Accidents sometimes happen; and when they do they usually leave a mark. As I look over the scars on my body I remember the, sometimes foolish, incidences in which I acquired those marks. Like the one on my right arm from when I dropped my cousin onto the sofa from her piggy back ride while she held on for dear life, resulting in her bracelet consisting entirely of stars and moons to cut me open. Or the one on my right knee from me falling off my bike in Margaret River, Western Australia on a very steep hill while showing off to a girl that I liked. Each scar has tied to it a memory, but what if we didn’t have to have these visible scars?
The skin is the largest organ in the human body and is a part of the integumentary system. The system, when considering all types of animals, consists of the skin along with appendages such as hair, nails, feathers, hooves and scales. Skin is broken up into 3 layers; the epidermis, dermis and subcutis or hypodermis layer. These layers work together to perform an array of jobs such as protection from pathogens (something that causes a disease), allow us to feel, thermoregulation (control internal heat) and provide water resistance. Fun fact; when getting a tattoo, ink is injected into the dermis layer (below where new skin is formed) so that it doesn’t disappear as new layers of skin develop. Though our skin is very resilient, there are times when it can become damaged.
Scars are a natural part of the biological repair process. When the dermis is damaged, the body forms collagen fibers to fix the wound resulting in a scar. A lot of the time, superficial wounds to the skin don’t usually result in scarring or if the animal has the ability of regeneration (axolotls and starfish), then scarring isn’t an issue at all. Skin normally has a particular amount of collagen but instead of a multi-directional weave of fibers, the collagen forms cross-links that form a prominent single direction of fibers; hence why scars are so visible. In comparison to the former multi-directional weave, scars are more susceptible to damage from UV light and don’t have the normal functions of skin as it doesn’t have sweat glands or hair follicles. This results in a few issues with scar tissues, especially if there is too much of it covering the body. Scar tissue is weaker, less elastic so problematic if over a joint limiting mobility, can’t assist in the internal and external exchange of substances and can have lost nerve sensitivity.
Unfortunately, your current scars can’t be fixed but thanks to scientists from the University of Pennsylvania’s Department of Dermatology new scarring might no longer be an issue. They found that during superficial skin damage, fat cells (adipocytes) and hair follicles are present and the skin repairs itself around these structures and eventually blends in; looking normal. When the skin is damaged further, these cells and structures are not present and are replaced with fibrous cells (myofibroblasts) which fill in the space between the normal skin giving it that very distinguished look (a scar). A new procedure will stop this from happening by turning the fibrous cells into fat cells and it all starts with hair.
By injecting hair follicles to grow into the new wound, they release a protein called Bone Morphogenetic Protein or BMP which turns the myofibroblasts into adipocytes. As the skin heals, the adipocytes and new hair follicles just blend into the skin around the wound. So far this has only been performed on mice and human skin samples so there is still away to go from this being performed successfully on a live human. The possibilities however for the treatment of fresh wounds when large amounts of damage are sustained (burn victims) is incredibly exciting and this might just be the first step to human regeneration.