Cu2Se/Bi2S3 nanocomposites as chemodynamic and photothermal agents for synergetic antibacterial therapy

Cuprous oxide–demethyleneberberine nanospheres for single near-infrared light-triggered photoresponsive-enhanced enzymatic synergistic antibacterial therapy

“…The ability of Cu 2 O–DMB nanospheres to serve as a Fenton-like agent for peroxidase-like activity is needed to be studied by using 3,3′,5,5′-tetramethylbenzidine (TMB), which can be oxidized by ˙OH with a maximum absorption at 652 nm. 48 As presented in Fig. 3a, a remarkable UV-vis absorption peak increase at 652 nm for the TMB + Cu 2 O–DMB + H 2 O 2 group suggests that the Fenton-like reaction occurs and ˙OH is generated.…”

pH-Responsive Nanogel for Photothemal-Enhanced Chemodynamic Antibacterial Therapy

“…Twenty milligrams of SF and STF nanogels were dispersed into 20 mL of PBS buffer (pH 5.5) and stirred for 30 min in the absence or presence of an 808 nm laser light (1.0 W cm −2 ), respectively. One milliliters of the suspension was taken out at different time points (5,10,15,20,25, and 30 min) and centrifuged at 8000 rpm for 5 min to obtain the supernatant. Next, 800 μL of the above supernatant and 800 μL of L-ascorbic acid (20 mM) were mixed and the mixture reacted for 12 h at room temperature.…”

“…Considering that bacterial resistance is caused by the overuse and misuse of conventional antibiotics, the exploitation of nonantibiotic antibacterial treatments has been proved to be a feasible strategy to alleviate this tough issue, including chemodynamic therapy (CDT) and photothermal therapy (PTT). − Profiting from the acidic bacterial infection microenvironment containing overexpressed hydrogen peroxide (H 2 O 2 ), CDT could lead to the efficient inactivation of bacteria by the generated toxic hydroxyl radicals (·OH) via Fenton or Fenton-like reactions without inducing bacterial resistance. , Unfortunately, further application of CDT is severely limited by the inherent insufficient efficiency of Fenton or Fenton-like reactions, which is attributed to the normal body temperature range and the inadequate supply of Fe 2+ ions at the infected site. Coincidentally, the local temperature could be significantly raised to facilitate CDT through near-infrared (NIR)-mediated PTT, which could convert light energy into thermal energy with high efficiency to kill bacteria via destructive damage to the cell wall and denaturation of proteins. − Consequently, synergistic PTT/CDT has been increasingly employed to achieve an enhanced CDT for antibacterial treatment. − Meanwhile, chelating or reductive agents, which could act as an extra source of Fe 2+ ions through continuous release or persistent reduction from as-formed Fe 3+ ions, were utilized to strengthen CDT. , Apparently, further improved antibacterial therapeutic efficiency of CDT could be realized in one platform by the combination of PTT and a sufficient supply of Fe 2+ ions as dual-augmentation strategies.…”