Nintedanib and miR-29b co-loaded lipoplexes in idiopathic pulmonary fibrosis: formulation, characterization, and in vitro evaluation

Objective This study was aimed to develop a cationic lipoplex formulation loaded with Nintedanib and miR-29b (LP-NIN-miR) as an alternative approach in the combination therapy of idiopathic pulmonary dibrosis (IPF) by proving its additive anti-fibrotic therapeutic effects through in vitro lung fibrosis model.Significance This is the first research article reported that the LP-NIN-MIR formulations in the treatment of IPF.Methods To optimize cationic liposomes (LPs), quality by design (QbD) approach was carried out. Optimized blank LP formulation was prepared with DOTAP, CHOL, DOPE, and DSPE-mPEG 2000 at the molar ratio of 10:10:1:1. Nintedanib loaded LP (LPs-NIN) were produced by microfluidization method and were incubated with miR-29b at room temperature for 30 min to obtain LP-NIN-miR. To evaluate the cellular uptake of LP-NIN-miR, NIH/3T3 cells were treated with 20 ng.mL-1 transforming growth factor-β1 (TGF-β1) for 96 h to establish the in vitro IPF model and incubated with LP-NIN-miR for 48 h.Results The hydrodynamic diameter, polydispersity index (PDI), and zeta potential of the LP-NIN-miR were 87.3 ± 0.9 nm, 0.184 ± 0.003, and +24 ± 1 mV, respectively. The encapsulation efficiencies of Nintedanib and miR-29b were 99.8% ± 0.08% and 99.7% ± 1.2%, respectively. The results of the cytotoxicity study conducted with NIH/3T3 cells indicated that LP-NIN-miR is a safe delivery system.Conclusions The outcome of the transfection study proved the additive anti-fibrotic therapeutic effect of LP-NIN-miR and suggested that lipoplexes are effective delivery systems for drug and nucleic acid to the NIH/3T3 cells in the treatment of IPF.