Microarchitectural analysis of decellularised unscarred and scarred dermis provides insight into the organisation and ultrastructure of the human skin with implications for future dermal substitute scaffold design

The three-dimensional spatial arrangement of dermal tissue plays a crucial role in directing cellular behaviour during wound healing. It is vital to elucidate a better understanding of the three-dimensional dermal architecture of human skin. We sought to understand the configuration in morphological structure of decellularised human dermis between unscarred skin and normotrophic scars. Skin biopsies underwent decellularisation (DNA removal = 88%). Histological analysis showed no change in gross morphology of decellularised unscarred and scarred dermis. Multiphoton and atomic force microscopies showed that collagen fibres in unscarred decellularised dermis were interwoven akin to a mesh-like structure. Collagen fibres in decellularised unscarred dermis were less stiff (mean: 2.155 ± 0.9595 MPa; p < 0.0001) with a rougher (R(q) = 16.5, R(a) = 12.5, R(max) = 198; p < 0.0001) surface topography. Scarred dermis had a higher collagen volume density (papillary dermis, p < 0.0082; reticular dermis, p < 0.0332). The results demonstrate that scaffolds should exhibit a mesh-like structure with a biomimetic surface and low stiffness.