Nanoparticles development for pulmonary vaccination: Challenges and opportunities

Pulmonary vaccination is unique immune system protection treatment for the respiratory tract. Lungs contain large surface area for interaction with antigens. Nanoparticles as efficient drug carriers have been used for pulmonary vaccination. These structures contribute to the process either by encapsulating, dissolving, surface adsorbing or chemically attaching the active ingredients. Development of pulmonary vaccines via sub-micron particles has been investigated in this study. The nanoparticles deposited on the respiratory mucus, based on their size and charge, are either locally trapped or diffuse freely. Therefore, different mechanisms of particle deposition are defined based on the particle size and surface charges. Advantages and disadvantages of nanoparticles preparation methods as they pertain to pulmonary vaccine applications are comprehensively depicted. The adverse side effects of nanoparticles encountering immune cells is also discussed. Finally, the side effects and challenges of nano-pulmonary vaccines are discussed, offering a series practical suggestion for further industrial development and manufacturing of nanoparticleempowered pulmonary vaccines.