Bis-PEG8-acid is widely used as a crosslinking agent in the synthesis of hydrogels and biomaterials due to its ability to form stable, flexible, and biocompatible networks. Its PEG (polyethylene glycol) spacers provide hydrophilicity and reduce protein adsorption, making it suitable for applications in drug delivery systems where controlled release and reduced immunogenicity are essential. Additionally, it is employed in surface modification to enhance the biocompatibility of medical devices and implants. Its bifunctional nature allows it to act as a linker in bioconjugation, facilitating the attachment of biomolecules such as peptides, proteins, or antibodies for diagnostic and therapeutic purposes. In nanotechnology, Bis-PEG8-acid is utilized to functionalize nanoparticles, improving their stability and targeting efficiency in biomedical applications.