Neutral rhenium(I) tricarbonyl complexes with sulfur-donor ligands: anti-proliferative activity and cellular localization.

Rhenium(I) tricarbonyl complexes are widely studied for their cell imaging properties and anti-cancer and anti-microbial activities, but the complexes with S-donor ligands remain relatively unexplored. A series of six fac-[Re(NN)(CO)3(SR)] complexes, where (NN) is 2,2'-bipyridyl (bipy) or 1,10-phenanthroline (phen), and RSH is a series of thiocarboxylic acid methyl esters, have been synthesized and characterized. Cellular uptake and anti-proliferative activities of these complexes in human breast cancer cell lines (MDA-MB-231 and MCF-7) were generally lower than those of the previously described fac-[Re(NN)(CO)3(OH2)]+ complexes; however, one of the complexes, fac-[Re(CO)3(phen)(SC(Ph)CH2C(O)OMe)] (3b), was active (IC50 ∼ 10 µM at 72 h treatment) in thiol-depleted MDA-MB-231 cells. Moreover, unlike fac-[Re(CO)3(phen)(OH2)]+, this complex did not lose activity in the presence of extracellular glutathione. Taken together these properties show promise for further development of 3b and its analogues as potential anti-cancer drugs for co-treatment with thiol-depleting agents. Conversely, the stable and non-toxic complex, fac-[Re(bipy)(CO)3(SC(Me)C(O)OMe)] (1a), predominantly localized in the lysosomes of MDA-MB-231 cells, as shown by live cell confocal microscopy (λex = 405 nm, λem = 470-570 nm). It is strongly localized in a subset of lysosomes (25 µM Re, 4 h treatment), as shown by co-localization with a Lysotracker dye. Longer treatment times with 1a (25 µM Re for 48 h) resulted in partial migration of the probe into the mitochondria, as shown by co-localization with a Mitotracker dye. These properties make complex 1a an attractive target for further development as an organelle probe for multimodal imaging, including phosphorescence, carbonyl tag for vibrational spectroscopy, and Re tag for X-ray fluorescence microscopy.

Synthesis and the photophysical and biological properties of tricarbonyl Re(I) diimine complexes bound to thiotetrazolato ligands.

Twelve Re(I) tricarbonyl diimine (2,2'-bipyridine and 1,10-phenanthroline) complexes with thiotetrazolato ligands have been synthesised and fully characterised. Structural characterisation revealed the capacity of the tetrazolato ligand to bind to the Re(I) centre through either the S atom or the N atom with crystallography revealing most complexes being bound to the N atom. However, an example where the Re(I) centre is linked via the S atom has been identified. In solution, the complexes exist as an equilibrating mixture of linkage isomers, as suggested by comparison of their NMR spectra at room temperature and 373 K, as well as 2D exchange spectroscopy. The complexes are photoluminescent in fluid solution at room temperature, with emission either at 625 or 640 nm from the metal-to-ligand charge transfer excited states of triplet multiplicity, which seems to be exclusively dependent on the nature of the diimine ligand. The oxygen-sensitive excited state lifetime decay ranges between 12.5 and 27.5 ns for the complexes bound to 2,2'-bipyrdine, or between 130.6 and 155.2 ns for those bound to 1.10-phenanthroline. Quantum yields were measured within 0.4 and 1.5%. The complexes were incubated with human lung (A549), brain (T98g), and breast (MDA-MB-231) cancer cells, as well as with normal human skin fibroblasts (HFF-1), revealing low to moderate cytotoxicity, which for some compounds exceeded that of a standard anti-cancer drug, cisplatin. Low cytotoxicity combined with significant cellular uptake and photoluminescence properties provides potential for their use as cellular imaging agents. Furthermore, the complexes were assessed in disc diffusion and broth microdilution assays against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) bacterial strains, which revealed negligible antibacterial activity in the dark or after irradiation.

Ligand-Mediated Control of the Surface Oxidation States of Copper Nanoparticles Produced by Laser Ablation.

