DLC coatings for UHMWPE: Relationship between bacterial adherence and surface properties

Abstract

Development of intrinsically antibacterial surfaces is of key importance in the context of prostheses used in orthopedic surgery. This work presents a thorough study of several plasma-based coatings that may be used with this functionality: diamond-like carbon (DLC), fluorine-doped DLC (F-DLC), and a high-fluorine-content-carbon-fluor polymer (CF(X)). The coatings were obtained by a radio-frequency plasma-assisted deposition on ultra high molecular weight polyethylene (UHMWPE) samples and physicochemical properties of the coated surfaces were correlated with their antibacterial performance against collection and clinical Staphylococcus aureus and Staphylococcus epidermidis strains. The fluorine content and the relative amount of C-C and C-F bonds were controlled by X-ray photoelectron spectroscopy, and hydrophobicity and surface tension by contact angle measurements. Surface roughness was studied by Atomic Force Microscopy. Additional nanoidentation studies were performed for DLC and F-DLC coatings. Unpaired t test and regression linear models evaluated the adherence of S. aureus and S. epidermidis on raw and coated UHMWPE samples. Comparing with UHMWPE, DLC/UHMWPE was the least adherent surface with independence of the bacterial species, finding significant reductions (p ≤ 0.001) for nine staphylococci strains. Bacterial adherence was also significantly reduced in F-DLC/ UHMWPE and CFx/UHMWPE for six strains.

Interplay between surface properties of standard, vitamin E blended and oxidised ultra high molecular weight polyethylene used in total joint replacement and adhesion ofStaphylococcus aureusandEscherichia coli

“…Anyway the conclusion that can be drawn is that the very early stage of colonization process is strongly affected by intrinsic intra and inter-species variability among different bacterial genera. 3,[25][26][27] At the moment clinical data about bacterial colonization of different biomaterials are still scanty. 28 The clinical significance of the data collected in this study must be emphasized if one considers that orthopedic implants that become infected are normally exposed to relatively small numbers of bacteria much lower than the bacterial inoculums size used in our in vitro assay.…”

Do Crosslinking and Vitamin E Stabilization Influence Microbial Adhesions on UHMWPE-based Biomaterials?

“…Septic failure of prosthetic implants causes patient morbidity and mortality and imposes a large economic burden on society. Microorganism attachment to prosthetic surfaces has been identified as the first step in biomaterialassociated infection pathogenesis [13,32]. Microbial adhesion on biomaterial implant surfaces depends on the physicochemical interactions between substratum and microorganisms as well as the physical properties of the biomaterial surface (roughness, hydrophobicity, surface energy, electrostatic charge, and coating), which can strongly influence the adhesion process [4,20,27,30,34].…”

Reduction in static friction by deposition of a homogeneous diamond-like carbon (DLC) coating on orthodontic brackets

“…There have some studies on reducing the friction between brackets and wire using surface treatments such as ion implantation, poly(tetrafluoroethylene) coating, and polyethylene coating of the wires and/or brackets [10][11][12][13] . Diamond-like carbon (DLC) coatings have recently been applied in many industrial applications because they confer excellent properties such as extreme surface hardness, low friction coefficients, chemical inertness, high wear resistance, and good biocompatibility [18][19][20] . Muguruma et al 14,15) deposited a DLC coating on stainless steel brackets and stainless steel and nickeltitanium wires using a plasma-based ion implantation/ deposition method, and successfully reduced the friction.…”