{Reference Type}: Journal Article {Title}: High-performance lung-targeted bio-responsive platform for severe colistin-resistant bacterial pneumonia therapy. {Author}: Cheng D;Tian R;Pan T;Yu Q;Wei L;Liyin J;Dai Y;Wang X;Tan R;Qu H;Lu M; {Journal}: Bioact Mater {Volume}: 35 {Issue}: 0 {Year}: 2024 May {Factor}: 16.874 {DOI}: 10.1016/j.bioactmat.2024.02.017 {Abstract}: Polymyxins are the last line of defense against multidrug-resistant (MDR) Gram-negative bacterial infections. However, this last resort has been threatened by the emergence of superbugs carrying the mobile colistin resistance gene-1 (mcr-1). Given the high concentration of matrix metalloproteinase 3 (MMP-3) in bacterial pneumonia, limited plasma accumulation of colistin (CST) in the lung, and potential toxicity of ionic silver (Ag+), we designed a feasible clinical transformation platform, an MMP-3 high-performance lung-targeted bio-responsive delivery system, which we named "CST&Ag@CNMS". This system exhibited excellent lung-targeting ability (>80% in lungs), MMP-3 bio-responsive release property (95% release on demand), and synergistic bactericidal activity in vitro (2-4-fold minimum inhibitory concentration reduction). In the mcr-1+ CST-resistant murine pneumonia model, treatment with CST&Ag@CNMS improved survival rates (70% vs. 20%), reduced bacteria burden (2-3 log colony-forming unit [CFU]/g tissue), and considerably mitigated inflammatory response. In this study, CST&Ag@CNMS performed better than the combination of free CST and AgNO3. We also demonstrated the superior biosafety and biodegradability of CST&Ag@CNMS both in vitro and in vivo. These findings indicate the clinical translational potential of CST&Ag@CNMS for the treatment of lung infections caused by CST-resistant bacteria carrying mcr-1.