Preparation And Properties Of Organic-inorganic Hybrid Materials For Cardiovascular Scaffolds

The extremely high mortality rate of cardiovascular diseases has always been a problem in modern medicine.Surgical transplantation has always been the most effective method for treating cardiovascular diseases,and the degradable stent material in the vascular substitute required for transplantation of blood vessels is one of the most promising tissue engineering scaffold materials.The ideal cardiovascular stent,especially the preparation and clinical application of small-diameter(internal diameter <6 mm)cardiovascular stent materials has attracted much attention.However,there are some deficiencies in the preparation process or clinical application of small diameter cardiovascular scaffold materials,such as difficult to endothelial change quickly,easy to form the blood clots.Therefore,a new type of organic-inorganic hybrid cardiovascular stent is needed to solve this medical problem of small diameter blood vessels.According to the research content,the experiment is divided into 2 stages.Firstly,the organic-inorganic hybridization composite small-diameter vascular tissue engineering scaffolds were prepared using sol-gel method using homemade precursors(CYC)and ?--(2,3-epoxypropoxy)propytrimethoxysilane(GPTMS)as raw materials,and carries on the characterization test and cell compatibility evaluation test.The experimental results show that CYC and GPTMS can be well combined and the organic-inorganic hybrid composites formed have a micron-sized microporous structure.Human umbilical vein endothelial cells(HUVECs)can grow,proliferate and differentiate on this composite.CYC/GPTMS hybrid scaffolds can be used as an alternative material for tissue engineering cardiovascular stents.However,in the process of culturing cells,it was found that the compatibility of HUVEC and organicinorganic hybrid composite material is insufficient,and further modification of the material is required.Secondly,the vascular tissue engineering scaffold prepared in the previous stage is blended and modified.We select two blend systems,organic blends and inorganic blends.Some features such as hydrophilicity,biocompatibility and low interaction with blood components should be taken into account when introducing organic components.Polyethylene glycol(PEG)and carbon nanomaterials were selected for organic and inorganic hybrid modification of the system to form special organic and inorganic composite scaffold materials.Low-molecular-weight polyethylene glycol 600(PEG)and multi-walled carbon nanotubes(MWCNTs)were respectively introduced into the precursor of the hybrid substrate,and two sets of composite tissue engineering scaffold substrates were prepared by sol-gel blending method.The scaffold substrates are tested by observing the microstructure of the blended materials,determining the thermal stability and swelling properties,comparing the compatibility of the introduced components with the substrate.The test results show that the inorganic blending system is superior to the organically modified system.The organic-inorganic blended modified materials were evaluated for cell compatibility.And the effects of surface hardness and porous structure on the morphology and adhesion behavior of umbilical vein endothelial cells(HUVECs)were compared.The experimental results show that after the introduction of the organic components PEG600 and MWCNTs in the original hybrid scaffold,the microstructure of the blended material does not change significantly,the blending system achieves thermodynamic compatibility,and the swelling rate increases with the amount of introduced components.The highest increase was 13.1% and 8.1%;HUVECs were well-proliferated and well-differentiated on the blended materials.The introduction of organic and inorganic components promoted the endothelialization of the cells to a certain extent.The modified scaffold material is more suitable for tissue engineering.Diameter vascular stent.