Poly (β-amino esters)-based biodegradable polymers were able to deliver a plasmid that encodes full-length CFTR in murine lungs and CFBE41o- cell lines expressing wt-CFTR or ΔF508 (Suk et al., 2014), as well as to penetrate in freshly expectorated mucus from CF patients (Mastorakos et al., 2015). This evidence concerns the gene CFTR and cystic fibrosis.