Combination of nanolamellae and PDA coating on promoting the long-term adhesion, proliferation, and differentiation of osteoblasts

Nanotopographical and chemical cues were collectively introduced onto the poly(L-lactic acid) (PLLA) surface via alkali etching and polydopamine (PDA) coating. The surface pattern was made of dense-packed PLLA lamellae, and the PDA coating did not change the feature of surface topography. Both nanotopographical pattern and PDA coating showed long-term stability in cell culture medium for two weeks. In vitro evaluations displayed that there was a synergy between nanotopography and PDA coating on cell adhesion, proliferation, and differentiation of osteoblasts, even for a culture period of two weeks. This sustained effect was attributed to the activation of the wnt/β-catenin pathway. These results hold a promising prospect for the application of bone repair grafts.