We report on studies that demonstrate how the chemical composition of the surface of copper nanoparticles (CuNPs) - in terms of percentage copper(I/II) oxides - can be varied by the presence of N-donor ligands during their formation via laser ablation. Changing the chemical composition thus allows systematic tuning of the surface plasmon resonance (SPR) transition. The trialed ligands include pyridines, tetrazoles, and alkylated tetrazoles. CuNPs formed in the presence of pyridines, and alkylated tetrazoles exhibit a SPR transition only slightly blue shifted with respect to CuNPs formed in the absence of any ligand. On the other hand, the presence of tetrazoles results in CuNPs characterized by a significant blue shift of the order of 50-70 nm. By comparing these data also with the SPR of CuNPs formed in the presence of carboxylic acids and hydrazine, this work demonstrates that the blue shift in the SPR is due to tetrazolate anions providing a reducing environment to the nascent CuNPs, thus preventing the formation of copper(II) oxides. This conclusion is further supported by the fact that both AFM and TEM data indicate only small variations in the size of the nanoparticles, which is not enough to justify a 50-70 nm blue-shift of the SPR transition. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) studies further confirm the absence of Cu(II)-containing CuNPs when prepared in the presence of tetrazolate anions.

Aryl bismuth phosphinates [BiAr2(O(O)PRR')]: structure-activity relationships for antibacterial activity and cytotoxicity.

To study and evaluate the structure-activity relationships in di-aryl bismuth phosphinates on antibacterial activity and cytotoxicity a series of complexes containing ortho-methoxyphenyl, meta-methoxyphenyl, meta-tolyl and para-tolyl aryl groups; [Bi(o-MeOPh)2(O(O)P(H)Ph)]n1, [Bi(o-MeOPh)2(O(O)PPh2)]n2, [Bi(o-MeOPh)2(O(O)P(p-MeOPh)2)]n3, [Bi(m-MeOPh)2(O(O)P(H)Ph)]n4, [Bi(m-MeOPh)2(O(O)PPh2)]n5, [Bi(m-MeOPh)2(O(O)P(p-MeOPh)2)]n6, [Bi(m-tol)2(O(O)P(H)Ph)]n7, [Bi(m-tol)2(O(O)PPh2)]n8, [Bi(m-tol)2(O(O)P(p-MeOPh)2)]n9, [Bi(p-tol)2(O(O)P(H)Ph)]n10, [Bi(p-tol)2(O(O)PPh2)]n11 and [Bi(p-tol)2(O(O)P(p-MeOPh)2)]n12, were synthesised and characterised. Complexes 4, 7, 8, 10 and 11 were structurally authenticated by X-ray crystallography. Evaluation of their antibacterial activity towards methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) showed that the bismuth bound aryl group has a profound influence on activity, with the o-MeOPh complexes 1-3 showing very little activity while the m-MeOPh complexes have the greatest activity towards MRSA and VRE in the range of 0.63 to 1.25 µM. Viability studies with Cos-7 cells showed that the di-aryl bismuth complexes 1-12 are less cytotoxic than their di-phenyl bismuth analogues, with a general trend of toxicity observed as p-tolyl > m-tolyl > m-methoxyphenyl > o-methoxyphenyl. The large difference in Cos-7 viability for complexes 1 (IC50 > 80 µM) and 4 (IC50 14.0 µM) was further investigated through bismuth uptake studies, where there was no obvious difference in Cos-7 bismuth uptake at 5 µM. This suggests that the bismuth-bound aryl group has a significant impact on biological activity, which is then further mediated by other ligands.

Medicinal chemistry and biomedical applications of bismuth-based compounds and nanoparticles.

Bismuth as a relatively non-toxic and inexpensive metal with exceptional properties has numerous biomedical applications. Bismuth-based compounds are used extensively as medicines for the treatment of gastrointestinal disorders including dyspepsia, gastric ulcers and H. pylori infections. Recently, its medicinal application was further extended to potential treatments of viral infection, multidrug resistant microbial infections, cancer and also imaging, drug delivery and biosensing. In this review we have highlighted the unique chemistry and biological chemistry of bismuth-209 as a prelude to sections covering the unique antibacterial activity of bismuth including a description of research undertaken to date to elucidate key molecular mechanisms of action against H. pylori, the development of novel compounds to treat infection from microbes beyond H. pylori and the significant role bismuth compounds can play as resistance breakers. Furthermore we have provided an account of the potential therapeutic application of bismuth-213 in targeted alpha therapy as well as a summary of the biomedical applications of bismuth-based nanoparticles and composites. Ultimately this review aims to provide the state of the art, highlight the untapped biomedical potential of bismuth and encourage original contributions to this exciting and important field.

