Nanoencapsulation of green tea catechins by electrospraying technique and its effect on controlled release and in-vitro permeability

Zein, a biocompatible, biodegradable macromolecule was employed for nanoencapsulation of green tea catechins by electrospraying technique. For this, the electrohydrodynamic behavior of zein solution was studied and the effective electrospraying concentration of zein was optimized. Later, the influence of nanoencapsulation and core-to-wall ratio on the gastrointestinal stability and permeability of green tea catechins were investigated. Among the various concentrations of zein studied (i.e. 1%-40% w/w), 5% w/w zein solution yielded spherical, monodisperse nanoparticles with mean diameter of 157 ± 36 nm. Nanoencapsulates with 1:50 core-to-wall ratio had highest encapsulation efficiency compared to 1:10 and 1:05 core-to-wall ratio samples. The nanoencapsulated catechins had significantly improved in-vitro gastrointestinal stability and Caco-2 cell monolayer permeability compared to unencapsulated catechins. Further, 1:50 and 1:10 samples possessed higher permeability of catechins compared to 1:05 nanoencapsulates. Hence, the study provides a one-step approach for production of green tea catechin nanoencapsulates with sustained release and enhanced permeability properties.