Biopolymers

Zein is the major storage protein of corn and comprises 40-50% of total endosperm proteins. Zein has been used as microspheres to delay the release of drugs and to protect the drugs from degradation by pepsin, thus can release the drugs for a long time. Our laboratory has developed zein as a novel and potential biomaterial for tissue engineering. Firstly, a three-dimensional zein porous scaffold was prepared and showed to be suitable for culture of various cell lines and primary cells such as human umbilical vein endothelial cells (HUVECs) and mesebchymal stem cells (MSCs) in vitro. The scaffolds are characterized with interconnected pore, controllable pore sizes, especially excellent mechanical properties, which are controllable and suitable to act as bone substitutes (Biomaterials 2004, 2005, 2006, J. Control Rel., 2005). Next, we examined its tissue compatibility in a rabbit subcutaneous implanting model, the histological analysis revealed a good tissue response and degradability. The third, zein porous scaffolds modified with fatty acids have shown great improvement in mechanical properties and also good cell compatibility in vitro (Biomaterials 2007). Besides, the complex of zein porous scaffold and mesenchymal stem cells (MSCs) could effectively promote the ectopic bone formation in nude mice and the repair of critical-sized bone defects in the rabbit model (Biomaterials 2009).