Protein colloidal nanoparticles (NPs) are ubiquitous present in nature and function as building blocks with multiple functions in both food formulations and biological processes. Food scientists are inspired by naturally occurring proteins to induce self-assembly behavior of protein by manipulating environmental parameters, providing opportunities to construct special and expected NPs. Zein and casein, the main proteins derived from corn and milk, are two examples of the most prevalently studied food proteins for nanoarchitectures in recent years. In this article, the compositions, structures, and physicochemical properties of these two proteins and casein derivatives are summarized as well as their interactions and characterizations. Strategies to fabricate zein-sodium caseinate based NPs are critically highlighted and illustrated. Particularly, applications such as encapsulation and delivery of bioactive compounds, producing food packaging for enhanced antioxidative and antimicrobial effects, and stabilization of emulsions to achieve fat replacement. Due to the imperative role of food proteins in diet composition, this review not only provides cutting-edge knowledge for nanoparticle construction but also opens new avenues for efficient utilization and exploitation of food proteins.

Oral administration of nutrient/drug is the most common and preferred route. However, a number of barriers are encountered after ingestion, limiting efficient oral nutrient/drug absorption. Both lipid-based (e.g., nanoemulsion, solid lipid nanoparticles) and polymer-based (e.g., protein and polysaccharide nanoparticles) nanoscale delivery systems have demonstrated capability to overcome some of these physiological barriers during transportation and metabolism stages. To better deal with those barriers, polymer-lipid complex nanoparticles are being explored and developed to merge the beneficial features and overcome the respective shortcomings of lipid-based and polymer-based nanoparticles. This paper aims to provide an overview of the various preparation strategies and supramolecular interactions of orally administered polymer-lipid complex nanoparticles by reviewing recent studies. Two types of polymer-lipid complex nanoparticles have been developed, i.e., lipid core with polymer shell nanoparticles and polymer core with lipid shell nanoparticles (lipid-polymer hybrid nanoparticles). Besides, both natural and synthetic polymers used for fabrication are discussed and their advantages and disadvantages are highlighted. Further research work is needed to optimize the fabrication and scaling up processes, so that these versatile polymer-lipid complex nanoparticles could have a significant impact on the oral delivery of nutrient/drug.