A comprehensive investigation of the variables affecting drug release from conventional and adaptive liposomes: Fundamental aspects of cancer therapy

Several clinically approved liposomal drug formulations have been developed to mitigate side effects associated with severe diseases such as cancer. However, drug release at the targeted site remains insufficient, as demonstrated in the case of Doxil®/Caelyx®. Various strategies have been proposed to utilize both the external and internal tumor environments for the activation of drug release from liposomes. This review article provides a detailed consideration of the numerous factors and variables involved in the optimization of liposome formulations aiming at improving drug release profiles. By screening the arrangement of phospholipids, cholesterol, and polyethylene glycol, the size of liposomes and the aqueous phase of the encapsulated drug can reach controlled drug-release vehicles. Stimuli-responsive liposomes, which respond to external stimuli such as light, heat, and magnetic fields, as well as internal stimuli like redox potential, pH changes, and enzymatic activity, have emerged as a promising approach for achieving controlled drug release. This approach has been discussed thoroughly in this review. Stimuli-responsive liposomes show potential for improving cancer therapies; however, additional investigation is required to connect laboratory discoveries with practical clinical implementation.