New Concepts for Production of Scalable Single Layer Oxidized Regions by Local Anodic Oxidation of Graphene.

A deep comprehension of the local anodic oxidation process in 2D materials is achieved thanks to an extensive experimental and theoretical study of this phenomenon in graphene. This requires to arrange a novel instrumental device capable to generate separated regions of monolayer graphene oxide (GO) over graphene, with any desired size, from micrometers to unprecedented mm2 , in minutes, a milestone in GO monolayer production. GO regions are manufactured by overlapping lots of individual oxide spots of thousands µm2 area. The high reproducibility and circular size of the spots allows not only an exhaustive experimental characterization inside, but also establishing an original model for oxide expansion which, from classical first principles, overcomes the traditional paradigm of the water bridge, and is applicable to any 2D-material. This tool predicts the oxidation behavior with voltage and exposure time, as well as the expected electrical current along the process. The hitherto unreported transient current is measured during oxidation, gaining insight on its components, electrochemical and transport. Just combining electrical measurements and optical imaging estimating carrier mobility and degree of oxidation is possible. X-ray photoelectron spectroscopy reveals a graphene oxidation about 30%, somewhat lower to that obtained by Hummers' method.

Identification of a novel 2-oxindole fluorinated derivative as in vivo antitumor agent for prostate cancer acting via AMPK activation.

The key metabolic sensor adenosine monophosphate-dependent kinase (AMPK) has emerged as a promising therapeutic target for cancer prevention and treatment. Besides its role in energy homeostasis, AMPK blocks cell cycle, regulates autophagy and suppresses the anabolic processes required for rapid cell growth. AMPK is especially relevant in prostate cancer in which activation of lipogenic pathways correlate with tumor progression and aggressiveness. This study reports the discovery of a new series of 2-oxindole derivatives whose AMPK modulatory ability, as well as the antitumoral profile in prostate cancer cells, was evaluated. One of the assayed compounds, compound 8c, notably activated AMPK in cultured PC-3, DU145 and LNCaP prostate cancer cells. Likewise, compound 8c caused PC-3, DU145 and LNCaP cells viability inhibition. Selective knocking down of α1 or α2 isoforms as well as in vitro assays using human recombinant α1ß1γ1 or α2ß1γ1 AMPK isoforms revealed that compound 8c exhibit preference for AMPKα1. Consistent with efficacy at the cellular level, compound 8c was potent in suppressing the growth of PC-3 xenograft tumors. In conclusion, our results show that a new 2-oxindole fluorinated derivative exerts potent in vivo antitumor actions against prostate cancer cells, indicating a promising clinical therapeutic strategy for the treatment of androgen-independent prostate cancer.