Therapeutic Improvement of Scarring: Mechanisms of Scarless and Scar-Forming Healing and Approaches to the Discovery of New Treatments
Scarring results from an abnormal deposition and organisation of collagen cutaneous scar in a noncaucasian subject at 12 months following a 1 cm full thickness incision to the inner aspect of the upper arm (a). Histological staining of the excised scar with Van Gieson’s stain demonstrating collagen (blue/green) and elastin (purple) staining in the normal skin compared to scar tissue and a normal undulating epidermis with rete ridges in the normal skin compared to a flattened epidermis overlying the scar (b). Picrosirius red staining of the same scar viewed using polarised light (c), illustrating the normal “basket-weave” organisation of collagen in the normal skin resulting in organised light scattering (birefringence) compared to the abnormal organisation of collagen fibres within the scar resulting in a lack of birefringence. Arrowheads indicate the border of normal skin and scar tissue. Scale bars in (b) and (c) are 500 mm. In (b) and (c), rr rete ridges; e epithelium.