In vivo efficacy of a silicone‒cationic steroid antimicrobial coating to prevent implant-related infection

Abstract

Active release antimicrobial coatings for medical devices have been developed to prevent and treat biofilm implant-related infections. To date, only a handful of coatings have been put into clinical use, with limited success. In this study, a novel antimicrobial compound was incorporated into a silicone (polydimethylsiloxane or PDMS) polymer to develop a novel active release coating that addressed several limitations of current device coatings. The efficacy of this coating was optimized using an in vitro flow cells system, then translated to an animal model of a simulated Type IIIB open fracture wherein well-established biofilms were used as initial inocula. Results indicated that the novel coating was able to prevent infection in 100% (9/9) of animals that were treated with biofilms and the novel coating (treatment group). In contrast, 100% (9/9) of animals that were inoculated with biofilms and not treated with the coating (positive control), did develop infection. Nine animals were used as negative controls, i.e., those that were not treated with biofilms, and showed a rate of infection of 11% (1/9). Eight animals were treated with the novel coating only to determine its effect on host tissue. Results indicated that the novel active release coating may have significant promise for future application to prevent biofilm implant-related infections in patients.

Does Vitamin E-blended UHMWPE Prevent Biofilm Formation?

“…First, our previously published studies have indicated that the MRSA isolate used in this study produces biofilms on PEEK material [19][20][21][22]. Second, PEEK is commonly used in spinal implant surgeries and these data may provide an indication of MRSA biofilm formation on PEEK materials that may be relevant to other clinical applications.…”

“…1A). To determine whether the growth of MRSA biofilms would be reduced or prevented on the surface of the two vitamin E-loaded samples (HXL VE 150 kGy and HXL VE 75 kGy) in comparison to the other three clinically relevant material types (HXL, CM, and PEEK), each material type was tested for biofilm formation using a flow cell system developed by the Bone and Joint Research Laboratory at the George E. Wahlen Department of Veterans Affairs (Salt Lake City, UT, USA) [19]. The flow cell consisted of six chambers, each having a dimension of 4 cm 9 4 cm 9 2 cm (Fig.…”

“…It was collected from the knee of an infected patient who underwent arthroscopic surgery and was kindly provided by ARUP Laboratories (Salt Lake City, UT, USA). This isolate has been confirmed to contain the icaADBC gene operon and has been used in previous studies to confirm its pathogenic and biofilm-forming properties [19,21,22]. The isolate was stored at À80°C and passaged fewer than two times on Columbia blood agar (Hardy Diagnostics, Midvale, UT, USA) before each use.…”

“…Examples include passive and active antimicrobial coatings [4,9,19], surface modifications [10], and bioabsorbable sleeves that contain antimicrobials [16]. Data suggest that implant materials alone, such as black silicon and silicon nitride, may have the ability to prevent bacterial attachment or eradicate bacteria that come in contact with the material [7,10].…”

“…A flow cell system was used to expose the materials to conditions that may model a physiologically relevant environment for biofilm formation on biomaterials [19]. The primary hypothesis was that the vitamin E-blended and radiation-crosslinked UHMWPE would resist the adhesion and formation of clinically relevant methicillin-resistant Staphylococcus aureus (MRSA) biofilms when compared to other polymeric materials that are currently used in clinical applications.…”