Gallic Acid-Loaded Electrospun Poly(L-Lactic Acid) Fiber Mats and their Release Characteristic

Ultra-fine fiber mats of poly(L-lactic acid) containing gallic acid were prepared by electrospinning from gallic acid-containing PLLA solution in 7:3v/v dichloromethane (DCM)/N,N-dimethylformamide (DMF). The amount of the as-loaded gallic acid was 40% w/w (based on the weight of PLLA in the solution) or 28.6 wt.-% (based on the weight of the resulting fiber mats). Both the neat and the gallic acid-loaded PLLA fibers were smooth, with the average diameters of 965 and 843 nm, respectively. No aggregates of gallic acid were observed on the fiber surface and the actual amount of gallic acid in the gallic acid-loaded PLLA fiber mats, determined in the acetate buffer, the citrate-phosphate buffer, and the normal saline, was 26.3, 27.1, and 24.6 wt.-%. The cumulative amount of gallic acid released from the gallic acid-loaded PLLA fiber mats was greatest in the normal saline, followed by those in the citrate-phosphate and the acetate buffer, respectively. Lastly, the free radical scavenging activity, based on the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay, of the as-loaded and the as-released gallic acid remained active.