[libribook.com] Traumatic Scar Tissue Management 1st Edition

Clinical Consideration
HA and its fragments may play crucial roles in the skin wound-healing
process by modulating the expression of fibroblast genes involved in
remodeling and repair of ECM (David-Raoudi et al. 2008).
Collectively the ECM defines the shape and form of our cells. It provides a
framework to which the cells can adhere, move about in and communicate
through. The ECM creates a medium by which appropriate balance can be
maintained between porosity, hydration and ionic environment, thus allowing
nutrients and metabolites to diffuse freely into and out of our cells. The ECM
acts as an immune barrier. It is also a repository for metabolites and toxins, and
for storing fat.
The ECM plays an important role in wound healing and repair. It serves as a
repository for signaling molecules and mediates signals from other cells to
promote cell proliferation and differentiation.
The ECM is responsive to mechanical strain and tensional loading (tissue
deformation). Mechanical forces exert influence on the tissue structural elements
(microfilaments) and the molecular composition of the ECM (Benjamin &
Ralphs 1998, Milz et al. 2005). Strain type, degree, direction and duration can
influence ECM composition and impact fibroblast functions that guide healing
and adaptation responses (Purslow 2002, Ingber 2003, Standley & Meltzer 2008,
Stecco et al. 2009, Blechschmidt & Gasser 2012). The clinical relevance of this
feature of the ECM will be noted throughout this book.
One of the mechanisms by which cells sense changes in mechanical
strain/tensional load is via specialized (matrix adhered) transmembrane receptors
(integrins). Integrins play a role in defining cellular shape, mobility, regulating
the cell cycle and mediating cell-to-cell and cell-to-ECM signals. Via integrins,
mechanical stimulus can evoke a biochemical response, which, in turn, can
trigger a variety of cellular responses and activities. Conversion of mechanical
stimulus into biochemical response is called mechanotransduction. The integrin–
mechanotransduction communication system works much faster than neurally