Inhibiting biofilm growth on ammonium salt-functionalized or fluorinated voice prostheses silicone

Voice prostheses (VPs) are largely limited by their relatively short functional lifespans, mainly due to colonization by heterogeneous fungal-bacterial biofilms. This biofilm-mediated degradation is a major contributor to VP failure and is associated with clinically significant complications such as impaired phonation, leakage through the tracheoesophageal fistula, and an increased risk of pneumonia. We performed a series of in vitro experiments to assess the antimicrobial and physicochemical properties of VPs constructed from quaternary ammonium salt-functionalized or fluorinated silicone. Biofilm development on each prosthesis was quantified by measuring crystal violet-stained biomass, and surface coverage was visualized using scanning electron microscopy. Furthermore, biofilm morphology and material adhesion characteristics were examined by atomic force microscopy. To evaluate cytocompatibility, fibroblasts were exposed to extracts obtained after 24 h incubation of each material in culture medium. This was followed by analysis of cell area, circularity index, haemolytic activity and cytokine secretion. Mechanical testing was performed to determine the physiochemical performance of the tested silicone materials. Crystal violet staining demonstrated substantial biofilm accumulation on VPs retrieved from patients after three months of use. In contrast, the modified silicone materials exhibited markedly reduced biofilm coverage. All tested materials supported normal fibroblast proliferation and showed minimal hemolytic activity, although they differed in their capacity to induce cytokine expression. Incorporation of ammonium salt-functionalised or fluorinated silicone in VP design may substantially reduce surface biofilm formation. Thereby, improving device longevity and decreasing the risk of use-related complications. Key points• Fluorinated and quaternary ammonium salt-modified silicones exhibit significant biofilm resistance.• The modified materials demonstrate established biocompatibility with human cells.• These findings suggest the potential for developing new, extended-lifespan voice prostheses.