Viscoelastic, physical, and bio-degradable properties of dermal scaffolds and related cell behaviour

Abstract

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 nano-fibres 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.

Design of a Novel Two‐Component Hybrid Dermal Scaffold for the Treatment of Pressure Sores

“…Binding between the polymerized Sil layer and fibrin/alginate layer seemed uniform for both the composites. As previously reported, one of the main features of the fibrin/alginate dermal scaffold Smart Matrix is the presence of both nanofibers and nanopores, thus resembling the natural extracellular matrix (ECM) which cells are exposed to in vivo . SEM suggests that these nanofeatures are still present in the two‐component hybrid scaffolds (Figure , images at 5000×, far right column).…”

“…Fibrin/alginate porous hydrogels (Smart Matrix) were manufactured from bovine fibrinogen using a foam‐based method. Further chemical cross‐linking with glutaraldehyde and freeze/drying of the structure produced a ≈2 mm thick white sheet that was 80–90% porous with interconnected pores in the ideal range for cell infiltration and skin regeneration (Figure B). For manufacturing the hybrid two‐component scaffold, the fibrin/alginate foam was cast on top of the Sil membranes prior to chemical cross‐linking and freeze‐drying steps.…”

“…Over the past decade, our laboratory has developed a novel dermal replacement scaffold composed mainly of fibrin with alginate as a filler component . The scaffold is branded Smart Matrix and is at the commercialization stage for the treatment of acute full thickness skin wounds such as third degree burns or acute surgical wounds.…”

“…The scaffold is branded Smart Matrix and is at the commercialization stage for the treatment of acute full thickness skin wounds such as third degree burns or acute surgical wounds. Smart Matrix is a porous hydrogel that possesses an open, interconnected porous structure with a micropore size distribution ideal for skin regeneration . Moreover, the material behaves like a viscoelastic solid, like skin and dermis tissues, and presents nanofeatures .…”

“…Smart Matrix is a porous hydrogel that possesses an open, interconnected porous structure with a micropore size distribution ideal for skin regeneration . Moreover, the material behaves like a viscoelastic solid, like skin and dermis tissues, and presents nanofeatures . In vitro cell studies suggest that a higher influx of cells, reduced wound contraction, and less scarring would be observed in vivo for Smart Matrix when compared to similar acellular commercially available dermal scaffolds, namely Integra and Matriderm …”