Characterization and Properties of Solid Lipid Nanoparticles Modified with Polyethylene Glycol-2000-1, 2-Distearoyl-Sn-Glycero-3-Phosphoethanolamine

To improve the physicochemical and pharmacokinetic properties, solid lipid nanoparticles (SLNs) modified with (Polyethylene glycol-2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (PEG2000-DSPE) were prepared using glyceryl monostearate as a lipid carrier and resveratrol as a model drug. Compared to ordinary SLNs, SLNs doped with low amount of PEG2000-DSPE [m(PEG2000-DSPE):m(lipids) = 1:5, w/w] exhibited improved physicochemical and pharmacokinetic properties, including higher entrapment efficiency (above 80%), smaller particle size (approximately 100 nm), more distinguished drug release at low pH values (pH < 6.0), and longer drug circulation in vivo. According to the characterizations performed, the DSPE moiety was doped into lipid matrix to form a PEG2000-DSPE/lipid eutectic dopant, inhibiting lipid polymorphism transformation from α-form to β-form, thereby preventing drug expulsion from the lipid. The dopant contained lattice defects, allowing for the incorporation of more resveratrol. Resveratrol was released in a sustained and pH-sensitive pattern due to nanoparticles destabilization induced by partial protonation of PEG2000-DSPE. PEG chains distributed on the nanoparticle surface caused steric hindrance and “stealth” properties, thus maintaining dispersion stability and extending circulation time of nanoparticles. These results confirm that PEG2000-DSPE modification effects are attributable to the matrix and surface structures of nanoparticles, which consist of a core containing DSPEinduced lattice defects and a shell coated with PEG chains.