Mechanical Matching 3D-printed GelMA/SA/Gelatin Artificial Vessel And Study On Restenosis Of Loaded GSNO

Small-diameter artificial vessels(diameter < 6 mm)can be used to treat coronary atherosclerosis,arteriovenous shunt and other diseases,which has great clinical demand.However,currently,small-caliber artificial vessels generally collapse due to mechanical properties mismatch with natural vessels,easily induce thrombosis and lead to collapse and restenosis,which seriously hinder their clinical application.Therefore,it is particularly urgent to develop small-caliber artificial vessels to prevent restenosis.Nitric oxide(NO),as an endogenous molecule,plays an important role in preventing thrombosis and restenosis,but it is seldom used in the study of restenosis.Based on this,in this study,a Gel MA/SA/Gelatin bio-ink with mechanical properties matching natural blood vessels was prepared by double-cross-linking technology,and NO sustained-release small-caliber artificial blood vessels were obtained by loading nitroso glutathione(GSNO),combined with 3D printing technology.The antithrombotic and restenosis effects were investigated.The main research contents of this paper are as follows:In this study,the photoresponsive Gel MA was compounded with Sodium Alginate(SA)and Gelatin,and then the printing conditions were explored by optimizing the preparation conditions and screening the ratio of raw materials.Gel MA/SA/Gelatin artificial vessels with different thickness and thickness and adjustable mechanical properties were prepared successfully.By optimizing the mechanical properties of printed artificial blood vessels,a small diameter artificial blood vessel matching the mechanical properties of natural blood vessels was obtained.The results showed that when Gel MA was 5 w/v%,SA was 4 W /v% and riddle was 3 w/v%,the radial tensile breaking strength,elongation at break and bursting pressure of the artificial vessels were 2.0±0.03 MB,673.5±3.83% and 1.04±0.01 MPa,respectively.The radial compliance was 8.41±0.31 %100mm Hg,close to the saphenous vein.By co-culture with endothelial cells,the results showed that the material was beneficial to the adhesion of endothelial cells,and the cell activity was good,and it could promote the proliferation of vascular endothelial cells.The results of plasma calcium enrichment and dynamic coagulation experiments showed that the activation of endogenous coagulation factors in Gel MA/SA/Gelatin was low when the endogenous coagulation system was activated,which indicated that Gel MA/SA/Gelatin had certain antithrombotic properties.Through platelet adhesion experiment,scanning electron microscope results showed that the material had less adhesion of platelets on the surface,indicating that the material has anti-platelet adhesion and aggregation properties.Furthermore,in this study,different cross-linking methods were used to explore the loading conditions of GSNO.GSNO was successfully loaded in Gel MA/SA/Gelatin complex hydrogel system,and NO release kinetics tests showed that the Gel MA/SA/Gelatin-GSNO artificial vessel could steadily and sustainably release NO.On this basis,in this study,microfluidic technology was used to simulate the dynamic blood flow environment in vivo.The Gel MA/SA/Gelatin-GSNO artificial vessels were co-cultured with whole blood,and the platelet marker CD 62 and the coagulation cascade activation marker F1+2 were detected by ELISA.The mechanism of Gel MA/SA/Gelatin-GSNO artificial blood vessel against platelet activation and thrombus formation was studied.The results showed that Gel MA/SA/Gelatin-GSNO could inhibit platelet aggregation and activation by regulating CD 62,and further inhibit thrombin synthesis,and achieve the effect of anti-thrombosis and restenosis.In conclusion,the Gel MA/SA/Gelatin printed small-caliber artificial blood vessels prepared in this study match the natural blood vessels in terms of tensile strength,elongation,bursting pressure and compliance,can promote the adhesion and proliferation of vascular endothelial cells,load GSNO,stable and sustained-release NO,and resist platelet adhesion and activation.The mechanism is related to the downregulation of the expression of platelet marker protein CD 62 and the protein F1+2 that activates the coagulation cascade.Therefore,Gel MA/SA/Gelatin-GSNO has good antithrombosis and anti-restenosis performance.This study provides a new idea and method for solving the problem of small diameter artificial blood vessel restenosis.