Untitled

Abstract

Patients who undergo a total laryngectomy usually receive a silicone rubber voice prosthesis for voice rehabilitation. Unfortunately, biofilm formation on the esophageal side of voice prostheses limits their lifetime to 3-4 mon on average. The effects of repeated argon plasma treatment of medical grade, hydrophobic silicone rubber on in vitro adhesion and growth of bacteria and yeasts isolated from voice prostheses, as well as in vivo biofilm formation are presented here. In vitro experiments demonstrated that initial microbial adhesion over a 4 h time span to plasma-treated, hydrophilized, silicone rubber was generally less than on original, hydrophobic silicone rubber, both in the absence and presence of a salivary conditioning film on the biomaterial. Growth studies over a time period of 14 d at 37 degrees C in a modified Robbins device, showed that fewer Candida cells adhered on plasma-treated, hydrophilized silicone rubber as compared to on original, hydrophobic silicone rubber. For the in vivo evaluation of biofilm formation on plasma-treated silicone rubber voice prostheses, seven laryngectomized patients received a partly hydrophilized "Groningen Button" voice prosthesis for a planned evaluation period of 4 wk. After removal of the voice prostheses, the border between the hydrophilized and the original, hydrophobic side of the prostheses was clearly visible. However, biofilm formation was, unexpectedly, less on the original, hydrophobic sides, although the microbial compositions of the biofilms on both sides were not significantly different. Summarizing, this study demonstrates that in vitro microbial adhesion and growth on silicone rubber can be reduced by plasma treatment, but in vivo biofilm formation on silicone rubber voice prostheses is oppositely enhanced by hydrophilizing the silicone rubber surface. Nevertheless, from the results of this study the important conclusion can be drawn that in vivo biofilm formation on voice prostheses is controlled by the hydrophobicity of the biomaterials surface used.

Candida biofilm formation on voice prostheses

“…Plasma treatment modifies the composition and structure of a few molecular layers at the surface of the material without affecting the bulk properties (Abbasi et al, 2002). Everaert et al (1998a) investigated the effects of repeated argon plasma treatment of medical grade hydrophobic silicone rubber on in vitro adhesion and growth of selected bacteria and yeasts isolated from VPs, as well as in vivo biofilm formation. The results obtained for in vitro experiments showed a reduction in microbial adhesion and growth on silicone rubber.…”

“…Everaert et al (1998a) demonstrated that biofilm formation on VPs surfaces in vivo is governed by hydrophobicity. Therefore, the improved antifouling performance of VPs may be achieved by increasing the hydrophobicity of the silicone rubber, such as by adsorption of fluorocarbons to the surface.…”

“…Fluorocarbon surfaces are slightly more hydrophobic than silicone rubber and were reported to retard the accumulation of dental plaque during 9 days of exposure to the dynamic conditions of the human oral cavity (Quirynen et al, 1989). Additionally, Everaert et al (1999) prepared reactive surfaces by argon plasma glow discharge prior to anchoring fluoro-alkyltrichlorosilanes. Long chain fluoro-alkylsiloxanes chemisorbed to silicone rubber were found to reduce microbial adhesion and to increase the percentage of detachment of adhering microorganisms.…”

Enhancement of polymer hydrophobicity by SF6 plasma treatment and argon plasma immersion ion implantation

“…This is important for bacteriological colony control in prostheses, therefore high water contact angles are desirable in situations where bacterial adhesion and colonization are grave problems. As an illustration, Everaert et al 3 observed that in vivo bacterial film formation onto silicone voice prostheses is controlled by the hydrophobicity of the biomaterial surface. Hydrophobic materials can be applied in several situations as non-sticking and impermeable surfaces.…”

Improvement of silicone endothelialization by treatment with allylamine and/or acrylic acid low‐pressure plasma

“…Silicone elastomers 13 have already been used in such biomedical applications as catheters and contact lenses and more generally in the cardiopulmonary bypass, 14 in the development of an artificial cornea, 15 and in voice protheses. 16 They have been used in plasma treatment, [17][18][19] mainly in the field of membrane techniques. But only a few investigations have been pursued in the field of endothelialization.…”