Fig. 1. Schematic illustration of the formation process on titanium surface from initial bacterial adhesion towards mature biofilms (modified from Ref. [116]). In general, the formation process includes five stages: bacterial adhesion (1-2), biofilms formation (3), biofilms maturation (4), and biofilms dispersal (5).

Fig. 2. (a) Schematic illustration of the passively periodic release of antibiotics and BMP-2 from self-assembled nanolayered coating. (b) Release kinetics of gentamicin (GS) and BMP-2. (c) In rat tibia model with induced osteomyelitis, tibial X-ray images of different implants (U and BG) after 3 weeks of implantation. (d) 3D reconstruction of new bone around different implants. (e) SEM images of new bone around BG implants. Reprinted with permission from Ref. [85]. Copyright 2016, American Chemical Society.

Fig. 3. (a) Preparation of the catechol-functionalized coating on Ti substrates (TNT@Van-LBLc) for antibacterial application. (b) Schematic illustration of preventing bacteria adhesion and simultaneously improving osteoblast adhesion on the modified Ti substrates (TNT@Van-LBLc). Reprinted with permission from Ref. [87]. Copyright 2018, Royal Society of Chemistry.

Fig. 4. (a) Schematic illustration of the constructed adaptive biointerface with sele-defensive anti-fouling while promoting cell adhesion for tissue engineering. (b) The anti-biofilms activities of the modified HEG-G-1 surfaces (aimed at gelatinase-secreting bacteria) against different species of bacteria evaluated by live/dead staining. Reprinted with permission from Ref. [31]. Copyright 2015, John Wiley and Sons.

Fig. 5. (a) Proposed bactericidal mechanisms of nanopillars on cicada wings and dragonfly wings. (b) Helium ion microscopy (HIM) image of four representative Escherichia coli attached on the surface of dragonfly wing. Reprinted with permission from Ref. [152]. Copyright 2017, American Chemical Society. (c) SEM images of bacterial morphology on flat titanium alloy surface and TiO2 nanopillar surface. (d) TEM images of TiO2 nanopillar-induced envelope deformation and penetration in S. aureus and E. coli. Reprinted with permission from Ref. [36]. Copyright 2020, Springer Nature.

Fig. 6. (a) Schematic illustration of the fabrication of a multifunctional hydrogel coating (GelMA-DOPA-AMP-SN) on Ti surface. (b) Morphologies characterization of different bacteria attached on GelMA-DOPA-SN and GelMA-DOPA-AMP-SN coatings by SEM. Reprinted with permission from Ref. [61]. Copyright 2017, American Chemical Society.

Fig. 7. (a) Preparation of DNase I-functionalized PMMA by polydopamine-mediated covalently coupling. (b) Schematic illustration of DNase I coating inhibiting biofilms formation by degrading the eDNA component of EPS. Reprinted with permission from Ref. [62]. Copyright 2013, John Wiley and Sons. (c) Preparation of DNase-mimetic artificial enzyme (DMAE) nanoparticles and schematic illustration of DMAE-modified surface inhibiting biofilms formation. (d) 3D-CLSM images of biofilms formed on different surfaces after different incubation times. The biofilms were stained with Calcein-AM. Reprinted with permission from Ref. [63]. Copyright 2016, John Wiley and Sons.

Fig. 8. Preparation of photo-triggered anti-biofilms coatings: (a) Ti-RP-IR780-RGDC and (b) Ti-MoS2-IR780-RGDC, and potential antibacterial mechanism, respectively. Reprinted with permission from Ref. [92], Copyright 2018, John Wiley and Sons, and Ref. [93], Copyright 2019, John Wiley and Sons, respectively.