Sulfated glycosaminoglycans (GAGs) are important constituents of the extracellular matrix, with roles in cell signaling, hydration, cell migration, and more. Chemical sulfation of alginate provides a structural and functional analog to sulfated GAGs, with additional properties not found in native GAGs making them promising candidates for novel biomaterials for multiple applications. These properties include the ability to form hydrogels in the presence of divalent ions, and tunability with respect to sulfation degree, monosaccharide sequence and biodegradability.
Sulfated alginates have demonstrated mitogenic properties on human cartilage in vitro, encouraging cell proliferation and prolonged survival, suppressing catabolic markers, and retaining the tissue-like phenotype of chondrocytes. Furthermore, sulfated alginates exhibit potent anti-inflammatory properties by suppressing the complement cascade and the expression and effects of inflammatory cytokines in response to hydrogels. Presently, sulfated alginates are being explored for establishing small-scale 3D cell cultures for high-throughput analysis, allowing simultaneous and automated screening of hydrogel properties against multiple cell types. Recent research thus indicates a great potential for the use of sulfated alginates in novel biomaterials, with applications in scaffold-based 3D cell cultivation and tissue engineering, surface functionalization of biomaterials, and more.