Triggering Cargo Release from Liposomes

There are multiple ways a cargo can be released from the aqueous interior of a liposome (see Figure Release Triggers). The ThermoDox© formulation is a liposome that releases Doxorubicin molecules once the tumor tissue is heated above 40 °C, which can be achieved, e.g., through focused ultrasound. After completion of two phase III clinical studies, the future of the drug product is unclear.

Figure Release Triggers: There are various ways to actively release a cargo molecule from a phospholipid liposome. The release triggers are either based on endogenous changes found in the human body (changes in temperature, enzymatic concentration, pH, redox, and shear stress) or changes that are applied exogenously (ultrasound or photoreaction pulses).