Strategies of stabilization of zein nanoparticles containing doxorubicin hydrochloride

Hybrid nanoparticles made up of zein and various stabilizers were developed and characterized. In detail, a zein concentration of 2 mg/ml was blended with various amounts of different phospholipids or PEG-derivatives in order to obtain formulations with suitable physico-chemical properties for drug delivery purposes. Doxorubicin hydrochloride (DOX) was used as a model of a hydrophilic compound and its entrapment efficiency, release profile and cytotoxic activity were investigated. Photon correlation spectroscopy showed that the best formulations were obtained using DMPG, DOTAP and DSPE-mPEG2000 as stabilizers of zein nanoparticles, which were characterized by an average diameter of ~100 nm, a narrow size distribution and a significant time- and temperature-dependent stability. The interaction between protein and stabilizers was confirmed through FT-IR analysis, while TEM analysis showed the presence of a shell-like structure around the zein core. The release profiles of the drug from the zein/DSPE-mPEG2000 nanosystems, evaluated at two pHs (5.5 and 7.4), showed a prolonged and constant leakage of the drug. The encapsulation of DOX within zein/DSPE-mPEG2000 nanosystems did not compromise its biological efficacy, demonstrating the potential application of these hybrid nanoparticles as drug carriers.