Alginate-Based Composites in Tissue Engineering: Design, Applications, and Translational Perspectives

Alginate, a naturally derived polysaccharide obtained from brown seaweed, has emerged as one of the most versatile biomaterials for tissue engineering applications. This is due to its excellent biocompatibility, mild gelation tendencies under physiological conditions, and its ability to form hydrogels with tunable mechanical and degradation properties. However, the native alginate lacks the inherent cell adhesion sites and the mechanical robustness, thereby limiting its stand-alone usage in regenerative medicine. To ameliorate/overcome these limitations, alginate-based composites have been developed by combining alginate with various polymers, ceramics, nanomaterials, and bioactive molecules. These hybrid materials exhibit enhanced physicochemical, mechanical, and biological properties that are tailored for specific tissue engineering applications, including bone, cartilage, cardiac, neural, and skin regeneration. This chapter provides a comprehensive overview of alginate chemistry, crosslinking mechanisms, composite fabrication strategies, and the recent advances in alginate-based scaffolds. Special emphasis is devoted to the biofunctionalization techniques, 3D bioprinting approaches, and the translational challenges often experienced in its clinical applications. Future perspectives highlight the integration of alginate composites with smart biomaterials and biofabrication technologies for the next-generation tissue regeneration platforms.