Ning Ding,Bo Zhang,Imran Mahmood Khan,Mingwei Qin,Shuo Qi,Xiaoze Dong,Zhouping Wang,Junsong Yang
The prevalence of pathogenic bacterial infections with high morbidity and mortality poses a widespread challenge to the healthcare system. Therefore, it is imperative to develop nanoformulations capable of adaptively releasing antimicrobial factors and demonstrating multimodal synergistic antimicrobial activity. Herein, an NIR-activated multifunctional synergistic antimicrobial nanospray MXene/ZIF-90@ICG was prepared by incorporating ZIF-90@ICG nanoparticles onto MXene-NH2 nanosheets. MXene/ZIF-90@ICG can on-demand release the antimicrobial factors MXenes, ICG, and Zn2+ in response to variations in pH and ATP levels within the bacterial infection microenvironment. Under NIR radiation, the combination of MXenes, Zn2+, and ICG generated a significant amount of ROS and elevated heat, thereby enhancing the antimicrobial efficacy of PDT and PTT. Meanwhile, NIR excitation could accelerate the further release of ICG and Zn2+, realizing the multimodal synergistic antibacterial effect of PDT/PTT/Zn2+. Notably, introducing MXenes improved the dispersion of the synthesized antimicrobial nanoparticles in aqueous solution, rendering MXene/ZIF-90@ICG a candidate for application as a nanospray. Importantly, MXene/ZIF-90@ICG demonstrated antimicrobial activity and accelerated wound healing in the constructed in vivo subcutaneous Staphylococcus aureus infection model with NIR activation, maintaining a favorable biosafety level. Therefore, MXene/ZIF-90@ICG holds promise as an innovative nanospray for adaptive multimodal synergistic and efficient antibacterial applications with NIR activation.
Fresh fish are highly perishable because their high content of protein and unsaturated fatty acids are easily oxidized and/or degraded under the influence of bacteria and the external environment. In this study, four natural preservatives (phenyllactic acid, kojic acid , tea polyphenols and thymol) were initially screened for antimicrobial activity against spoilage bacteria commonly found in fish by in vitro antibacterial tests. The results suggested that kojic acid (KA) and tea polyphenols (TP) exhibited a strong synergistic antibacterial effect against spoilage bacteria. Hence, the effects of KA and/or TP on the preservation of refrigerated sea bass ( Lateolabrax japonicus ) fillets after soaking treatments were determined. Changes in physicochemical parameters, indexes of fish freshness and microbial enumeration were examined. KA, TP and KA-TP treatments were effective in inhibiting bacterial growth and delaying lipid oxidation in fish flesh, resulting in lower TVB-N and TBARS than the control. Meanwhile, the freshness and physical qualities (color and texture) of fish fillets were also stabilized by the three treatments. Moreover, the KA-TP treatment showed the best effect on refrigerated fish preservation among the three treatments and extended the shelf-life by 5–6 days, suggesting that KA-TP have the potential to become a compound preservative for aquatic products.