| Electrospining is a method to yield continue fibers of nanometer scale.The electrospun fibers with high porosity,large surface to volume ratio,and is extremely similar to extracellular matrix,thus has broad applications in biomedical fields.In this paper,the PLGA grafted gelatin electrospun nanofibers,electrospun gelatin crosslinked PLGA nanofibers and coaxial PLGA grafted gelatin/PLGA electrospun nanofibers are investigated,its fiber composition,thermal stability,surface morphology,tensile properties,hydrophilic properties,in vitro degradation and drug release properties were studied.The main contents are as followed:Firstly,PLGA-g-GE electrospun fibers were prepared by chemical grafting method.The effects of activation and grafting time on the properties of electrospun fibers were investigated under the optimal spinning conditions.Compared with pure PLGA electrospun fibers,the hydrophilicity of PLGA-g-GE electrospun fibers increased significantly,and its water uptake reached 141.84 %,the degradation rate in vitro increased also,but the tensile properties decreased.Secondly,the PLGA-g-GE electrospun fibers were prepared and crosslinked to obtain PLGA-c-GE electrospun fibers.Under the best electrospinning parameters(concentration 100 mg/m L,voltage 13 k V,the flow rate was 0.5 m L/h,the distance was 10 cm),it were significantly uniform and highly smooth without the occurrence of bead defects.The tensile strength of the fiber increased 33.31 MPa and the fiber water absorption rate reached 162.65 %,the water contact angle is reduced to 22.5°,and the crosslinked fibers also accelerate the degradation rate.Finally,the coaxial electrospun fibers PLGA-g-GE/PLGA were prepared by coaxial electrospinning.The core-shell structure of the PLGA-g-GE/PLGA was observed by scanning electron microscopy and the surface was smooth and without defects.Its hydrophilic,tensile properties and in vitro degradation are also improved compared with pure PLGA electrospun fibers. |
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