The Use of Nanocarriers for Drug Delivery in Cancer Therapy

The use of nanocarriers as drug delivery systems for chemotherapeutic agents can improve the overall pharmacological properties of commonly used drugs in chemotherapy. The clinical success, as well as the ease with which surface modifi cations can be made to both liposomes and micelles to accommodate targeting ligands have made these nanocarriers in particular attractive candidates for future work involving targeted drug delivery. Although not targeted, there are clinically approved liposomal-based drugs that are currently used to treat various types of cancers. Furthermore, there are several other formulations involving both of these nanocarriers which are now in various stages of clinical trials. This review discusses the use of liposomes and micelles in cancer therapy and attempts to provide some current information regarding the clinical status of several of these nanocarrier-based drugs. In addition, recent work involving the incorporation of targeting ligands to systems such as these in order to improve colocalization between the drug and cancer cells is also addressed. Furthermore, while the use of these nanocarriers in particular is the primary focus here, this review also contains a discussion on other commonly used nanocarriers in cancer therapy to include various polymer-based and polymer-protein conjugates. Finally, the possibility of using combinatorial approaches involving multiple surface modifi cations made to both liposomes and micelles in order to further improve their drug delivery capabilities is also discussed.