Effects of an enamel matrix derivative on human osteoblasts and PDL cells grown in organoid cultures

Objective. The objective of this study was to investigate cellular effects of enamel matrix derivative (EMD) in human derived, primary osteoblasts and periodontal ligament (PDL) cells grown in organoid cultures. Study design. Cell replication was assessed by BrdU-incorporation. [H-3]-proline incorporation was measured to determine the synthesis of proline-containing proteins, such as collagen. In addition, calcium accumulation and alkaline-phosphatase-activity were quantified. Electron microscopy for morphological analysis was performed. Results. Our results showed that EMD enhances BrdU-incorporation in PDL cells and osteoblasts. Also, in osteoblast organoid cultures [H-3]-proline incorporation was 3-fold increased (P < .01). Extensive matrix deposition was noted in osteoblast cultures by electron microscopy. In osteoblasts, high levels of calcium accumulation and alkaline-phosphatase-activity were found. However, EMD did not promote mineralization. Conclusion. Our results indicate that under organoid culture conditions EMD is able to promote the synthesis of proline-containing proteins such as collagen but not matrix mineralization of primary human osteoblastic cells.