CHO-PEG-COOH is widely used in bioconjugation and drug delivery systems due to its reactive aldehyde (CHO) and carboxyl (COOH) functional groups. The aldehyde group enables site-specific conjugation with amine-containing molecules, such as proteins or peptides, through Schiff base formation, while the carboxyl group allows further modification or coupling with other functional groups. This makes it a valuable tool for creating targeted drug delivery systems, where it can link therapeutic agents to carriers like nanoparticles or antibodies. It is also employed in surface modification to enhance biocompatibility and stability of biomaterials. Additionally, CHO-PEG-COOH is utilized in the development of hydrogels and other scaffolds for tissue engineering, where it promotes cell adhesion and growth. Its versatility and biocompatibility make it a key component in various biomedical and biotechnological applications.