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In human beings and domestic pets, scarring in the skin after trauma, surgery, burns or a sports injury is an important medical problem, often resulting in altered aesthetics, loss of function, restriction of tissue elasticity and/or growth and adverse psychological effects.

Current treatments are strictly empirical, unreliable and uncertain. There are no prescription medicines for the avoidance or treatment of dermal scarring. Skin injuries on early mammalian embryos heal perfectly with no scars, whereas injuries to adult mammals are prone to scarring.

In scar treatment research, scientists are exploring the cellular and molecular differences between scar-free healing in embryonic injuries and scar-forming healing in adult injuries. Relevant differences include the inflammatory response, which in embryonic injuries consists of lower numbers of less differentiated inflammatory cells. This occurrence, together with high levels of morphogenetic molecules involved in skin growth and morphogenesis, means that the growth factor profile of an embryonic injury is very different from that of an adult injury.

These experiments proved the possibility of scar-less healing in the adult subject and have lead to the recognition of appropriate therapeutic targets. It has been found that effective skin care highly improves or completely prevents scarring during adult injury healing in experimental animals. Some of these new drugs have successfully passed safety and other studies, such that they have entered human clinical trials with approval from the appropriate regulatory authorities. Based on auspicious results from such volunteer studies, the leading drugs have now entered human patient-based trials e.g. in skin graft donor sites.

Proposing Solutions

The theory is that evolutionary factors have been exerted on intermediate sized, widespread, dirty injuries with considerable tissue damage e.g. bites, bruises and contusions. Modern injuries (e.g. produced by trauma or surgery) made by sharp objects, are recent situations not previously found in nature, in which the evolutionary selected wound healing responses are somewhat useless. It has been demonstrated that both repair with scarring and regeneration can happen within the same animal, including man, and of course within the same tissue, thereby suggesting that they share similar procedures and regulators.

Consequently, by subtly altering the ratio of growth factors present in adult wound healing, we can induce adult injuries to heal perfectly with no scars, with accelerated healing and with no adverse effects, e.g. on wound strength or wound infection rates. This means that scarring may no longer be an inevitable consequence of modem injury or surgery, and that a completely new pharmaceutical approach to the avoidance of human scarring is now possible. Scarring after injury occurs in many tissues in addition to the skin.

Thus scar-improving drugs could have widespread benefits and avoid complications in various tissues, e.g. the prevention of blindness after scarring due to eye injury, support of neuronal reconnections in the peripheral and central nervous system by the elimination of glial scarring, restitution of normal gut and reproductive function by preventing strictures and adhesions after injury to the gastrointestinal or reproductive systems, and the recovery of locomotor function by preventing scarring in tendons and ligaments.