SIHSP47-NP

Lipid nanoparticles (LNPs) have shown promising potential in the development of nucleic acid therapeutics and vaccines; however, unsatisfactory endosomal escape efficiency and physiological stability hinder their clinical applications. Herein, we design and synthesize a novel topologically engineered cyclodextrin-cored lipid (cyclolipid) featuring seven tertiary amine groups, seven secondary amine groups, and 14 hydrophobic alkyl tails to fabricate two-component supramolecular cyclolipid nanoparticles (CNPs). Benefiting from its cone-shaped structure, the cyclolipid facilitates the transition of endosomal membranes from the lamellar phase to the unstable hexagonal II phase, thereby promoting membrane destabilization and endosomal escape of CNPs. Additionally, the high density of ionizable sites enhances the binding capacity with RNA, while multiple hydrophobic alkyl chains strengthen the stability of CNPs, thus guaranteeing the in vivo circulation stability. Interestingly, the cavity of the cyclolipid enables the encapsulation of pirfenidone (PFD, an antifibrotic drug) through host-guest interactions, offering a promising strategy for synergistic therapy. Rationally optimizing the components and physicochemical properties of CNPs dramatically promotes mucus penetration capability, thereby enhancing their bioavailability in the lungs and avoiding unwanted side effects toward other organs. Leveraging their exceptional ability for achieving physiological stability, mucus penetration, and endosomal escape, siRNA targeting heat shock protein 47 (siHsp47) and PFD are codelivered by CNPs (CNPs@siHsp47/PFD) for the treatment of pulmonary fibrosis. CNPs@siHsp47/PFD synergistically alleviates pulmonary fibrosis, achieving therapeutic outcomes comparable to those of healthy mice, highlighting the outstanding potential of CNPs as the next-generation delivery platform for drug and gene combination therapy.

In chronic hepatic diseases where treatment strategies are not available, deposited fibrotic tissues deteriorate the intrinsic regeneration capacity of the liver by creating special restrictions. Thus, if the anti‐fibrosis modality is efficiently applied, the regeneration capacity of the liver should be reactivated even in such refractory hepatic diseases.

Rat liver fibrosis was induced by dimethyl‐nitrosamine (DMN). Another liver fibrosis model was established in CCl4 treated Sox9CreERT2ROSA26: YFP mice. To resolve hepatic fibrosis, vitamin A‐coupled liposomes containing siRNA HSP47 (VA‐liposome siHSP47) were employed. EpCAM + hepatic progenitor cells from GFP rats were transplanted to DMN rat liver to examine their trans‐differentiation into hepatic cells after resolution of liver fibrosis.

Even under continuous exposure to such strong hepatotoxin as DMN, rats undergoing VA‐liposome siHSP47 treatment showed an increment of DNA synthesis of hepatocytes with the concomitant restoration of impaired liver weight and normalization of albumin levels. These results were consistent with the observation that GFP + EpCAM hepatic progenitor cells transplanted to DMN rat liver, trans‐differentiated into GFP + mature hepatic cells after VA‐liposome siHSP47 treatment. Another rodent model also proved regeneration potential of the fibrotic liver in CCl4 administered Sox9CreERT2ROSA26: YFP mice, VA‐liposome siHSP47 treatment‐induced restoration of liver weight and trans‐differentiation of YEP + Sox9 + cells into YFP + hepatic cells, although because of relatively mild hepatotoxicity of CCl4, undamaged hepatocytes also proliferated.

These results demonstrated that regeneration of chronically damaged liver indeed occurs after anti‐fibrosis treatment even under continuous exposure to hepatotoxin, which promises a significant benefit of the anti‐fibrosis therapy for refractory liver diseases.