Research / 2020 / Article / Fig 3

Research Article

Biofilm Microenvironment-Responsive Nanotheranostics for Dual-Mode Imaging and Hypoxia-Relief-Enhanced Photodynamic Therapy of Bacterial Infections

Figure 3

In vitro Ce6 releasing behavior of MBP-Ce6 NSs and photodynamic treatment of MRSA biofilms. (a) 3D CLSM images of MRSA biofilms after being incubated with MBP-Ce6 (MnO2 NSs: 100 μg/mL; Ce6: 80 μg/mL) at different times. The scale bar is 200 μm. (b) CLSM images of WPMY-1 cells after being treated with MBP-Ce6 (MnO2 NSs: 100 μg/mL; Ce6: 80 μg/mL) at different times. The green fluorescence and the red fluorescence originate from Calcein-AM and Ce6, respectively. The scale bar is 200 μm. (c) The fluorescence intensity of Ce6 after MBP-Ce6 NSs (MnO2 NSs: 100 μg/mL; Ce6: 80 μg/mL) incubated with MRSA biofilms and WPMY-1 cells at different times. (d) T1-weighted MR images of MBP-Ce6 NSs solutions with different concentrations and pH values in PBS. (e) The transverse relativities () for MBP-Ce6 NSs under different pH values in PBS. (f) 3D CLSM images of live bacteria (green fluorescence) inside MRSA biofilms after various treatments and stained with Calcein-AM. The scale bar is 200 μm. (g) The CFU number of bacteria inside MRSA biofilms after different treatments. and (two-tailed Student’s -test). (h) SEM images of MRSA biofilms treated with saline, MBP NSs (MnO2 NSs: 100 μg/mL), and MBP-Ce6 NSs (MnO2 NSs: 100 μg/mL; Ce6: 80 μg/mL) under different conditions. The scale bar is 2 μm. The concentration of H2O2 is 50 μM. The laser irradiation was carried out by using the power density of 20 mW/cm2 at 635 nm for 30 min. Error bars indicate s.d. ().