**3. Conclusions**

The naturally available biopolymer alginate is cheaper which forms hydrogel by cross-linking with various salts like BaCl2, CaCl2, and ZnCl2 which showed good biocompatibility and printability.

This is broadly applied for cartilage, bone, and vascular tissue printing. Few drawbacks of alginate are slow degradation and poor cell adhesion; in many research, it is shown that alginate has poor cell differentiation and cell proliferation, and for this reason, it is used as a blend with other polymers. To improve these limitations, blending alginate with other polymers like honey, gelatin, and Arg-Gly-Asp adhesions is done. Furthermore, for faster normal degradation in regenerative medicine, oxidized alginate and/or sodium citrate is found to be useful. The combination of 3D printing alginate for cartilage and electrospinning is used positively in various tissue engineering fields. Furthermore, mixing alginate with biopolymers like polycaprolactone and nanocellulose has shown positive results. In bioprinting using coaxial or triaxial nozzles is found out to be promising and provided brilliant results. To improve the mechanical properties of the alginate-based structures used in bone tissue engineering, mixing alginate with other polymers like bio-silica, polyphosphate, polycaprolactone hydroxyapatite, and gelatin is found to produce an excellent result. We think this review will allow researchers to investigate more advanced and improved bioink for 3D printing and also help to invent suitable and more appropriate bioink for various tissue engineering applications
