Zein nanoparticles for drug delivery: Preparation methods and biological applications

Zein, a vegetable protein extracted from corn (Zea mays L.), forms a gastro-resistant and mucoadhesive polymer that is cheap and easy to obtain and facilitates the encapsulation of bioactives with hydrophilic, hydrophobic, and amphiphilic properties. The methods used for synthesizing these nanoparticles include antisolvent precipitation/nanoprecipitation, pH-driven, electrospraying, and solvent emulsification-evaporation methods. Each method has its advantages in the preparation of nanocarriers, nevertheless, all of them enable the production of zein nanoparticles that are stable and resistant to environmental factors, with different biological activities required in the cosmetic, food, and pharmaceutical industries. Therefore, zein nanoparticles are promising nanocarriers that can encapsulate various bioactives with anti-inflammatory, antioxidant, antimicrobial, anticancer, and antidiabetic properties. This article reviews the principal methods for obtaining zein nanoparticles containing bioactives, the advantages and characteristics of each method, as well as the main biological applications of nanotechnology-based formulations.