Abstract:
Fibroin, derived from cocoon, is a natural polymer used widely and increasingly in various
fields. In recent years, the development of fluorescent fibroin has gained attention in the field
of tissue engineering, because of its biocompatibility, oxygen/water vapor permeability, adaptive
biodegradability, and ability to be tested non-invasively. In this work, silk fibroin and fluorescent
silk fibroin fibers were fabricated via electrospinning, a simple process through which continuous
submicron fibers can be produced. Degummed fibroin was extracted by dissolving in a calcium
chloride solution. The fibroin powder was dissolved in 98% formic acid to form 10, 12 and
14 wt.% solutions. Fluorescent fibroin solutions were achieved with addition of fluoresceine
sodium (FS) as fluorescent dye. The fluorescent solutions were prepared at 10 wt% fibroin with
varying FS concentration at 0.1, 0.3 and 0.5 wt% and at varying 0.5 wt% FS with fibroin
concentration at 10, 12, 14 wt%. The fibroin solutions were fabricated into fibers
via electrospinning. The applied voltage at 20 kV. The surface morphology of silk fibroin fibers
and fluorescent fibroin fibers, observed by scanning electron microscope (SEM) , showed long
continuous fibers. The average fiber diameter, in sub-micron range, was found to increase with
fibroin concentration. The fluorescence intensity observed by fluorescence spectrophotometer
was found to increase with decreasing fluorescent dye concentration. The functional groups and
chemical structure of silk fibroin fibers analyzed by infrared spectroscopy (IR) were not affected
by the addition of fluorescent dye.