Functionalized Mn₃O₄ Nanosheets with Photothermal, Photodynamic, and Oxidase‐Like Activities Triggered by Low‐Powered Near‐Infrared Light for Synergetic Combating Multidrug‐Resistant Bacterial Infections

Abstract

Multidrug‐resistant (MDR) pathogenic bacterial infections have become a major danger to public health. Synergetic therapy through multiple approaches is more powerful than the respective one alone, but has been rarely achieved in defeating MDR bacterial infections so far. Herein, indocyanine green‐functionalized Mn3O4 nanosheets are engineered as an efficient and safe antibacterial agent with photothermal, photodynamic, and oxidase‐like activities, which display powerful ability in treating MDR bacterial infections. Therein, photothermal and photodynamic activities can be triggered by a single low‐powered near‐infrared laser (808 nm, 0.33 W cm−2), resulting in the generation of localized hyperthermia (photothermal conversion efficiency, 67.5%) and singlet oxygen. Meanwhile, oxidase‐like activity of this material further leads to the generation of hydroxyl radical as well as superoxide radical. Sheet‐like structure with rough surfaces make them tends to adhere on bacterial surface and thus damage membrane system as well as influence bacterial metabolism. As a result, Gram‐positive and Gram‐negative bacteria can both be eradicated. Animal experiments further indicate that the functionalized Mn3O4 nanosheets can effectively treat methicillin‐resistant Staphylococcus aureus‐infected wounds through the triple synergetic therapy. Moreover, toxicity evaluation in vitro and in vivo has proved the superior biosafety of this material, which is promising to apply in clinical anti‐infective therapy.

Gold-based nanostructures for efficient NIR-II photothermal conversion: hybridizing nanoplates with solid/hollow nanospheres

“…6d). 31 Compared with our previous work on in situ growth of Au quasi-spherical nanoparticles on Pt/Ag doped plate-like Au seeds, AuPtAg HSOP exhibited superior PTCE under 1064 nm laser irradiation. This is mainly due to the deposition of hollow Ag nanoparticles, which leads to the absorption loss of AuPtAg HSOP at 450 nm and the main absorption center at greater than 1100 nm, which is highly concentrated in the NIR-II region, so it has a stronger LSPR effect and better light absorption capacity.…”

Porous Silicon Carrier Endowed with Photothermal and Therapeutic Effects for Synergistic Wound Disinfection

“…The photothermal performance of a CuPPSi-based mild-temperature PTT platform was first assessed in vivo. As shown in Figure S11, after 5 min of NIR irradiation with the power density at 0.33 W/cm 2 (the American National Standard for biosafe application in vivo), 77 the wound region temperature of CuPPSi and CuPPSi-Cur was raised to ∼45 °C, while the local temperature of the PBS + NIR groups was only enhanced to ∼39 °C under the same conditions. Representative photographs of wound after different treatments on Day 0, Day 2, Day 4, and Day 7 are shown in Figure 7b and the corresponding statistical results are summarized in Figure 7c.…”

eg Occupancy as a Predictive Descriptor for Spinel Oxide Nanozymes

“…Since the report on the POD-like activity of Fe 3 O 4 nanoparticles, spinel oxides (AB 2 O 4 ) have attracted great attention due to their well-defined but tunable crystal structures (containing both tetrahedral and octahedral sites at a ratio of 1:2), which is very beneficial for regulating enzyme-like activity − and discovering predictive descriptorsparameters that indicate enzyme-like activity . Although a variety of descriptors have been reported for other catalysts (especially electrocatalysts), − the descriptors for nanozymes have rarely been identified, and no descriptors for the enzyme-like activity of spinel oxides have been reported yet.…”