Tissue engineering of dermal substitutes based on porous PEGT/PBT copolymer scaffolds: comparison of culture conditions.

Previously, it was found that chondrocytes and fibroblasts could be efficiently seeded onto three-dimensional scaffolds in spinner flasks. In this study different culture conditions were compared to create a living dermal substitute as rapidly as possible. Human dermal fibroblasts were dynamically seeded onto biodegradable porous PEGT/PBT copolymer (PolyActive) scaffolds for 24 h in spinner flasks. Subsequently, the cell-seeded scaffolds were cultured in two conditions: statically (without medium flow, S) and dynamically (with slow medium flow, D). Qualitative analyses (scanning electron microscopy and histology) and quantitative assays for DNA, total collagen (hydroxyproline) and glycosaminoglycans were done with samples cultured for 3, 7, 14 and 21 days. In dynamically cultured constructs, human dermal fibroblasts were uniformly distributed throughout the pores of the scaffolds and had deposited higher amounts of extracellular matrix (ECM). Significantly higher numbers of fibroblasts were found (p<0.001), and significantly more collagen (hydroxyproline content) (p<0.001) and glycosaminoglycan (GAG) (p<0.05) were deposited at all the investigated time points when compared to static cultured constructs. In conclusion, medium flow stimulated the proliferation of human dermal fibroblasts and accelerated the ECM deposition in PolyActive dermal substitutes when compared to static culture. Dynamic culture reduced the time to create a dermal substitute containing autologous fibroblasts.