Designing Liposomal Anticancer Drug Formulations for Specific Therapeutic Applications

Liposomal drug delivery systems have progressed significantly over the past 10 years, where technical barriers to the development of liposome-based pharmaceutical agents have been largely overcome and the clinical benefits of such systems have been established in several disease applications, particularly for cancer chemotherapy. We now have the ability to design sophisticated liposomal drug delivery systems with multifunctional properties including steric stabilizing lipids, targeting ligands, pH and temperature sensitive lipid compositions as well as components that induce intracellular delivery. However, the design of liposomes that exhibit optimized therapeutic activity will depend on the specific disease application as well as the chemical and biophysical properties of the pharmacological agent to be delivered. This is highlighted by the correlation between liposome physical characteristics and their biological behaviour as delivery systems for the anticancer drugs vincristine and doxorubicin. Taken together, the results described above highlight the importance of designing chemical and physical properties for liposomal formulations of anticancer drugs not only with respect to the agent being encapsulated but also the specific clinical applications for which they will be used. This approach is not only applicable for conventional and sterically stabilized liposomal formulations but should also be applied for more complex multifunctional liposomes.