Surface modulation of wounds: heal by inhalants! Novel drug-based treatment for excessive scars and chronic wounds. (SUMOWO)
Aberrant skin wound healing is characterized by an increased and prolonged inflammatory reaction that leads to either chronic wounds or – in the long-run – to excessive scarring. In the lung, a substance termed “lung surfactant” is produced that lubricates the alveolar surface towards the air and that can calm down the inflammatory reaction during wound healing. Lung surfactant consists of various lipids and anti-bacterial surfactant proteins.
Because the lung with its huge surface towards the air is very similar to the skin that is our outer barrier against the air, microbes, physical and chemical influences, we hypothesized that lung surfactant has also beneficial effects when applied onto skin. Our project aimed at transferring the positive effects of lung surfactant to skin wounds. In pre-clinical experiments, we showed successfully that lung surfactant has a similar effect on skin cells as seen in the lung. The inflammatory reaction seen in experimental skin wounds was reduced as well.
In the present project SUMOWO, pre-clinical experimental findings were transferred into a clinical setting. The aim was to analyze if lung surfactant had any adverse effects if it was applied topically onto the intact skin and if human skin wound healing was altered by lung surfactant treatment. In a clinical phase I study, standardized superficial wounds were made on the forearms of healthy volunteers and treated with lung surfactant or the dissolvent saline. Wounds and the surrounding skin were treated every other day and different parameters were documented, such as skin redness, rash, pain, wound closure and transepidermal water loss (water evaporation from the skin surface as an objectively measurable parameter of an open wound). Topical lung surfactant treatment was well tolerated and had no adverse effects on either normal skin or wounds. No differences in skin redness or pain were stated between the treatments. Skin wounds healed significantly faster in comparison to control treatment. The onset of healing was significantly faster in women in comparison to men on day 4 but skin wound closure equalled in both genders at day 6. In summary, lung surfactant is well tolerated and, as a consequence, well suited for topical treatment of the intact skin, inflammatory skin diseases or skin wounds where it seems to exert the same beneficial effects as seen in the lung. Currently, the next phase of experiments are planned, namely a clinical phase II study with treatment of standardized skin wounds and deeper burns in patients.
