Preparation of polydopamine-modified PLGA porous microcarrier loaded with IGF-1 and its effect on proliferation and differentiation of MC3T3-E1 cells

Abstract

Objective To investigate the effect of polydopamine-modified poly (lactic-co-glycolic acid) (PLGA) and loaded with insulin-like growth factor 1 (IGF-1) on the material performance, and proliferation and differentiation of MC3T3-E1 cells. Methods The PLGA porous microcarriers were prepared by emulsion-solvent evaporation. The microcarriers were surface-modified with polydopamine and loaded with IGF-1. The surface morphology, surface groups and hydrophilicity of PLGA porous microcarriers were determined by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and contact angle tester before and after polydopamine modification. Lysozyme was used as the model protein, and BCA method was used to examine the protein adsorption of the material before and after the modification. PLGA microcarriers (PLGA group) , polydopamine-modified PLGA microcarriers (PD-PLGA group) and IGF-1-loaded polydopamine-modified PLGA microcarriers (PD-PLGA/IGF-1 group) were co-cultured with MC3T3-E1 cells, respectively. The effect of polydopamine-modified and IGF-1-loaded PLGA microcarriers on proliferation, adhesion and osteogenic differentiation of MC3T3-E1 cells were determined by MTT assay, DIPI staining and alkaline phosphatase (ALP) activity assay. Results Scanning electron microscopy showed that the surface of PLGA microcarriers was porous. Infrared spectroscopy analysis showed that polydopamine was successfully adhered to the surface of PLGA microcarriers. The hydrophilicity of PLGA microcarriers modified by polydopamine was greatly improved, and the adsorption capacity of surface protein was increased significantly (both P<0.05) . At 7 d after co-culture with MC3T3-E1 cells, the cell proliferation and ALP activity in the PD-PLGA group and PD-PLGA/IGF-1 group were significantly higher than those in the PLGA group (all P<0.05) . At 3 d after co-culture with MC3T3-E1 cells, DIPI staining showed that the number of adherent cells in the PD-PLGA group and PD-PLGA/IGF-1 group was higher than that in the PLGA group. Conclusion After the surface modification with polydopamine, the biological properties of PLGA porous microcarriers can be significantly improved; and loaded with IGF-1, it can significantly promote cell proliferation and osteogenic differentiation. Key words: Poly (lactic-co-glycolic acid); Polydopamine; Insulin-like growth factor 1; Microcarrier