The Effect of Silicone Gel on Basic Fibroblast Growth Factor Levels in Fibroblast Cell Culture

Abstract

Background: Topical silicone gel has shown promise in the treatment of hypertrophic and keloid scars. However, its mechanism of action remains undetermined. Objective: To investigate whether the presence of silicone alters the secretion of basic fibroblast growth factor (bFGF), a key cytokine involved in the scar formation process. Design: Serum-free fibroblast cell cultures were established from normal, keloid, and fetal skin, which heals without scarring, and exposed to silicone gel. Serial cell counts were performed, and supernatants were collected for bFGF quantification by enzyme-linked immunosorbent assay at 4, 24, 72, and 120 hours. Results: Growth curves were similar and no statistically significant differences in population doubling times were observed between treated and untreated specimens. Statistically significant differences in bFGF levels between treated and untreated normal fibroblasts were observed at 24, 72, and 120 hours after cell culture initiation. Differences in bFGF levels between treated and untreated fetal fibroblasts that approached statistical significance were observed at 72 and 120 hours. Conclusions: These results suggest that silicone gel is responsible for increased bFGF levels in normal and fetal dermal fibroblasts. We postulate that silicone gel treats and prevents hypertrophic scar tissue, which contains histologically normal fibroblasts, by modulating expression of growth factors such as bFGF. Our data support the hypothesis that substances that favorably influence wound healing do so by correcting a deficiency or overabundance of the growth factors that orchestrate the tissue repair process.

The Use of Silicone Adhesives for Scar Reduction

“…14,15 SGS, unlike other dressings, provide a level of occlusion similar to normal skin, which is thought to explain why cytokine and fibroblast activity and collagen formation are significantly reduced in SGS-treated scars [16][17][18] and stratum corneum hydration is normalized. 19 It is worth noting that the gentle removal of SGS compared with alternative adhesive sheeting also minimizes skin stripping of the newly formed stratum corneum, further contributing to its treatment potential.…”

Scar Revision Review

“…Some have suggested that it is the hydration of the stratum corneum rather than the inherent properties of the silicone itself that affects wound healing. 64,65 In 2004, Hanasono et al 66 performed in vitro testing on human fibroblasts from various tissues including normal, keloid, and fetal skin. Their results suggested that silicone gel is responsible for increased basic fibroblast growth factor levels in normal and fetal dermal fibroblasts and acts as a modulator in the expression of such growth factors.…”

“…Their results suggested that silicone gel is responsible for increased basic fibroblast growth factor levels in normal and fetal dermal fibroblasts and acts as a modulator in the expression of such growth factors. 66 It has also been shown that SGS may act by down-regulating fibroblasts and decreasing fibrogenic cytokines such as TGF-␤2. 67 Gallant-Behm et al 68 showed that SGS significantly decreased the epidermal expression of the profibrotic cytokine interleukin-1␤ and increased the epidermal expression of the antifibrotic cytokine tumor necrosis factor.…”

Normal skin and hypertrophic scar fibroblasts differentially regulate collagen and fibronectin expression as well as mitochondrial membrane potential in response to basic fibroblast growth factor

“…The laboratory protocol was approved by the Medical and Ethics Committee of Southern Medical University and the People's Hospital of Guangdong Province and written informed consent was obtained from the patients. Fibroblasts were isolated from the dermis of the biopsies according to a method previously described (14,15). The cells, at 70-80% confluence, were treated with different concentrations of bFGF in a serum-free medium.…”