A hydrogel-functionalized silver nanocluster for bacterial-infected wound healing.

The ever-growing challenges of traditional antibiotic therapy and chronic wound healing have created a hot topic for the development and application of new antimicrobial agents. Silver nanoclusters (Ag NCs) with ultrasmall sizes (<2 nm) and antibacterial effects are promising candidates for next-generation antibiotics, particularly against multi-drug resistant strains. However, the biosafety in the clinical application of Ag NCs remains suboptimal despite some existing studies of Ag NCs for biomedical applications. Considering this, an ultrasmall Ag NC with excellent water solubility was synthesized by a two-phase ligand-exchange method, which exhibits broad-spectrum antibacterial performance. The minimum inhibitory concentrations of Ag NCs against MRSA, S. aureus, P. aeruginosa and E. coli were evaluated as 50, 80, 5 and 5 µg mL-1, respectively. Furthermore, a carbomer hydrogel was prepared to be incorporated into the Ag NCs for achieving excellent biocompatibility and biosafety. In vitro experiments demonstrate that the Ag NC-gel exhibits good antibacterial properties with lower cytotoxicity. Finally, in vivo experiments suggest that this ultrasmall Ag NC functionalized with the hydrogel can serve as an effective and safe antimicrobial agent to aid in wound healing.

Ultrathin Cu9S5 Nanosheets with Sulfur Vacancy for Multimodal Tumor Therapy.

Multimodal tumor therapy with nanotechnology is an effective and integrative strategy to overcome the limitations of therapeutic efficacy and possible side effects associated with monotherapy. However, the construction of multimodal treatment nanoplatforms often involves various functional components, leading to certain challenges, such as time-consuming synthesis processes, low product yield, and inadequate biocompatibility. To address these issues, we have developed a straightforward method for preparing ultrathin Cu9S5 nanosheets (NSs) with surface defects for photothermal/photodynamic/chemodynamic therapy. The ultrathin morphology of the Cu9S5 NSs (with 2-3 nm) not only confers excellent biocompatibility but also enables broad-spectrum absorption with a remarkable photothermal conversion efficiency (58.96%) under 1064 nm laser irradiation. Moreover, due to the presence of a S vacancy, these Cu9S5 NSs exhibit favorable enzyme-like properties, including reactive oxygen species generation and glutathione consumption, particularly under laser irradiation. The efficacy of related tumor therapy and antibacterial treatment is significantly enhanced by the synergistic activation of photothermal/photodynamic/chemodynamic therapy through 1064 nm laser irradiation, as demonstrated by both in vitro and in vivo experiments. This study presents a novel strategy for multimodal tumor therapy with the prepared ultrathin Cu9S5 NSs, which holds promising pathways for photodynamic therapy in the NIR-II region.

Large-scale synthesis, mechanism, and application of a luminescent copper hydride nanocluster.

Elucidating the structure-property relationships of ultra-small metal nanocluster with basic nuclear is of great significance for understanding the evolution mechanism in both the structures and properties of polynuclear metal nanoclusters. In this study, an ultra-small copper hydride (CuH for short) nanocluster was simply synthesized with high yield, and the large-scale preparation was also achieved. Single crystal X-ray diffractometer (SC-XRD) analysis shows that this copper NC contains a tetrahedral Cu4 core co-capped by four PPh2Py ligands and two Cl in which the existence of the central H atom in tetrahedron was further identified experimentally and theoretically. This CuH nanocluster exhibits bright yellow emission, which is proved to be the mixture of phosphorescence and fluorescence by the sensitivity of both emission intensity and lifetime to O2. Furthermore, the temperature-dependent emission spectra and density functional theory (DFT) calculations suggest that the luminescence of CuH mainly originates from the metal-to-ligand charge transfer and cluster-centered triplet excited states. This work offers new insights into understanding the structure-property relationship of basic nuclear CuH nanocluster.