In man and domestic pets, scarring left after a trauma, surgery, burn or sports injury is a major health problem, often resulting in adverse aesthetics, loss of function, restriction of tissue elasticity and/or growth and negative psychological effects.

Current treatments are empirical, unreliable and unpredictable: there are no prescription medicines for the prevention or treatment of dermal scarring. Skin injuries on early mammalian embryos heal flawlessly with no scars whereas injuries in adult mammals scar.

Scientists are researching the cellular and molecular differences between perfect healing in embryonic and adult injuries. Relevant differences include the inflammatory response, which in embryonic injuries consists of lower numbers of less differentiated inflammatory cells. This, along with high levels of morphogenetic molecules involved in skin growth and morphogenesis, implies that the growth factor profile in a healing embryonic injury is very different from that in an adult injury.

These experiments produced scar-free injury healing in adults. Such studies have allowed the identification of therapeutic targets; an appropriate treatment evidently improves or completely prevents scarring during adult injury healing in experimental animals. Some of these new drugs have satisfyingly completed safety tests and others. This has allowed them to enter human clinical trials with approval from the appropriate regulatory authorities. Based on favorable results achieved in these studies lead drugs have now entered human patient-based tests e.g. in skin graft donor sites.

The hypothesis is that evolutionary factors have been exerted on medium sized, widespread, dirty injuries with high tissue damage e.g. bites, bruises and contusions. Modern injuries (e.g. produced by trauma or surgery) caused by sharp objects and healing in a clean or sterile environment with close tissue apposition are recent occurrences, not previously found in Nature and to which the evolutionary selected wound healing reactions are somewhat inappropriate. It has been shown 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 mechanisms and regulators.

Consequently, by subtly altering the proportion of growth factors present in adult wound healing, we can induce adult injuries to heal flawlessly with no scars, with accelerated healing and without negative consequences, e.g. on wound strength or wound infection rates. This implies that scarring may no longer be an inevitable consequence of modem injury or surgery and that a completely new pharmaceutical concept to the prevention of human scarring is now possible. Not only skin suffers from scarring; they can appear in many other tissues as well.

Thus scar-healing drugs could have extensive benefits and avoid complications in several tissues, e.g. prevention of blindness after scarring due to eye damage, facilitation of neuronal reconnections in the central and peripheral nervous system by the elimination of glial scarring, restitution of normal gut and reproductive function by avoiding strictures and adhesions after damage to the gastrointestinal or reproductive tracts, and recovery of locomotor function by avoiding scarring in tendons and ligaments.