Preparation and in vitro evaluation of an ultrasound-triggered drug delivery system: 10-Hydroxycamptothecin loaded PLA microbubbles

► Lactone-formed 10-hydroxycamptothecin (HCPT) loaded PLA microbubbles were fabricated by a double emulsion-solvent evaporation method. ► The HCPT loaded PLA microbubbles had the typical characteristics of drug carrier, and possessed ultrasound-triggered drug release mechanism. ► The HCPT loaded PLA microbubbles combined with ultrasound exposure showed more cytotoxic than the microbubbles alone. ► The combination of drug loaded microbubbles and diagnostic ultrasound exposure exhibit an effective intracellular drug uptake by tumor cells, indicating their great potential for antitumor therapy.