A novel anti-angiogenic radio/photo sensitizer for prostate cancer imaging and therapy: 89Zr-Pt@TiO2-SPHINX, synthesis and in vitro evaluation.

Prostate cancer is the most common malignancy and leading cause of cancer deaths in men. Thus, the development of novel strategies for performing combined prostate cancer imaging and therapy methods is crucial and could have a significant impact on patient care. This current study aimed to design a multimodality nanoconjugate to be used for both PET and optical imaging and as a therapeutic radio/photo sensitizer and anti-angiogenesis agent. Initial characterization of this novel nanoconjugate was performed via HPLC, FTIR, TEM and DLS analyses. Pt@TiO2-SPHINX was further evaluated using fluorometric and radiochromatographic methods. Cytotoxicity, cell uptake and internalization were also investigated as well as therapy with photodynamic/radio therapy combinations. Both nanoparticles and nanoconjugates were robustly synthesized according to literature methods. Radiochemistry and cell culture assays showed high 89Zr radiolabeling efficiency with sufficient stability for studies at later time points. Pt@TiO2-SPHINX was shown to target prostate cancer cells (PC3 and LNCaP), and was non-toxic to normal prostate cells (RWPE-1). This finding was supported by the WST-8 assay and AFM images. The uptake of the compound in prostate cancer cells is significantly higher than prostate normal cells and according to ELISA results, Pt@TiO2-SPHINX can increase anti-angiogenic VEGFA165b. Additionally, Pt@TiO2-SPHINX dramatically decreased the cell viability of prostate cancer cells when photodynamic and radio therapy were performed at the same time. In vitro results are promising for future studies of Pt@TiO2-SPHINX as a PET imaging agent and anti-angiogenic radio sensitizer.

Diethylenetriamine pentaacetic acid derivative of toremifene and in vitro evaluation in human breast cancer cell line MCF-7.

Cytotoxic and apoptotic effects of toremifene-diethylenetriamine pentaacetic acid (TOR-DTPA), formed by conjugation of TOR and DTPA, on the MCF-7 cell line were evaluated. TOR-DTPA was synthesized and qualified via gas chromatography-mass spectrometry system, thin layer chromatography, and high performance liquid chromatography methods. To screen the biological properties of TOR-DTPA at determined concentrations, our ongoing effort was to evaluate apoptotic and cytotoxic effects on the MCF-7 cell line. Trypan blue dye exclusion test, XTT, ELISA, and TUNEL assays were utilized to evaluate cytotoxicity and apoptosis. TOR-DTPA has no cytotoxic and limited apoptotic effect on the MCF-7 cell line according to the results of in vitro studies. It is concluded that the lack of obvious apoptotic and cytotoxic effects allows the already proposed ligand, TOR-DTPA, to be improved as a novel hydrophilic ligand for breast imaging.

Synthesis and biodistribution studies of two novel radiolabeled estrone derivatives.

BACKGROUND: Two 99mTc-DTPA attached estrone derivatives were synthesized and their radiopharmaceutical potential was determined using female albino Wistar rats. MATERIALS AND METHODS: Two novel radiolabeled estrone derivatives, 99mTc-2,2',2"2"'-(2,2'-(2-(3-methoxy-13-methyl-17-oxo-7, 8, 9, 11, 12, 13, 14, 15, 16, 7-decahydro-6H- cyclopenta[a]phenanthren-2-ylamino)-2- oxoethylazanediyl) bis(ethane-2,1-diyl)) bis(azanetriyl) tetraacetic acid (99mTc-2-DTPA-3-methoxy estrone) and 9mTc-2,2',2",2'"-(2,2'- (2-(3-methoxy-13-methyl-17-oxo- 7,8,9,11,12,13,14,15,16,17-decahydro- 6H-cyclopenta[a]phenanthren-4-ylamino)-2-oxoethylazanediyl) bis(ethane-2,1-diyl))bis(azanetriyl)tetraacetic acid (99mTc-4-DTPA-3-methoxy estrone) were synthesized starting from estrone (3-hydroxy-13-methyl-7,8, 9,11,12,13,15,16-octahydro-6H-cyclopenta[a]phenanthren-17(14H)-one) and DTPA anhydride (2-(bis(2-(2,6-dioxomorpholino)ethyl)amino)acetic acid) as potential estrogen receptor imaging agents. The products were crystallized in ethyl alcohol (95%), purified by high performance liquid chromatography (HPLC) and characterized by nuclear magnetic resonance (NMR) and infrared spectroscopy (IR). The effect of the radiolabeled compounds on the biological behaviour of the molecules was evaluated through biodistribution studies in female albino Wistar rats. The rats were sacrificed at various time intervals, their organs were removed, and the activities of organs were counted using a gamma counter equipped with a Cd(Te) solid state detector. RESULTS AND CONCLUSION: Organ uptake was calculated as activity/gram tissue and time versus activity curves were generated. The tissue distribution studies exhibited a receptor-mediated uptake in the target organs of the rats for each compound. Both 99mTc-2-DTPA-3-methoxy estrone and 99mTc-4-DTPA-3-methoxy estrone were stable in vitro and were mainly excreted through the hepatobiliary pathway. The biological data showed that the 99mTc-2-DTPA-3-methoxy estrone had higher uptake in the target tissues than the 99mTc-4-DTPA-3-methoxy estrone. The favourable in vitro/in vivo stability and biodistribution profiles suggest that these radioligands are good candidates for further exploration of their potential clinical applications.