(676d) Characterizing the Uptake of Quinic Acid and Tannic Acid Coated Iron Oxide Nanoparticles for Labeling of Cancer Cells

Brain related malignances are extremely aggressive and current diagnostic as well as therapeutic techniques have proved largely ineffective in targeting these tumors. In the context of diagnostics, methods to label cancer cells during and after the onset of carcinogenesis are being investigated. Herein, we have investigated the utility of ultrasmall iron oxide nanoparticles (USIONPs) to label U87, glioblastoma cell line (primary brain cancer) and MDA-MB-231Br, brain metastasizing variant of MDA-MB-231 triple negative breast cancer cells. Specifically, we have characterized the uptake of two types of USIONPs coated with quinic acid and tannic acid by U87 and MDA-MB-231Br cells. Based on the Prussian blue staining (qualitative) and ferrozine colorimetric iron detection (quantitative), we determined that the uptake of quinic acid coated USIONPs was significantly greater compared to that of the tannic acid coated USIONPs. In the case of MDA-MB-231Br cells, the uptake of quinic acid coated USIONPs was ~3 fold higher than the uptake of tannic acid coated USIONPs. Further, it was observed that the ratio of the uptake of quinic acid coated USIONPs to the tannic acid counterpart was highest at the early time point (i.e.,4 hr) and decreased at later time points (i.e., 72 hr). Endocytosis mainly mediated the uptake of USIONPs however, increased uptake of quinic acid coated USIONPs at earlier time point suggests that they have a tendency to selectively bind to the cancer cells before being up taken whereas, the tannic acid coated USIONPs are non-selectively up taken through endocytosis. In addition, we have observed that both versions of USIONPs do not significantly impact the proliferation of either cell line. Thus, these cells can be effectively labeled without compromising cell viability. We are currently performing transmission electron microscopy to confirm that quinic acid coated USIONPs are indeed selectively binding the cancer cells before being up taken. We are also investigating the differences between the uptake of quinic acid versus tannic acid coated USIONPs; specifically, the role of selectins in mediating the selective uptake of quinic acid coated USIONPs. This mechanistic understanding can lead to more effective targeting of cancer cells for diagnostic and therapeutic purposes.