Chondroitin sulfate and chitosan-coated liposomes as a novel delivery system for betanin: Preparation, characterization and in vitro digestion behavior

Betanin, a water-soluble pigment known for its high bioactivity, is hindered by pH and temperature sensitivity, weak ionic strength, and low bioavailability. In this study, nanoliposome (NPS), chitosan-coated NPS (CNPS), and chondroitin sulfate-chitosan bilayer-modified nanoliposomes (SCNPS) were prepared based on a layer-bylayer electrostatic interaction method for betanin encapsulation. The increase of polymer layers from NPS to SCNPS led to a monotonic increment from 223.57 to 522.33 nm in size, from -27.73 to 16.70 mV in negative charge and from 0.22 to 0.35 in polydispersity index. The chemical stability against pH (ranging from 2 to 10), ionic type (KCl, CaCl2, ALCl3) and ionic strength (100, 500 mM) significantly impacted the appearance and particle size of the double-layered nanoliposome. In vitro digestion experiment showed that SCNPS displayed higher stability and slower betanin release compared to NPS and CNPS. This study demonstrates that betanin can be efficiently encapsulated by SCNPS with improved stability and bioavailability.