Systematic comparison of two novel,thiol-reactive prosthetic groups for <Superscript>18</Superscript>F labeling of peptides and proteins with the acylation agent succinimidyl-4-[<Superscript>18</Superscript>F]fluorobenzoate ([<Superscript>18</Superscript>F]SFB)

A systematic comparison of 4-[¹⁸F]fluorobenzaldehyde-O-(2-{2-[2-(pyrrol-2,5-dione-1-yl)ethoxy]-ethoxy}-ethyl)oxime ([¹⁸F]FBOM) and 4-[¹⁸F]fluorobenzaldehyde-O-[6-(2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-hexyl]oxime ([¹⁸F]FBAM) as prosthetic groups for the mild and efficient ¹⁸F labeling of cysteine-containing peptides and proteins with the amine-group reactive acylation agent, succinimidyl-4-[¹⁸F]fluorobenzoate ([¹⁸F]SFB), is described. All three prosthetic groups were prepared in a remotely controlled synthesis module. Synthesis of [¹⁸F]FBOM and [¹⁸F]FBAM was accomplished via oxime formation through reaction of appropriate aminooxy-functionalized labeling precursors with 4-[¹⁸F]fluorobenzaldehyde. The obtained radiochemical yields were 19% ([¹⁸F]FBOM) and 29% ([¹⁸F]FBAM), respectively. Radiolabeling involving [¹⁸F]FBAM and [¹⁸F]FBOM was exemplified by the reaction with cysteine-containing tripeptide glutathione (GSH), a cysteine-containing dimeric neurotensin derivative, and human native low-density lipoprotein (nLDL) as model compounds. Radiolabeling with the acylation agent [¹⁸F]SFB was carried out using a dimeric neurotensin derivative and nLDL. Both thiol-group reactive prosthetic groups show significantly better labeling efficiencies for the peptides in comparison with the acylation agent [¹⁸F]SFB. The obtained results demonstrate that [¹⁸F]FBOM is especially suited for the labeling of hydrophilic cysteine-containing peptides, whereas [¹⁸F]FBAM shows superior labeling performance for higher molecular weight compounds as exemplified for nLDL apolipoprotein constituents. However, the acylation agent [¹⁸F]SFB is the preferred prosthetic group for labeling nLDL under physiological conditions.     

Purification and characterization of extracellular lipases from <Emphasis Type="Italic">Pseudomonas monteilii</Emphasis> TKU009 by the use of soybeans as the substrate

A lipase-producing bacterium was isolated and identified as Pseudomonas monteilii TKU009. A lipase (F2) and lipase-like materials (F1) were purified from the culture supernatant of P. monteilii TKU009 with soybean powder as the sole carbon/nitrogen source. The molecular mass of F1 and F2 was estimated to be 44 kDa by SDS-PAGE and gel filtration. The optimum pH, optimum temperature, and pH and thermal stabilities of F2 were 7, 40°C, 8–11, and 50°C; and of F1 were 6, 40°C, 6–7, and 50°C, respectively. F2 was completely inhibited by EDTA and slightly by Mg²⁺, Fe²⁺, Mn²⁺, and SDS. F1 was completely inhibited by EDTA and Fe²⁺ and strongly by Zn²⁺, Mn²⁺, Ca²⁺, Mg²⁺, and SDS. The activities of both the enzymes were enhanced by the addition of non-ionic surfactants Triton X–100 and Tween 40, especially for F1. F2 preferably acted on substrates with a long chain (C10–C18) of fatty acids, while F1 showed a broad spectrum on those with chain length of C4–C18. The marked activity of F2 in organic solvents makes it an ideal choice for application in a water-restricted medium including organic synthesis. Li-June Ming is a visiting Professor at the National Cheng Kung University.     

