Collagen Membranes Adsorb the Transforming Growth Factor‐β Receptor I Kinase‐Dependent Activity of Enamel Matrix Derivative

Background: Enamel matrix derivative (EMD) and collagen membranes (CMs) are simultaneously applied in regenerative periodontal surgery. The aim of this study is to evaluate the ability of two CMs and a collagen matrix to adsorb the activity intrinsic to EMD that provokes transforming growth factor (TGF)‐β signaling in oral fibroblasts. Methods: Three commercially available collagen products were exposed to EMD or recombinant TGF‐β1, followed by vigorous washing. Oral fibroblasts were either seeded directly onto collagen products or were incubated with the respective supernatant. Expression of TGF‐β target genes interleukin (IL)‐11 and proteoglycan 4 (PRG4) was evaluated by real time polymerase chain reaction. Proteomic analysis was used to study the fraction of EMD proteins binding to collagen. Results: EMD or TGF‐β1 provoked a significant increase of IL‐11 and PRG4 expression of oral fibroblasts when seeded onto collagen products and when incubated with the respective supernatant. Gene expression was blocked by the TGF‐β receptor I kinase inhibitor SB431542. Amelogenin bound most abundantly to gelatin‐coated culture dishes. However, incubation of palatal fibroblasts with recombinant amelogenin did not alter expression of IL‐11 and PRG4. Conclusion: These in vitro findings suggest that collagen products adsorb a TGF‐β receptor I kinase‐dependent activity of EMD and make it available for potential target cells.