Preparation And Characterization Of Zein-based Nanoparticle As The Anti-oxidation Drug Delivery System

Natural antioxidants,which are widely distributed in vegetables and fruits,act as protective agents in response to the oxidative stress in human bodies,and show great potential in preventing numerous chronic diseases,e.g.cancers,cardiovascular diseases,etc.However,poor solubility,instability or low bioavailability hinder the application of antioxidants.In this work,to overcome the limitation of antioxidants,two novel antioxidant delivery systems were prepared by using resveratrol?RES?as the model drug,and zein as the basic carrier material,where polydopamine?PDA?and casein or zwitterion surfactant lecithin were used for the further modification on the surface of zein particles.The first antioxidant delivery systems was zein-PDA-casein nanocomposites?ZPCs?loaded with RES?RES-ZPCs?,which were prepared by phase separation technology.The surface of zein particles was firstly modified with polydopamine?PDA?,and then coated with casein,forming stable colloidal particles against environmental stresses including pH,salinity,storage and UV irradiation.Compared with free RES,the antioxidant activity of RES-ZPCs enhances approximately 5-fold for DPPH assay and 2.5-fold for ABTS assay.Meanwhile,cellular H₂O₂ scavenging assay of RES-ZPCs presents 100%exogenous reactive oxygen species elimination,whereas free RES eliminates only 63.5%.In vitro cell uptake and cytotoxicity assay show that ZPCs can be uptake and exhibit nontoxic on the cell proliferation.This concept of combining polyphenols and PDA with self-antioxidative property and stability may provide new insights into designing highly active,stable polyphenol delivery systems.Although RES-ZPCs present great stability and antioxidant activity,mucus and epithelium barriers of intestinal tract will hinder its absorption in oral process.Thus,the lecithin was selected for the further modification of zein-PDA nanocomposites?ZPLs?with the encapsulation of RES?RES-ZPLs?.The results show that ZPLs are very stable in the simulated gastrointestinal environment,such as acidic pH,neutral pH and salinity.Meanwhile,RES-ZPLs shows lower degradation rate and higher antioxidative activity during the long time storage.More importantly,due to the coating of lecithin,RES-ZPLs exhibit higher mucus permeability,which changes the surface charge and decreases the absorption between particles and mucins.These results suggest that ZPLs are potential materials for oral delivery of antioxidants.