Nanotopographical polymeric surface with mussel-inspired decoration to enhance osteoblast differentiation

Abstract Simultaneous existence of topographic and chemical cues on the polymeric surface was demonstrated to be a valid route to accelerate osteoblast differentiation. Herein, nanotopographical pattern and bioactive components were sequentially introduced onto the poly( l -lactic acid) (PLLA) surface via etching treatment followed by mussel-inspired polydopamine (PDA) coating. The PLLA nanolamellae were formed on nanotopographical surface with the roughness of 62.0 nm by extracting the amorphous phase of annealed PLLA. Subsequently, uniform PDA decoration was obtained on the etched surface without changing the surface roughness via dopamine self-polymerization. In vitro cell culture revealed that the combination of nanolamellae and PDA decoration showed more significant promotion of cell viability, alkaline phosphatase activity, osteopontin, and collagen type I expression than only using nanolamellae or PDA decoration. The enhanced osteoblast differentiation was mediated by the integrin β1 signaling pathway. Our proposed approach opens a simple, universal, and promising gateway to construct polymeric surface with comprehensive cues for enhancing osteogenic differentiation.