Influences of physical and chemical crosslinking techniques on electrospun type A and B gelatin fiber mats

This work has investigated the factors influencing the production of electrospun gelatin fibers including electrical potential and concentration of gelatin solution. Electrospun gelatin fibers were prepared from both type A and B gelatin solutions at the concentration of 2.5-60% w/v and 10-25 kV. Concentration of gelatin solution at 20-40% w/v was found to be the optimized range to produce the gelatin fibers with smooth surface throughout the fiber length. The electrical potential did not exhibit a dominant effect on the gelatin fibers obtained. Further study of the different crosslinking techniques for the gelatin fiber mats showed the various effects on the crosslinking degrees and fiber structure. Physical crosslinking such as dehydrothermal treatment, plasma treatment and their combination resulted in low crosslinking extent of gelatin fiber mats due to the crosslinking occurring only at the surface of the material. Combination of dehydrothermal and chemical crosslinking using 1-ethyl-3-(3-dimethylamino propyl) carbodiimide hydrochloride (EDC) or glutaraldehyde (GA) indicated higher crosslinking degree since both the surface and the bulk of the material were crosslinked. Spraying/immersion in EDC solution, a modified technique, resulted in swollen fibers while interconnected pores remained. Merged fibers were obtained from the crosslinking by GA vapor. We concluded that crosslinking is one of the key methods to control structure and degradation of the gelatin fiber mats. Various structures of gelatin fiber mats are expected to be useful for numerous applications.