Anticoagulation And Modification Of Silk Fibroin Material

Cardiovascular disease has become a big threat to human health, the problem ofthrombosis formation of artificial blood vessels in clinical application has become thefocus of attention. Some researchers have studied the preparation of artificial blood vesselswith synthetic polymer materials, but they are easy to thrombosis when used for smallcaliber (≤6mm) vascular grafts. Silk fibroin is a natural biological material, has betterbiocompatibility compared with synthetic polymer materials. For the application of silkfibroin in artificial blood vessels, the anticoagulant property of the regenerated silk fibroinmaterials and hirudin modified materials were studied.Dacron and polytetrafluoroethene (PTFE) are commonly used for preparatingartificial blood vessels. In the study, Dacron and PTFE were parallel studied as the controls,the anticoagulant property of ethanol treated SF films was studied. Hemolysis rate testsshowed that hemolysis rate of ethanol treated SF films was lower than Dacron and PTFE.The SEM photographs and platelet adhesion ratios showed that platelet adhesion ratios ofethanol treated SF films were significantly less than that of the control samples, the plateletactivation measures also proved this conclusion; recalcification time assay showed time ofethanol treated SF films was slightly lower than that of Dacron and PTFE.The use of crosslinking agent is a kind of important method for preparating waterinsoluble regenerated silk fibroin material. Polyethylene glycol diglycidyl ether (PEG-DE)is a flexible polymer and can improve the flexibility of regenerated silk fibroin material,the anticoagulant property of PEG-DE crosslinked SF materials was studied. Hemolysisrate tests showed that hemolysis rate of PEG-DE crosslinked SF films was slightly higherthan that of ethanol treated SF films; SEM photographs showed that platelet adhesionamount increased along with the increase of content of PEG-DE, platelet adhesion ratiosand activation measures showed that platelet adhesion ratios and activation increased compared with ethanol treated SF films; recalcification time assay showed that time ofPEG-DE crosslinked films increased, compared with ethanol treated SF films.In order to improve the anticoagulant property of regenerated silk fibroin materials,especially PEG-DE crosslinked silk fibroin materials, anticoagulant property of hirudinmodified silk fibroin materials were studied. Hemolysis rate results showed that damage ofred cells was not obvious when hirudin was added; platelet adhesion tests showed thatplatelet adhesion amounts decreased significantly compared with PEG-DE crosslinked andethanol treated SF films, along with increase of content of hirudin; recalcification timeassay showed that time increased with the increase of the content of hirudin. Studyindicates that anticoagulant property of hirudin modified PEG-DE crosslinked regeneratedsilk fibroin materials enhances.