Effects of Gelatin Sponges on Several Cell Lines

Objectives: To clarify the mechanisms of pulp wound healing and local regeneration of dentin-pulp complex, we have reported formation of dentin bridge on surface of regenerated dental pulp in dentin defects by controlled release of fibroblast growth factor-2 from gelatin hydrogels and activation of BMP-2 induced Smad signaling pathway on odontoblastic-like cell (KN-3 cell). In addition, we have showed that hyaluronic acid inhibited NGF-induced neuronal differentiation on PC12 cells, which are often used as a model for studying neuronal signaling pathways and neuronal differentiation. In the present study, we examined the effects of gelatin sponges on KN-3 cells and PC12 cells. Methods: After 3 days-culture of the cells on sponges, we observed morphologies of the cells on sponges by scanning electron microscopy analysis. To analyze effects of these sponges, we next soaked gelatin sponges in medium of dishes in which the cells were cultured for 3 hours, and observed by phase-contrast microscopy. Especially, we counted PC12 cells with neurites that were more than double length of shortest diameter of cell body. We also examined the viability of the cells by WST-1 assay. Results: The porous structure of gelatin sponges was maintained throughout the cell culture, and the cells adhered to the inner surface of the pores inside the sponges. The results of the WST-1 assay showed no differences in viability of the cells. Gelatin sponges had no effects on KN-3 cells morphology, while sponges induced the neurite outgrowth of PC12 cells in the absence of NGF. Conclusions: Our results suggest that gelatin sponges may have appropriate structures and effect on the functional capabilities in the KN-3 cells and PC12 cells. Supported by Grants (Kitamura) from The Ministry of Education, Science, and Culture of Japan, Tokyo, Japan.