A perspective on magnetic ionic liquids as multifunctional platforms for drug delivery and biomedical applications

The demand for advanced field-responsive materials has positioned magnetic ionic liquids (MILs) as a transformative class of tunable fluids that bridge materials science and biomedicine. Initially valued for magnetically induced behaviors, MILs excel in surface activity, solubility enhancement (up to 39,000-fold for poorly soluble drugs), colloidal stabilization, and polymer-surfactant interactions at interfaces. Recent computational advances, Density Functional Theory (DFT) for electronic structures and ion reactivity, alongside Molecular Dynamics (MD) simulations, predict properties across timescales, enabling design-driven synthesis of low-viscosity, high-magnetic-moment formulations with thermal stability to 345 °C. In biomedicine, MILs promise targeted drug delivery, NIR-fluorescent theranostics, and dual-mode MRI contrast via paramagnetic chelates, with 2025 breakthroughs in magnet-guided tumor nanocomplexes outperforming traditional nanoparticles. Their significance lies in their use as stimuli-responsive platforms for oncology, neurology, and antimicrobial therapies, thereby enhancing bioavailability and enabling green, recyclable pharmaceutical processes. Yet, critical gaps persist. Fe-based MILs suffer from hydrolysis and reproducibility issues, while Co/Mn variants raise toxicity concerns, limiting biocompatibility, in vivo biodistribution studies, and pharmacokinetics data. Scalability hurdles, such as high costs, non-standardized characterization, and inadequate models for field effects on transport, hinder clinical translation. This perspective critically reflects on the evolution of MIL research, integrating experimental and computational advances, and underscores the need for design-driven synthesis, standardised characterisation, and application-oriented strategies. By highlighting achievements, addressing key challenges, and mapping future directions, we aim to stimulate cross-disciplinary dialogue and accelerate the translation of MILs into next-generation technological and biomedical platforms.