Under normal “uncompromised” circumstances skin wounds are “seen” to progress through
the stages of inflammation, new tissue formation and new tissue remodelling - which
results in the formation of scar tissue (a virtually avascular & acellular tissue
functionally and aesthetically inferior to normal skin).
The cellular profile of wound tissue changes with time after injury.
Initially, inflammatory cells that are responsible for clearing wound site debris
(such as neutrophils and monocyte-macrophages) predominate; later as the wound heals
(matures) proliferative cells which are responsible for the generation of replacement
tissues (i.e. fibroblasts & endothelial cells) predominate.
Consequently, the cellular profile of a wound can be used to describe its maturity.
Wound tissues with a relatively high proportion of inflammatory cells are considered
less mature (less advanced) than similar tissues containing relatively few inflammatory
The relative contribution of inflammatory cells (neutrophils & monocyte-macrophages)
and proliferative cells (fibroblasts & endothelial cells) to wound cellularity—at
a given point in time after injury and treatment — allows the impact of an investigational
agent on wound progression to be determined.
Cell specific histological staining techniques are used to label and measure the
involvement of specific cellular lineages (see below).
Neutrophils (Chloroacetate Esterase staining)
Macrophages (ED-1 immuno-staining)
Angiogenesis (anti-CD31 immuno-staining)
Scar Tissue Analysis is performed using our in house Cica Scar Analysis System (C-SAS)
C-SAS generates data describing the directionality of collagen bundles within scar
The output generated by C-SAS describes the directionality of collagenous structures
in twelve 15° segments (see graphic).
Scar tissue is composed of a collagen bundles
largely orientated parallel to the surface of the skin; whereas, normal skin has
a more multi-directional structure.
Severe scars have more horizontally-orientated
structures; less severe scars display a greater variation in directionality.
Routine H&E staining of a diabetic wound showing histological planimetry measurements: