Table 2.

Structural determinants of regenerative activity of two scaffolds based on ECM analogues.

structural parameter of scaffold that is required for regenerative activity	skin regeneration (DRT; figure 5a)	nerve regeneration (filling of silicone chamber; figure 5b)	structural features of scaffold involved in contraction blocking
type I collagen/GAG, w/w	98/2	98/2	ligand identity required for binding of α2β1 integrin and other fibroblast integrins
residual collagen fibre banding (Yannas 1990)	ca 5% of native collagen	ca 5% of native collagen	platelet aggregation downregulated
average molecular weight between crosslinks, Mc (kDa)	5–15	40–60	scaffold maintains undegraded structure during contraction process
average pore diameter (μm)	20–120	5–10	maximum ligand density
pore channel orientation	random	axial	ligand orientation specific for stroma of organ

Sources: skin regenerations—Yannas et al. (1989) ; nerve regeneration—Yannas (2001). GAG: glycosaminoglycan.