Electrospun gelatin/hyaluronic acid fiber mats for medical applications

The natural polymers chosen to produce fibrous structure using the electrospinning process were gelatin (a form of denatured collagen) and hyaluronic acid (a type of glycosaminoglycan) (GAG). The electrospun fibers had the average diameters of 100-120 nm and were cross-linked by glutaraldehyde vapor for 30 minutes, 1, 2, and 4 hours at 37°C. The cross-linked electrospun fiber mats were characterized by scanning electron microscopy (SEM). The images showed a network of cross-linked fibers. Fourier transform infrared spectroscopy (FTIR) was used to determind the change in functional groups of the electrospun fiber mats after the cross-linking process. The thermal degradation temperature of the resulting fiber mats were evaluated from thermogravimetry (TG) profiles which showed thermal degradation temperature of approximately 300°C. The degree of cross-linking were evaluated by using swelling test in simulated body fluid (SBF) which showed a decrease in swelling percentage relative to dry weight with increasing cross-linking time. The strain at break was measured and found to increase with decreasing cross-linking time. Before the cross-linked fiber mats were subjected to biocompatibility tests, they were immersed in a solution of sodium bimetasulfite to remove residue cross-linking agent which has been reported to be toxic to living organisms. The fiber mats were subjected to an indirect cytotoxicity testing with mouse fibroblast cells (L929), the results indicated that it was not toxic.