EMPs on proliferation and attachment of BMSCs to root surfaces

Objectives: The purpose of this study was to determine which concentration do the enamel matrix proteins(EMPs)provide for optimal stimulation on the proliferation of cultured porcine bone marrow stromal cells (BMSCs).Furthermore , to investigate if the EMPs could enhance the BMSCs to adhere to the autogeneous root surfaces . Methods: BMSCs were obtained from porcine bone marrow aspiration and cultured in DMEM medium with 10% FBS.The third passage cells were exposed to various concentrations of EMPs (25,50,100 and 200ug/ml).Controls were BMSCs cultured in DMEM medium without EMPs. BMSCs proliferation rates were carried out over a 9-day period and assessed by an MTT assay.Thirty root dentine specimens were prepared from extracted teeth of three porcines and distributed into 2 groups.In the control group , BMSCs were directly cultured on the specimen surfaces.BMSCs of the experiment group were cultured on a specimen surface pretreated with EMPs at a concentration of 200ug/ml. After 72h incubation,the medium was removed, specimens were fiexed,processed for HE , SEM and photographed at 800X. BMSCs adherence was measured by counting number of cells within a standard test area. Results: It was shown that BMSCs well attached and spread on EMPs-coated substrata. The proliferation of BMSCs was significantly stimulated by EMPs in a dose- and time- dependent manner,and EMPs at a concentration of 200ug/ml significantly enhanced BMSCs proliferation from day 3 over the experiment. In specimens coated with EMPs, HE stain showed a continuous line of BMSCs on the root surface, and the SEM sanning demonstrated a highly significant increase in number of adherent BMSCs when compared to the control group(P<0.01).Conclusions: The results demonstrate that EMPs at concentration of 200ug/ml stimulate the proliferation of BMSCs and enhance the BMSCs adhere to the root surface. These findings lend theoretical support to the combined application of EMPs and BMSCs in repairing periodontal defects.