Optimizing <Superscript>19</Superscript>F NMR protein spectroscopy by fractional biosynthetic labeling

In protein NMR experiments which employ nonnative labeling, incomplete enrichment is often associated with inhomogeneous line broadening due to the presence of multiple labeled species. We investigate the merits of fractional enrichment strategies using a monofluorinated phenylalanine species, where resolution is dramatically improved over that achieved by complete enrichment. In NMR studies of calmodulin, a 148 residue calcium binding protein, ¹⁹F and ¹H-¹⁵N HSQC spectra reveal a significant extent of line broadening and the appearance of minor conformers in the presence of complete (>95%) 3-fluorophenylalanine labeling. The effects of varying levels of enrichment of 3-fluorophenylalanine (i.e. between 3 and >95%) were further studied by ¹⁹F and ¹H-¹⁵N HSQC spectra,¹⁵N T₁ and T₂ relaxation measurements, ¹⁹F T₂ relaxation, translational diffusion and heat denaturation experiments via circular dichroism. Our results show that while several properties, including translational diffusion and thermal stability show little variation between non-fluorinated and >95% ¹⁹F labeled samples, ¹⁹F and ¹H-¹⁵N HSQC spectra show significant improvements in line widths and resolution at or below 76% enrichment. Moreover, high levels of fluorination (>80%) appear to increase protein disorder as evidenced by backbone ¹⁵N dynamics. In this study, reasonable signal to noise can be achieved between 60–76% ¹⁹F enrichment, without any detectable perturbations from labeling.     

Physiological and cellular responses to fluoride stress in tea (<Emphasis Type="Italic">Camellia sinensis</Emphasis>) leaves

Tea (Camellia sinensis (L.) O. Kuntze) hyper-accumulates fluoride (F), mainly in the leaves. To understand how tea copes with the stress caused by F, we tracked photosynthesis, antioxidant defense, and cell ultrastructure under different F concentrations (0–50 mg L^?1). High F (≥5 mg L^?1) caused decreases in photosynthetic and chlorophyll fluorescence parameters. Activated oxygen metabolism was altered by F, as manifested in increasing lipid peroxidation, electrolyte leakage (EL), and accumulation of H₂O₂. The activities of ascorbate peroxidase (APX, EC 1.11.1.1) and catalase (CAT, EC 1.11.1.6) increased at 0–5 mg L^?1 F, but sharply decreased less than 10–50 mg L^?1 F. The activity of manganese superoxide dismutase (Mn-SOD, EC 1.15.1.1) decreased with increasing F concentration. Expression of genes encoding antioxidant enzymes were in accordance with their measured activities. The results suggest that the antioxidant enzymes in the tea plant can eliminate reactive oxygen species (ROS) at <5 mg L^?1 F, but not at 20–50 mg L^?1 F. High F increased the number of epidermal hairs on tea leaves and decreased the stomatal aperture, reducing water loss. The leaf cellular structure appeared normal under 1–50 mg L^?1 F, although starch grains in chloroplast increased with increasing F. Proline and betaine play important roles in osmotic regulation in tea plant tolerating F stress. ROS scavenging and greater number of epidermal hairs are likely parts of the tea plant F-tolerance mechanism.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation and shoot regeneration in elite breeding lines of western shipper cantaloupe and honeydew melons (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.)

A reliable Agrobacterium-mediated transformation and shoot regeneration protocol was developed for breeding lines of commercially important western-shipper cantaloupe and honeydew melons, ‘F39’ and ‘150’, respectively. Different media were tested to select a shoot regeneration system for each of three elite breeding lines ‘F39’, ‘141’ and ‘TMS’. Murashige &; Skoog (MS) basal medium supplemented with 1 mg l^?1 benzyladenine (BA), 0.26 mg l^?1 abscisic acid (ABA) and 0.8 mg l^?1 indole-3-acetic acid (IAA) was used for shoot regeneration from cotyledonary explants in ‘F39’ and ‘150’. Kanamycin sensitivity as well as Timentin^? and Clavamox^® were evaluated using wild-type ‘F39’ and ‘150’ cotyledons. Kanamycin concentrations of 200 and 150 mg l^?1 were chosen as the threshold levels for ‘F39’ and ‘150’, respectively. No significant differences were found between Timentin^? and Clavamox^® in ‘F39’; however, Clavamox^® reduced the incidence of vitrification and increased the frequency of shoot elongation in ‘150’. A. tumefaciens strain EHA105, harboring pCNL56 carrying neomycin phosphotransferase II (nptII) and gusA reporter genes, was selected to establish a transformation protocol for ‘F39’ and ‘150’. Putative transformants were evaluated using β-glucuronidase (GUS) histochemical assay, polymerase chain reaction (PCR) and Southern blot analyses. Based on these parameters, the transformation efficiency for cantaloupe ‘F39’ was 0.3% and that for honeydew ‘150’ was 0.5%.     

