Abstract 3881: Formulating a cell membrane lipid-extracted nanoliposome (CLENS) drug platform for the treatment of prostate cancer

Abstract

Abstract Background: Liposome-encapsulated doxorubicin has proven to be an effective drug delivery method to cancer cells. Lipid extracts derived from human prostate cancer cells along with conventional components were employed to develop cell membrane lipid-extracted nanoliposomes (CLENs) for prostate cancer treatment. In an effort to balance efficiency of drug loading with cellular targeting efficiency we report on physicochemical characteristics (i.e., particle size, zeta potential, drug loading efficiency) and cellular uptake studies. Methods: Five preparations of CLENS were prepared consisting of variable concentrations of DOPC and CRL-1740 lipid extract material varying as a function of optimized fixed ratios of conventional components (Cholesterol and DSPE-PEG5000). The controls used to investigate the effect of the different components on drug incorporation efficiency were preparations of DOPC (100%) and CRL-1740 (100%). Doxorubicin hydrochloride (5 mol%) was employed during the preparation of all formulations. Samples were readily prepared by thin film evaporation. For cellular uptake studies CRL-1740 cells were seeded at 1 x 104 mL in 48-well plate and incubated for 24 hours prior to use. The cells were next exposed to various amounts of rhodamine labeled CLENS for 24 hrs. Cellular uptake was determined using fluorescence intensity values determined by a fluorescence microplate reader. Fluorescence microscopy supplement cellular uptake studies. Results: The DOPC drug-loaded liposome preparation consistently achieved the lowest percent of drug incorporation. Likewise, 100% CRL-1740 CLENs demonstrated a significant degree of formulation instability, resulting in a relatively low percent of drug incorporation compared to preparations that consisted of lipid extract and conventional components. The finding were supported by values determined for zeta potential and particle size. Cellular uptake studies also favored the preparations that consisted of lipid extract material and conventional components compared to each alone. The results collectively support the importance of balancing lipid extract material derived from prostate cancer target cells with cholesterol and DSPE-PEG5000 for formulation development and cellular uptake. Conclusion: We formulated seven preparations of CLENS as part of the drug platform. The most promising candidates were determined following completion of the study. Future studies should evaluate the cytotoxicity and safety profile of the most promising formulations vivo. Citation Format: Abubker Omaer, Ali Alqarni, Carlos Randulfe, Hanan Alharbi, Robert Campbell. Formulating a cell membrane lipid-extracted nanoliposome (CLENS) drug platform for the treatment of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3881.