Apolipoprotein B-100-targeted negatively charged nanoliposomes for the treatment of dyslipidemia.

BACKGROUND

Anionic nanoliposomes can interact with serum lipoproteins and regulate lipid metabolism through several mechanisms. This study aimed to evaluate the lipid-modifying effects of anionic immunoliposomes targeted against apoB, an important component of atherogenic lipoproteins.

METHODS

Two sets of nanoliposomes (20mM) were prepared with low (including soy phosphatidylcholine [SPC] and egg phosphatidylglycerol [EPG]) and high (including hydrogenated soy phosphatidylcholine [HSPC] and distearoyl phosphatidylglycerol [DSPG]) phase transition temperature values without cholesterol. In each set, the anionic phospholipid (EPG or DSPG) constituted 75% of total phospholipid content. Immunoliposomes were prepared by conjugating a monoclonal antibody against apoB-100 to the liposomal surface using a post-insertion technique. Fluorescently-labeled immunoliposomes were assessed for their uptake by J774.A1 macrophages. Lipid-modifying effects of immunoliposomes were tested at different doses (50, 100 or 200μmole/g weight) using a tyloxapol-induced hyperlipidemic mouse model. Blood sampling was performed 1h after the injection of each immunoliposomal formulation.

RESULTS

ApoB-targeted HSPC/DSPG and SPC/EPG nanoliposomes were both taken up by cultured macrophages but the uptake rate was higher with the former formulation. Both immunoliposomal formulations significantly reduced serum LDL-cholesterol concentrations of hyperlipidemic animals at all tested doses (p<0.001) and this effect lasted for at least 48h. Significant reductions of serum levels of apoB, non-HDL-C, total cholesterol and triglycerides, and elevations of HDL-C levels were also observed.

CONCLUSION

Intravenous injection of a single dose of apoB-targeted anionic nanoliposomes improves serum lipid profile parameters. These findings might have implications for the treatment of patients with severe dyslipidemias or statin intolerance.