Preparation And Performance Of PLGA/Gelatin Nanofibers Based On Coaxial Electrospining

Coaxial electrospining is a novel electrospining method. Coaxial electrospun nanofibers has broad application in biomedical fields because of unique core shell structure, high specific surface area and porosity. In this paper, the coaxial PLGA/gelatin nanofibers with PLGA as core layer and gelatin as shell layer produced by the coaxial electrospinning technique. We studied the effects of different factors on the morphology, the biodegradability and drug release of the coaxial electrospun fibers. The main content includes the following several aspects:Firstly, the influences of PLGA with different LA/GA, solvents, solution concentration,flow rate, voltage and receiving distance on coaxial nanofibers internal structure, surface morphology and diameter distribution are studied by transmission electron microscopy (TEM),scanning electron microscope (SEM) and fiber diameter. It is found that the optimum parameters of the preparation of coaxial PLGA/gelatin electrospining nanofibers are as follows: PLGA (85/15 LA/GA) as the core layer, trifluoroethanol as solvent, concentration of gelatin solution is 70 mg/mL, flow rate of gelatin solution is 0.5 mL/h, voltage is 12.5 kV,receiving distance is 12 cm. The coaxial PLGA/gelatin electrospining nanofiber membrane using the optimum parameters of the preparation has good hydrophilicity and good performance of tensile strength.Then, the influences of PLGA with different LA/GA, solvents, solution concentration,flow rate, voltage and receiving distance on the in vitro degradation behaviors of coaxial nanofibers membrane are studied by SEM and weight loss at different time points. The result shows that the weight loss increases with the increasing of the percentage of GA,concentration of gelatin solution and flow velocity. When the trifluoroethanol is used as the solvent of the core layer, the weight loss is greater than methylene chloride. The weight loss increases at first, then decreases with the increasing of the voltage and the receiving distance.Finally, the influences of solution concentration, flow rate, crosslinking time and buffer pH on the drug release of FBF-loaded PLGA/gelatin coaxial electrospining nanofiber membrane are studied by the UV-vis spectra. The result shows that the drug release decreases with the increasing of concentration of gelatin solution, flow velocity and crosslinking time.The amount of drug release is larger in the buffer solution with high the pH value.