Effect of cross-linkers in fabrication of carrageenan-alginate matrices for tissue engineering application

The three-dimensional (3D) scaffold serves as a structural substrate and as a niche for cell proliferation to ensure tissue regeneration. Ideal scaffolds should have porous structures with high pore interconnectivity to allow cell adherence, differentiation, and proliferation while ensuring suitable mechanical strength and biodegradability without inflicting any immune response. Cross-linker is one of the major factors that affect the mechanical and biological properties of scaffolds. In this study, different chemical cross-linker effects on scaffold architecture were examined. Porous 3D scaffolds based on carrageenan and alginate (CA) were successfully fabricated by a freeze-drying technique and using various cross-linkers like glutaraldehyde (GA), genipin, and ethyl (dimethylamino propyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS). The chemical cross-linker effects on the CA scaffold were characterized by scanning electron microscopy, differential scanning calorimetry, and thermogravimetry. A human fibroblast cell line (L929) was seeded into the fabricated scaffold, and cell proliferation was assessed by MTT and live/dead assay. Overall results suggested the potential cross-linkers for ideal CA biomaterial could be EDC/NHS among other agents tested as the scaffold CAEN was found to be porous, interconnected, and physically and mechanically stable. When compared to matrices with other cross-linkers, higher cell attachment, better cellular response, and higher metabolic activity could be observed in the scaffold synthesized using EDC/NHS as cross-linker.