Nanotechnology-Enabled Strategies to Overcome Antibiotic Resistance in Respiratory Infections: Mechanisms, Platforms,...

Antimicrobial resistance (AMR) in respiratory infections represents a major global health challenge, compounded by biological barriers that limit the effectiveness of conventional antibiotics, including mucus hypersecretion, biofilm formation, and intracellular pathogen persistence. Nanotechnology has emerged as a promising platform for addressing these limitations through advanced drug-delivery strategies. This narrative review provides an integrated overview of nanocarrier systems-including lipid-based (e.g., liposomes, solid lipid nanoparticles), polymeric (e.g., PLGA, chitosan), and inorganic nanoparticles (e.g., silver, gold, zinc oxide)-with emphasis on their pharmaceutical design parameters for pulmonary delivery. Key mechanisms by which nanotechnology enhances antimicrobial efficacy include targeted and controlled drug delivery, improved penetration of mucus and biofilms via surface engineering, synergistic combination therapies, and intrinsic antimicrobial activity through mechanisms such as reactive oxygen species generation. Preclinical studies targeting major respiratory pathogens, including Pseudomonas aeruginosa, Mycobacterium tuberculosis, Streptococcus pneumoniae, and methicillin-resistant Staphylococcus aureus, demonstrate enhanced biofilm disruption, intracellular drug delivery, and reductions in bacterial burden. However, important translational challenges remain, including long-term safety, manufacturing scalability, regulatory complexity, and the potential for microbial adaptation. Future directions focus on stimuli-responsive systems, inhalable formulations, and biomimetic platforms to improve targeting and therapeutic precision. Collectively, nanotechnology represents a delivery-oriented strategy with the potential to enhance existing antimicrobial therapies and support the development of more effective interventions against resistant respiratory infections.