Fabrication Of Spermidine-contained And Bioinspired Membrane And Study Of Its Biological Activity

Skin,the largest organ,plays an important role in protecting body and its physiological function.Inspired by the structure and components of human skin,a thin fibrous electrostatic membrane composed of chitosan,collagen,and spermidine was designed and fabricated employing electrospinning technique.Using polyvinyl alcohol(PVA)as an additives,fibers can be obtained from a chitosan/collagen solution via electrospinning.It was found that the optimized mass concentrations of chitosan,collagen,and PVA in spinning solution are 2 %,8 %,and 10 %,respectively.Using this proportion,fibers with uniform diameter(734.0 nm)could be obtained.The formed chitosan/collagen/PVA membranes were crosslinked by a bioactive Schiff base crosslinker containing spermidine and terephthaldicarboxaldehyde.With three-dimensional network structures,the water stabilities of the crosslinked bioactive membranes were substantially enhanced.As the increase of crosslinker amount,the volume of water absorbed by the films decreased significantly.Spermidine is known as a bioactive compound.The MTT assay result suggested that the presence of spermidine promotes the growth of NIH/3T3 cells,when its concentration was lower than 0.1 mM/L.The instable and reversible nature of ethylene-imine bonds results in the release of spermidinefrom the membranes to the culture mediums,which might benefits cell growth.The theoretical concentrations of spermidine released from the bioinspired membranes in this work were all in the bioactive range.NIH/3T3 cells had grown well on the crosslinked membrane.After 30 h,the fraction of coverage was about 90-95 %.Compared with the smooth surfaces of culture Petri dishes,NIH/3T3 cells prefer to grow on the crosslinked membranes.Above results indicate that the spermidine-contained bioinspired membranes have good biocompatibility,excellent cell adhesion property,and similar chemical components with human skin.Therefore,these membranes are good candidate materials for artificial skin applications.