Fabrication Of Bionic Anti-inflammatory Films Using Coaxial Electrospinning And Study Of Bioactivity

Coaxial electrospinning is a special fiber manufacturing technique,which is widely utilized in the preparation of polymer materials and biological materials.Herein,coaxial spinning has been adopted to design and fabricate a bionic biomaterial mimicking natural skin components and structure,which can be used for artificial skin.Coaxial-electrospun fiber films(CEFF)with collagen(CLG)/polyvinyl alcohol(PVA)/ shells and chitosan(CTS)/PVA cores are designed and fabricated.PVA is chosen as the assisting reagent.All electrospinning solutions are prepared in 10% PVA solutions.A series of CLG solutions of concentrations of 6%,8%,and 10% are used as the shell solutions.While 1% and 2% of CTS solutions are employed as the core solutions.Various combinations of the electrospinning solutions are used for film fabrication.Based on the comprehensive comparison of obtained CEFFs,it is found that the CEFF obtained from 10 wt% CLG and 2 wt% CTS exhibits better performance than others.To optimize the fabrication of CEFFs,the influence of the collagen to chitosan ratio of the starting solutions and the coaxial electrospinning parameters such as voltage,temperature on the quality of the obtained film is studied.Electron microscopy and Fourier-transform infrared spectroscopy are used to spectral characterize theation have also verified that the fiber films have good physical structure and chemical structures of CEFFs properties.The images of transmission electron microscopy verify the core-shell structures of the CEFF fibers.The Tscanning electron microscopy images reveal that the fiber showed a good s of CEFFs show surface structure under scanning electron microscope(SEM),with asurface structures of uniform texture and a narrow diameter distribution between 200 nm and 350 nm.The observation of transmission electron microscope(TEM)reveals that the fiber has a core-shell structure.The infrared spectruma analysis proves that the rawall starting materials are well integrated within into the fiber films.Spermidine,a bioactive small molecule with natural anti-inflammatory activity,has been introduced into CEFF as a crosslinking agent to yield electrospun bionic anti-inflammatory film(EBAF).Cell culture experiment with NIH/3T3 shows that the as-prepared materials has excellent biocompatibility.Subsequently,the secretions of two pro-inflammatory cytokines,interleukin-2(IL-2)and interleukin-6(IL-6),have been measured.The results demonstrate that when the volume fraction of spermidine-crosslinker introduced in ordinary films and coaxial films is higher than 0.125% and 0.25%,respectively,the secretion of interleukins gradually declines as the volume fraction of spermidine-crosslinker increases,suggesting an anti-inflammatory effect of the EBAF.In contrast,the control sample crosslinked with an agent made of diethylenetriamine(DETA)displays continuous elevations of interleukin as the volume fraction of crosslinker increases.Moreover,the comparison of the concentrations of interleukin secreted in presence of ordinary electrospun film and coaxial-electrospun film,shows that the concentration of interleukin secreted in presence of the coaxial-electrospun film is lower,indicating a weaker inflammatory response from stimulated cells.The drug loading and release capacity of EBAF has been evaluated by introducing doxorubicin to the core of the coaxial-electrospun film and measuring the released drug within different peroids.It is found that EBAF has a good drug release capacity and can be used for drug delivery.In this work,a bionic biomaterial is designed with the concept of coupled bionics.Mimicking the components and structure of dermis layer of human skin,bioactive CEFF films are fabricated.Then EBAF are obtained by crosslinking with spermidine based crosslinkers.Additional to the good bioactivity inherited from the CEFFs,the EBAFs exhibit a anti-inflammatory capability,which is seldom reported for biomaterials.Therefore,the applications of EBAFs as artificial skin and other forms of anti-inflammatory cell scaffolds are promising.