Chitooligosaccharide facilitated the Co-stabilization of ferritin-based dual-compartmental Pickering emulsions: The effect and contribution of chitooligosaccharide molecular weight

Abstract

Ferritin based dual-compartmental Pickering emulsions possess great potential for co-encapsulating different cargos and facilitating their synergetic functionalities. However, the poor stability of such emulsions has greatly limited their practical application. Herein, the aim of this study was to fabricated a stable dual-compartmentalized emulsion through the self-assembly of Marsupenaeus japonicus ferritin (MF) and chitooligosaccharide (COS) into robust interfacial and continuous network structure. Compared to individual MF and COS, MF/COS assemblies exhibited great amphiphilicity and were easier to adsorb onto the oil/water interface, thus generating stable emulsion even at higher oil phase fraction (70%). Moreover, the different molecular weight (1000 Da, 1500 Da, and 3000 Da) of COS significantly affected the properties of MF/COS emulsions. Specifically, COS with molecular weight of 3000 Da (COS3000) displayed the best stability against creaming and phase separation during storage and thermal treatments. Rheological analysis confirmed that COS3000 can significantly improve the viscoelasticity and anti-deformation performance of MF/COS stabilized emulsion due to the long mainchain structure. Moreover, confocal laser scanning microscopy revealed that MF/COS assemblies can not only generate the interfacial layer but also form dense continuous phase networks. Besides, a combination of UV/Vis absorption spectrometry and chemical reagent interference analysis implied that electrostatic interactions, hydrogen bonding, and hydrophobic interactions were mainly involved in the intermolecular binding between MF and COS, and COS3000 with more charges and binding sites allowed for stronger interactions with MF at the oil/water interface and continuous network, resulting in a higher emulsion stability. Overall, this work highlighted that COS can significantly facilitate the co-stabilization of ferritin-based dual-compartmental emulsions, promoting their application for the co-encapsulation and delivery of different cargos.