Preparation And Properties Of Collagen/carbon Nanotube Composite Fiber Membranes

Bone tissue engineering materials generally require materials with excellent biological properties,and can also be similar to functional organs in the human body in mechanical properties and other properties.Excellent bone tissue engineering materials generally have good biological activity and degradation performance,and can also exert bone conduction and osteoinductivity during bone repair.More and more materials can be used clinically to repair or even replace human organs.With the development of science,more and more bone tissue engineering materials have appeared.Collagen,as a natural polymer material,is very easy to obtain and has good biological properties.Therefore,more and more biological materials using collagen as raw materials,such as skin dressings,biomimetic blood vessels,bone scaffolds and so on.The collagen nanofiber membrane or scaffold prepared by electrospinning can imitate the structure and composition of the extracellular matrix and is an excellent bone tissue engineering material.However,its mechanical properties have always been the focus of people's research,usually by compounding other materials to solve this problem.Carbon nanotubes have excellent mechanical properties,and studies have shown that carbon nanotubes are very worthy of research in the field of biomaterials.Because carbon nanotubes have excellent osteoinductivity,they can induce osteogenic differentiation of cells.For the above reasons,this article will use collagen(Col)as a substrate to prepare electrospun fiber membrane materials,and doped with a certain amount of multi-walled carbon nanotubes(MWCNTs),to improve its mechanical properties and improve its osteoinductive properties.The main research contents and results are as follows:(1)Through orthogonal experiment design,when the concentration of Col solution is 10%,the receiving distance between the receiving plate and the needle is 14cm,and the spinning positive voltage is 10KV,the spinning result is optimal.Using two different cross-linking methods and comparing,it can be concluded that the nanofiber membrane cross-linked by EDC has better toughness,mechanical properties and cross-linking degree are better than the material cross-linked by GA,and EDC cross-linking The material does not introduce foreign substances,the cytotoxicity is lower,and the degradation rate is also slower,which improves the problem of collagen degradation too fast and is more suitable for application(2)From the SEM photos of Col/MWCNTs nanofiber membranes,it can be seen that due to the high surface energy of nano-sized MWCNTs,the fibers are agglomerated to a certain extent,the fibers are no longer completely uniform and smooth,but the surface roughness of the material is increased,When the roughness of the surface of the material increases,it will be more conducive to cell growth,adhesion and proliferation on it.By comparing the cell proliferation and adhesion of nanofiber membranes with different concentrations of MWCNTs,it was found that a certain amount of carbon nanotubes promotes cell adhesion,but when too much,there is slight cytotoxicity,which is not conducive to cell proliferation.By measuring the effect of fibrous membrane on the level of osteogenic differentiation markers of cells,it was found that the addition of carbon nanotubes can promote the osteogenic differentiation of cells by materials.(3)By conducting animal experiments on SD rats,the prepared Col/MWCNTs nanofiber membranes were loaded with rBMSCs as seed cells on the material,and transplanted into the rat artificial bone defect site to observe its promotion of osteogenesis.By comparing collagen/carbon nanotube fiber membrane with rBMSCs-loaded collagen/carbon nanotube fiber membrane and blank control group,it can be concluded that the bone tissue engineering material loaded with seed cells can promote the bone formation of rat bone marrow mesenchymal stem cells It is the strongest and has a strong osteoinductive ability.It is believed that this material can be used as an excellent bone defect repair material.