149. Theranostic Aptamer-Conjugated Liposomal Nanoparticle for Triple Negative Breast Cancer

Triple-negative breast cancers (TNBC) have been focused because of their pathologic features like absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2/neu) expressions and a higher rate of metastasis. Especially, their lack of HER2 expression and aggressive progression make it difficult to utilize HER2-targeted therapeutics and diagnostics to the metastatic TNBC. In this study, first of all quantum dots were incorporated into cationic liposomes consisting of O,O’-dimyristyl-N-lysyl glutamate (DMKE). The quantum dot-incorporating cationic liposomes (QCLs) were then complexed with therapeutic small interfering RNA (siRNA) for sequence-specific RNA interference. The cationic characteristics of the QCLs provided an effective siRNA transfection in vitro, but it had limitations in in vivo applications. To enhance cancer-directed delivery, epidermal growth factor receptor (EGFR) aptamer-polyethylene glycol conjugates were inserted into the prepared QCLs. The advantage of the two-step strategy of QCL preparation includes enhanced diagnostic feature, in vivo long circulation, and TNBC specific gene silencing. This research suggests that aptamer-conjugated QCL can be utilized as a useful theranostic agent for TNBC subtype breast cancers.