Lipid-core/polymer-shell hybrid nanoparticles: synthesis and characterization by fluorescence labeling and electrophoresis.

Among the lipid nanoparticles, lipid polymer hybrid nanoparticles (HNPs) composed of an oily core and a polymeric shell display interesting features as efficient drug carriers due to the high loading capability of the oil phase and the stability and surface functionalization of the polymer shell. Herein, we formulated lipid-core/polymer-shell hybrid nanoparticles (HNPs) using a simple nanoprecipitation method involving Vitamin E Acetate (VEA) as the oily core and a tailor-made amphiphilic polymer as a wrapping shell. The fluorescence labeling of the oil, using a newly developed green fluorogenic BODIPY tracker, and of the polymer using a covalent attachment of a red emitting rhodamine was done to assess the formation, the composition and the stability of these new hybrid nanoparticles using dual color electrophoresis gel analysis. This technique, combined to conventional DLS and electronic microscopy analysis, allowed us to quickly determine that 20 wt% of the polymer was an optimal ratio for obtaining stable HNPs by nanoprecipiation. Finally, we showed that using different polymeric shells, various HNPs can be obtained and finely discriminated using a combined approach of electrophoresis and two-color labeling.