Involved In The Treatment Of Surface Blood Compatibility Modification

The hemocompatibility still exists as a main challenge in the field of interventional medical devices. Getting the inspiration from modern bionics, the work aimed to figure out the difficulties concerning the biocompatibility of interventional medical devices through the "biomembrane mimicry" technique. Three novel surface modification methods were developed to improve the blood compatibility of interventional medical devices:First, the methacryloyloxyethyl phosphorylcholine (MPC) were attached onto the aminolysised stents by the Michael reaction to mimic the anti-thrombogenicity of the cell membrane. The experimental result showed that the bio-mimic surface has good stability. The plasma recalcification time (PRT) and platelet adhesion indicated that biomimic modification evidently improved the hemocompatibility of stents. Similarly, PC groups also incorporated covalently onto poly(ethylene terephthalate)(PET) surfaces via the ring-opening reaction between COP and trimethamine, which successfully produced good hemocompatible surface by mimicking bio-membrane. The modification proved to improve the hemocompatibility of PET.Second, the bio-inert multilayer membrane containing external cell matrix (ECM) was fabricated onto 316L stainless steel and PET via the layer-by-layer assemble of alginate and chitosan. The glutaraldehyde was employed to cross-link the multilayer membrane to improve its stability. The result of contact angle and confocal laser scanning microscopy (CLSM) confirmed the improvement of its stability. The MPC was then incorporated onto the multilayer by Michael reaction to enhance its hemocompatibility.Third, the macromonomer PEG is polymerized on PET surface by atom transfer polymerization (ATRP) to optimize its hemocompatibility. The surface-initiated polymerization was proved by contact angle, AFM and XPS. The modification contributed to the hemocompatibility of PET. The terminal hydroxyl groups of polymer brushes were supposed to be very useful for end-tethering ligand.The dissertation is carried on by the above three routes to design the bio-mimic and bio-inert surface to enhance the hemocompatibility of interventional medical devices. The experimental results indicate that these designations are available and valuable for research of hemocompatibility.