Structure Control Of Electrospun Fiber Materials And Their Application In The Field Of Biomedicine

Electrospinning is a highly versatile technology used to prepare fiber materials with micro-nano diameters.Electrospun fiber material has extremely high specific surface area,porous structure with interconnected pores and adjustable fiber morphology.These remarkable characteristics impart a series of ideal properties to electrospinning materials,which can meet the needs of various advanced biomedical applications.In this dissertation,we have constructed nanofiber materials with various structures for biomedical applications such as blood purification,tumor treatment,wound disinfection,and wound exudate management.The main points are as follow:1.We prepared a 3D nanofiber sponge by combining electrospinning and gas-foaming techniques.The amino groups and BSA molecules were immobilized on the fiber surface as affinity groups for rapid and efficient adsorption of excess bilirubin in blood.The 3D nanofiber sponge has layered structure and significantly higher porosity than two-dimensional nanofiber membrane.The special 3D structure makes the sponge fully contact with the adsorbed liquid,which reduces the diffusion distance of the adsorbate,thus increasing the sponge's adsorption rate.The maximum adsorption capacity of BSA immobilized nanofiber sponge in aqueous solution and plasma can respectively reach 36.824 mg/g and 25.291 mg/g.And it can achieve adsorption equilibrium within 60 minutes,with fast adsorption speed.In addition,the nanofiber sponge also showed good biocompatibility and blood compatibility,so it is an excellent blood perfusion adsorbent.2.We prepared a fiber membrane with a porous structure on the fiber surface by combining the "breath figure" mechanism with electrospinning technology.By doping CuS nanoparticles in porous nanofibers and loading chemotherapeutic drugs in the pores,a controllable local drug delivery system was obtained.It can achieve the chemo-photothermal synergistic treatment of melanoma.The porous structure significantly improved the fiber's drug loading capacity.Since the drug was loaded on the surface of the fiber,it can be released more thoroughly during the treatment period.The composite membrane can kill melanoma cells in vitro with an efficiency of 76%and effectively inhibit tumor growth in vivo experiments.In addition,the fiber membrane can promote the vascularization of the skin by releasing copper ions,thereby promoting wound healing.Therefore,this work achieved the treatment of skin tumor and the repair of normal skin tissue through a single system.3.We first prepared a hydrophilic nanofiber membrane doped with ZIF-8 derived carbon nanoparticles by electrospinning technology,and then expanded the membrane through gas foaming technology to obtain a new type of nanofiber sponge wound dressing with layered structure.The dressing can effectively kill bacteria through chemo-photothermal synergistic therapy,the antibacterial efficiency against E.coli and S.aureus in vitro reached 94.8%and 97.4%,respectively.At the same time,the hydrophilic sponge can quickly absorb exudate around the wound.Through its special layered structure and photothermal effect,the rate of liquid evaporation can be increased by more than 11 times,so it can effectively adjust the wetness of itself.The dressing showed good biocompatibility in co-culture experiments with 3T3 and JB6 cells.In addition to providing mechanical support and structural cues,effective infection control and wound exudate management can also facilitate complex wound healing processes.