Nanoscale PDA disassembly in ionic liquids: structure-property relationships underpinning redox tuning.

Nanoscale disassembly of mussel-inspired polydopamine (PDA) in ionic liquids (ILs) was recently shown to induce an electron paramagnetic resonance (EPR)-detectable reorganization of free radical centers in the resulting nanoparticles (NPs) in an IL-controlled manner. Herein, we report electrical impedance spectroscopy (EIS) data showing that PDA NPs produced by suspending samples obtained in Tris and bicarbonate buffer (PDA-T and PDA-C) in different ILs display different redox activity as a result of structural control combined with IL-surface interactions. In particular, susceptibility to oxidation was found to correlate closely with the spin density in an ion pair-tunable fashion in ILs. Structural control over free radical properties and redox behavior of PDA NPs in ILs opens novel perspectives for the rational design of functional nanovectors of possible interest for drug delivery and theranostic applications.

Vinca alkaloids and analogues as anti-cancer agents: Looking back, peering ahead.

Cancer still represents a "nightmare" worldwide, causing annually millions of victims. Several antiproliferative molecules are currently used as drugs market and offer a pharmaceutical opportunity for attenuating and treating tumor manifestations. In this context, natural sources have a relevant role, since they provide the 60% of currently-used anticancer agents. Among the numerous natural products, acting via different mechanisms of action, microtubule-targeting agents (MTAs) have a high therapeutic potential, since they disrupt the abnormal cancer cell growth, interfering with the continuous mitotic division. Vinca alkaloids (VAs) are the earliest developed MTAs and approved for clinical use (Vincristine, Vinblastine, Vinorelbine, Vindesine, and Vinflunine) as agents in the treatment of hematological and lymphatic neoplasms. Here, we review the state-of-art of VAs, discussing their mechanism of action and pharmacokinetic properties and highlighting their therapeutic relevance and toxicological profile. Additionally, we briefly disclosed the technological approaches faced so far to ameliorate the pharmacological properties, as well as to avoid the drug resistance. Lastly, we introduced the recent advances in the discovery of new derivatives.

Hydration-controlled anisotropic and giant permittivity in TEG-functionalized eumelanin.

Although it has long been known that the peculiar electronic-ionic conductor behavior of eumelanin is critically dependent on hydration, the detailed mechanisms by which water-polymer interactions control and affect the conduction properties have remained largely obscure. In this paper, we report a remarkable anisotropy and giant polarization effect in a synthetic eumelanin (TEGMe) chemically functionalized with hydrophilic TEG residues. FT-IR analyses of water sorption isotherms and AC measurements were consistent with a microporous structure binding or hosting mainly isolated water molecules. In contrast, similar experiments on a commercial synthetic eumelanin (AMe) used as a reference were suggestive of a bulk macroporous scaffold binding or hosting liquid water. These data disclosed for the first time the differential impact on eumelanin conductivity of vapor, liquid and ice-like forms of water adsorbed onto or embedded into the polymer layer. It is thus demonstrated, for the first time, that hydration controls the conduction properties of eumelanin in a more complex manner than is commonly believed, involving, besides the reported semiquinone comproportionation equilibria, the mode of interaction of water molecules as governed by both the chemical and morphological features of the polymer.

Morphometrical and Morphological Alterations of Human Leukocytes Exposed to 1.8 GHz Electromagnetic Radiations: In Vitro Protective Effects Induced by Polyphenols.

BACKGROUND: Our recent findings have demonstrated that electromagnetic radiations (EMR) (1.8 GHz radiofrequency) are able to in vitro induce morphometrical and morphological modifications of human leukocytes from normal donors. METHODS: In view of the evidence that polyphenols exert many beneficial effects on plants, animals and humans, leukocytes from human peripheral blood were pre-treated for 1 h with two polyphenol preparations from red grape before EMR exposure (1.8 GHz). RESULTS: Our data will show that polyphenol pre-treatment reverts to normality the morphology of irradiated leukocytes in comparison to irradiated cells only. Conversely, leukocyte morphometry seems to be not affected by this treatment. CONCLUSION: Here, we demonstrate that polyphenols are also able to normalize leukocyte morphology per se altered before as well as after irradiation. Finally, a working hypothesis aimed at clarifying the protective mechanisms exerted by polyphenols on irradiated leukocytes will be illustrated.