Fig. 2

In vitro anti-biofilm activity of Ti-PDA@SNP-OGP with or without NIR irradiation. a. Representative images of MRSA colonies in agar plates from each group with or without NIR irradiation. b Elimination efficacy of MRSA biofilms based on the results of agar plates in each group. c Scanning electron microscopy (SEM) images of MRSA biofilms from each group withor without NIR irradiation. Scale bar = 2 μm. Red arrows indicate the damaged cell membranes. d ROS FL intensity of MRSA from each group by DCFH-DA probe under NIR irradiation. e Relative FL intensity of MRSA under various conditions by NPN fluorescent probe, polymyxin B was used as the positive control. The fluorescence intensities of the experimental groups were normalized to that of pristine Ti without NIR irradiation. f Relative ATP intensity of MRSA in each group measured with a fluorescence spectrophotometer. The relative fluorescence intensity of the experimental groups was obtained by normalizing the fluorescence intensity to that of pristine Ti without NIR irradiation. g ONPG hydrolysis of MRSA from each group using a spectrophotometric microplate reader. ^**P < 0.01; Ti titanium, PDA polydopamine nanoparticles, SNP sodium nitroprusside, OGP osteogenic growth peptide, NIR near-infrared light, MRSA methicillin-resistant Staphylococcus aureus scanning, ROS reactive oxygen species, DCFH-DA 2′,7′-dichlorofluorescein diacetate, NPN 1-N-phenylnaphthylamine, FL fluorescence, ATP adenosine triphosphate, ONPG o-nitrophenyl-β-D-galactopyranoside