Study On Different Methods To Graft RGD On PET Surface And Their Biocompatibility

This article is the part of "Recognizable Molecular Mode on the Polymer Materials Surface Cell and Study on the mechanism of Endothelialization." And it is a Nature Science Fund Project.Polyethylene terephthalate (PET) was widely used in many field, but its bio-compatibility limited it was used in many field, such as biomaterial. Cardiovascular system have higher requirement on biomaterials which be used as substitute. The material must not only have suitable physical capability, but also have good bio-capability. Traditionally, artificial cardiovascular material trend to happen complement activation and blood coagulation when it was exposed to blood. Complement activation and blood coagulation will induce thrombus directly or indirectly. Finally, they result in failure of implant material and the complication will threaten the patient's life. Therefore it has been an important subject in the materials study to improve the blood compatibility of cardiovascular materials.Arg-Gly-Asp (RGD) is the minimum ammonia serial on the ligand, which can be recognized by most of the integrins, a kind of Cell Adhesion molecule. Connectthe RGD serial on the materials surface, integrin, which comes from membrane, one of the cell adhesion molecule (CAM) on the cell surface, combines with RGD on the materials surface through ligand-acceptor. It can to some extent help the cell adhesion, spreads, grow, and finally mix to layers on the materials surface. Cell layers with biological activities form on the material surface which can promote the blood compatibility of the biomaterials.Three methods were employed to graft RGB on material. The first way was grafting crylic acid on PET film, and intRGDucing RGD on -COOH. Second way was grafting 4-azidobenzoic acid on PET film, and intRGDucing RGD on -COOH. Third way was grafting Az-RGD. After RGD was intRGDuce on surface, endothelial cells were attached to compare their bio-compatibility. 4-azidobenzoic acid and RGD peptide were reacted with EDC, and photoreactive azidophenyl group was intRGDuced on RGD peptide. TLC trail the reaction and separate Az-RGD, and best reactive condition was chosen. UV graft Az-RGD on PET film, and analyze elements of the surface with XPS. And IR analysis also shows RGD was grafted. Microscope and SEM observed endothelial cells on material, and MTT confirmed that RGD could enhance attachment and growth of endothelial cells.Three kinds of material grafted RGD were used to plant endothelial cells. Results show that PET grafted Az-RGD have the best bio-compatibility. It was proved that the material could enhance attachment and growth of endothelial cells. And the material can be cover with endothelial membrane that can enhance its blood compatibility.