens and the three results for each case were overlapped in the Raman shift charts basically, except for some problematic exceptional cases.…”

“…The peak at 1400 cm −1 could be assigned to that for lipids [75]. Three peaks seen from 1100 to 1400 cm −1 belong to lipids or proteins [72,79]. We presume that the new peak just over 3000 cm −1 would belong to lipid [79] (However, we could not deny the possibility of nucleic acids [73]).…”

“…Three peaks seen from 1100 to 1400 cm −1 belong to lipids or proteins [72,79]. We presume that the new peak just over 3000 cm −1 would belong to lipid [79] (However, we could not deny the possibility of nucleic acids [73]). Other new ones at 1000 cm −1 would be assigned to amino acid (phenylalanine) [71].…”

Biofilm Formation Plays a Crucial Rule in the Initial Step of Carbon Steel Corrosion in Air and Water Environments

“…If the color is violet, a* assumes a positive value and b* a negative value. We calculated the three-dimensional vector values (i.e., (a * ) 2 + (b * ) 2 + (100 − L * ) 2 ) to infer the extent to which the sample formed a biofilm, indicating how a sample formed a biofilm [23].…”