Keynote Video
Wound Healing and its Relevance to Dermal Needling
Wound healing in embryos (Scarless wound healing)
In embryo wound healing the following has been discovered:
Wounds in embryo heal without scarring.
Wound healing is much quicker.
Neovascularisation is absent.
PDGF does not play a part in wound healing.
The keratinocyte plays a larger role in wound healing.
Embryonic wounds that heal have low levels of TGF 1 and 2, PDGF and high levels of TGF 3 indicating that the keratinocyte plays an important role in scarless wound healing.
Wound healing in adults
Vasoconstriction and Platelet Activation: When tissue is injured, blood vessels constrict to minimize blood loss. Platelets aggregate at the injury site and release factors that promote clot formation.
Formation of Fibrin Clot: Fibrin, a protein, forms a mesh-like structure that reinforces the platelet plug, sealing the wound temporarily.
Inflammatory Phase:
Vasodilation and Increased Permeability: Upon injury, blood vessels in the affected area dilate, leading to increased blood flow. Blood vessel walls become more permeable, allowing immune cells and molecules to enter the injured tissue.
Release of Inflammatory Mediators: Immune cells release cytokines, histamine, and other signalling molecules that promote inflammation. These mediators attract immune cells to the injury site and initiate the immune response.
Immune Cell Infiltration: Neutrophils arrive first, followed by macrophages. Neutrophils phagocytose debris, pathogens, and dead cells. Macrophages clear debris and release cytokines to orchestrate the healing process.
Cytokine Release: Cytokines, signalling molecules, attract immune cells and stimulate fibroblasts and keratinocytes to participate in wound healing.
Proliferative Phase:
Granulation Tissue Formation: Fibroblasts migrate to the wound and start producing collagen, the main protein of the extracellular matrix. Granulation tissue forms, providing a scaffold for tissue regeneration.
Angiogenesis: New blood vessels form within the wound, supplying oxygen and nutrients to support healing.
Epithelialization: Epithelial cells at the wound’s edge migrate to cover the wound. Cell division and migration occur until the wound is fully covered, re-establishing the skin’s protective barrier.
Remodelling Phase:
Collagen Remodelling: Collagen fibres initially deposited during wound healing undergo remodelling and realignment by enzymes like collagenases. This strengthens the wound and gradually restores its tensile strength.
Scar Formation: Scar tissue forms as collagen fibres reorganize. The appearance and extent of scarring depend on factors such as wound size and depth.
Maturation: Over time, the scar tissue matures and becomes less prominent. However, the skin’s structural and functional properties may not fully match the original tissue.
Micro needling can be divided into cosmetic and medical needling.