Fibroblast colonization of modified silicone films.

Hypothesis: Development of silicone films with hydrophilic surface properties and with associated fibroblast colonization for tympanic membrane reconstruction.

Background: Silicone films are used in ear surgery for splinting fresh eardrum perforations. The cure rate is high if the perforation is small and fresh. Persistent eardrum perforations have been treated in tympanoplasty procedures by splinting the tympanic membrane with silicone film. Silicone has hydrophobic properties and is poorly populated by cells.

Methods: Silicone films with a thickness of 0.13 mm were treated in a low-pressure oxygen plasma for different times. Oxidation of the surface allowed hydroxyl groups to form. The altered surface properties of the film were measured using the method of contact angle against water. Treated and untreated films (d = 22 mm) were placed in 12-well culture plates with 50000 L929 fibroblasts and in a standard medium for different lengths incubated at 37 °C. The quantification of the vegetation was performed after 5 days using WST-1 Cell Proliferation Reagent. The resulting cell growth was visualized after different incubation times through the Live/Dead Assay by fluorescence microscopy and scanning electron microscopy.

Results: The treatment of the films with low-pressure oxygen plasma resulted in a hydrophilic film surface. There were significant differences in fibroblast colonization in treated compared with untreated films. The hydrophilic silicone films had a higher quantity and quality of fibroblasts.

Conclusion: Further surface modifications could improve the film in respect of fibroblast vegetation. The effectiveness of the modified silicone sheets should be evaluated in vivo before clinical trials.