Electrospinning of Fish Gelatin Solution Containing Citric Acid: An Environmentally Friendly Approach to Prepare Crosslinked Gelatin Fibers

Abstract

The majority of the crosslinking approaches employed to confer water resistance properties to electrospun gelatin mats are based on the use of potential cytotoxic agents, turning out to be not suitable for biomedical applications. Environmentally friendly chemical strategies based on the use of non-toxic agents are, therefore, strongly demanded. In the present work, the possibility to produce crosslinked electrospun fish gelatin mats by electrospinning an aqueous solution, containing citric acid as a crosslinking agent, is reported. The effect of pH on solution rheological properties, as well as on the electrospun mat morphology, chemistry, and crosslinking degree, is assessed. The increase of solution pH from 1.8 to 3.7 allows for obtaining fibers that maintain the fibrous morphology also in the mat. Subsequent thermal treatment of the electrospun mat (80 °C for 30 min) turns out to increase the crosslinking degree and morphological stability of the mat.

The Effect of Cross-Linking with Citric Acid on the Properties of Agar/Fish Gelatin Films

“…Thermally treated films were darker, redder, and yellower (p < 0.05), and this increase with regards to the control film was significantly (p < 0.05) higher for the films heated at 105 • C, which showed the lowest L* values and the highest a*, b*, and ∆E* parameters. The yellow appearance is believed to occur due to the dehydration of citric acid, producing a colored, unsaturated acid after heating [29]. The films did not show glossy surfaces, with the gloss values lower than 10 GU.…”

“…The cross-linking of polysaccharides with citric acid occurs mainly through the hydroxyl groups of the polysaccharide and the carboxyl groups of the acid; it is known as an esterification reaction [28]. In regards to the cross-linking of proteins, the mechanism lies in the nucleophilic substitution falling between the carboxyl groups of the acid and the amino groups of the protein, forming stable amide bonds [29].…”

Electrospinning Live Cells Using Gelatin and Pullulan

“…The amide I (AmI) band at 1630 cm −1 in pullulan/gelatin was the strongest among the three and shifted slightly to a higher wavelength, which can be associated with AmI sensitivity to hydrogen bonding at the C=O group [32,33]. Hydrogen bonding plays a significant role in the stabilization of protein secondary structure which can result from the presence of pullulan here [34].…”

Electrospun Nano-Fibers for Biomedical and Tissue Engineering Applications: A Comprehensive Review

“…There is a lot of research investigating antimicrobial biomedical application [22][23][24][25][26][27]. Many researchers have studied the electro-spinning method for biomedical application [28][29][30][31][32][33][34][35][36][37].…”