Advances in zein- based hybrid bio-nanocomposite: a short review

This paper contains synthetic approach and characterization study of bio-hybrid material based on zein. A novel zein is found as a mixture of protein complexes whose molecular size, solubility and charge depend on the corn variety and the separation method used for extraction. Zein is soluble in various primary, binary and ternary solvent systems, mainly determined by the balance between the polar/nonpolar groups in those systems. Because of the large proportion of hydrophobic residues in zein, this protein is not soluble in pure water. Due to their biocompatibility and null toxicity, bionanocomposites based on zein and conformed as beads were also investigated as slow-release systems of bioactive molecules, such as drugs. montmorillonite containing Na ions or quaternary alkylammonium cations in the interlayer region was used. By different strategies of synthesis and the use of several techniques, it was possible to investigate the zein intercalation mechanism into montmorillonite, as well as the structure and properties of the resulting zein–montmorillonite bio-hybrids. It was deduced that the intercalation processes, as well as the cation located in the interlayer region of the clay, are strongly influenced by the solvent used for zein solubilization. The resulting bionanocomposite films loaded with zein-based bio-hybrids exhibited good compatibility, homogeneity and mechanical properties. These introduced results point out that these new bio-hybrid materials prepared from different approaches could be associated with other polymers of different nature, being a promising ecological alternative to common organoclays based on alkyl ammonium cations, increasing the possibilities of research and applications in this innovative field.