Study On The Controllable Preparation Of Electrospun Silk Fibroin Bead-on-string Material And Its Drug Release Behaviors

Drug release is crucial for the treatment of tumor,which could efficiently improve the efficacy of drugs and reduce the hurt to healthy cells.Various nanocarriers including polymeric micelles,nanofibers,nanoparticles and liposomes have been studied to be used for drug delivery systems.Among those nanocarriers,electrospun nanofibers can load and envelope drugs efficiently due to their high specific surface area and high porosity.However,electrospun nanofibers still have some problems,for example,uncovering and gathering of drugs on fiber surfaces,poor biocompatibility of materials,toxicity of solvents,etc.The unique structure,alternating distribution of micron size beads and nano size fibers of bead-on-string fiber materials can completely coat water-soluble drugs or solid particles,which could effectively cover of drugs uncovering in smooth fiber materials,and achieve sustained drug release.Therefore,it is of great significance to develop bead-on-string fiber materials with size-controllable beads for the development of efficient drug delivery system.In this paper,biocompatible and biodegradable silk fibroin(SF)and poly ethylene oxide(PEO)were used as electrospun materials and water was used as solvent.The optimum concentration of electrospinning solution was explored by using the different mixing ratio of SF and PEO.Further,based on the theory of the formation of bead-on-string fiber materials,the effect of electrospinning parameters(spinning speed,voltage and receiving distance)and solution properties(surface tension,viscosity,conductivity)on the morphology and size of bead-on-string fiber materials were further explored.Finally,adjustable morphology and size of bead-on-string fiber materials and the influence of electrospinning parameters and solution properties on beads size were obtained.In order to investigate the sustained drug release of bead-on-string fiber materials,we studied the release behavior of doxorubicin hydrochloride from SF/PEO smooth fiber and bead-on-string fiber materials under different conditions.The results showed that drug release of bead-on-string fiber materials obviously slower than smooth fiber materials,which indicated the property of sustained release of bead-on-string fiber materials is better than that of electrospun smooth fiber materials.Furthermore,the preparation conditions of coaxial bead-on-string fiber materials and its drug controlled release were also studied.The results showed that the ability of drug release of coaxial bead-on-string fiber materials of SF/PEO was significantly better than other two materials.In summery,SF and PEO were used as electrospun materials and water was used as solvent in this paper.We has been successfully prepared bead-on-string fiber materials with size-controllable beads by changing spinning process parameters and solution properties.The prepared bead-on-string fiber materials showed better sustained drug release capacity than soomth fiber materials.Materials prepared in this paper have potential applications in biomedical and filtration materials fields.