RESUMO
Aqueous electrolytes typically suffer from poor electrochemical stability; however, eutectic aqueous solutions-25â wt.% LiCl and 62â wt.% H3 PO4 -cooled to -78 °C exhibit a significantly widened stability window. Integrated experimental and simulation results reveal that, upon cooling, Li+ ions become less hydrated and pair up with Cl- , ice-like water clusters form, and Hâ â â Cl- bonding strengthens. Surprisingly, this low-temperature solvation structure does not strengthen water molecules' O-H bond, bucking the conventional wisdom that increasing water's stability requires stiffening the O-H covalent bond. We propose a more general mechanism for water's low temperature inertness in the electrolyte: less favorable solvation of OH- and H+ , the byproducts of hydrogen and oxygen evolution reactions. To showcase this stability, we demonstrate an aqueous Li-ion battery using LiMn2 O4 cathode and CuSe anode with a high energy density of 109â Wh/kg. These results highlight the potential of aqueous batteries for polar and extraterrestrial missions.
RESUMO
APO866 inhibits nicotinamide phosphoribosyltransferase (NMPRTase), a key enzyme involved in nicotinamide adenine dinucleotide (NAD) biosynthesis from the natural precursor nicotinamide. Intracellular NAD is essential for cell survival, and NAD depletion resulting from APO866 treatment elicits tumor cell death. Here, we determine the in vitro and in vivo sensitivities of hematologic cancer cells to APO866 using a panel of cell lines (n = 45) and primary cells (n = 32). Most cancer cells (acute myeloid leukemia [AML], acute lymphoblastic leukemia [ALL], mantle cell lymphoma [MCL], chronic lymphocytic leukemia [CLL], and T-cell lymphoma), but not normal hematopoietic progenitor cells, were sensitive to low concentrations of APO866 as measured in cytotoxicity and clonogenic assays. Treatment with APO866 decreased intracellular NAD and adenosine triphosphate (ATP) at 24 hours and 48 to72 hours, respectively. The NAD depletion led to cell death. At 96 hours, APO866-mediated cell death occurred in a caspase-independent mode, and was associated with mitochondrial dysfunction and autophagy. Further, in vivo administration of APO866 as a single agent prevented and abrogated tumor growth in animal models of human AML, lymphoblastic lymphoma, and leukemia without significant toxicity to the animals. The results support the potential of APO866 for treating hematologic malignancies.
Assuntos
Acrilamidas/uso terapêutico , Antineoplásicos/uso terapêutico , Citocinas/antagonistas & inibidores , Neoplasias Hematológicas/tratamento farmacológico , NAD/biossíntese , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Piperidinas/uso terapêutico , Acrilamidas/farmacologia , Animais , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HL-60 , Neoplasias Hematológicas/metabolismo , Humanos , Células Jurkat , Células K562 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , NAD/efeitos dos fármacos , Piperidinas/farmacologia , Células Tumorais Cultivadas , Células U937 , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We developed and tested a potent hexameric Fas agonist, termed MegaFasL, for its cytotoxic effects on a panel of human haematopoietic malignant cells and healthy human haematopoietic progenitor cells (CD34+CD38low). Results demonstrated that MegaFasL induced apoptosis in cell lines and primary cells representing multiple myeloma (MM), acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) and Burkitt's lymphoma. Cells from a chronic myeloid leukaemia (CML) line and from patients with chronic lymphocytic leukaemia (CLL) were resistant. Furthermore, CD34+CD38low progenitor cells were also resistant to MegaFasL. The data indicate that MegaFasL could be a highly efficient therapeutic agent ex vivo or potentially in vivo.