Studies On The Inhibitory Effect Of MsFGFR2c On Pulmonary Fibrosis By Airway Administration

Since the first time in the early 1920 s when humans attempted to treat diabetes by inhaling insulin,a mode of non-invasive administration of proteins gradually appeared,which was called airway transmission.Chitosan-based nanocarriers have been widely used in drug development to improve drug efficacy.In order to improve the bioavailability of peptides and to achieve high efficiency in anti-fibrotic protein drug delivery to lungs,we intend to study the respiratory epithelial transport efficiency of chitosan nano-loaded anti-fibrotic protein msFGFR2 c and its effect on fibroblast transdifferentiation by in vitro experiments.First,msFGFR2 c was used as the loaded protein.The HTCC/msFGFR2c-NP complex was prepared by a gel ion gelation method.The Malvern Nano ZS3000 had a particle size of 201±7.5 nm,a Zeta potential of 6.3±0.27,an encapsulation efficiency of 27.63±0.47%,and a drug loading of 5.82±0.33%.Atomic force microscope and transmission electron microscopy were used to analyze the shape of the carrier nanoparticle as a smooth round or oval shape.The in vitro release curves of HTCC/msFGFR2c-NP nanoparticles in pH 7.4 and pH 5.5 solutions were detected by BCA method.The results showed that after 2 hours,the release efficiency of both reagents for drug loading were more than 40%.The drug release efficiency reached 80% within 24 hours,indicating that drug-loaded nanoparticles have a good sustained release effect.The results of the CCK8 assay showed that the nanoparticles were not toxic to human lung epithelial cells.A Transwell model of epithelial respiratory drug transport was established.The results showed that the chitosan nanoparticles can instantly open the tight junction between cells by down-regulation of the tight junction protein ZO-1,and the TEER value can recover more than 90% after 24 h,which suggested that this effect is reversible.Western blotting showed that the nanoparticles could inhibit the transdifferentiation of MRC-5 fibroblasts(Fb)to myofibroblasts(MFb)induced by TGF-?.The results of immunofluorescence showed that the extracellular domain of msFGFR2 c was mainly bound to the cell membrane surface,and the nanoparticles were easily absorbed by epithelial cells.The bleomycin-induced lung fibrosis model in Wistar rats was established.From the weight of the rats,the HE and Masssion staining of the lung tissue and the X-ray,the results showed that the HTCC/msFGFR2 c nanoparticles could significantly inhibit pulmonary fibrosis.Summing-up,HTCC/msFGFR2c-NP nanosphere particles are potential drug dosage form for the pulmonary administration of pulmonary fibrosis.