There are various groups of silicones, including silanes, hydroxyl-containing compounds (silanols), linear polysiloxanes (dimethicone/polydimethylsiloxane), cyclicdimethyl siloxanes (cyclomethicone/decamethylcyclopentasiloxane), silicates (inorganic) and silsesquioxanes (RSiO3/2)n. Silicone gels (SGs) and SG sheeting are commonly used to reduce scarring. They have been found to significantly reduce the texture, color and height of scars, with reported reductions of 86%, 84% and 68%, respectively. The international advisory panel for hypertrophic scar and keloid management recommends SG sheeting as a reasonable first-line treatment for these conditions. 

The exact mechanism of action of SG is not fully understood, but improved occlusion and hydration of the wound bed are believed to play a key role. SG acts as a flexible hydrophobic barrier, regulates temperature and increases hydration at the site of the scar, leading to reduced capillary activity, hyperemia and collagen deposition. Silicone sheets decrease the rate of water vapor evaporation, resulting in increased moisture on the skin surface. Silicone modulates the expression of tumor growth factor (TGF) and fibroblast growth factor (FGF), which are involved in the production and breakdown of collagen by fibroblasts. This modulation helps restore the balance between collagen synthesis and breakdown, promoting proper healing of the scar tissue. Silicone also protects the scarred tissue from bacterial invasion and prevents excessive collagen production induced by bacteria. 

Silicone can be applied topically as an SG twice a day or as an SG sheet for 12 to 20 hours a day with daily washing for a period ranging from 3 to 6 months. The advantages of topical SG include nonocclusiveness, waterproofing, gas permeability, ease of application, suitability for sensitive skin, use on children, irregular skin or scar surfaces, the face, moving parts and scars of any size. 

In recent years, silicone compounds have emerged as crucial ingredients in a wide range of skincare products. This significant growth can be attributed to a deeper understanding of their beneficial properties, including bio inertness, stability, flexibility, nontoxicity, good tissue compatibility and anti-adhesive properties. Silicone polymers have not only revolutionized the formulation of skincare and hair care products but have also found applications in specific dermatological therapies for scar management and wound healing. The increasing demand for aesthetically pleasing products may drive the creation of more silicone-based skincare solutions in the future. Overall, the rapid growth and versatile applications of silicone compounds highlight their importance and potential in the field of skincare.

Source: Bains P, Kaur S. Silicone in dermatology: an update. J Cutan Aesthet Surg. 2023;16(1):14-20.