Used in bioconjugation to link proteins, peptides, or other biomolecules due to its reactive vinyl sulfone groups. The 4-arm structure allows for multi-directional crosslinking, making it ideal for creating hydrogels in tissue engineering and drug delivery systems. Forms stable thioether bonds with thiol-containing molecules under mild conditions. Commonly used in controlled release formulations and 3D cell culture scaffolds. Also applied in modifying therapeutic agents to improve solubility and reduce immunogenicity.