Like wound healing process, scar formation is also divided into three phases. These stages are similar to those which are required for wound healing process. As the scar formation is an integral natural event of the wound healing process, the stages of scar formation would be the same.
Those stages are named as inflammatory stage, proliferative stage and remodeling or maturation stage. These stages of scar formation were measured by tensile strength of the wound with the passage of time. Tensile strength is the measure of the capability of the skin to be stretched or the capability of the wound to be drawn out.
With the clotting of blood and homeostasis, inflammatory phase begins. The inflammatory phase is responsible for activating the defensive system of the wound. After this, the proliferative phase begins. This phase is also known as Collagen phase. The tensile strength increases as a big number of collagen enters into the wounded area. Collagen is a protein that is found in connective tissues. Connective tissues connect different body parts especially bones, ligaments, tendons and skin. The collagen protein is primarily used in stretching of the skin to replace the wounded or damaged skin. Therefore, presence of collagen means greater tensile strength. Tensile strength is greatest at the last stage, i.e. the maturation stage. There is no collagen increment, yet the tensile strength is increased and a white scar is formed.
The inflammatory phase is divided into two types of events. One is cellular and other is vascular. The vascular event is comprised of vasoconstriction and vasodilatation. Vasoconstriction occurs to stop the bleeding and to form a scab. Once the bleeding is stopped, vasodilatation occurs. The supply of blood increases, hence, increasing the supply of histamine, kinins, collagen type I, etc. In a cellular event, platelets, growth factors, neutrophils, and macrophages migrate to the wounded area. Platelets are helpful in blood clotting. White blood cells help in fighting against different types of infections. Neutrophils and macrophages are fighting cells which battle against bacterial growth. The growth factors help in boosting the healing process and increasing the tensile strength as well. Wound-Be-GoneĀ® reduces inflammation and the pain associated with inflammation.
The second phase is the proliferative stage. There are two important events in this stage. Extra cellular matrix is formed that is a combination of collagens and other matrices. The second important event is the supply of a new vascular system to the wounded region. Collagen is an important substance that increases the tensile strength of the skin. As said earlier, they are found in connective tissues and stretches skin to heal the wound by giving an almost similar look of the skin as it was original.
There are 19 types of collagens, each having chains of amino acids arranged in a triple helical structure that makes the collagen strong enough to perform its action of stretching. The internal events of wound healing in this stage signal the skin for scar formation. These signals determine the nature and type of the scar. If the wound is left open for a long time, the factors that prevent the scar formation are vanished. Therefore it is advisable to cover the wound and apply Wound-Be-GoneĀ® to trigger the actions of those scar formation controlling factors.
TGF-beta is a factor that is involved in hypertropic scar formation.