A23 Session 7: Advances in Thermal Medicine : Thermally activated targeted drug delivery

Abstract

A number of nanoparticle drug delivery systems are available for heat- or cold-mediated local drug delivery. One example currently in clinical trials includes Temperature-sensitive liposomes (TSL), which release their contents in response to localized hyperthermia above ∼40 °C. This presentation describes advantages and disadvantages of this targeted drug delivery strategy, explains the drug transport kinetics, and identifies relevant properties of drug and nanoparticle that affect delivery. Further, specific devices for heat-activated drug delivery are reviewed, including tumor ablation devices currently in clinical use. One particularly elegant method of localized tissue heating is via high-intensity focused ultrasound (HIFU). HIFU focuses ultrasound with mm accuracy into deep tissue regions to locally heat tissue non-invasively, while MR thermometry allows monitoring of tissue temperature during HIFU. Computational models and corroborating animal studies of the HIFU + TSL approach are presented showing the ability to facilitate locally targeted drug delivery. To monitor amount and location of drug delivery, TSL can be loaded with contras t agents that allow real-time monitoring under MR imaging. Thermally activated nanoparticles thus have the potential to become a clinically relevant drug delivery system for loco-regional cancer treatment.