| PLGA(poly(lactic-co-glycolic acid))was biodegradable and biocompatible, and the degrade rate could be regulated by changing the molecular and composition of PLGA. So far, PLGA has been widely used as carriers to realize controlled release systems of drugs in forms of micro-capsules or micro-particles. In this paper, PLGA fibers loading drugs and PLGA(shell)/PVP(core), PLGA/PLGA and PLLA(shell)/PLGA(core) coaxial fibers loading drugs were prepared by electrospinning and coaxial electrospinning. Scanning electron microscope (SEM), transmission electron microscope (TEM), Contact Angle tester and infrared spectrometer were used to characterize the morphology and core-shell structure of fibers. Then the drug-loading rate and the cumulative releases of drug from drug-loaded fibers were examined by high performance liquid chromatograph (HPLC) and ultraviolet spectrophotometer. The experimental results indicated that hollow fibers and core-shell fibers could be attained by adjusting the concentration of the inner solution. Meanwhile, the mechanical property of PLGA/PVP coaxial fibers reduced with the increase of the concentration of inner solution. PLGA (LA/GA=50/50) was more suitable for drug carrier than other PLGA with different ratio of LA and GA. With the degradation of PLGA, the release profiles of 5-FU exhibiter a great burst release and a slow release at later stage. PLLA/PLGA coaxial fibers could reduce the burst release to a great degree, and the shell material PLLA could maintain morphology of fibers after 40days' release. But drug-loaded fiber with PLGA (LA/GA=50/50) as shell material appeared a large number of holes because of degradation of PLGA. Meanwhile annonaceous acetogenins-loaded coaxial fibers with PLGA as shell and PVP, PLGA as core displayed a little burst release and stable release at later stage. In a word, coaxial electrospun fibers with PLGA as shell could meet the requirements in release time and release rate, which could be applied in drug delivery system in the future. |
