Antimicrobial Peptides and Proteins for Inhalation

Antimicrobial peptides and proteins (APPs) are gaining attraction as powerful agents against multidrug-resistant bacteria. The inhalation delivery of APPs has emerged as a potent tool for treating respiratory infections, given the ability to achieve high local drug concentrations in the lungs and minimizing systemic exposure. This chapter reviews recent in vitro and in vivo research on inhaled APPs, focusing on APP modification and formulation strategies to develop stable and inhalable forms of APPs. These strategies include using d-enantiomers, dendrimers, and prodrugs as APP modification strategies and applying new nebulizers, spray drying, and hydrogel techniques as formulation strategies. Despite the substantial progress in enhancing the biological activity of APPs, the biological stability of these novel molecules when aerosolized is yet to be further explored. Similarly, the formulation and production of inhalable liquid and powder formulations of APPs remain relatively unexplored. These domains are, however, critical for successful clinical translation and hence deserve further research efforts.