Research On Polyelectrolyte/polyurethane/decellularized Stent Vascular Patch

Tissue engineering blood vessel is based on the methods of tissue engineering to construct,which has strong compatibility and biomechanical properties,close to living blood vessels.The biological research range vascular scaffolds,seed cells and construction of tissue-engineered blood vessels.The current study focus on the research of vascular scaffolds.Decellularized vascular matrix material,as a kind of decellularized scaffold,can effectively avoid the occurrence of antigenicity and avoid the defects of other materials so that it has become a research hotspot in the field of organization stent in recent years.Polyurethane has been widely applied in the biomedical materials due to their excellent mechanical properties and good biological compatibility.Chitosan is a natural cationic weak alkaline polysaccharide with good biocompatibility and biodegradable,as contact materials which would promote blood clotting response.However the blood clotting response isn't suitable for some situation sometimes,so many research is going to efforts to modify the chitosan in order to improve its blood compatibility.Heparin,which is a negative natural anionic polysaccharide,could form polyelectrolyte complex with chitosan by electrostatic interactions.So heparin is commonly used to improve the blood compatibility chitosan.Tissue vascular stent coating and layer by layer self-assembly technology on modified decellularized scaffolds were used in the experiment,and discussed characteristic of the modified product.The main research contents are as follows:Using the synergistic effects of sodium dodecyl sulfate and TritonX-100 to obtain acellular materials and characterize the prepared decellularized scaffold by HE staining and immunohistochemistry,results show that the structure of vessel wall cells and endothelial cells have been successfully removed;The polyurethane was coated onto the decellularized scaffold by coating method.The results of X-ray photoelectron spectroscopy,material surface amino content determination and scanning electron microscopy(SEM)showed that polyurethane was successfully modified onto the decellularized scaffold;Layer by layer self-assembly technology is used to make the heparin and chitosan by electrostatic force between the molecules of polyelectrolyte on the modification to the polyurethane/decellularized scaffold.In an attempt to characterize the mechanical properties,blood compatibility and cell compatibility test and so on were performed on the obtained polyelectrolyte/polyurethane/decellularized scaffold vasculature.The experimental results showed that the mechanical performance of material was not affected but the blood compatibility and cytotoxicity have been improved;The polyelectrolyte/polyurethane/decellularized scaffold was implanted into the body of experimental small suckling pig.B-test and doppler experimental results show that without the use of anticoagulants the blood in the vascular patch implantation site can flow smoothly.This suggests that the polyelectrolyte/polyurethane/decellularized vascular patch have the function of the alternative to normal blood vessels...