Figure 3.

In vitro evaluation on the H₂O₂ and GSH consumption. (a) UV–Vis absorption spectra of TMB solutions treated with different groups (TMB, PLLA+TMB, CN/PLLA+TMB, CN-MnO₂/PLLA+TMB). Color variation images (insert) of TMB solutions without treatment (I) and treated with the PLLA (II), CN/PLLA (III), and CN-MnO₂/PLLA (IV). (b) Peroxidase activity of the CN-MnO₂/PLLA dressing under different pH conditions (pH = 5.5, 6.5 or 7.4). (c) Changes of H₂O₂ concentration in the solutions treated with different groups (H₂O₂, PLLA+ H₂O₂, CN/PLLA+ H₂O₂, CN-MnO₂/PLLA+ H₂O₂) over time at pH 5.5. (d) Concentration of O₂ generated in different groups (H₂O₂, PLLA+ H₂O₂, CN/PLLA+ H₂O₂, CN-MnO₂/PLLA+ H₂O₂), and O₂ bubble images in the PLLA and CN-MnO₂/PLLA groups (insert). (e) Concentration of O₂ generated from CN-MnO₂/PLLA at different pHs (5.5, 6.5 and 7.4). (f) Concentration of O₂ generated from CN-MnO₂/PLLA in different amounts of H₂O₂ (0, 2, and 4 mM). (g) Loss of GSH with blank, PLLA, CN/PLLA, and CN-MnO₂/PLLA with no light. (h) Loss of GSH by CN-MnO₂/PLLA under different light (blank, NIR, VL, dual lights) irradiation. (i) Images of the color reaction of DTNB with GSH in pore. (j) Mechanism of color reaction of DTNB with GSH. (k) Loss of GSH in blank after different treatments (blank, NIR, VL, dual lights). Loss of GSH in the bacteria S. aureus (l) and P. aeruginosa (m) grown on different groups (PLLA, CN/PLLA, CN-MnO₂/PLLA) without H₂O₂ for 30 min under dual-light (660 nm VL + 808 nm NIR) irradiation. The significant difference represent ^*p < 0.05, ^**p < 0.01, ^***p < 0.001 compare with PLLA. UV-Vis Ultraviolet-visible spectroscopy, TMB 3,3′,5,5′-Tetramethylbenzidine, PLLA poly-L-lactic acid, CN graphitic phase carbon nitride, MnO₂ manganese dioxide, pH pondus hydrogenii, H₂O₂ hydrogen peroxide, VL visible light, NIR near-infrared, GSH glutathione, GSSG oxidized glutathione, DTNB 5,5′ dithiodithio 2-nitrobenzoic acid, TNB 2-nitro-5-thiobenzoic acid, O₂ oxygen