Zein-phosphatidylcoline mixed nanoparticles as a hydrophobic drug carrier

Introduction: Zein is an amphiphilic and hydrophobic protein obtained from corn. It use in the fields of food science and biomedicine have brought widespread interest due to its FDA “GRAS” status and ease of fabrication... [ view full abstract ]

Introduction: Zein is an amphiphilic and hydrophobic protein obtained from corn. It use in the fields of food science and biomedicine have brought widespread interest due to its FDA “GRAS” status and ease of fabrication into spherical colloidal particles. The present study was undertaken to develop zein-phosphatidylcholine mixed nanoparticles (Z/PC-NPs) in order to combine the beneficial features of both zein nanoparticles and liposomes as a hydrophobic drug carrier.

Methods: Formation of Z/PC-NPs was investigated by differential scanning calorimetry and fourier transform infrared spectroscopy analysis. Size and morphology of various nanoparticles were determined by dynamic light scattering method and negative staining transmission electron microscopy. Drug concentration loaded in various nanoparticles were determined by HPLC (paclitaxel, docetaxel and celecoxb) and fluorescence spectroscopy (curcumin). Stability of various nanoparticles during storage or after lyophilization was assessed by the changes in the mean particle size and retained drug content. Drug release profile of various nanoparticles was assessed in physiologically relevant conditions by using a docetaxel as a loaded model drug. 

Results: Formation of Z/PC-NPs were confirmed by the lowered phase transition temperature of PC by DSC analysis and the appearance of weakened but clear amide bond of zein by FTIR analysis. Z/PC-NPs were spherical particles with <200 nm mean particle size. Compared to Z-NPs and PC-NPs, Z/PC-NPs exhibited the higher drug-loading capacity in cases of all four hydrophobic drugs and the highest stability during storage and after lyophilization. The time-dependent release of docetaxel was the fastest in case of Z-PC, followed by Z/PC-NPs and the slowed in case of PC-NPs. Lyophilization-induced changes in terms of particle size and retained docetaxel content was the smallest in Z/PC-NPs regardless of cryoprotectant supplementation.

Discussion: Z/PC-NPs exhibited improved hydrophobic drug-loading capacity and colloidal stability compared to PC-NPs and Z-NPs, while exhibiting the drug release rate in the middle of PC-NPs and Z-NPs. Taken together, Z/PC-NPs has a promising potential as an effective hydrophobic drug platform dosage form.