Insights into the supramolecular self-assembly of sodium caseinate and calixarene

Casein is widely used in the creation of biocompatible and functional particles, which are of interest as a delivery system based on the use of colloidal protein aggregates for the encapsulation of nutritional supplements and drugs. A very promising method for the functionalization and ordering of casein molecules is supramolecular self-assembly, which makes it possible to create nanosized materials using bottom-up approach. In this work, three-dimensional calixarene, namely the amphiphilic viologen calix[4]resorcinol, was used for the first time for spontaneous co-aggregation with sodium caseinate in an aqueous medium. A wide range of physicochemical methods were used to study the mechanisms of interaction between sodium caseinate and viologen calix[4]resorcinol, which lead to the formation of functional nanoparticles. Such nanoparticles, obtained spontaneously and without the use of organic solvents, are able to solubilize both hydrophobic (quercetin and oleic acid) and hydrophilic molecules (doxorubicin hydrochloride). In addition to encapsulating and stimulus-sensitive properties, the cytotoxic and penetrating properties of the formed nanoparticles were determined, as well as their distribution in cells.