Characterisation of human fetal progenitor populations and response to osteogenic growth factors: a model system for mesenchymal lineage differentiation

We have previously demonstrated that porous poly-(epsiloncalprolactone) films with regularly spaced, controlled pore sizes provide adhesion and support for cultured dermal fibroblasts. We have determined the effects of applying various sized porous films (n¼3 for each treatment) on 4mm punch biopsy wounded mice to assess wounding response. Films with pores ranging in size from 3–20 microns, elicited a mild lymphocytic and foreign body perifollicular immune response, regardless of pore size but this treatment failed to significantly shorten wound healing time or increase the rate of wound closure. By 21 days after wounding the grafted porous films had become fully incorporated into or completely biodegraded in the wounded tissue. Finally, we assessed the proof of principle that live cultured fibroblasts can be delivered using porous films and sustained in model SCID mouse wounds. Human fibroblasts (30,000 cells) were subconfluently cultured on 5 micron porous films. These cell/film combinations were then transplanted onto wounded mice but failed to significantly affect wound healing. However, these transplanted fibroblast cells were readily detected using anti-human HLA antibodies in wounded SCID mice skin 21 days after treatment, when the wounds had completely healed. Taken together, these data demonstrate for the first time the feasibility of using porous films to deliver living human cells into skin wounds as part of our aim to use cell therapy to improve the wound healing response.