Page 173 - Demo

SECTION I: MOLECULAR GENETIC ENGINEERING AND BIOCHEMICAL TECHNOLOGY 177Dataphysics OCA 50 (Germany). A small droplet (5 %u00b5L) of deionized water was placed on the surface of nanofibers. The contact angle was measured using a digital camera at 60 seconds after the droplet touched the nanofiber surface. This measurement was repeatedly performed three times. The result was presented as mean %u00b1 SD [20].2.4. Antibacterial assayThe antibacterial activity of the nanofibers was conducted on 96-well microplates according to the methods of Vlietinck (1999) and Mckane (1996) [21,22]. Test bacterial strains included Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 10145 (gram negative), Bacillus subtillis subsp. spizizenii ATCC 6633, Staphylococcus aureus subsp. aureus ATCC 25923 (gram positive), Aspergillus niger ATCC 6275, Fusarium oxysporum ATCC 7601 (filamentous fungi), Candida albicans ATCC 10231, Saccharomyces cerevisiae VTCC%u2013Y%u201362 (yeast). Streptomycin, tetracyclin, and nystatin were used as positive control for gram positive, gram negative, yeast and fungi, respectively. The microplates were incubated for 24 h at 37%u00b0C for bacteria and 48 h at 30%u00b0C for fungi. The lowest concentration of the fibers that inhibited the visible growth of a microorganism (MIC) after incubation was observed and recorded.3. RESULTS3.1. Characterization of electrospun nanofibers CS/PLA/PEG loaded capsaicinFigure 1 showed that the surface of the nanofibers CS/PLA/PEG loaded with 12% capsaicin was smooth, uniform, without any beads. The average diameter of the nanofibers was 269 %u00b1 54 nm. The histogram of diameter distribution of the nanofibers (Figure 2) indicated about 85% of fibers population had a diameter between 200 - 350 nm.