TS41 is a trisulfide-derived ionizable lipid engineered for lipid nanoparticles (LNPs) to deliver mRNA therapeutics against multidrug-resistant bacterial pneumonia. Its optimized formulation, TS41S LNP, combines TS41 with helper lipids (e.g., DOPE, cholesterol) at a precise ratio, achieving a hydrodynamic diameter of ~105 nm, low polydispersity, and high mRNA encapsulation efficiency (~84%). This design enables efficient pulmonary delivery via intratracheal administration, with luminescence signals in lungs 4.8-fold higher than clinical benchmarks like SM-102 LNPs, ensuring targeted expression in epithelial cells, macrophages, and neutrophils. Crucially, TS41 LNPs exhibit potent anti-inflammatory properties by scavenging reactive oxygen species (ROS), reducing neutrophil infiltration and proinflammatory cytokines (e.g., IL-6, TNF-α) in infected lungs. In preclinical models, TS41S LNP encoding PB9 peptibody mRNA eradicated pathogens like Staphylococcus aureus and Pseudomonas aeruginosa, improved survival rates to 80%, and minimized tissue damage without systemic toxicity. Its ROS-scavenging capability synergizes with antibacterial effects, offering a promising, translatable platform for combating resistant infections while controlling inflammation. Future enhancements, such as codon optimization or inhalation delivery, could further broaden its therapeutic potential.