Preparation Of Chitosan-based Injectable Nanocomposite Gel And Its Study On Tissue Engineering Vascularization

Tissue engineering for organ damage and tissue defect treatment i has a good prospect in the field of biomedical science.The current clinical application is limited to the implanted tissue and cannot achieve tissue vascularization,resulting in tissue implantation failure.Vascularization is a key factor to affect the result of tissue engineering implantation..The study on the impact of biological materials on the process of vascularization and the development of vascularized scaffold material is a big challenge fortissue engineering Many studies have shown that the three-dimensional structure of the material,surface properties and growth factor releasing behavior can significantly affect angiogenesis process.Therefore,in view of the above problems,three-dimensional porous hydrogel scaffolds were prepared by using the methods of medical and materials science,and the growth factor was encapsulated by nanoparticles.The factors were used to promote the blood vessels through the double release of nanoparticles and gel Process.The main contents of the paper are as follows:(1)The nanoparticles were prepared by the electrostatic action of chitosan(CS)and fucoidan(F).C5F5 and C2F5 nanoparticles were identified by measuring the Zeta potential,PDI and particle size.Infrared results show that nanoparticles are effectively manufactured,and the nanoparticles C5F5 and C2F5 were loaded with VEGF and SDF-1,The C5F5-SDF-1 and C2F5-VEGF nanoparticles were obtained and selected by measuring the Zeta potential,PDI,particle size and other parameters.Successful implementation of factor load,transmission electron microscopy showed that nanoparticles are spherical shape withsize range of 50?200nm.(2)Preparation of injectable thermosensitive hydrogel with chitosan(CS)/?-glycerophosphate(GP)/gelatin(G).The gel time,dynamic viscoelasticity,rheological properties and gel morphology and cell growth behavior were determined.The results showed that CS/GP/G hydrogel had temperature sensitivity,and the gel time could be adjusted by the volume ratio of CS and GP.The concentration of CS/GP was 5:1 at 37?.At the same time SEM electron microscopy showed that the hydrogel was porous network structure with pore size of 20?50?m.Cell behavior studies showed that the gel had no cytotoxicity and the cells were rounded on the surface of the three-dimensional gel.(3)The release of factor(VEGF/SDF-1)in different carriers was determined by ELISA.The results showed that the release of nanoparticles in the hydrogel was more stable than that of the hydrogel as a slow release carrier.The chemotaxis of bone marrow mesenchymal stem cells(MSC)was significant.CCK-8 results showed that cell viability remained stable after encapsulation of MSC by three-dimensional gel.At the same time,post-slice HE staining showed that embedding could achieve uniform distribution of cells within the material.(4)The establishment of blood vessel model of chicken chorionic villus and the preliminary application in the evaluation of vascularization of tissue engineering scaffold were explored.In this paper,the study explores the possibility of promoting vascularization in stent applied in tissue engineering from the perspective of slow and stable release of growth factors in order to solve the problem of tissue engineering vascularization.