Epidermal and fibroblast growth factors enhance fibrovascular integration of Porous polyethylene implants

Porous implants used in functional and aesthetic reconstruction of the orbit, face, and cranium are less likely to develop complications after they become biointegrated. We investigated whether the administration of exogenous growth factors could increase the rate of implant integration. High-density porous polyethylene cubes were placed in dorsal paraspinal muscles of rabbits, and daily transcutaneous injections of saline, epidermal growth factor, or basic fibroblast growth factor were administered directly over the cubes for 10 days. At serial time points up to 10 weeks, cubes were explanted and the fibroblasts present at the center of the cubes were counted. Injections of epidermal growth factor and basic fibroblast growth factor increased the rate at which fibroblasts accumulated in porous polyethylene implants and decreased the time required to achieve a maximal rate of cellular accumulation within the cubes. At 4 weeks, when all cell populations had attained a linear rate of accumulation, cubes previously injected with saline, epidermal growth factor, or basic fibroblast growth factor contained an average of 10, 40, and 80 cells per 0.0156 mm2, at their centers, respectively. Enhancement of the rate of biointegration of porous polyethylene cubes in rabbits is achievable by repeated, transcutaneous administration of exogenous growth factors.