Transplantation of embryonic stem cells improves the regeneration of periodontal furcation defects in a porcine model

Objectives Stem cell-based therapy promises to regenerate lost tissue. Embryonic stem (ES) cells are pluripotent and may provide a virtually unlimited source for transplantation. We investigated whether ES cell transplantation improved the regeneration of furcation defects in a porcine model. Material and Methods Experimental periodontitis was induced in the buccal furcations of the bilateral mandibular 2nd premolars of six minipigs. After 4 weeks, the lesions were surgically debrided and implanted with collagen matrix alone (control site) or collagen matrix overlaid with porcine ES cells expressing green fluorescent protein (pES/GFP⁺) (test site). After 3 months of healing, the clinical parameters were measured again. The treated teeth with adjacent tissue, and part of the major organs, were processed for GFP immunohistochemistry. Results We found no obvious teratoma or rejection. The test group had significantly better clinical parameters. Immunohistochemistry (IHC) showed that transplanted pES/GFP⁺ cells had differentiated to new periodontal ligament and cementum in the test sites. Surprisingly, GFP⁺ cells were also detectable in the repaired control cementum and remote organs. Conclusions We conclude that using ES cells to improve the regeneration of periodontal furcation defects is feasible. More studies are required to assess this potential treatment's efficacy and safety.