mPEG-CHO is widely used in bioconjugation and polymer chemistry due to its reactive aldehyde group. It is commonly employed to modify proteins, peptides, and other biomolecules, enabling the creation of PEGylated compounds. This process enhances the solubility, stability, and bioavailability of therapeutic agents, making it valuable in drug delivery systems. Additionally, it is utilized in surface modification to improve biocompatibility of materials used in medical devices. Its role in crosslinking reactions also makes it useful in hydrogel formation for tissue engineering and controlled release applications.