Alginate microgels loaded with temperature sensitive liposomes for magnetic resonance imageable drug release and microgel visualization

•Temperature sensitive liposomes were (TSL) were loaded with a dye and an MRI contrast agent.•TSL were loaded into MR-imageable alginate microgels crosslinked with holmium ions.•Microgels rapidly release the dye and MRI contrast agent upon hyperthermia (42°C).•Holmium crosslinked microgels were observed in an ex vivo kidney after injection.