Neutral Re(I) Complex Platform for Live Intracellular Imaging.

Luminescent metal complexes are a valuable platform for the generation of cell imaging agents. However, many metal complexes are cationic, a factor that can dominate the intracellular accumulation to specific organelles. Neutral Re(I) complexes offer a more attractive platform for the development of bioconjugated imaging agents, where charge cannot influence their intracellular distribution. Herein, we report the synthesis of a neutral complex (ReAlkyne), which was used as a platform for the generation of four carbohydrate-conjugated imaging agents via Cu(I)-catalyzed azide-alkyne cycloaddition. A comprehensive evaluation of the physical and optical properties of each complex is provided, together with a determination of their utility as live cell imaging agents in H9c2 cardiomyoblasts. Unlike their cationic counterparts, many of which localize within mitochondria, these neutral complexes have localized within the endosomal/lysosomal network, a result consistent with examples of dinuclear carbohydrate-appended neutral Re(I) complexes that have been reported. This further demonstrates the utility of these neutral Re(I) complex imaging platforms as viable imaging platforms for the development of bioconjugated cell imaging agents.

Antimicrobial innovation: a current update and perspective on the antibiotic drug development pipeline.

As bacteria continue to develop resistance to our existing treatment options, antibiotic innovation remains overlooked. If current trends continue, then we could face the stark reality of a postantibiotic era, whereby routine bacterial infections could once again become deadly. In light of a warning signaled by the WHO, a number of new initiatives have been established in the hope of reinvigorating the antibiotic drug development pipeline. In this perspective, we aim to summarize some of these initiatives and funding options, as well as providing an insight into the predicament that we face. Using clinical trials data, company website information and the most recent press releases, a current update of the antibiotic drug development pipeline is also included.

Impact of structural changes in heteroleptic bismuth phosphinates on their antibacterial activity in Bi-nanocellulose composites.

To study and evaluate the effect of ligand choice and distribution in bismuth phosphinates on toxicity and antibacterial activity, a series of novel diphenyl mono-phosphinato bismuth complexes, [BiPh2(O(O[double bond, length as m-dash])P(H)Ph)] 1, [BiPh2(O(O[double bond, length as m-dash])PPh2)] 2, [BiPh2(O(O[double bond, length as m-dash])PMe2)] 3 and [BiPh2(O(O[double bond, length as m-dash])P(p-MeOPh)2)] 4, were synthesised, characterised and structurally authenticated by X-ray crystallography. Evaluation of their antibacterial activity towards Staphylococcus aureus (S. aureus), methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococci (VRE), Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) showed all four mono-phosphinato bismuth complexes to be highly active. However, unlike their less soluble bis-phosphinato analogues, they displayed an increased level of toxicity towards mammalian cells (COS-7, human and murine fibroblasts), where it was shown the complexes disrupt cellular membranes leading to cytotoxicity. The mono-phosphinato bismuth complexes were used to produce antibacterial nanocellulose composites. Leaching studies showed that complex 1 had the highest levels of leaching, at 15% of the total available bismuth when the composite was soaked in water. The aqueous leachates of 1 were bacteriostatic towards MRSA and VRE at concentrations between 4.0 and 4.6 µM, while being bactericidal towards E. coli above 2.8 µM. At similar concentrations the complex showed toxicity towards human fibroblast cells, with cell viability reduced to 2% (1, 2.4 µM). The possibility to control leaching of the bismuth complexes from cellulose composites through structural changes is evidence for their potential application in antibacterial surfaces and materials.

Bismuth(III) Flavonolates: The Impact of Structural Diversity on Antibacterial Activity, Mammalian Cell Viability and Cellular Uptake.

A series of homoleptic and heteroleptic bismuth(III) flavonolate complexes derived from six flavonols of varying substitution have been synthesised and structurally characterised. The complexes were evaluated for antibacterial activity towards several problematic Gram-positive (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE)) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. The cell viability of COS-7 (monkey kidney) cells treated with the bismuth flavonolates was also studied to determine the effect of the complexes on mammalian cells. The heteroleptic complexes [BiPh(L)2 ] (in which L=flavonolate) showed good antibacterial activity towards all of the bacteria but reduced COS-7 cell viability in a concentration-dependent manner. The homoleptic complexes [Bi(L)3 ] exhibited activity towards the Gram-positive bacteria and showed low toxicity towards the mammalian cell line. Bismuth uptake studies in VRE and COS-7 cells treated with the bismuth flavonolate complexes indicated that Bi accumulation is influenced by both the substitution of the flavonolate ligands and the degree of substitution at the bismuth centre.

