Concentration effect of Chromolaena odorata (Siam weed) crude extract on size and properties of gelatin nanofibers fabricated by electrospinning process

Gelatin nanofibers containing Chromolaena odorata (C. odorata) crude extract were fabricated via electrospinning process to study the effect of C. odorata concentration on their size and properties for biomedical applications, especially for the purpose of wound healing and covering. C. odorata extracts, 0-20% weight by volume (w/v), in 20% (w/v) gelatin solutions, were spun at an operating voltage of 8 kV and flow rate of 0.5 mL/h. The distance between the needle tip and collector was fixed at 10 cm. The average diameters of the electro-spun fibers obtained did not exhibit significant difference when the concentration of the C. odorata extract was equal to or less than 10% (w/v). This was true in the case of both cross-linked and uncross-linked fibers with 0.04% (w/w) glutaraldehyde. The average diameters of the fibers obtained increased significantly when the concentration of the C. odorata extract was increased from 10% to 20% (w/v). All the uncross-linked fibers had smaller average diameters than those of the cross-linked fibers under all conditions. An increase in the C. odorata content of the fibers provided more hydrophilicity to the fiber surfaces. The novel finding from this study was that the gelatin fibers fabricated with C. odorata extract exhibited 180 times greater water adsorption than those of the commercial healing and covering films used presently. Moreover, all the fibers collected showed excellent antimicrobial activity against the Gram-positive bacterium, Staphylococcus aureus, but not against the Gram-negative bacterium, Escherichia coli.