Mal-PEG5-mal is widely used as a crosslinking agent in bioconjugation and chemical synthesis. Its primary application is in linking two molecules or functional groups through its maleimide ends, which react specifically with thiol groups. This makes it valuable in modifying proteins, peptides, or other biomolecules, enabling the creation of stable conjugates for research, diagnostics, or therapeutic purposes. It is also utilized in the development of drug delivery systems, where it helps attach targeting ligands to carriers like nanoparticles or liposomes. Additionally, Mal-PEG5-mal is employed in surface functionalization to modify materials for biomedical applications, such as biosensors or tissue engineering scaffolds. Its PEG spacer provides flexibility and solubility, enhancing the stability and biocompatibility of the resulting constructs.