TPGS-based and S-thanatin functionalized nanorods for overcoming drug resistance in Klebsiella pneumonia.

Tigecycline is regarded as the last line of defense to combat multidrug-resistant Klebsiella pneumoniae. However, increasing utilization has led to rising drug resistance and treatment failure. Here, we design a D-alpha tocopheryl polyethylene glycol succinate-modified and S-thanatin peptide-functionalized nanorods based on calcium phosphate nanoparticles for tigecycline delivery and pneumonia therapy caused by tigecycline-resistant Klebsiella pneumoniae. After incubation with bacteria, the fabricated nanorods can enhance tigecycline accumulation in bacteria via the inhibitory effect on efflux pumps exerted by D-alpha tocopheryl polyethylene glycol succinate and the targeting capacity of S-thanatin to bacteria. The synergistic antibacterial capacity between S-thanatin and tigecycline further enhances the antibacterial activity of nanorods, thus overcoming the tigecycline resistance of Klebsiella pneumoniae. After intravenous injection, nanorods significantly reduces the counts of white blood cells and neutrophils, decreases bacterial colonies, and ameliorates neutrophil infiltration events, thereby largely increasing the survival rate of mice with pneumonia. These findings may provide a therapeutic strategy for infections caused by drug-resistant bacteria.