Ligand-free biodegradable poly(beta-amino ester) nanoparticles for targeted systemic delivery of mRNA to the lungs

Non-viral nanoparticles (NPs) have seen heightened interest as a delivery method for a variety of clinically relevant nucleic acid cargoes in recent years. While much of the focus has been on lipid NPs, non-lipid NPs, including polymeric NPs, have the possibility of improved efficacy, safety, and targeting, especially to non-liver organs following systemic administration. A safe and effective systemic approach for intracellular delivery to the lungs could overcome limitations to intratracheal/intranasal delivery of NPs and improve clinical benefit for a range of diseases including cystic fibrosis. Here, engineered biodegradable poly (beta-amino ester) (PBAE) NPs are shown to facilitate efficient delivery of mRNA to primary human airway epithelial cells from both healthy donors and individuals with cystic fibrosis. Optimized NP formulations made with differentially endcapped PBAEs and systemically administered in vivo lead to high expression of mRNA within the lungs in BALB/c and C57 B/L mice without requiring a complex targeting ligand. High levels of mRNA-based gene editing were achieved in an Ai9 mouse model across bronchial, epithelial, and endothelial cell populations. No toxicity was observed either acutely or over time, including after multiple systemic administrations of the NPs. The non-lipid biodegradable PBAE NPs demonstrate high levels of transfection in both primary human airway epithelial cells and in vivo editing of lung cell types that are targets for numerous life-limiting diseases particularly single gene disorders such as cystic fibrosis and surfactant deficiencies. [Display omitted] •Biodegradable polymeric NPs are capable of targeting and delivering mRNA to the lungs without requiring a targeting ligand.•PBAE-63 achieved 90% transfection in immortalized CFBEs and primary nasal and bronchial cells from healthy and CF individuals.•Small chemical modifications to the PBAE structure significantly enhanced lung targeting and in vivo transgene expression.•No toxicity was observed either acutely or within a 2-week window, including after up to 9 systemic administrations of NPs.•Multiple cell type transfection has high relevance for therapeutic delivery to treat CF, COPD, PPH1 and surfactant disorders.