Kappa-carrageenan bioink is the first ever commercialized kappa-carrageenan bioink for 3D bioprinting. Carrageenan is a hydrophilic polymer extracted from algae and is used as a gelling agent and emulsifying agent. Among different types of carrageenan, Kappa-carrageenan (κCA), a natural linear water-soluble polysaccharide with one sulphated group per disaccharide (25 to 30% ester sulfate content), is one of the appropriate biomaterial in tissue engineering.  Kappa-carrageenan bioink has been seen as a potential candidate for this area in injectable form, due to its gelation properties, mechanical strength and resemblance to chondroitin-4-sulfate anddermatan sulfate, which are the major components of native extracellular matrices (ECM) called glycosaminoglycans (GAGs).

Kappa-carrageenan bioink is a thixotropic polymer and can be converted into hydrogel form via ionic crosslinking method. However, these crosslinking methods offer hydrogels that have low stability in physiologic conditions. In order to overcome this drawback, Kappa-carrageenan methacrylating to synthesis KapMA with photopolymerization potential.

Kappa-carrageenan bioink has a characteristic of tunable viscosity depending on concentration, temperature, the presence of ions and molecular weight and has properties of high strength, nontoxic and cellular compatibility. As its shear-thinning and thermo-reversible properties are suitable for bioinks, Kappa-carrageenan could been chosen as a bioink material for 3D extrusion-based bioprinting.