1. Dispersion: Proper solubility ensures a uniform dispersion of nanoparticles in a medium, which is essential for applications like drug delivery, coatings, and composites. 2. Reactivity: The solubility of nanoparticles affects their chemical reactivity and interaction with other substances, influencing processes such as catalysis and sensing. 3. Bioavailability: In biomedical applications, the solubility of nanoparticles affects their bioavailability and distribution within biological systems, impacting their efficacy and safety.