HO-PEG-NH2 is widely used in bioconjugation and drug delivery systems due to its biocompatibility and water solubility. It serves as a linker to attach therapeutic molecules, such as drugs or proteins, to nanoparticles or other carriers, enhancing their stability and circulation time in the body. In tissue engineering, it is utilized to modify surfaces of biomaterials, improving cell adhesion and growth. Additionally, it plays a role in the development of hydrogels for controlled drug release and wound healing applications. Its amine group allows for further functionalization, making it versatile in creating targeted delivery systems for cancer therapy and other medical treatments.