Preparation and characterization of paclitaxel-loaded DSPE-PEG-liquid crystalline nanoparticles (LCNPs) for improved bioavailability.

Lipid-based liquid crystalline nanoparticles (LCNPs) have attracted growing interest as a new drug nanocarrier system for improving bioavailability for both hydrophilic and hydrophobic drugs. In this study, self-assembled LCNPs based on soy phosphatidyl choline and glycerol dioleate, which was known possessing low toxicity and negligible hemolysis, were prepared using poly(ethylene glycol)-grafted 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE-PEG) as the dispersing agent. Paclitaxel (PTX) was used as a model hydrophobic drug. The particle size of the optimized DSPE-PEG-LCNPs and PTX-loaded DSPE-PEG-LCNPs were around 70nm. Crossed polarized light microscopy was used to characterize the phase behavior of liquid crystalline (LC) matrices, which showed a fan-like birefringent texture in dark background indicating the coexistence of reversed cubic and hexagonal phase in the optimized LC matrix. Transmission electron microscopy and cryo-field emission scanning electron microscopy revealed its internal water channel and "twig-like" surface morphology. PTX-loaded DSPE-PEG-LCNPs exhibited a biphasic drug sustained release pattern with a relatively fast release at the initial stage and a sustained release afterwards. PTX-loaded DSPE-PEG-LCNPs presented higher AUC (410.942±72.522μg/Lh) when compared with commercial product Taxol (212.670±41.396μg/Lh). These results indicated that DSPE-PEG-LCNPs might serve as a potential sustained release system for poorly water-soluble agents.