Lipid nanoparticle-mediated mRNA delivery in lung fibrosis.

mRNA delivery enables the specific synthesis of proteins with therapeutic potential, representing a powerful strategy in diseases lacking efficacious pharmacotherapies. Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by excessive extracellular matrix (ECM) deposition and subsequent alveolar remodeling. Alveolar epithelial type 2 cells (AEC2) and fibroblasts represent important targets in IPF given their role in initiating and driving aberrant wound healing responses that lead to excessive ECM deposition. Our objective was to examine a lipid nanoparticle (LNP)-based mRNA construct as a viable strategy to target alveolar epithelial cells and fibroblasts in IPF. mRNA-containing LNPs measuring ∼34 nm had high encapsulation efficiency, protected mRNA from degradation, and exhibited sustained release kinetics. eGFP mRNA LNP transfection in human primary cells proved dose- and time-dependent in vitro. In a bleomycin mouse model of lung fibrosis, luciferase mRNA LNPs administered intratracheally led to site-specific lung accumulation. Importantly, bioluminescence signal was detected in lungs as early as 2 h after delivery, with signal still evident at 48 h. Of note, LNPs were found associated with AEC2 and fibroblasts in vivo. Findings highlight the potential for pulmonary delivery of mRNA in IPF, opening therapeutic avenues aimed at halting and potentially reversing disease progression.