G-CSF/laponite/collagen composite inducing stem cells of apical papilla homing for dental pulp regeneration.

OBJECTIVE

Irreversible pulpitis in immature teeth is a serious dental disease which may lead to unclosed apical foramen and even tooth loss. Our study proposed a system of G-CSF/laponite/collagen composite and investigated its effects for stem cells of apical papilla (SCAPs) homing, targeting a potential treatment for immature dental pulp regeneration.

METHODS

In vitro, the effect of G-CSF on SCAPs proliferation, migration and differentiation was investigated. The microporous scaffold structure, sustained-release capability and cytotoxic effects of G-CSF/laponite/collagen composite was evaluated. In vivo, dentin cannulas model filled with G-CSF/laponite/collagen composite implanted in the back of nude mice was utilized to verify the effects of SCAPs homing for pulp regeneration.

RESULTS

In our study, the promoting effects of G-CSF on SCAPs proliferation and migration were verified, and the optimal concentration was chosen at 10 and 50 ng/ml. Interestingly, G-CSF had a slight effect on osteogenesis but significantly increased the gene expression of odontogenesis (DSPP, DMP-1). Laponite was observed to adsorb and slowly release G-CSF in a sustained manner, and the "laponite + collagen" contained micropore scaffold structure without biotoxicity for SCAPs. In vivo, 50 ng/ml G-CSF/laponite/collagen composite appeared to be the best combination for pulp regeneration, among the aspects of neo-tissue area, regenerative cells, odontoblast-like ratio, and number of blood vessels.

CONCLUSION

Our study proposed that 50 ng/ml G-CSF/laponite/collagen composite has a great potential to induce SCAPs homing for immature dental pulp regeneration, providing a new strategy to treat irreversible pulpitis in immature teeth.