Investigation of Chitosan-glycol/glyoxal as an Injectable Biomaterial for Vocal Fold Tissue Engineering

Injectable hydrogels offer promising tissue engineering approaches for vocal fold (VF) tissue repair. Research on VF tissue engineering scaffolds has largely been focused on derivatives of hyaluronan and collagen. Although chitosan hydrogels have been extensively investigated for various soft tissues, their potential use for VF tissue engineering has been overlooked. The aim of the present study was to investigate cross-linked Chitosan-glycol (GCs)/glyoxal (Gy) hydrogels for VFLP tissue engineering. The effects of Gy concentration on cell viability, viscoelastic properties, enzymatic degradation, and cell migration were studied. Six different groups of cell-seeded hydrogels, consisting of immortalized human vocal fold fibroblasts encapsulated in GCs/Gy hydrogels, were prepared to obtain target concentrations of 2×106 cells/ml, GCs 2% and Gy 0.02% (Group#1), 0.015% (Group#2), 0.01% (Group#3), 0.0075% (Group#4), 0.005% (Group#5), or 0.0025% (Group#6). The storage and loss moduli were 629±35 Pa and 9±1 Pa, 560±28 Pa and 9±1 Pa, 489±41 Pa and 8±1 Pa, 307±25 Pa and 4±1 Pa, 149±31 Pa and 3±1 Pa, 55±17 Pa and 3±1 Pa for groups 1, 2, 3, 4, 5, and 6, respectively. The viability rates were above 90% for all groups, 3 hours after encapsulation. The viability rates were 60.0±2.2%, 80.3±2.2%, 83.5±0.5%, 83.1±1.3%, 88.2±0.1%, and 88.0±1.1% for groups 1,2,3,4,5, and 6, respectively, one week after encapsulation inside GCs/Gy hydrogels. The average cell motility speed was 0.09±0.03 μm/minute, 0.07±0.043 μm/minute, and 0.09±0.02 μm/minute for groups 4, 5, and 6, respectively. Following four weeks enzymatic degradation study, the mass loss was 10%, 21%, and 100% for groups 4, 5, and 6, respectively. Our results indicated that GCs/Gy hydrogels could be potential candidates for use in human VF tissue repair and regeneration.