Nano-encapsulation of EGCG in dextran 70-stabilized chitosan/SDS nanoparticles: Characterization, permeability behavior and oral bioavailability

Abstract

Epigallocatechin gallate (EGCG) declares massive health benefits, while poor oral absorption and susceptibility to oxidation and degradation constrained clinical applications. EGCG-encapsulated chitosan/SDS nanoparticles coated with dextran 70（EDCSNs）were here prepared by ionic interaction. The nano-formulations stabilized by dextran 70 presented sizes less than <200 nm, > 30 mV zeta potential, excellent dispersion action and higher encapsulation efficiency, which outdistanced pluronic F-68 as stabilizer. Interaction mechanism of EGCG, chitosan, dextran 70 and SDS in EDCSNs were through hydrogen bond, ion–dipole and electrostatic of opposite charge. Compared with EGCG, EDCSNs demonstrated a superior stability and retention ability with the pH-responsive protection EGCG against degradation under the simulated gastrointestinal fluids. Furthermore, EDCSNs emanated remarkably antioxidant activity and permeability through the intestinal epithelial barrier. Oral administration of nano-formulations in rats evidently increased the plasma Cmax and area under-the-curve 1.95-fold than naked EGCG. Results evidenced that EDCSNs, as a new delivery system, has great potential improvement the stability of EGCG and enhancement the oral absorption and bioavailability.