Biomechanics of macrophage-like cells exposed to subtoxic concentrations of ionic liquids

A clear understanding of the bioactivity of room temperature ionic liquids (RTILs) remains limited. Here, we report the effects of subtoxic RTIL concentrations on THP-1 macrophage-like cells serving as an immune model for estimating their cellular interactions and biomedical potential. Atomic force microscopy (AFM) reveals significant morphological changes, including cytoskeletal softening and a morphological change from spread to rounded. Quantifications of actin and tubulin validate these mechanical alterations. An increase in intracellular vesicles is evident for enhanced autophagy as a protective response. Artificially induced autophagy improves cell viability, while autophagosome density increases across all RTIL treatments. Actin's known role in intracellular trafficking and biomechanical observations suggest that cytoskeletal remodeling occurs along with autophagy induction. Overall, this study demonstrates macrophages' adaptive response to RTIL stress via autophagy and provides critical insights into tuning RTIL-cell interactions for safe and effective applications in targeted therapies and drug delivery systems.