Examination of surface properties and in vitro biological performance of amorphous diamond‐like carbon‐coated polyurethane

Abstract

Despite the emerging use of diamond-like carbon (DLC) as a coating for medical devices, few studies have examined the resistance of DLC coatings onto medical polymers to both microbial adherence and encrustation. In this study, amorphous DLC of a range of refractive indexes (1.7-1.9) and thicknesses (100-600 nm) was deposited onto polyurethane, a model polymer, and the resistance to microbial adherence (Escherichia coli; clinical isolate) and encrustation examined using in vitro models. In comparison to the native polymer, the advancing and receding contact angles of DLC-coated polyurethane were lower, indicating greater hydrophilic properties. No relationship was observed between refractive index, thickness, and advancing contact angle, as determined using multiple correlation analysis. The resistances of the various DLC-coated polyurethane films to encrustation and microbial adherence were significantly greater than that to polyurethane; however, there were individual differences between the resistances of the various DLC coatings. In general, increasing the refractive index of the coatings (100 nm thickness) decreased the resistance of the films to both hydroxyapatite and struvite encrustation and to microbial adherence. Films of lower thicknesses (100 and 200 nm; of defined refractive index, 1.8), exhibited the greatest resistance to encrustation and to microbial adherence. In conclusion, this study has uniquely illustrated both the microbial antiadherence properties and resistance to urinary encrustation of DLC-coated polyurethane. The resistances to encrustation and microbial adherence were substantial, and in light of this, it is suggested that DLC coatings of low thickness and refractive index show particular promise as coatings of polymeric medical devices.

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

“…As seen, random incorporation of increasing amount of fluorine atoms to an initial DLC structure or a raw UHMWPE surface resulted in the presence of more oxidized CF X species, and this was correlated to an increase of the WCA. The WCA not only can indicate the hydrophilic/hydrophobic behavior of the surface, but also it seems to be intimately related to the surface roughness and the surface tension 31, 34. Surface roughness could significantly influence bacterial adherence because interstitial spaces or irregularities on the surface can supply extra anchorage sites for bacteria 35.…”

Oral Bacterial Adhesion and Biocompatibility of Silver-Amorphous Carbon Films: A Surface Modification for Dental Implants

“…Limited studies regarding bacterial adhesion on the different carbon films have been published before (Wang et al, 2004, Ishihara et al, 2006, Jones et al, 2006, Katsikogianni et al, 2006, Morrison et al, 2006, Kwok et al, 2007, Zhao et al, 2007, Zhou et al, 2008, Kinnari et al, 2008. These works included mainly DLC or modified-DLC films and concluded that the carbon surface has great biocompatibility properties and good resistance to microbial adhesion.…”

Microbial Colonization of Medical Devices and Novel Preventive Strategies

“…Furthermore, a sequence of events that leads to the foreign body reaction following implantation of a medical device, prosthesis, or biomaterial is also presented in a review [4]. Therefore, owing to the problems associated with the use of medical devices, there is a clinical need for the development of novel materials [5] and novel coatings including diamond-like carbon (DLC) coatings over existing materials that will offer resistance to infection and encrustation [6][7][8][9], design of biomaterials with antimicrobial surfaces through some new surface modification techniques [10,11], and finally the use of novel approaches to deliver antimicrobial agents for eradicating the biofilm consortia from the medical devices.…”