Preparation And Properties Of Polylactic Composite Nanofiber Scaffold Materials For Tissue Engineering

The loss or dysfunction of human tissues and organs has always been a relatively common disease,which seriously affects people’s health and normal life.Tissue engineering technology as a new type of tissue and organ repairing treatment gradually attracts the attention of researchers.The scaffold is the basis of tissue engineering technology and plays a vital role in the entire repairing and treatment process.Polylactic nanofiber is a porous scaffold material prepared by electrospinning technology,which has the characteristics of non-toxic and nonirritating polylactic acid,good biocompatibility and mechanical properties,and nanofiber has a large specific surface area,high porosity mimic the extracellular matrix,which has been rapidly developed into a promising tissue engineering scaffold material.However,the generally poor surface hydrophilicity of polylactic materials,the lack of reactive functional groups on the main chain,weak cell adsorption,and slow degradation rate,etc.have limited its application in tissue engineering scaffolds.This study is based on the good biological application prospects of polylactic composite nanofiber scaffolds.In order to further improve the hydrophilicity of polylactic nanofibers and introduce the good biological activity of natural polymer,this research proposed to electrospin polylactic blended with natural polymer and then graft another natural polymer on the fibre scaffolds via crosslinking agent.In this study,polylactic composite nanofiber scaffold PLA/CS-Algi was prepared by mixing electrospinning of polylactic and chitosan in different proportions,and then using EDC/NHS crosslinking agent to graft-modify the blended fiber with alginate in aqueous solution.Microscopic morphology analysis shows that the composite fiber scaffold has smooth and straight fiber morphology,good porosity and large surface area to volume ratio,and as the ratio of chitosan in the component increases,the diameter of PLA/CS-Algi fiber is reduced.Compared with pure polylactic fiber scaffold materials,the introduction of chitosan and alginic will slightly reduce the thermal stability and mechanical properties of the fiber scaffold.Static water contact angle test and protein adsorption test results show that PLA/CSAlgi fiber composite fiber scaffold has stronger hydrophilicity than PLA and PLA/CS.The static water contact angle is as low as 65 °,which significantly improves the hydrophilicity of polylactic fiber materials.At the same time,in vitro degradation experiment showed that the composite modification of chitosan and alginate can improve the degradation rate of polylactic materials.In this study,a hydrophobic synthetic polyester material and a hydrophilic natural polymer material were cleverly made into nano-sized composite fiber scaffolds,which combined the good biocompatibility,degradability,processability and mechanical properties of polylactic with natural polymer polysaccharides such as chitosan and alginate,which have good antibacterial blood circulation,solid water retention and other properties.This simple and effective method has certain reference significance in the preparation and functional modification of tissue engineering scaffolds.