Improved osteogenic differentiation of human dental pulp stem cells in a layer-by-layer-modified gelatin scaffold

Dental pulp stem cell is a new type of mesenchymal stem cell that has a potential for tissue regeneration. Gelatin sponges are often used for hemostasis in dental surgery. In this study, we aimed to evaluate the dental pulp stem cells' proliferation and osteogenic differentiation in different layer-by-layer-modified gelatin sponge scaffolds including the G, G+P (gelatin sponge+ poly-l-lysine modification), G+M (gelatin sponge+mineralization modification), and G+M+P (gelatin sponge+mineralization modification+poly-l-lysine modification) groups in vitro and assessed them in vivo. The results showed that dental pulp stem cells had a great potential for osteogenic differentiation. In vitro, the G+M+P group not only enhanced the adhesion and proliferation of dental pulp stem cells but also facilitated their osteogenic differentiation. However, alkaline phosphatase activity was prohibited after modification. In vivo, both dental pulp stem cells and cells from nude mice grew well on the scaffold, and G+M and G+M+P groups could promote the mineralization deposit formation and the expression of osteocalcin in osteogenic differentiation of dental pulp stem cells. In conclusion, the combination of dental pulp stem cells and G+M+P scaffold has a great potential for bone tissue engineering.