Is Bismuth Really the "Green" Metal? Exploring the Antimicrobial Activity and Cytotoxicity of Organobismuth Thiolate Complexes.

Antimicrobial resistance is becoming an ever-increasing threat for human health. Metal complexes and, in particular, those that incorporate bismuth offer an attractive alternative to the typically used organic compounds to which bacteria are often able to develop resistance determinants. Herein we report the synthesis, characterization, and biological evaluation of a series of homo- and heteroleptic bismuth(III) thiolates incorporating either one (BiPh2L), two (BiPhL2), or three (BiL3) sulfur-containing azole ligands where LH = tetrazolethiols or triazolethiols (thiones). Despite bismuth typically being considered a nontoxic heavy metal, we demonstrate that the environment surrounding the metal center has a clear influence on the safety of bismuth-containing complexes. In particular, heteroleptic thiolate complexes (BiPh2L and BiPhL2) display strong antibacterial activity yet are also nonselectively cytotoxic to mammalian cells. Interestingly, the homoleptic thiolate complexes (BiL3) were shown to be completely inactive toward both bacterial and mammalian cells. Further biological analysis of the complexes revealed the first insights into the biological mode of action of these particular bismuth thiolates. Scanning electron microscopy images of methicillin-resistant Staphylococcus aureus (MRSA) cells have revealed that the cell membrane is the likely target site of action for bismuth thiolates against bacterial cells. This points toward a nonspecific mode of action that is likely to contribute to the poor selectivity's demonstrated by the bismuth thiolate complexes in vitro. Uptake studies suggest that reduced cellular uptake could explain the marked difference in activity between the homo- and heteroleptic complexes.

Ruthenium(II)-Arene Thiocarboxylates: Identification of a Stable Dimer Selectively Cytotoxic to Invasive Breast Cancer Cells.

RuII -arene complexes provide a versatile scaffold for novel anticancer drugs. Seven new RuII -arene-thiocarboxylato dimers were synthesized and characterized. Three of the complexes (2 a, b and 5) showed promising antiproliferative activities in MDA-MB-231 (human invasive breast cancer) cells, and were further tested in a panel of fifteen cancerous and noncancerous cell lines. Complex 5 showed moderate but remarkably selective activity in MDA-MB-231 cells (IC50 =39±4 µm Ru). Real-time proliferation studies showed that 5 induced apoptosis in MDA-MB-231 cells but had no effect in A549 (human lung cancer, epithelial) cells. By contrast, 2 a and b showed moderate antiproliferative activity, but no apoptosis, in either cell line. Selective cytotoxicity of 5 in aggressive, mesenchymal-like MDA-MB-231 cells over many common epithelial cancer cell lines (including noninvasive breast cancer MCF-7) makes it an attractive lead compound for the development of specifically antimetastatic Ru complexes with low systemic toxicity.

Synthesis, structural characterisation, and cytotoxicity studies of Bi, W, and Mo containing homo- and hetero-bimetallic polyoxometalates.

Three new and different homo- and hetero-bimetallic polyoxometalate (POM) species have been synthesised by simple one-pot synthetic methods utilising naturally occurring bismite (Bi2O3) (or Bi(NO3)3·5H2O) and aryl sulfonic acids. The POM species isolated are (NH4)14[Bi2W22O76]·14H2O (1·14H2O), (NH4)[Bi(DMSO)7][Mo8O26]·H2O (2·H2O) and [(NH4)4(Mo36O108(OH)4·16H2O)]·45H2O (3·45H2O). The compounds have been characterised by X-ray crystallography, energy dispersive X-ray spectroscopy (EDX), powdered X-ray diffraction (PXRD), mass spectrometry (ESI-MS), Raman spectroscopy, thermogravimetric (TGA) and ICP analyis. In vitro cytoxicity and proliferation studies conducted on 1 and 3, highlight the low toxicity of these species.

Bismuth Phosphinates in Bi-Nanocellulose Composites and their Efficacy towards Multi-Drug Resistant Bacteria.

