Preparation of PDA-GO/CS Composite Scaffold and Its Effects on Biological Properties of Human Dental Pulp Stem Cells

Objective: PDA-GO polymers combining polydopamine (PDA) and graphene oxide(GO)were prepared. Combining different masses of PDA-GO with chitosan (CS) to synthesize PDA-GO/CS composite scaffolds with different mass fractions. The antibacterial and physicochemical properties of PDA-GO/CS composite scaffolds with different mass fractions were detected to screen the optimal mass fraction. Test the biocompatibility of composite scaffolds and their effects on the proliferation, migration, and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Methods: : The surface functional groups of the materials were detected using Fourier-transform infrared spectroscopy (FTIR).The optimal mass fraction for PDA-GO was screened by antibacterial experiment, observation of scaffold surface morphology and physicochemical performance test. The composite scaffolds were cultured with hDPSCs. By analyzing the biological effects on the proliferation, migration and osteogenic differentiation of hDPSCs, the biological properties of the composite scaffolds were further investigated. Results: : FTIR showed that the oxygen-containinggroups of PDA-GO reduced compared with GO, and new groups were produced in PDA-GO/CS compared with GO/CS. The count colony forming units of the 0.3% PDA-GO/CS group decreased, the pore size and porosity met the requirements of bone tissue engineering scaffolds, the swelling ratio increased, and the degradation rate decreased.The migration ability of the 0.3% PDA-GO/CS group was higher than that of the control group, while ALP staining and alizarin red staining were deeper than those of the blank control group. Real time fluorescence quantitative PCR results showed that the 0.3%PDA-GO/CS group showed an increase in osteogenic gene expression compared to the control group. Conclusions: : Successfully prepared PDA-GO/CS composite scaffold.0.3%PDA-GO/CS scaffolds improves the antibacterial activity and hydrophilicity of CS, while reducing the degradation rate. In vitro, 0.3%PDA-GO/CS has superior biocompatibility and promote the early proliferation, migration and osteogenic differentiation of hDPSCs.