Development and characterization of glutaryl thiourea crosslinked novel hydrogel; a detailed analysis of biocompatibility, angiogenesis, and antibacterial potential

In this study, we successfully synthesized four novel chitosan hydrogels by carefully crosslinking them with varying concentrations of glutaryl di-isothiocyanate (GTU). This thoughtful approach not only imparts a subtle yellowish tint to the polymer films but also enhances their potential applications as biomaterials. Comprehensive characterization using FTIR, XRD, and CHNS analyses provided important insights into the successful chemical interactions within the hydrogel matrix. Scanning electron microscopy (SEM) revealed a well-defined porous microstructure in the films. Thermal degradation analysis indicated that 50 % weight loss occurred at 270 °C for the crosslinked hydrogel GTU-CS4, compared to 303 °C for pure chitosan, suggesting a manageable decrease in thermal stability due to crosslinking. Mechanical testing showed that increasing the crosslinker concentration by 1.2 mmol resulted in an impressive percentage elongation of the hydrogel films at 30.64 %, in contrast to 18 % for pure chitosan, highlighting significant improvements in flexibility and strength. Our biological evaluations suggested that higher crosslinker concentrations effectively reduced inflammation and promoted angiogenesis, with blood vessel formation increasing to 28 vessels and an enhanced expression of transforming growth factor-beta 1 (TGF-β1). The WST-8 assay demonstrated a noteworthy increase in cell viability, reaching as high as 180 % in the crosslinked hydrogels. Additionally, antibacterial tests showed promising inhibition rates of 80 % against Staphylococcus aureus and 60 % against Escherichia coli. These findings underscore the considerable potential of GTU-crosslinked chitosan hydrogels in advancing skin tissue regeneration applications,