As the micro-needles glide over the skin, microscopic punctures are lightly stamped in the skin’s matrix stimulating an inflammatory, or wound healing response. This promotes the most intense repair, renewal and skin rejuvenation. Natural growth factors are released to stimulate reformation and depositing of fresh collagen. Unlike most rejuvenation treatments a microneedling device can target various cell types.
Keratinocytes: The main cells of the epidermis formed by cell division at its base. New cells continually move towards the surface. As they move, they gradually die and become flattened.
Corneocytes: The flattened dead keratinocytes that together make up the very outer layer of the epidermis, this layer is constantly worn away or shed
Melanocytes: Produce the pigment melanin that protects against UV radiation and gives the skin its colour.
Fibroblasts: Fibroblasts produce collagen, which supports the tissues within the dermis and provides structure within the skin.
When a microneedle punctures the epidermis wound healing is being promoted reducing the risk of irregular collagen deposition.
As the skin is made up of 3 layers, each layer contains major cells groups. The dermis and the epidermis are the key skin layers to be targeted.
Wound healing response
The wound healing response is the biological repair action that occurs within the skin after deep trauma. The process is commonly has 4 specific stages:
The pinpoint bleeding of created during the microneedling treatment creates the addition of Haemorrhage/haemostasis as a starting point. As microneedling is non-thermolytic and non-ablative it ensures controlled wound healing stimulation of fibroblast division and the deposition of tightly woven collagen fibres.
Bleeding Stage
When tissue is first wounded, blood comes in contact with collagen, triggering blood platelets to begin secreting inflammatory factors. Fibrin and Fibronectin cross link together and form a plug that traps protein and particles
Inflammation Stage- Lasts 0–4 plus days
Begins once the blood clot is formed the blood vessels can expand to allow the area to be flooded with healing tissue fluid. This increase in tissue fluid will cause oedema/inflammation.
The coordinated reaction of tissue fluid reacts to cell injury/death.
The macrophage cells involved are –
Neutrophils- main white blood cells that repairs damaged tissue and fight infection
Monocytes- fight infection
This stage stimulates growth hormone within the epidermis to become active. These growth hormones assist with the next stage of the wound healing response.
Proliferative stage- Last day 4-6 weeks
3-4 days after the wound occurs, fibroblasts, within the dermis, begin to enter the wound site and begin producing collagen.
Gaps in tissues are replaced with collagen, produced by the fibroblasts, endothelial cells and keratinocytes take over synthesis of growth factors.
Proliferation and formation of new capillaries.
Synthesis of extracellular matrix components.
Maturation or Remodelling Phase- Last up to 18 months after wound closure
When the levels of collagen production equalize and become tougher, therefore the wound can become less visible over time.
As a recap…