Articles - Snippits

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

Current treatments are empirical, troublesome and unpredictable: there are no prescription drugs for the avoidance or treatment of dermal scarring. Skin wounds on early mammalian embryos cure flawlessly with no scars whereas wounds in adult mammals scar.

Scientists are researching the cellular and molecular differences between scar-free healing in embryonic and adult wounds. Important differences include the inflammatory reaction, which in embryonic wounds consists of fewer quantities of less differentiated inflammatory cells. This, along with augmented levels of morphogenetic molecules involved in skin growth and morphogenesis, means that the growth factor profile in a healing embryonic injury is very different from that in an adult injury.

These experiments result in scar-free injury healing in adults. Such studies have allowed the recognition of therapeutic targets; an adequate treatment markedly improves or completely prevents scarring during adult injury healing in experimental animals. Some of these new medications have successfully passed safety studies and others. This has allowed them to enter human medical trials with approval from the appropriate regulatory authorities. Based on encouraging results attained from these studies lead medications have now entered human patient-based tests e.g. in skin graft donor sites.

The theory is that evolutionary pressures have been exerted on medium sized, widespread, dirty wounds with considerable tissue damage e.g. bites, bruises and contusions. Modern wounds (e.g. produced by trauma or surgery) made by sharp objects and healing in a clean or aseptic environment with close tissue apposition are new 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 occur within the same animal, including man, and of course within the same tissue, thereby implying that they share similar procedures and regulators.

Consequently, by slightly altering the proportion of growth factors present in adult wound healing, we can induce adult wounds to heal flawlessly 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 sequel 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 prevent complications in several tissues, e.g. 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, recovery of normal gut and reproductive function by avoiding strictures and adhesions after injury to the gastrointestinal or reproductive tracts, and recovery of locomotor function by avoiding scarring in tendons and ligaments.