A series of poorly soluble phenyl bis-phosphinato bismuth(III) complexes [BiPh(OP(=O)R1 R2 )2 ] (R1 =R2 =Ph; R1 =R2 =p-OMePh; R1 =R2 =m-NO2 Ph; R1 =Ph, R2 =H; R1 =R2 =Me) have been synthesised and characterised, and shown to have effective antibacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The bismuth complexes were incorporated into microfibrillated (nano-) cellulose generating a bismuth-cellulose composite as paper sheets. Antibacterial evaluation indicates that the Bi-cellulose materials have analogous or greater activity against Gram positive bacteria when compared with commercial silver based additives: silver sulfadiazine loaded at 0.43 wt % into nanocellulose produces a 10 mm zone of inhibition on the surface of agar plates containing S. aureus whereas [BiPh(OP(=O)Ph2 )2 ] loaded at 0.34 wt % produces an 18 mm zone of inhibition. These phenyl bis-phosphinato bismuth(III) complexes show potential to be applied in materials in healthcare facilities, to inhibit the growth of bacteria capable of causing serious disease.

2D and 3D Coordination Networks of Polynuclear Bismuth Oxido/Hydroxido Sulfonato Clusters from Low Temperature Solid-State Metathesis Reactions.

Solid-state metathesis (SSM) reactions between Bi(NO3 )3 ⋅5 H2 O and potassium benzene-1,2-disulfonate (=1,2-BDSK2 ), sodium benzene-1,3-disulfonate (=1,3-BDSNa2 ) allows access to the first 2D, {[Bi6 O4 (OH)4 (1-2BDS)2 (NO3 )2 ⋅4 H2 O]⋅11 H2 O}∞ and {[Bi22 O24 (OH)6 (1,3-BDS)6 ⋅12 DMSO]⋅3 DMSO⋅4 H2 O}∞ , and 3D, {[Bi6 O4 (OH)4 (1,3-BDS)3 ⋅4 H2 O]⋅6 H2 O}∞ , polymeric networks of sulfonato encapsulated polynuclear bismuth oxido/hydroxido clusters.

Transformation of Indium and Gallium Metal into Mixed Group†11/13 Ternary Sulfide Nanoparticles by Using a Dithioic Acid.

Heterobimetallic Group 11/13 sulfide nanoparticles (AgInS2 , CuInS2 , Ag9 GaS6 , and CuGaS2 ) are formed by treatment of [M(S2 CAr)3 ] (M=Ga or In) with either AgNO3 or CuCl under mild conditions. The intermediary gallium or indium tris(aryldithioate) complexes are easily prepared by stirring the appropriate metal and aryldithioc acid at room temperature. Overall, this two-step process is a simple solution-based method for transforming Ga and In metal into valuable ternary metallosulfide nanoparticles at relatively low temperatures.

Formation of Group†11 Bismuth Sulfide Nanoparticles Using Bismuth Dithioates under Mild Conditions.

The formation of mixed-metal sulfides with the general structure AgBiS2 and Cu3 BiS2 by a simple two-step process utilizing bismuth dithiocarboxylates as Bi and S precursors is described. A sonochemical reaction of Bi2 O3 with six different aryl dithioic acids: dithiobenzoic acid (BDT-H), 4-methoxydithiobenzoic acid (4-MBDT-H), 3-methyldithiobenzoic acid (3-MBDT-H), 2-mesitylenedithioic acid (2-MDT-H), 4-fluorodithiobenzoic acid (4-FBDT-H), and 2-thiophenedithioic acid (2-TDT-H) resulted in the corresponding complexes: [Bi(BDT)3 ] 1, [Bi(4-MBDT)3 ] 2, [{Bi(3-MBDT)3 }2 ⋅C7 H8 ] (32 ⋅C7 H8 ), [Bi(2-MDT)3 ] 4, [Bi(4-FBDT)3 ] 5 and [Bi(2-TDT)3 ] 6. Microwave irradiation of these bismuth(III)aryldithioate complexes with AgNO3 or CuCl under mild reaction conditions (140 °C) resulted in the respective mixed-metal sulfides. Attempt to synthesize AuBiS2 using similar reaction protocols were unsuccessful, resulting only in the formation of elemental Au0 , S8 and BiOCl.

Polynuclear Bismuth Oxido Sulfonato Clusters, Polymers, and Ion Pairs from Bi2O3 under Mild Conditions.

