Fig. 1 a Preparation process of Zn/PDA/ CS-C coating; b Fourier infrared spectra of CS, PDA and CS-C; c ultraviolet-visible spectrograms of CS and CS-C; d Fourier infrared spectra of different samples; e Fourier infrared spectra of each sample in the range of 1500-1700 cm−1; f, g and h represent the surface topography of samples Zn-3 h, Zn/PDA, Zn/PDA/CS-C-24 h and EDS analysis

Fig. 2 a Contact angle diagram and b quantitative analysis of different samples

Fig. 3 a Potentiodynamic polarization curves; b Nyquist plots of different samples; Bode plots c and phase angles d of different samples, with solid lines showing the fitting results (equivalent circuit diagram e); f schematic diagram of corrosion mechanism

Fig. 4 a The amount of Zn2+ and b Ni2+ released from different samples

Fig. 5 a SEM morphologies of S.aureus cultured at 37 °C for 12 h in different samples; b optical photographs of S.aureus cultured at 37 °C on AGAR plates; c antibacterial rates of different samples, *p < 0.05, **p < 0.01

Fig. 6 a Qualitative results of hemolysis tests; b quantitative results of hemolysis tests, *p < 0.05, **p < 0.01

Fig. 7 a Fluorescent images of cytoskeleton (green) and nucleus (blue); b fluorescent images of osteoblasts after 1, 3 and 5 days of culture; c MTT results of osteoblasts after 1, 3, and 5 days of culture. *p < 0.05, **p < 0.01

Fig. 8 a Absorbance values; b antioxidant rate; c and d quantitative results of cell proliferation of normal and H2O2-stimulated osteoblasts; e intracellular ROS fluorescence images of osteoblasts (staining ROS with DCFH-DA); f quantitative analysis of DCFH-DA mean fluorescence intensity of internal ROS of cells on each sample, *p < 0.05, **p < 0.01, ***p < 0.001

Fig. 9 Qualitative images a ALP activity; b collagen secretion and c ECM mineralization; quantitative results d collagen secretion and e ECM mineralization, *p < 0.05, **p < 0.01, ***p < 0.001