[Effects of electrospun collagen nanofibrous matrix on the biological behavior of human dental pulp cells].

OBJECTIVE

To compare cell adhesion, proliferation and odontoblastic differentiation of human dental pulp cells (hDPCs) on electrospun collagen nanofibrous matrix (Col_NFM) with that on collagen flat film (Col-FF), to investigate the biological effect of collagen nanofibrous matrix on hDPCs.

METHODS

The surface morphology of the two different collagen scaffold was analyzed by scanning electron microscopy (SEM), and the contact angle and the swelling ratio were also measured. Then hDPCs were implanted on the two different collagen scaffolds, the cell morphology was observed using SEM and laser scanning microscope (LSM), and cell proliferation was evaluated by the CCK-8 assay. After hDPCs cultured on the two different collagen scaffold with odontoblastic medium for 14 days, the expression of odontoblastic differentiation related genes was detected by real-time PCR, and alizarin red staining was used to test the formation of mineralized nodules.

RESULTS

From the SEM figures, the fibers' diameter of Col_NFM was (884±159) nm, and there were abundant three dimensional connected pore structures between the fibers of Col_NFM, while the surface of Col_FF was completely flat without pore structure. The contact angle at 0 s of Col_NFM was 85.03°±4.45°, and that of Col_FF was 98.98°±5.81°. The swelling ratio of Col_NFM was approximately 3 folds compared with dry weight sample, while that of Col_FF was just 1 fold. Thus Col_NFM indicated better hydrophilicity and swelling property. SEM and LSM showed that hDPCs on Col_NFM presented an irregular and highly branched phenotype, and could penetrate into the nanofibrous scaffold. In contrast, the cells were spread only on the surface of Col_FF with a spindle-shaped morphology. CCK-8 assays showed that hDPCs on Col_NFM showed higher proliferation rate than on Col_FF. After hDPCs were cultured on the two different collagen scaffolds with odontoblastic medium for 14 days, more expressions of odontoblastic differentiation related genes, such as dentin sialophosphoprotein (DSPP) and dentin matrix proten-1 (DMP1) were determined in Col_NFM group (P<0.05), and more mineralization depositions were also observed in Col_NFM group according to the results of alizarin red staining.

CONCLUSION

Col_NFM with nanoscale microstructure achieves better hydrophilic and swelling properties than Col_FF, and hDPCs cultured with Col_NFM present higher activity on cell adhesion, proliferation and odontoblastic differentiation.