Some of the same properties that make<unk> s efficient drug carriers also contribute to their toxicity. For example, gold<unk> s are known to interact with proteins through surface adsorption, forming a protein corona, which can be utilized for cargo loading and immune shielding. However, this protein-adsorption property can also disrupt normal protein function that is essential for homeostasis, especially when the protein contains exposed sulfur groups. The photothermal effect, which can be induced to kill tumor cells, may also create reactive oxygen species that impose oxidative stress on surrounding healthy cells. Gold<unk> s of sizes below 4-5 nm fit in DNA grooves which can interfere with transcription, gene regulation, replication, and other processes that rely on DNA-protein binding. Lack of biodegradability for some<unk>  chemistries can lead to accumulation in certain tissues, thus interfering with a wide range of biological processes. Currently, there is no regulatory framework in the United States for testing<unk> s for their general impact on health and on the environment.
Nanoparticle drug delivery
Targeted drug delivery
Drug recycling
Drug detoxification
Magnetic-targeted carrier
Thin-film drug delivery
Drug metabolism
Magnetic drug delivery