The Biocompatibility Evaluation And The Applied Study Of A New Phospholipid Polymer And Zein

We studied a new phospholipid polymer and a native protein——zein, and the final objectives of this work were to prepare the coatings for cardiovascular devices (e.g. stent), and the three-dimensional porous scaffolds for bone tissue engineering. We made the research on the blood compatibility and cell compatibility about both materials, designs of the three-dimensional zein porous scaffolds and active nano zein porous scaffolds, and the heterotopic ossification ability of the porous scaffolds. The results showed that the better cell compatibility and hemocompatibility of the new phospholipids polymer were main due to the suitable hydrophilic properties and the nano-structure with 20-45 nm diameters of round and elliptical vesicles on its surface. The slow-releasing drug from the heparin-loaded zein microsphere film made the blood anticoagulable, and the anticoagulable period could be maintained 10 days. In addition, the proliferation of human umbilical vein endothelial cells could be prompted by zein and its degraded product with suitable content. Therefore, the heparin-loaded zein microsphere film had potential applications as a new biomaterial coating for cardiovascular devices. The three-dimensional zein porous scaffolds were prepared through a compression molding-salt leaching method, which had better spacial structure and the excellent mechanical properties that is lacking in other native organic macromolecule materials. The scaffolds were characterized by porosities 60%-80%, macropores of 150-450μm of, the compressive strength of 2-12 MPa, and the compressive modulus of 50-110 MPa. Especially, the scaffold didn’t affect the functions of bone mesenchymal stem cells. The implantation of zein porous scaffolds in subcutaneous and muscle indicated the better tissue compatibility, the biodegradability was finished in 3-8 months, and there appeared abundant new blood vessels and bone. We also fabricated dexamethasone-zein microspheres porous scaffolds by ices-freeze drying method, which were characterized by porosities ranging from 44.37±8.99% to 80.25±3.67%, the compressive strength of 9.9±3.1MPa, and the compressive module of 65.3±12.1MPa. In vitro, the degradability and dexamethasone slow-release of the active scaffolds could be finished in 26 days under the effect of pepsin, and keep linear without burst-release. And the composite of cell and the scaffolds was implanted in the muscle of rats; histochemistry and immunochemistry assays indicated the obvious osteogenic activity.