mPEG-SH is widely used in bioconjugation and surface modification due to its thiol group, which allows for easy attachment to various molecules or surfaces. In drug delivery systems, it is employed to enhance the solubility and stability of therapeutic agents, improving their pharmacokinetics. It is also utilized in the functionalization of nanoparticles, enabling targeted delivery and reducing immunogenicity. In biotechnology, mPEG-SH is used to modify proteins or peptides, protecting them from degradation and extending their circulation time in the body. Additionally, it plays a role in creating biocompatible coatings for medical devices, preventing unwanted interactions with biological tissues.