Upcycling Eggshell Matrix for Sustainable Production of Glycosaminoglycans.

Glycosaminoglycans (GAGs) are biomolecules with applications in the pharmaceutical, cosmetic, and nutraceutical industries. However, traditional GAG sources, such as animal tissues and marine organisms, present imminent challenges, including structural heterogeneity, contamination risk, and geographical sourcing limitations. This review explores the potential of the eggshell matrix, an abundant yet underutilized by-product of the egg industry, as a sustainable and cost-effective alternative source of GAG production. This review examined the composition of the eggshell matrix, highlighting its rich content of hyaluronic acid, chondroitin sulfate, and other valuable GAGs, coupled with their extraction and purification techniques. The advantages of eggshell matrix-derived GAGs, including their consistent molecular properties, lower allergenicity, and alignment with circular economy principles, are also discussed. Additionally, this review highlights the industrial scalability of eggshell matrix valorization and its potential to mitigate environmental waste while meeting global GAG demand. The eggshell matrix shows promise for GAG production, with hyaluronic acid, chondroitin sulfate, and dermatan sulfate already identified, but more work is needed to improve extraction efficiency, broaden industrial uses, and ensure commercial success. This represents the broad areas of process optimization, technological integration, and comprehensive economic evaluation. By addressing current challenges and future research directions, this review underscores the transformative potential of eggshell matrix-derived GAGs for advancing sustainable biomaterial production.