Nanoengineered immunosuppressive therapeutics modulating M1/M2 macrophages into the balanced status for enhanced idiopathic pulmonary fibrosis therapy.

Effective treatment in clinic for idiopathic pulmonary fibrosis (IPF) remains a challenge due to low drug accumulation in lungs and imbalanced polarization of pro/anti-inflammatory macrophages (M1/M2 macrophages). Herein, a novel endogenous cell-targeting nanoplatform (PNCE) is developed for enhanced IPF treatment efficacy through modulating M1/M2 macrophages into the balanced status to suppress fibroblast over-activation. Notably, PNCE loaded with nintedanib (NIN) and colchicine (COL) can firstly target endogenous monocyte-derived multipotent cells (MOMCs) and then be effectively delivered into IPF lungs due to the homing ability of MOMCs, and detached sensitively from MOMCs by matrix metalloproteinases-2 (MMP-2) over-expressed in IPF lungs. After PNCE selectively accumulated within fibrosis foci, COL can mildly modulate the polarization of M1 macrophages into M2 macrophages to balance innate immune responses, which can enhance the suppressing effect of NIN on fibroblast activation, further improving the IPF therapy. Altogether, PNCE has two collaborative steps including the inhibition of innate immune responses accompanied by the decrease of fibroblast populations in IPF lungs, achieving a stronger and excellent anti-fibrotic efficacy both in vitro and in vivo. This endogenous cell-based engineered liposomal nanoplatform not only allows therapeutic drugs to take effect selectively in vivo, but also provides an alternative strategy for an enhanced curative effect by modulating innate immune responses in IPF therapy.