Fabricating pectin and chitosan double layer coated liposomes to improve physicochemical stability of beta-carotene and alter its gastrointestinal fate.

To improve storage stability and gastrointestinal (GI) stability of liposomes, pectin and chitosan double layer coated liposome (P-C-L) was proposed and optimized using electrostatic deposition technique. The physical-chemical properties and GI fate of the carrier were then investigated in comparison to that of chitosan coated liposomes (C-L) and un-coated liposomes (L). The results showed P-C-L was successfully prepared at 0.2 % chitosan and 0.06 % pectin. It was hydrogen bonds between the amino groups in chitosan and liposomal interfacial region, and the interaction between the carboxyl groups in pectin layer and amino groups in chitosan layer maintained the structure of P-C-L after absorption by electrostatic interaction. The double layer coatings could improve chemical stability of the encapsulated β-carotene (βC), as well as the thermal stability of liposomes. What's more, the permeability of liposomal bilayers and βC release mechanism in simulated GI fluids was changed by the polymer coating. P-C-L exhibited better controlled release for βC than C-L and L, and displayer beneficial effect on delivering bioactive agents passing through intensity tract. This may assistant developing more efficient delivery system for bioactive agent.