In vitro wound healing responses to enamel matrix derivative

Background: Enamel matrix derivative (EMD) contains a variety of hydrophobi c enamel matrix proteins and is extracted from developing embryonal enamel of porcine origin. EMD has been associated with the formation of acellular cementum and it has been found to stimulate periodontal regeneration. The p resent study was established to investigate the influence of EMD on human p eriodontal ligament (PDL) cells, gingival fibroblasts (GF), and osteosarcom a (MG-63) cells on wound-fill rates using an in vitro wound model. Methods: Wounds were created by making 3 mm incisions in cell monolayers ac ross the length of tissue culture plates. The wounded PDL, GF, and MG-63 ce ll monolayers were treated with media containing EMD over a concentration r ange of 5 to 100 mug/ml, platelet-derived growth factor (PDGF-BB) at 20 ng/ ml as a positive control and insulin-like growth factor (IGF-I) at 100 ng/m l as a negative control. PDL cell wounded monolayers also were treated in E MD coated tissue culture plates. After an incubation period (up to 9 days), the cells were fixed and stained and cellular fill was measured across the width of the wound by computer-assisted histomorphometry. Results: When PDL, GF, and MG-63 cells were exposed to EMD in culture mediu m, an enhanced wound-fill was observed for all cells compared to untreated conditions. At early time points, PDL wound-fill rates in the presence of E MD were statistically greater than the rates of GF and MG-63 treated with E MD (P <0.001). There were no significant differences in wound-fill rates of PDL cells treated with EMD in medium versus EMD coated on culture plates. At days 3 and 6 post-wounding, PDL cells showed a significantly greater res ponse to EMD than to PDGF-BB (P <0.001). EMD also had a greater effect on G F wound-fill rates than PDGF-BB at days 6 and 9. MG-63 cells were less resp onsive to PDGF-BB and EMD than PDL cells and GE An 3 cell types treated wit h IGF-I showed no significant increase of wound-fill rates. Conclusion: The present data support the concept that clinical. application of enamel matrix derivative may enhance periodontal wound regeneration by specifically modifying periodontal ligament cell proliferation and migratio n.