| The material life in today’s society is greatly enriched.People are suffering from cardiovascular disease while enjoying a good life.According to relevant statistics,since1990,the global prevalence of cardiovascular disease has increased from 271 million to523 million,and the deaths from cardiovascular disease increased from 12.1 million to 18.6million.In addition,China has the highest incidence of death from cardiovascular disease.From the perspective of disease trend,cardiovascular diseases are becoming younger and younger.At present,the main clinical treatment for cardiovascular diseases is "autologous transplantation",but this method is only equivalent to "robbing Peter to pay Paul",the effect is not ideal.Similar to vascular disease,peripheral nerve injury is also a common clinical disease.The main causes of the disease are accidents and iatrogenic trauma.The patients often present sensory disorders,movement disorders,and even paralysis in severe cases.The nerve conduits are the same as the blood vessels,both of which are tubular tissues of the human body.It is imperative to construct tubular scaffolds with highly biomimetic structure and composition of human blood vessel and nerve conduit using the current hot subject tissue engineering.There are many ways to construct tissue engineering scaffolds.Among them,the nanofiber network prepared by electrospinning can effectively simulate the extracellular matrix and provide a perfect growth space for cell adhesion and proliferation.In this paper,nanofiber tubular scaffolds were constructed by conjugated electrospinning technology and applied to tissue engineering of blood vessels and nerve conduits.The main research contents are summarized as follows:(1)The SF/PLCL composite nanofibers with different mass ratios were prepared by traditional electrospinning technique using the biofriendly materials Silk Fibroin(SF)and Poly(L-lactic acid-co-ε-caprolactone)(PLCL)as raw materials.Then,the morphology,physical and chemical structure,mechanical properties,hydrophilicity and protein adsorption of SF/PLCL nanofibers with different weight ratios were characterized.The results show that the composite nanofibers have the best comprehensive properties when the mass ratio of SF/PLCL is 40:60.The results provide an important research basis for the follow-up experiments.(2)The nanofiber membrane prepared by traditional electrospinning technology is only two-dimensional in structure.However,in order to obtain a tubular scaffold with a three-dimensional structure,we used conjugate electrospinning technology to fabricate nanofiber core-spun yarns with nylon filament as the core,and then extracted the core to obtain nanofiber vascular scaffolds.Subsequently,the morphology,physical and chemical properties,mechanical properties,and biocompatibility of SF/PLCL composite nanofiber vascular scaffolds were characterized.The results showed that SF/PLCL composite nanofiber vascular scaffolds had uniform tubular structure,excellent mechanic al properties and good biocompatibility.The results of in vitro cell culture showed that the scaffold could effectively promote the adhesion and proliferation of vascular endothelial cells(VECs),which provided a proof for the feasibility of vascular scaffold.(3)Based on the research of nanofiber vascular scaffold,further innovations were made to prepare nerve scaffolds with a composite tubular structure.Firstly,several nanofiber core-spun yarns were bundled,and then a layer of nanofibers was spun on the surface of the bundle by conjugate electrospinning technique.Finally,the nanofiber neural scaffolds with tube-in-tube structure were obtained by extracting nylon yarn.Subsequently,the morphology,essential performance,and biocompatibility of SF/PLCL composite nanofiber neural scaffolds were characterized.The results showed that the prepared neural scaffolds had a multi-channel tubular structure,excellent mechanical properties and good biocompatibility.In vitro cell culture tests showed that the neural scaffold could significantly promote the migration and proliferation of Schwann cells(SCs).The scaffold holds great promise in replacing damaged peripheral nerve tissue. |
