Bacterial infections and antibiotic resistance have become a global healthcare crisis. There is an urgent need to develop visualized therapeutic platforms that allow accurate imaging of the bacterial infections, successful eradication of bacteria and real-time monitoring of treatment progress. In this work, we report a novel NIR imaging and synergistic antibacterial nano-system ( [email protected] ) for resistance bacterial infection therapy. The multifunctional nano-system is fabricated by a MIL-101 core, which is covalently connected with Vancomycin and modified with targeted antimicrobial peptides LL-37 on the surface. The ability of monitoring the progress of infection treatment and effective promoting wound healing of bacterial infection are proved by in vivo MRSA -infected mice models. Under the environment of endogenous H 2 O 2 overexpression and slightly acid bacterial infection, the excellent Fenton-like reaction activity of [email protected] could effectively catalyze the decomposition of H 2 O 2 to produce hydroxyl radicals (•OH), which trigger highly efficient chemo-dynamic therapy (CDT) and tissue protection effect. By combining CDT with antibacterial peptides and antibiotics therapy, special targeting and synergistic killing of MRSA are successfully achieved in in vitro and in vivo antibacterial assays with excellent biocompatibility. Due to this, this study proposes a novel, high-efficient, multifunctional imaging and therapy system, which will open a new avenue for the design of synergistic antibacterial and diagnostic platforms in the future.
Shue Jin,Renli Yang,Chen Hu,Shiqi Xiao,Yi Zuo,Yi Man,Yubao Li,Jidong Li
The regeneration of oral tissues is a challenging clinical problem because of the complex microbial and biological stress environments. Electrospun fibrous scaffolds have attracted significant interest as effective barrier membranes for guided bone regeneration (GBR); however, no mature strategy yet exists for the surface modification of fibers to provide versatility to satisfy clinical requirements. This study demonstrated a practical biosafety strategy: the combined use of plant polyphenols and LL-37 peptides to modify the fiber surface to endow the fibrous scaffold with antimicrobial activity, immunoregulation, and vascularized bone regeneration. We confirmed that the LL-37 peptides interacted with tannic acid (TA) through noncovalent bonds through experiments and molecular docking simulation analysis. In vitro experiments showed that the TA coating imparted strong antibacterial properties to the fibrous scaffold, but it also caused cytotoxicity. The grafting of LL-37 peptide promoted the spreading, migration, and osteogenic differentiation of mesenchymal stem cells and was also conducive to the M2 polarization of RAW264.7 cells. In vivo experiments further verified that the LL-37 peptide-grafted fibrous scaffold significantly enhanced angiogenesis, anti-inflammatory effects, and type-H vascularized bone regeneration. Overall, the fibrous scaffold modified by the LL-37 peptide through TA grafting has significant potential for GBR applications.
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