Self-redox reaction driven in situ formation of Cu2O/Ti3C2Tx nanosheets boost the photocatalytic eradication of multi-drug resistant bacteria from infected wound

Abstract

Background MXenes with interesting optical and electrical properties have been attractive in biomedical applications such as antibacterial and anticancer agents, but their low photogeneration efficiency of reactive oxygen species (ROS) and poor stability are major concerns against microbial resistance. Methods Water-dispersible single layer Ti3C2Tx-based MXene through etching tightly stacked MAX phase precursor using a minimally intensive layer delamination method. After addition of Cu(II) ions, the adsorbed Cu(II) ions underwent self-redox reactions with the surface oxygenated moieties of MXene, leading to in situ formation of Cu2O species to yield Cu2O/Ti3C2Tx nanosheets (heterostructures). Results Under NIR irradiation, the Cu2O enhanced generation of electron–hole pairs, which boosted the photocatalytic production of superoxide and subsequent transformation into hydrogen peroxide. Broad-spectrum antimicrobial performance of Cu2O/Ti3C2Tx nanosheets with sharp edges is attributed to the direct contact-induced membrane disruption, localized photothermal therapy, and in situ generated cytotoxic free radicals. The minimum inhibitory concentration of Cu2O/Ti3C2Tx nanosheets reduced at least tenfold upon NIR laser irradiation compared to pristine Cu2O/Ti3C2Tx nanosheets. The Cu2O/Ti3C2Tx nanosheets were topically administrated on the methicillin-resistant Staphylococcus aureus (MRSA) infected wounds on diabetic mice. Conclusion Upon NIR illumination, Cu2O/Ti3C2Tx nanosheets eradicated MRSA and their associated biofilm to promote wound healing. The Cu2O/Ti3C2Tx nanosheets with superior catalytic and photothermal properties have a great scope as an effective antimicrobial modality for the treatment of infected wounds. Graphical Abstract

Intercalation and Encapsulation of In Situ Grown Black Phosphorus within Ti3C2Tx MXene Sheets for Energy Storage

“…The electric double layer (EDL) along with the contribution of redox reactions at the electrode–electrolyte interface acts from both portions. The overall charge-storage contribution is in the form of eq . , i false( V false) = K 1 false( υ false) + K 2 false( υ false) 0.5 Equation can be further written as eq . − ,, …”

“…41,42 (4) Equation 3 can be further written as eq 5. [41][42][43]53,54 The total current contribution of the combined capacitive and diffusion-controlled zones is represented by K 1 (υ) and K 2 (υ) 0.5 : (5) The slope and intercept of i(V)/υ 0.5 versus (υ) 0.5 of the plot are utilized to calculate the K 1 and K 2 . At a scan rate of 100 mV/s, Figure 7a shows the diffusion and capacitive-controlled regions of the MX−BP-10 hybrid, exhibiting a 98% capacitivecontrolled nature.…”

“…Equation 3 can be written as eq 5. [41][42][43]53,54 The total current contribution of the combined capacitive and diffusion-controlled zones is represented by K 1 (υ) and K 2 (υ) 0.5 :…”

Facilitation of Osteogenic Differentiation of hASCs on PEDOT:PSS/MXene Composite Sponge with Electrical Stimulation

“…The preparation method for the MXene nanoflakes followed a previously reported protocol. ,, The wet etching method was applied for the removal of the Al layer of the MAX phase (Ti 3 AlC 2 ) to obtain a multilayer Ti 3 C 2 T x ( m -MXene) colloidal suspension. 3g of lithium fluoride (LiF, >99.99%) was carefully dissolved in 30 mL of HCl (9 M) solution in a plastic vial.…”

“…The surface zeta potential of MXene nanoflakes was determined to be −42.4 ± 15.4 mV (Figure 2e), revealing the addition of surface functionalities such as −O, −F, or −OH (represented by T x in the formula as Ti 3 C 2 T x ) on MXene in-plane position during etching, which provides excellent water solubility (dispersibility). 40,41 In previous studies, the conductive polymer PEDOT:PSS has been recognized as a biomaterial due to its remarkable conductivity and minimal cytotoxicity. 46−48 PEDOT:PSS 3D scaffolds were made by adding the crosslinker, lyophilizing, and heating for the more robust crosslinking (Figure 3a).…”