TGF-beta is associated with preparations of Enamel Matrix Proteins

Objectives: A decade after the first reported clinical uses of Enamel Matrix Derivative, the cellular mechanisms behind its ability to regenerate periodontal tissues are still poorly understood. The contribution and interactions between amelogenins and growth-factor-like proteins are complex and are only recently being elucidated. An area of contention is whether the TGF-â1 like activity attributed to EMD, is actually due to the presence of exogenous TGF-â1. The objective of this study was to identify whether Emdogain gel and lyophilised EMD contained physiologically relevant concentrations of TGF-â1, as well as investigating its potential association with other EMD proteins.

Methods: Emdogain® Gel and freeze dried EMD were analysed for TGF- â1 content using the Human TGF- â1 DuoSet ELISA kit (R&D systems). Additional samples were precipitated at 37°C and the TGF- â1 content determined as above for the washed pellet and the supernatant, the protein profiles were also evaluated using SDS-PAGE.

Results: The results suggest that EMD preparations contain 843-1885 pg of TGF-â1 per mg of protein. Substantial levels of TGF- â1 were observed in the precipitated fractions of EMD, with significant differences between Emdogain gel and freeze dried EMD of 127 and 297 pg/mg respectively (P<0.05).

Conclusion: These findings suggest that EMD contains TGF- â1 at concentrations capable of eliciting physiological effects. Additionally, the detection of TGF-â1 in precipitate indicates that it may be associated directly with enamel matrix proteins, suggesting a possible role for EMD as a growth factor delivery device. The in vitro precipitating capacity of Emdogain gel is also reduced in comparison to freeze dried EMD, most likely due to the reduction in pH caused by the inclusion of PGA.