What Are Scars?
Wound healing after dermal injury is an imperfect process, inevitably leading to scar formation as the skin re- establishes its integrity. The resulting scars have different characteristics to normal skin, ranging from fine-line asymptomatic scars to problematic scarring including hypertrophic and keloid scars.
Hypertrophic and keloids resulting from trauma and burns can be associated with physical and psychological distress, and they can be accompanied by significant pain, inflammation, erythema, dryness and puritis.
Keloids and hypertrophic scars are skin abnormalities that are unique to humans and are characterized by excessive deposition of collagen in the dermis and subcutaneous tissues secondary to traumatic or surgical injuries. The main pathological characteristics of scars are an overproduction of extracellular matrix and collagens. The abnormal architecture of collagen that results is the cause of the visible cutaneous scar.
The immediate response in the derma to injury is the infiltration of inflammatory cells and release of cytokines for wound healing. While the proper level of each cytokine is essential for healing, aberrant levels of inflammatory cytokines result in excessive fibroblast proliferation causing
scarring, which can cause significant disfigurement of the skin.
Current Methods to Manage Scarring
Current treatments of excessive scars with intralesional corticosteroids injections have been the golden standard for treatment of scars since the middle 1960s, however the mechanism of action of this treatment is mainly symptomatic, not completely understood, painful and often followed by several side effects, such as atrophy of the surrounding normal skin, fat and muscle and osteoporosis and pain at the injection side. Combination therapies, particularly surgical removal of scars followed by cryotherapy, pressure therapy, radiotherapy and application of silicon sheets seem to yield the highest rate of success and lowest recurrence rates, but have significant side effect and in some cases, poor patient compliance can affect outcomes. Emerging techniques based on the use of inhibitors of transforming growth factor (TGF-β) activation, inflammatory mediators and growth factors have been tested in clinical trials giving promising results.
Treatment such as electrical stimulation, photodynamic therapy and steroids are only available in a clinical setting. The most cited treatment option for keloids is surgical excision, followed by combination therapy including intralesional steroid injections, most commonly triamcinolone (TAC), with silicone gel or sheeting
and/or pressure bandages. However, recurrence rates following keloid revision surgery are high and are difficult to define, varying considerably. Hydration and occlusion, facilitated by silicone gels and sheeting, are thought to potentially influence burn, hypertrophic and keloid scar maturation, suppressing the inflammatory response triggered by keratinocytes and the epidermis in response to a compromised stratum corneum.
Topical treatments have proven to have variable success in reduction of hypertrophic and keloid scars. Steroid-based creams, due to poor solubility, have limited capacity to induce reduction in scar size, while silicone-based gels have been shown to have some positive effects in scar reduction. This reduction is thought mainly to result from the occlusive effect of the silicone, reducing epidermal water loss, rather than reduction of the inflammatory process.
Many pharmaceutical agents, for example corticosteroids, and phytochemical extracts, that are active in wound healing, inflammation modulation and reduction of scarring, are hydrophobic. This makes their transdermal delivery problematic. CWEK has overcome this issue by developing proprietary methods to solubilise active agents. The incorporation of these solubilised active agents in an oil-in-water nanoemulsion can provide the benefits of delivering hydrophobic compounds in nanosized lipophilic particles through the tough outer surface of the skin. These nanoparticles are able to cross the dermal layer and exert their anti-inflammatory, wound-healing and scar reducing effects upon the site of inflammatory scar formation.
CWEK proprietary treatment incorporates a nanoemulsion of these active agents into gel formulation that, when dried, provides a flexible, occlusive layer over the scar. This formulation is capable of delivering active agents through the skin to modulate the mechanisms of scar formation, whilst reducing transdermal water loss, thereby aiding in scar reduction.