[Effects of enamel matrix proteins loaded in chitosan thermosensitive hydrogel on bone marrow stromal cells in vitro].

Purpose: To investigate the effects of enamel matrix proteins (EMPs ) on proliferation, alkaline phosphate (ALP) activity of bone marrow stromal cells (BMSCs) seeded on the scaffold of chitosan thermosensitive hydrogel.

Methods: Chitosan thermosensitive hydrogel was prepared and its slow-releasing effect of EMPs was checked by coomassie blue staining kit. Rat BMSCs were obtained from rat bone marrow aspiration and cultured in DMEM medium with 10% fetal bovine serum (FBS). Rat BMSCs were exposed to various concentrations of EMPs (0,50,100 and 150 microg/mL) and their proliferation rates were assessed by MTT assay. The proliferation rates and ALP activity of rat BMSCs were examined by MTT assay and ALP kit when BMSCs cultured on the scaffolds of chitosan thermosensitive hydrogel loading with or without 100 microg/mL EMPs .The data was statistically analyzed with SPSS11.0 software package for a parametric one-way analysis of variance (ANOVA) and two-sample t test.

Results: The release of EMPs in chitosan thermosensitive hydrogel lasted for more than 3 weeks. In DMEM medium, 50 microg/mL EMPs significantly enhanced BMSCs proliferation from day 3 over the experiment(P<0.01). In chitosan thermosensitive hydrogel scaffolds loading 100 microg/mL EMPs, both the proliferation at day 3 and 5 (P<0.05)and the ALP activity at day 7 (P<0.05) and 9(P<0.01) of BMSCs in the experiment were promoted.

Conclusion: EMPs loaded on the chitosan thermosensitive hydrogel exhibits significant effects on proliferation and ALP activity of rat BMSCs.