Evaluation of new amphiphilic PEG derivatives for preparing stealth lipid nanoparticles

Two novel amphiphilic conjugates of mPEG2000 and mPEG5000 carboxylic acids with a lipoamino acid as a lipid anchor (mPEG-C–LAA18), recently described as surface modifiers for drug nanocarriers, were used to decorate solid lipid nanoparticles (SLN). The SLN were produced using a suitably adapted solvent injection method (the Quasi-emulsion solvent diffusion) and, for the sake of comparison, were also prepared using a commercial phospholipid PEG derivative (DSPE–PEG) and a lipid PEG (PEG 40 monostearate), commonly used to make stealth nanocarriers. The SLN were characterized in terms of technological properties and stability in serum. An in vitro assay using murine macrophage cultures confirmed the ability of the PEG–LAA conjugates to hinder or retard the internalization of the nanoparticles by the endocytic cells.