Pre-operative in vitro fibroblast coating of porous polyethylene compound grafts - Cell survival in vivo and effects on biocompatibility

BACKGROUND: Key factors for successful porous polyethylene (PPE) implantation are rapid vascularization and low inflammatory response. Dermal fibroblasts produce a variety of pro-angiogenic and immunmodulatory factors. OBJECTIVE: The aim of this tissue engineering study was to investigate whether coating PPE implants with dermal fibroblasts in vitro is sustainable in vivo and whether the kinetics of blood vessel ingrowth and immunological responses are hereby affected. METHODS: PPE implants were cultured with syngeneic GFP-transfected dermal fibroblasts. Cells on the biomaterial were quantified before implantation into dorsal skinfold chamber preparations of C57Bl/6 mice. Uncoated implants served as controls. Angiogenic activity and leukocyte-endothelial cell interactions were repeatedly analyzed. After 10 days, mechanical integration was measured and surviving fluorescently labeled fibroblasts were quantified. Expression of inflammatory cytokines was assessed by quantitative real time-reverse transcription PCR. RESULTS: PPE implants were successfully coated with dermal fibroblasts in vitro and 69% of the cells were still detectable at the end of observation. Angiogenic parameters increased during the observation period in both groups. IL-2, IL17A and IL-10 tended to be increased in coated implants, but did not affect leukocyte-endothelial cell interactions. CONCLUSIONS: Dermal fibroblast-coating of porous polyethylene implants is feasible and sustainable in vivo. Alone it does not improve biocompatibility but may be beneficial in combination with specific growth factor supplements.