Polymer nanoparticles deliver mRNA to the lung for mucosal vaccination
Alexandra Suberi, Molly K. Grun, Tianyang Mao, Benjamin Israelow, Melanie Reschke, Julian Grundler, Laiba Akhtar, Teresa Lee, Kwangsoo Shin, Alexandra S. Piotrowski-Daspit, Robert Homer, Akiko Iwasaki, Hee‐Won Suh, W. Mark Saltzman
Abstract
An inhalable platform for messenger RNA (mRNA) therapeutics would enable minimally invasive and lung-targeted delivery for a host of pulmonary diseases. Development of lung-targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here, we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine- co -ester) (PACE) polyplexes for mRNA delivery using end-group modifications and polyethylene glycol. These polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for severe acute respiratory syndrome coronavirus 2 and found that intranasal vaccination with spike protein–encoding mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected susceptible mice from lethal viral challenge. Together, these results demonstrate the translational potential of PACE polyplexes for therapeutic delivery of mRNA to the lungs.