Amino acid conjugated alginate - graphene oxide scaffolds

Abstract

In this thesis, fabrication and characterization of neat alginate and alginate/graphene oxide (GO) composite 3D porous scaffolds were investigated in order to achieve a material suitable for wound care applications with enhanced properties such as biocompatibility, high mechanical strength, stability, high absorbance and positive cell behaviour. Alginate (Al) was used as the main polymer and GO was used as additive. L-Cysteine (Cys) was conjugated on GO in order to enhance biocompatibility. Initially, neat Al scaffolds were fabricated by ionic crosslinking (CaCl2 as cross-linker) and lyophilisation. Then GO (1mg/ml) was added to the structure and Al/GO scaffolds with different crosslinker concentrations (0.01-0.03 M) were fabricated in order to determine optimal crosslinker concentration. Next, 0.03M crosslinker concentration was kept constant and scaffolds with different GO concentrations (0.5-2 mg/ml) were prepared in order to determine optimal GO concentration. Finally, Cys was immobilized to GO (1:1 ratio) and Al-3/CysGO-0.5 scaffold was fabricated. FTIR and SEM were used for the characterization of Al/GO scaffolds. Swelling ratio and porosity were investigated by conducting swelling test. Viscoelasticity of the non-lyophilized hydrogels was investigated with rheometry method. Viability of fibroblast cells was investigated by MTT assay. According to the results, adding GO to the structure provided stability and immobilization of Cys increased biocompatibility, and a porous, more stable material with high absorbance, biocompatibility and positive cell response was obtained.|Keywords : Alginate, 3D scaffold, graphene oxide, wound healing, composite.