Continous migration and proliferation of osteoblasts on ECM-proteins vs. Emdogain

Objectives: Migration of osteogenic cells plays a crucial role in bone remodelling and osseointegration of dental implants. Various single ECM proteins have been proofed to affect bone repair. One potential clinical candidate to influence hard tissue regeneration are enamel-matrix-derivatives (Emdogain). The assessment of dynamic migratory cell pattern is difficult; established experimental set-ups display discontinuous observation methods by only measuring net changes of the cell population. METHODS: For continuous observation of individual cells, the Time-lapse-Individualcell-Migration-Assay (TIM-Assay) was established, recording migratory and proliferative behaviour of up to 12 vital cells over a period of 24 hours. Consecutive positions of nuclei in all cells are tracked. Three osteogenic cell cultures were obtained from routine surgical procedures. Using the TIM-Assay, we investigated the migratory and proliferative pattern of 328 cells, having coated the culture plates with type I collagen, laminin and Emdogain, respectively. For reverence values we observed cells on BSA and on untreated glass to assess intrinsic migration and proliferation attributes. RESULTS: The investigated cells stayed vital with a constant migration pattern over the whole observation period (see below). The presence of Collagen and Laminin supported migration. The application of Emdogain resulted in intermediate behaviour. Proliferation rates were heterogenous for all agents (4,2 - 50%). CONCLUSION: The TIM-Assay serves as a tool to analyse dynamic cell responses to distinct ligands. One limitation of the method is the small subpopulation observed by cycle. In our study, solitaire ECM components proofed to enhance migration. Emdogain is likely to consist both of stimulatory and inhibitory components.