posted on 2022-08-30, 00:05authored byJeonghwan Kim, Antony Jozic, Yuxin Lin, Yulia Eygeris, Elissa Bloom, Xiaochen Tan, Christopher Acosta, Kelvin D. MacDonald, Kevin D. Welsher, Gaurav Sahay
Despite lipid nanoparticles’ (LNPs) success in
the effective
and safe delivery of mRNA vaccines, an inhalation-based mRNA therapy
for lung diseases remains challenging. LNPs tend to disintegrate due
to shear stress during aerosolization, leading to ineffective delivery.
Therefore, LNPs need to remain stable through the process of nebulization
and mucus penetration, yet labile enough for endosomal escape. To
meet these opposing needs, we utilized PEG lipid to enhance the surficial
stability of LNPs with the inclusion of a cholesterol analog, β-sitosterol,
to improve endosomal escape. Increased PEG concentrations in LNPs
enhanced the shear resistance and mucus penetration, while β-sitosterol
provided LNPs with a polyhedral shape, facilitating endosomal escape.
The optimized LNPs exhibited a uniform particle distribution, a polyhedral
morphology, and a rapid mucosal diffusion with enhanced gene transfection.
Inhaled LNPs led to localized protein production in the mouse lung
without pulmonary or systemic toxicity. Repeated administration of
these LNPs led to sustained protein production in the lungs. Lastly,
mRNA encoding the cystic fibrosis transmembrane conductance regulator
(CFTR) was delivered after nebulization to a CFTR-deficient animal
model, resulting in the pulmonary expression of this therapeutic protein.
This study demonstrated the rational design approach for clinical
translation of inhalable LNP-based mRNA therapies.