238 JOURNAL OF COSMETIC SCIENCE extract concentration increased (see Table I). The SEM images of the GM extract-loaded electrospun PV A fibers revealed no presence of beads, GM extract crystals, or other types of the extract aggregates on the surface of the fibers. This implies that the GM extracts were incorporated well within the electrospun fibers. SWELLING BEHAVIOR OF NEAT AND GM EXTRACT-LOADED ELECTROSPUN PVA FIBER MATS AND CAST PV A FILMS The degree of swelling of the neat and the GM extract-loaded electrospun PVA fiber mats and films after submersion in distilled water at room temperature for 24 h is illustrated in Figure 2. In each of the sample types investigated, the property values of the electrospun PVA fiber mats were greater than those of the cast PVA films, which should be a result of the highly porous nature of the electrospun fiber mats hence the much greater surface area when compared with that of the cast films. These results are consistent with previous results in which electrospun PVA fiber mats showed a greater degree of swelling than cast PV A films (24). RELEASE OF GM EXTRACTS FROM GM EXTRACT-LOADED ELECTROSPUN PVA FIBER MATS AND CAST PV A FILMS Prior to investigating the release characteristics of the GM extracts from both the GM extract-loaded electrospun PVA fiber mats and cast PVA films, the actual amount of the GM extracts within these samples was measured. Table II summarizes the actual amount of the GM extracts present in these samples (reported as the percentage of the initial content of GM extracts loaded in both the spinning and the casting solutions, i.e., 10 wt% based on the weight of PVA powder). The antioxidant activity was evaluated by using the 2,2-diphenyl-1-picryhydrazyl (DPPH) method. The actual amounts of the GM extracts in electrospun PVA fiber mats that were prepared from the base solution containing 2.5%, 5%, and 10% w/w of the extract were 9.6%, 9.7%, and 10.8% of the initial GM extract loading, respectively. On the other hand, those of the corresponding films were 23.9%, 14.5%, and 21.0%, respectively. Ideally, the actual amount of the GM extracts presented in the drug-loaded cast PVA films should be 100%. The dis­ crepancy from the ideal could be due to the inhomogeneity of the GM extracts in different parts of the samples despite careful preparation of the spinning and the casting solutions, or due to an adverse effect of the sample preparation methods on the anti­ oxidative activity of the loaded GM extracts. The determination of the release characteristics of the GM extracts from the GM extract­ loaded electrospun PVA fiber mats and cast PVA films was carried out by the total Table I Fiber Diameters of Electrospun PVA Fiber Mats With and Without GM Extract Loading Formulation Neat electrospun PVA fiber mats 2.5% GM extract-loaded electrospun PVA fiber mats 5% GM extract-loaded electrospun PVA fiber mats 10% GM extract-loaded electrospun PVA fiber mats Size (nm) 197.3 ± 49.8 159.6 ± 43.1 176.2 ± 58.7 140.7 ± 52.7

ELECTROSPUN PVA FIBER MATS AS EXTRACT CARRIERS 239 700 600 * * * * 500 400 300 200 100 0 PVA 2.5% GM-loaded 5% GM-loaded 10 % GM-loaded Figure 2. Degree of swelling (%) of (D) electrospun PVA fiber mats and (■) cast PVA films of bare and GM extract-loaded mats. Each point represents the mean ± S.D. of three to five experiments. *p 0.05 compared with cast PVA films. Table II Actual Amount of GM Extract(%) Within the GM Extract-Loaded Electrospun PVA Fiber Mats and Cast PVA Films Prepared From the Initial Amount of GM Extract Load of 2.5%, 5%, and 10%, Based on the Weight of PV A Initial amount of GM extract load (%) 2.5 5 10 Actual amount of GM extract(%) GM extract-loaded electrospun PVA fiber mats 9.6 9.7 10.8 GM extract-loaded cast PV A films 23.9 14.5 21.0 immersion method. The experiments were carried out in distilled water at a controlled temperature of 32°C. Each of the withdrawn solutions (i.e., the sample solution) was analyzed for the antioxidant activity of the GM extracts by the DPPH method. The cumulative amount of the GM extracts released from the GM extract-loaded specimens is shown in Figure 3. At 120 min after submersion in the medium, the cumulative amounts of the GM extracts released from the GM-loaded fiber mats that were prepared from the base PVA solution containing 2.5%, 5%, and 10% w/w were 73%, 84%, and 81 %, respectively, while those of the corresponding cast films were 4%, 29%, and 41 %, respectively. The results showed that the electrospun PVA fiber mats exhibited a rapid release of the GM extracts, most likely a result of the high swelling ability as well as the high solubility of the extracts in the medium. Noticeably, at a given submersion time point, the cumulative amount of the GM extracts released from the electrospun PVA fiber mats