Rheological properties

Dermal scaffolds promote healing of debilitating skin injuries caused by burns and chronic skin conditions. Currently available products present disadvantages and therefore, there is still a clinical need for developing new dermal substitutes. This study aimed at comparing the viscoelastic,
physical and bio-degradable properties of two dermal scaffolds, the collagen-based and clinically well established Integra® and a novel fibrin-based dermal scaffold developed at our laboratory called Smart Matrix®, to further evaluate our previous published findings that suggested a higher influx of cells, reduced wound contraction and less scarring for Smart Matrix® when used in vivo. Rheological results showed that Integra® (G′ = 313.74 kPa) is mechanically stronger than Smart Matrix® (G′ = 8.26 kPa), due to the presence of the silicone backing layer in Integra®. Micro-pores were observed on both dermal scaffolds, although nano-pores as well as densely packed nanofibres
were only observed for Smart Matrix®. Average surface roughness was higher for Smart Matrix® (Sa = 114.776 nm) than for Integra® (Sa = 75.565 nm). Both scaffolds possess a highly porous structure (80–90%) and display a range of pore micro-sizes that represent the actual in vivo
scenario. In vitro proteolytic bio-degradation suggested that Smart Matrix® would degrade faster upon implantation in vivo than Integra®. For both scaffolds, the enzymatic digestion occurs via bulk degradation. These observed differences could affect cell behaviour on both scaffolds. Our results suggest that fine-tuning of scaffolds’ viscoelastic, physical and bio-degradable properties can maximise cell behaviour in terms of attachment, proliferation and infiltration, which are essential for
tissue repair.