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This paper describes the possibility of controlling and reducing the laser energy density of nanosecond 193 nm laser radiation in order to selectively ablate biological material from a glass substrate for LA-ICP-MS bioimaging applications. Atomic force microscopy and optical profilometry were used to study the shape of single-shot craters in dried gelatin droplets, ablated at low energy (

In this study, we report on the selective esterification of the carboxyl group in a coordinated ligand based on the Fischer reaction. The new [Ru(N–O)(bipy)(dppb)]PF6 complex 1 was used as a precursor to obtain the ester derivative [Ru(N–Oet)(bipy)(dppb)]PF6 (2), and in order to establish the influence of either the free carboxyl group or the ethoxycarbonyl group on biological properties, the [Ru(pic)(bipy)(dppb)]PF6 complex (3) was synthesized for comparison (dppb = 1,4-bis(diphenylphosphino)butane, bipy = 2,2′-bipyridine, N–O = mono-deprotonated 2,4-pyridinedicarboxylic acid, N–Oet = 4-ethoxycarbonyl-2-pyridinecarboxylic acid). All three complexes interact weakly with human serum albumin (HSA) with Kb values ranging from 101–104 M−1, suggesting a spontaneous interaction with this protein by electrostatic (1–2) or van der Waals interactions (3). Moreover, complex/DNA-binding experiments indicate that complexes 2 and 3 interact weakly with DNA, while no interaction is observed between complex 1 and DNA, probably due to the repulsion involving the free carboxylate group/DNA-phosphate. Anti-Mycobacterium tuberculosis (MTB) activity and cytotoxicity assays against one normal cell line V79 (hamster fibroblast) and three human cancer cell lines A549 (lung), MCF7 and MDA-MB-231 (breast) revealed that complexes 2 and 3 exhibit good activity against MTB and tumor cells, presenting high cytotoxicity (low IC50). On the other hand, complex 1 is practically inactive. Therefore, the best biological results found for complex 2 can be attributed to its esterification, improving the lipophilicity and cellular uptake, in order to facilitate its passive permeation through the tumor cell membranes allowing for cell death, as well as DNA and HSA interactions, when compared with complex 1.

Four new organoruthenium complexes with formula [RuCl(η6-p-cymene)(μ-FCZ)]2[Cl]2 (1), [RuCl(FCZ)(η6-p-cymene)(PPh3)]PF6 (2), [RuCl(CTZ)(η6-p-cymene)(PPh3)]PF6 (3) and [RuCl(KTZ)(η6-p-cymene)(PPh3)]PF6 (4) (where FCZ: 2-(2,4-difluorophenyl)-1,3-di(1H-1,2,4-triazol-1-yl)-2-propanol, CTZ: 1-[(2-chlorophenyl)-diphenylmethyl-1H-imidazole] and KTZ: cis-1-acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazine) were synthesized, characterized and evaluated as potential inhibitors for Leishmania amazonensis growth by widely reported methods. Complexes 3 and 4 displayed effective IC50 activities against Leishmania amazonensis promastigotes and intracellular amastigotes in the range of nanomolar concentration. Scanning and transmission electron microscopy analysis of Leishmania amazonensis promastigotes after treatment with 300 or 500 nM of complexes 3 and 4 for 48 h showed morphological alterations in the cell surface, a shortening of the flagellum, loss of mitochondrial matrix, disorganization of the kDNA and abnormal chromatin condensation. Thus, our strategy of incorporating a ruthenium atom into the structure of clinical drugs to improve their efficacy continues to demonstrate suitability for metallodrug discovery purposes.

The new complexes [Cu(PPh3)2(KTZ)2]NO3 (1), [Cu(PPh3)2(CTZ)2]NO3 (2), [Au(KTZ)2]Cl (3), [Au(CTZ)2]Cl (4) and Pt(KTZ)2Cl2 (5) were prepared by reaction of KTZ, CTZ (where CTZ: 1-[(2-chlorophenyl)-diphenylmethyl]-1H-imidazole and KTZ: cis-1-acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazine) and their respective metal salts or metal complexes under mild conditions. They were characterized using NMR, UV-vis and IR spectroscopies, microanalytical analysis and mass spectrometry. Complex (5) was also investigated using computational methods (DFT) to evaluate the geometry configuration around the Pt(II) coordination sphere; the results showed that the trans complex is the most stable one. The antifungal activities of these new compounds 1–5 and some of our reported metal-based azole drug derivatives such as Pt(CTZ)2Cl2 (6), [Au(PPh3)(KTZ)]PF6 (7) and [Au(PPh3)(CTZ)]PF6 (8) were evaluated against sporotrichosis agents (Sporothrix schenckii, Sporothrix brasiliensis and Sporothrix globosa). Their selectivities towards fungal cells were also evaluated. Complexes [Cu(PPh3)2(KTZ)2]NO3 (1), [Cu(PPh3)2(CTZ)2]NO3 (2), [Au(PPh3)(KTZ)]PF6 (7) and [Au(PPh3)(CTZ)]PF6 (8) inhibited fungal growth and killed fungi at concentrations in the nanomolar range and were more active than CTZ or KTZ alone. Microscopy analysis using scanning electron microscopy showed that the complexes 1, 2, 7 and 8 interfered with the cell shape. All the metal–azole complexes tested were more selective for fungi than for mammalian cells and human red blood cells, revealing that they are promising molecules for the development of new antifungal compounds.