Eight novel bismuth(III) sulfonato compounds have been synthesized and characterized using the sonochemical reaction of Bi2O3 with a range of sulfonic acids, including 2,5-dimethylbenzenesulfonic acid (2,5-DMSH), 2,4-dinitrobenzenesulfonic acid (2,4-DNSH), 2,5-dichlorobenzenesulfonic acid (2,5-DCSH), 1,2-benzenedisulfonic acid (1,2-BDSH2), 1,3-benzenedisulfonic acid (1,3-BDSH2), 2-sulfobenzoic acid (2-SBH2), 3-sulfobenzoic acid (3-SBH2), and 2-naphthalenesulfonic acid (NPSH). Six of the complexes (1, 2, 4, and 6-8) were structurally characterized through single-crystal X-ray crystallography. In the presence of the monosulfonic acids 2,5-DMSH, 2,4-DNSH, and 2,5-DCSH, polynuclear bismuth(III) oxido clusters were isolated: namely, [Bi6O4(OH)4(2,5-DMS)6(H2O)6]·10H2O (1·10H2O), [Bi6O4(OH)4(2,4-DNS)6(H2O)6]·6H2O (2·6H2O), and [Bi6O4(OH)4(2,5-DCS)6(H2O)6] (3). The disulfonic acid 1,3-BDSH2 also produced an oxido cluster: [Bi6O4(OH)4(1,3-BDS)3]·8H2O (5·8H2O). The remaining diacid ligands (1,2-BDSH2, 2-SBH2, and 3-SBH2), upon reaction with Bi2O3, produced polymeric Bi(III) sulfonato complexes: namely [Bi(1,2-BDS)(OH)(H2O)2]∞ (4), [Bi(2-SB)(2-SBH)H2O]∞·2H2O (6·2H2O), and [NH2(Me)2]2[Bi2(3-SB)4]∞ (7). The larger NPSH ligand produced the monomeric contact ion pair [Bi(NPS)2(H2O)6][NPS]·3H2O (8·3H2O), upon sonication with Bi2O3.

A Molecular Probe for the Detection of Polar Lipids in Live Cells.

Lipids have an important role in many aspects of cell biology, including membrane architecture/compartment formation, intracellular traffic, signalling, hormone regulation, inflammation, energy storage and metabolism. Lipid biology is therefore integrally involved in major human diseases, including metabolic disorders, neurodegenerative diseases, obesity, heart disease, immune disorders and cancers, which commonly display altered lipid transport and metabolism. However, the investigation of these important cellular processes has been limited by the availability of specific tools to visualise lipids in live cells. Here we describe the potential for ReZolve-L1™ to localise to intracellular compartments containing polar lipids, such as for example sphingomyelin and phosphatidylethanolamine. In live Drosophila fat body tissue from third instar larvae, ReZolve-L1™ interacted mainly with lipid droplets, including the core region of these organelles. The presence of polar lipids in the core of these lipid droplets was confirmed by Raman mapping and while this was consistent with the distribution of ReZolve-L1™ it did not exclude that the molecular probe might be detecting other lipid species. In response to complete starvation conditions, ReZolve-L1™ was detected mainly in Atg8-GFP autophagic compartments, and showed reduced staining in the lipid droplets of fat body cells. The induction of autophagy by Tor inhibition also increased ReZolve-L1™ detection in autophagic compartments, whereas Atg9 knock down impaired autophagosome formation and altered the distribution of ReZolve-L1™. Finally, during Drosophila metamorphosis fat body tissues showed increased ReZolve-L1™ staining in autophagic compartments at two hours post puparium formation, when compared to earlier developmental time points. We concluded that ReZolve-L1™ is a new live cell imaging tool, which can be used as an imaging reagent for the detection of polar lipids in different intracellular compartments.

Taking bismuthinite to bismuth sulfide nanorods in two easy steps.

The transformation of mineral bismuthinite, to Bi2S3 nanoparticles, via a simple two-step process is described. The reaction of bismuthinite with two aryldithoic acids gave the complexes; [Bi(S2C(C6H4)-4-CH3)3] and [Bi(S2C(C6H4)-4-OCH3)3]. Mild solution decomposition (120 °C) of these bismuth aryldithioates produced crystalline Bi2S3 nanorods.