Use of Infrared Attenuated Total Reflectance Spectroscopy for the in vivo Measurement of Hydration Level and Silicone Distribution in the Stratum corneum following Skin Coverage by Polymeric Dressings

Abstract

The ability of wound dressings to hydrate the stratum corneum has been tested experimentally using attenuated total reflectance (ATR) infrared spectroscopy. A silicone gel dressing was able to hydrate the stratum corneum to the extent that its water content within the sampled volume was >60% after 5 h of contact compared with about 15% of normal exposed skin and about 30% for a highly permeable hydrophilic polyurethane dressing. An ATR method was devised to determine the presence and depth of penetration of silicone in the stratum corneum as a result of skin coverage by the polymeric dressing.

A Review of the Biologic Effects, Clinical Efficacy, and Safety of Silicone Elastomer Sheeting for Hypertrophic and Keloid Scar Treatment and Management

“…There are several hypotheses that try to explain the efficacy of silicone sheeting in treating hypertrophic and keloid scars; several studies have gathered evidence supporting or refuting each, but no distinct mechanism has been defined. Possible mechanisms include increased temperature, 40 hydration caused by occlusion of the underlying skin, [41][42][43][44][45][46] increased oxygen tension, 47 direct action of the silicone oil, 44 and polarization of the Low-cross-link-density silicone is cross-linked through a polytetrafluoroethylene (PTFE) membrane, resulting in an interpenetrating polymer network (IPN), which has greater physical strength and durability than the low-crosslink-density silicone elastomer alone and retains its adhesive properties. 39 scar tissue caused by the negative static electric charge generated by movement of the silicone.…”

“…40,52,53 Hydration Effects Many investigators have studied the hydration effects of silicone elastomer sheeting on the stratum corneum. [41][42][43][44][45][46] Quinn and colleagues 44 have observed that, when applied to a scar, the treated skin area loses water via evaporation at a rate of half that of the untreated skin area. After removal of the silicone gel, the water loss from the underlying treated skin area increases significantly for a period of 15 to 20 minutes.…”

“…Hydration Effects Many investigators have studied the hydration effects of silicone elastomer sheeting on the stratum corneum 41–46 . Quinn and colleagues 44 have observed that, when applied to a scar, the treated skin area loses water via evaporation at a rate of half that of the untreated skin area.…”

“…In an in vivo study comparing silicone gel sheets to polyurethane membranes applied to healthy skin, the presence of silicone was detected in the stratum corneum of skin exposed to silicone gel sheets using Fourier transform infrared attenuated total reflectance spectroscopy. The researchers found the concentration of silicone in the stratum corneum decreased with depth, indicating that the silicone probably did not reach the underlying viable layers of skin 41 . Shigeki and colleagues 59 also demonstrated the in vitro release of silicone‐related compounds from a silicone gel sheet and their water‐soluble distribution into the skin.…”

Beyond a Glimpse at Seasonal Dry Skin: A Review

“…Infrared spectroscopy by attenuated total reflectance [13,28,29] and magnetic resonance imaging [30] are also very sensitive methods to assess the water content of the stratum corneum in vivo. In a series of dry skin conditions, the severity of the clinical aspect is also correlated with an altered permeability barrier function of the stratum corneum as assessed by an increased transepidermal water loss [31].…”