Formulating plant-based hexosomes for the sustained delivery of food proteins

Hexosomes (HEXs) are nanoparticles formed by dispersing a lipid reverse hexagonal phase in water. Although they have attracted a great interest in the development of delivery systems, few lipids have been employed in their production. Galactolipids, especially monogalactosyldiacylglycerol (MGDG), are the main lipid constituents of plants and can be obtained from vegetal biomass, making them good candidates for the obtention of HEXs. In this work, the aqueous phase behavior of MGDG from sweet potato leaves was investigated and the resulting hexagonal phase was downsized into HEXs with the aid of stabilizer decaglycerol monooleate (DGMO), a foodgrade emulsifier from vegetable oils. The nanoparticles presented enhanced long-term colloidal stability in different storage conditions and their inner liquid crystalline structure could be tuned by the amount of DGMO employed. Moreover, by adding sodium oleate (NaO) HEXs displayed enhanced loading efficiency of lysozyme, an edible protein with biological properties. Finally, the sustained release of incorporated protein could be finely tuned by changing HEXs composition. Collectively, the results demonstrate, for the first time, the viability of producing biobased, renewable sourced galactolipid hexosomes with potential applications in the development of functional foods, also contributing to a sustainable management of biomass waste.