Efficacy evaluation of the fibroblast-seeded collagen/chitosan scaffold on application in skin tissue

There remains a need for dressings which aid the healing of chronically refractory wounds. To this end, we formulated and tested a collagen/chitosan scaffold supporting basic fibroblast growth factor (bFGF) producing cells. Collagen was blended with chitosan derived from crab shell (in ratio 7:3 of 3% weight of total polymer), crosslinked with glutaraldehyde, and then cast into a film. Tensile strength and elongation at break values of the scaffold was 8.5 0.1 MPa and 2.4 0.6%, respectively. The swelling degree was 77 4%, and the weight remaining after collagenase degradation for 1 month was 30.5 6.3%. Our scaffolds showed bio-compatibility because they encouraged attachment and proliferation of spindle-shaped human dermal fibroblasts (HDFs) which secreted surface-bound bFGF. Next, the fibroblast-seeded scaffold was prepared by seeding HDFs on the collagen/chitosan scaffold (5 10 5 cells/cm 2 ) and further cultured for 7 days. These fibroblast-seeded scaffolds were used to dress full depth wounds in domestic pigs. The wounds with fibroblast- seeded scaffolds showed reduced swelling at day 7 and at all time points (7, 14, and 21 days), and re-epithelialization was faster than controls. Thus at day 21 of treatment, wounds treated with the fibroblast-seeded scaffold provided the highest percent re-epithelialization (69.7 9.6%), which was higher than untreated (49.9 6.3%) and cell-free scaffold treatment (54.3 6.9%). The wound tissue of the fibroblast-seeded scaffold treated group showed regular arrangement of host collagens and the rete ridge-like structure at the epidermal layer was also found at day 21. The results indicate the potential of the fibroblast-seeded scaffold for application in skin tissue engineering.