Used in bioconjugation and drug delivery systems, it serves as a linker molecule to attach drugs, proteins, or other biomolecules. The maleimide group enables specific reaction with thiol groups, while the carboxylic acid allows further functionalization. Its PEG spacer enhances solubility and reduces immunogenicity, making it valuable in creating targeted therapies. Commonly applied in antibody-drug conjugates (ADCs) and peptide modifications to improve stability and efficacy. Also utilized in research for labeling and tracking biomolecules in cellular studies.