Advances of Chitosan-based Hydrogel Scaffolds for Cartilage Tissue Engineering: Preparation, Modification, and Future Perspective

A cutting-edge field of study to create biological substitutes to maintain, restore, or enhance cartilage function is articular cartilage (AC) tissue engineering. Employing this innovative approach, polymer composites that mimic the structure and function of real cartilage tissues are created by carefully mixing biomaterials of scaffolds, cells, and biochemical components. Naturally polymers have recently gained attention as biomaterials to fabricate scaffolds, for instance, chitosan. Despite its shortcomings such as poor mechanical strength and low stiffness, chitosan-based hydrogel scaffolds have been cross-linked with other synthetic polymers, namely hybrid scaffolds, for future perspective of AC tissue engineering. To mimic AC compartment design, additive manufacturing closely resembles native tissue, and its flexibility is possibly tailored. HIGHLIGHTS Chitosan emerges as a valuable scaffold due to its structural similarity to glycine aminoglycan of extracellular matrix (ECM). Overcoming obstacles in scaffold design, innovative approaches like gradients and composite multilayer scaffolds resembling cartilage tissue are developed. The integration of elements like minerals, growth factors, and cells, along with advancements in mechanobiology and bioreactor design, is set to play a crucial role in cartilage tissue engineering. The advent of three-dimensional (3D) printing, especially with chitosan and synthetic polymer hydrogel inks, holds promise for creating stable structures.