Lithium Ion Nanocarriers Self-Assembled from Amphiphiles with Aggregation-Induced Emission Activity

Lithium salts are extensively used to treat diseases such as bipolar disorder or chronic reduction, but they often trigger undesirable side effects in patients due to the accumulation of lithium ions in peripheral organs. A conventional strategy for fabricating nanocarriers is not applicable to lithium ions because of their difficulty in binding firmly to molecules in water and easy leakage due to their small size and high water solubility. We report here the successful fabrication of lithium ion nanocarriers in water with an amphiphile containing two ethylene oxide tetramers attached to a hydrophobic core showing aggregation-induced light emission (AIE). The amphiphile self-assembles into fluorescent spherical aggregates in water. Lithium ions are loaded into the spherical aggregates by binding to the ethylene oxide tetramer. This nanocarrier can enter cells facilely via an endocytosis process and does not affect the cell viability at concentrations of up to 100 μM. Moreover, the self-imaging ability of the nanocarriers can be used to track the location of lithium-based drugs. We expect that this strategy of fabricating lithium nanocarriers will pave the way for reducing the practical doses of lithium salt that are used in clinical therapy.