gms | German Medical Science

Introduction: Autologous cells inside a tissue engineered construct must be supplied as soon as possible with nutrients by angiogenesis. However, it is known that the vascularization in-vivo requires several days. The aim of this study was to find out if seeded cells proliferate on a human acellular dermis (hAD) despite the absence of blood supply in irradiated and unirradiated tissues after transplantation. In addition, we investigated whether pores inside the hADs affect the cell proliferation and vascularization.

Material and methods: 24 rats received a dorsal skinfold chamber and were divided into 2 main groups, irradiated and unirradiated. Rats were unilateral irradiated with 20Gy. Each of these 2 groups received either matrices with or without pores. Fibroblasts were transduced with a fluorescent protein for cell tracking and seeded statically onto the hADs. Cell proliferation was examined at day 0,3,6,9,12 by intravital microscopy. Visible cells and vessel density were quantified semi-automatically using Fiji.

Results: In all groups there was initially a decrease in cell numbers until day 3. Between day 3 and 6 cell numbers increased continuously until day 12 with varying extents. In the group without irradiation but with pores significantly more cells and vessels were counted compared to the group without pores. In the groups with irradiation we found that the treatment significantly inhibits cell proliferation and vessel density, wherein the pore group had significantly more visible cells and vessels than the group without pores.

Conclusion: We have shown that autologous cells proliferated within the human dermis in-vivo, but the irradiation significantly affected the proliferation of the autologous cells and the vessel density. Further, pores within the dermis increased significantly the cell proliferation and vessel growth, particularly in irradiated tissues.