Bioinspired Crystallization of Continuous Calcium Phosphate Films on a Langmuir Monolayer of Zein Protein: Their Mechanical Performance, Hydrophilicity, and Biocompatibility

Abstract

In this article, zein, a major protein of corn, has been used as biomimetic mineralization template to synthesize calcium phosphate by a bioinspired approach. A zein Langmuir monolayer, formed by self-assembling nanoglobules, is used to induce the mineralization of calcium phosphate at the air–liquid interface of the 10 times concentrated simulated body fluid. After biomimetic mineralization, zein films are covered with continuous minerals, grown from a small, curved morphology to straight, flake-like morphology, which are a mixture of dicalcium phosphate dehydrate and hydroxyapatite. With the continuous calcium phosphate incorporation, the modulus and hardness of mineralized zein films are enhanced to 11.6 and 0.32 GPa, higher than the values of pure zein films. The hybridization of inorganic minerals decreases the water contact angles from about 63° to 20°. The higher mechanical properties and hydrophilic properties could endow a friendly environment for fibroblast cells attachment, spread, and proliferation. These results suggested that the biomimetic mineralized zein film could serve as a new biomimetic scaffolds for bone tissue engineering.