Glutaraldehyde: Introducing Optimum Condition For Cross-Linking the Chitosan/Gelatin Scaffolds For Bone Tissue Engineering

Large bone defects caused by trauma or disease needs extra intervention. gelatin/chitosan complex is one of the most valuable compositions for bone healing, but fast degradation in aqueous solution and low mechanical properties increase the need for cross-linking agent. the cross-linker concentration and cross-linking method had a significant effect on the properties of fabricated scaffolds. here, three different cross-linking methods of glutaraldehyde (ga), including addition to the solution, vapor exposure, and immersion, were studied by different in-vitro analyses to find the best ga cross-linker concentration and cross-linking method. scanning electron microscopy showed homogeneous microstructures in all samples. fourier transform infrared spectrophotometry revealed cross-linking reactions in all samples. swelling ratio and biodegradation ratio was reduced by increasing cross-linking concentration and exposure time. nonetheless, higher cross-linker concentration and exposure time improved mechanical properties, while it seems the cross-linking exposure time had more effect than concentration. accordingly, ga (1 wt%) cross-linked scaffold with solution addition method showed suitable performance with 39.3° contact angle, 1.45±0.05 mpa compressive strength, 22.31±1.3 (%) swelling ratio, and 26.33±4.47 (%) biodegradation ratio. in-vitro experiments indicated cells were spread all over the scaffolds with higher than 80 (%) cell viability in all time points. the expression of alkaline phosphatase (alp) and osteo-related genes (osteocalcin and related transcription factor 2) were improved during 14 days of cell incubation and showed the high capacity of the scaffold support in mineralization and osto-differentiation. therefore ga (1 wt% ) cross-linked scaffold with solution addition was introduced as the best candidate for bone repair and further studies.