Zein- vs PLGA-based nanoparticles containing rutin: A comparative investigation

In the last few decades, several natural and synthetic polymers have been used as starting material for the development of innovative polymeric nanoparticles able to encapsulate biologically active substances and to modulate their biopharmaceutical features and/or therapeutic efficacy. This investigation focused on the comparison of the physico-chemical properties of nanosystems made up of two of the most successfully used biodegradable biomaterials, namely poly(lactic-co-glycolic acid) (PLGA) and zein, belonging to the synthetic and natural family of polymers, respectively. Rutin, a polyphenolic bioflavonoid characterized by peculiar antioxidant properties, was chosen as the model drug to be encapsulated in the polymeric systems. The results demonstrated a greater ability of zein-based nanosystems to effectively retain the active compound with respect to the PLGA particles. The integration of rutin in the protein matrix favored a controlled drug leakage, and was influenced by the surfactant used to stabilize the formulation. Moreover, rutin-loaded zein nanoparticles showed significant in vitro antioxidant activity, evidencing a synergistic action between the intrinsic antioxidant activity of the protein and the pharmacological properties of the active compound. Finally, the intracellular localization of the zein nanosystems was demonstrated through confocal laser scanning microscopy.