Development of a glomerular specific targeted nanoparticles for lupus nephritis

Abstract

Lupus nephritis requires immunosuppressive therapy, which unfortunately, are associated with severe side effects. Thus, development of new treatment strategies which minimize the side effects while maintaining high therapeutic efficiency is essential. Perfluorocarbon (PFC) nanoparticles (NPs), with a nominal size of ~200 nm, are primarily limited to intravascular space. Collagen IV (col4) expresses in the glomerular basement membrane (GBM), where is the only place that col4 has direct contact with blood via fenestrated capillary endothelium. Accordingly, we designed a novel col4‐targeted NPs by coupling PFC NPs with amine‐carboxyl to a col4‐targeting ligand, which selectively target glomeruli by binding to col4 of GBM.The binding specificity and efficiency of the col4‐targeted NPs were evaluated on col4 surface, in vitro and in vivo. First, rhodamine labeled col4 targeted or non‐targeted PFC NPs were applied in col4 pre‐coated 96 wells plate at stepwise doses (1, 2, 5, 10 and 20 ul/ml). The binding affinity was determined by fluorescence intensity with IVIS. The wells incubated with col4 targeted PFC NPs showed a dose dependent fluorescence in radiant efficiency e10 (0.37 ± 0.03, 0.51 ± 0.05, 1.33 ± 0.07, 2.38 ± 0.19, 2.71 ± 0.28) (n=5, p<0.01 vs non‐targeted NP). Second, to evaluate the targeting properties in vitro, 1 μl/ml rhodamine labeled col4 targeted or non‐targeted NPs were applied on mouse primary glomerular endothelial cells and mouse primary mesangial cells for 2 h at 37°C. At the same confocal imaging settings, significant cellular uptake of the col4 targeted NPs was visualized, while it was not detectable in the cells incubated with non‐targeted NPs (n=3). Then, to evaluate the targeting properties in vivo, C57BL/6 mice were administered i.v. with 100 μl rhodamine labeled col4 targeted or non‐targeted NPs. At 24 hours after injections, col4 targeted NPs were selectively visualized at glomeruli in kidney sections, while non‐targeted NPs were barely detectable anywhere (n=3).Furthermore, the therapeutic effect of the col4 targeted NPs loaded with prednisone for lupus nephritis was evaluated in MRL‐lpr mice, a lupus‐prone animal model. The prednisone loaded col4 targeted NPs (1 ml/kg) were intravenously injected in MRL‐lpr mice (male, 8 weeks old) twice a week for 8 weeks. Compared with untreated animals, MRL‐lpr mice receiving therapeutic NPs exhibited less glomerular deposition of IgG (142±25 vs.193±18) and C3 (28±11 vs.41±13) evaluated by intensity of immunofluorescence (n=5, p<0.05 vs control), decreased proteinuria (54±17 vs.82±21 mg/dl) measured by with MultistixTM dipsticks (n=6, p<0.05 vs control), a better preservation of GFR (157±16 vs. 118±12 ml/min) assessed by clearance of plasma FITC‐inulin after a single intravenous bolus injection (n=6, p<0.01 vs control), and reduced glomerular pathology (1.3±0.8 vs. 2.4±0.6) evaluated by scoring 50 glomerular cross sections per kidney with periodic acid‐Schiff stain (n=5, p<0.05 vs control).In conclusion, we developed novel NPs that selectively target glomeruli by binding to col4 of GBM, which provide a novel tool to achieve precise therapeutics with minimum side effects for lupus nephritis.Support or Funding InformationNIH: DK099276 DK098582 HL137987 DK102691 AR067491 HL073646‐08ASN Fellowship Awards AHA: 18CDA34110441This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.