Scar free healing
[5] The exception to this is the much studied urodele species' of amphibians, also known as salamanders, which carry their ability of complete regeneration into adulthood.
[2] These vertebrates possess an exceptional ability to allow regeneration of entire limbs and their tails (as well as a multitude of their internal organs as well, including their spinal cord)[2] through a process known as blastema formation.
[6] It is this area that is known as the blastema which has the potential to differentiate and proliferate once again allowing regrowth of the limb similar to how it occurs during development.
In one study, it was found that limbs would not regenerate in those urodeles with depleted macrophages and instead would scar with permanent loss of functionality.
[8] Knowing how regeneration occurs in animals such as these may have great implications for how wound-healing is tackled in medicine and research has been aimed at this area, as a result.
Reparation of tissue in the mammalian fetus is radically different than the healing mechanisms observed in a healthy adult.
During early gestation fetal skin wounds have the remarkable ability to heal rapidly and without scar formation.
Scar free healing has been documented in fetuses across the animal kingdom, including mice, rats, monkeys, pigs and humans.
While the exact mechanisms of scar free healing in the fetus remain unknown, research has shown that it is thought to be due to the complex interaction of the components of the extracellular matrix (ECM), the inflammatory response, cellular mediators and the expression of specific growth factors.
[9] Originally, it was thought that the intrauterine environment, the sterile amniotic fluid surrounding the embryo, was responsible for fetal scar free healing.
Proteins and cell surface receptors found in the ECM differ in fetal and adult wound healing.
It is this ability of the fetal fibroblast to quickly express and deposit fibronectin and tenascin, which ultimately allows cell migration and attachment to occur, resulting in an organised matrix with less scarring.
The expression of HA is known to down-regulate the recruitment of inflammatory cytokines interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-α); since fetal wounds contain a reduced number of pro-inflammatory mediators than adult wounds it is thought that the higher levels of HA in the fetal skin aid in scar free healing.
Induced regeneration is currently being trialled to replace organ transplants as issues such as rejection, lack of donors and scarring would be eliminated.
Currently, it is only possible to reduce scar visibility, and the NHS suggests a number of different methods of doing this including corticosteroid injections, skin creams, silicone gels, pressure dressings, dermal fillers, radiotherapy and laser therapy.
In addition to this, 68% tried to hide their scars, whilst reporting their work life, self-confidence and ability to communicate with others had been negatively affected.
[26] Future research and advances in scar-free healing could lessen the cost to the NHS whilst also improving the quality of life to many people affected.
