利用乳液静电纺丝法制备具有稳定芯壳结构的PLGA/DEX电纺纤维

Preparation of PLGA/DEX Electrospun Fibers with Stable Core-shell Structure by Emulsion Electrospinning Technology

目的 通过乳液静电纺丝法制备具有稳定芯壳结构的聚乳酸-羟基乙酸共聚物[poly(lactic-co-glycolic acid),PLGA]/葡聚糖(dextran,DEX)电纺纤维并优化相关的工艺参数,为利用乳液静电纺丝法制备载药纤维膜奠定实验基础。方法 将PLGA溶液作为油相,DEX溶液作为水相,通过改变油相溶剂的成分、水相溶液的浓度以及水油两相体积比来观察并比较6组电纺液的乳液体系是否稳定;通过乳液静电纺丝法制备PLGA/DEX电纺纤维,利用扫描电子显微镜、透射电子显微镜观察6组纳米纤维是否具有稳定的芯壳结构。结果在PLGA的溶剂中引入一定比例的三氟乙醇能够适当减小水油两相的界面张力,提高两相的相容性。但当水相浓度过大时,仅调整溶剂的成分不足以得到性质稳定的电纺液;适度减小水相浓度,纺丝液黏度也随之降低,两相的相容性提高,乳液越趋于稳定。水油两相的体积比是影响纤维芯壳结构以及形貌尺寸的重要因素,适宜的水油体积比形成的乳液,其性质更稳定,可纺性更好。结论 将浓度为0.15 g·mL^(-1)的PLGA(溶剂为N,N-二甲基甲酰胺和三氯甲烷,体积比为1∶3)作为油相溶液,浓度为0.15 g·mL^(-1)的DEX作为水相溶液,水油体积比为1∶13时配制的乳液静电纺丝液性质最稳定,将该纺丝液在速度为0.2 mm·min^(-1)、接收距离为15 cm、电压为14 kV的条件下进行电纺能够得到具有稳定芯壳结构的电纺纳米纤维。

Objective Poly(lactic-co-glycolic acid)(PLGA)/dextran(DEX) electrospun fibers with stable core-shell structure were prepared using emulsion electrospinning technology and the related technological parameters were optimized.This study provided an experimental basis for the preparation of drug-loaded fibrous membrane by emulsion electrospinning technology.Methods The PLGA solution was used as the oil phase and the DEX solution was used as the aqueous phase.Then,the composition of the oil phase solvent,the concentration of the water phase solution and the volume ratio of water phase to oil phase were changed to observe and compare the stability of the emulsion system of six groups of electrospinning solution.PLGA/DEX electrospun fibers were prepared by emulsion electrospinning,and scanning electron microscope and transmission electron microscope were used to observe whether the six groups of nanofibers had stable core-shell structure.Results The addition of a certain proportion of trifluoroethanol into the solvent of PLGA properly reduced the interfacial tension and improved the compatibility of the two phases.However,when the concentration of water phase was too large,it was not enough to obtain stable electrospinning solution only by adjusting the composition of solvent.When the concentration of water phase was reduced moderately,the viscosity of electrospinning solution also decreased,the compatibility of two phases was improved and the emulsion became more stable.The volume ratio of water phase to oil phase was an important factor affecting the morphology and core-shell structure of the fibers.The emulsion-electrospinning solution with the appropriate volume ratio of water phase to oil phase had more stable property and better spinnability.Conclusion PLGA(solvent:N,N-dimethylformamide and trichloromethane,volume ratio of 1∶3)with a concentration of 0.15 g·m L^(-1)was used as oil phase and DEX with a concentration of 0.15 g·m L^(-1)was used as water phase.When the volume ratio of water phase to oil phase was 1∶13,the property of the prepared emulsion-electrospinning solution was the most stable.Electrospinning at a speed of 0.2 mm·min-1,a receiving distance of 15 cm and a voltage of 14 k V could obtain electrospun nanofibers with stable core-shell structure.