The Stability Profiles of Novel Peptide Modified Liposomes Designed to Treat Metastatic Breast Cancer

Metastatic breast cancer is the second most commonly diagnosed cancer worldwide. Therefore, improved chemotherapeutics are desperately needed. One promising potential drug construct involves the use of drug delivery vesicles. A major advantage associated with the use of drug delivery vesicles such as liposomes to transport otherwise unencapsulated cytotoxic agents is their ability to improve the therapeutic and pharmacological properties of these chemotherapeutic drugs. While the encapsulation of cytotoxic agents in liposomes have proven to be quite effective clinically, these drug constructs do in fact lack targeting capabilities to selectively bind cancerous versus non-cancerous cells. Another advantage associated with use of liposomes is that they can easily be surface-modified to incorporate targeting ligands designed to preferentially bind specific upregulated cell surface receptors, such as integrins, present on cancer cells. In fact, the α3β1 integrin is known to be overexpressed in metastatic breast cancer rendering it as a potentially promising target for this type of drug delivery. Therefore, in this study a unique single stranded peptide construct known to selectively bind the α3β1 integrin has been incorporated directly into the liposomal bilayer. Furthermore, in order to verify that the presence of the peptide within the bilayer did not negatively influence the overall structural integrity of the liposome, stability studies were conducted. These results suggest that we have designed a stable, targeted liposomal construct intended for the treatment of metastatic breast cancer.