▎ 摘　　要

A single functional coating is far from enough to meet the high requirements of complex bone microenvironments for titanium (Ti)-based implants. In this study, multilayered polydopamine (PDA)/graphene oxide (GO)/type I collagen (Col I) (PGC) nanofilms on the basis of bioinspired design make it possible to develop a versatile, personalized, and biocompatible Ti-based implant. The nanofilms were successfully prepared by layer by layer (LBL) self-assembly of PDA, GO, and Col I, which was confirmed by surface physical and chemical characterization. In vitro biological assessments demonstrated the outstanding biological properties of PGC nanofilms coated Ti substrates, including enhanced protein adsorption, excellent biocompatibility, and accelerated osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Importantly, the more layers of PGC nanofilms were, the more significant osteogenic differentiation of rBMSCs was. In addition, PGC nanofilms displayed a powerful capacity of controllably releasing bioactive substances. And the encapsulated amount and release rate of bioactive substances (e.g., silver (Ag) ions and bovine serum albumin (BSA)) could be precisely controlled by the layer number of PGC nanofilms. The work provides a fairly feasible approach for developing a multifunctional bioactive coating on the surfaces of Ti-based implants.