THE PROCESS OF PERCUTANEOUS COLLAGEN INDUCTION (PCI)
IS SEPARATED INTO 3 PHASES:
- Starts with blood coagulation immediately after the clinical microneedling treatment
Phase I of the inflammatory response showing the cascade of cytokines and growth factors following the initial injury of needling. At this stage, neutrophils are the dominant leucocytes but are gradually replaced by monocytes, the dominant leucocytes in phase II.
- Proliferation / tissue formation
- Starts after about 5 days and lasts about 8 weeks
Phase II of the inflammatory response, which is predominantly the stage of tissue proliferation. Monocytes, keratinocytes and fibroblasts continue to influence and are influenced by the release of growth factors. Keratinocytes stimulate growth of the epidermis and release growth factors to promote collagen deposition by the fibroblasts. New blood vessels are created, and there is a surge of matrix deposition.
- Tissue remodeling
- From 8 weeks after the treatment to about 1 year
Phase III is the final remodeling phase of healing after clinical microneedling. Collagen type III is converted into collagen type I, and the skin becomes tighter. Blood supply is normalized, so the skin becomes smoother and has a natural color.