The C-terminus of DSX<Superscript>F5</Superscript> protein acts as a novel regulatory domain in <Emphasis Type="Italic">Bombyx mori</Emphasis>

The doublesex gene regulates the somatic sexual development of Bombyx mori by alternatively splicing into sex-specific splice forms. In our previous study, the splice form Bmdsx ^F7 , which encodes the BmDSX^F5 protein, was found to be expressed in a female-specific manner and to contain a novel C-terminus. In this study, we aimed to investigate the role of this C-terminus. Two transgenic lines, L1 and L2, were constructed to ectopically express Bmdsx ^F7 in males. Phenotype and W chromosome-specific polymerase chain reaction (PCR) analysis showed that developmental abnormalities and sex reversal did not occur. Moreover, the sex ratio was also normal. Quantitative PCR revealed that the expression levels of SP1 and Vg were upregulated in the fat body of transgenic males. Additionally, the expression level of PBP was downregulated in the antenna of transgenic males. The results suggested that the C-terminus of BmDSX^F5 functioned as a regulatory domain during regulation of downstream target gene expression and that BmDSX^F5 participated in the sexual development of somatic cells together with other DSX proteins in B. mori.     

<Superscript>19</Superscript>F labelled glycosaminoglycan probes for solution NMR and non-linear (CARS) microscopy

Studying polysaccharide-protein interactions under physiological conditions by conventional techniques is challenging. Ideally, macromolecules could be followed by both in vitro spectroscopy experiments as well as in tissues using microscopy, to enable a proper comparison of results over these different scales but, often, this is not feasible. The cell surface and extracellular matrix polysaccharides, glycosaminoglycans (GAGs) lack groups that can be detected selectively in the biological milieu. The introduction of ¹⁹F labels into GAG polysaccharides is explored and the interaction of a labelled GAG with the heparin-binding protein, antithrombin, employing ¹⁹F NMR spectroscopy is followed. Furthermore, the ability of ¹⁹F labelled GAGs to be imaged using CARS microscopy is demonstrated. ¹⁹F labelled GAGs enable both ¹⁹F NMR protein-GAG binding studies in solution at the molecular level and non-linear microscopy at a microscopic scale to be conducted on the same material, essentially free of background signals.     

Biodistribution of N-alkyl and N-fluoroalkyl derivatives of spiroperidol; Radiopharmaceuticals for PET studies of dopamine receptors

There is great interest in the application of positron labeled ligands to map the dopamine receptor in vivo. A series of fluorine-18-labeled N-alkyl and N-fluoroalkyl spiroperidol (SP) derivatives N-methyl[¹⁸F]SP; N-ethyl[¹⁸F]SP; N-(2-[¹⁸F]fluoroethyl)SP; N-propyl[¹⁸F]SP; N-(3-[¹⁸F]fluoropropyl)SP; N-(3-fluoropropyl) [¹⁸F]SP; N-(2-[¹⁸F]fluoropropyl)SP; N-(2-[¹⁸F]fluorobutyl)SP; N-(2-[¹⁸F]fluoropentyl)SP; and N-(2-[¹⁸F]fluorohexyl) SP were synthesized. The lipophilicity of these ligands (log octanol/water partition coefficient) varies from 2.67 to 5.56 and the initial brain uptake in rats, measured at 2 min, was greatest with the methyl, ethyl, propyl, fluoroethyl, and fluoropropyl derivatives. The highest striatum/cerebellum values 1 h after administration were obtained with the N-methyl, N-propyl, and N-3-fluoropropyl derivatives, while that of N-2-fluoroethyl showed the greatest uptake of total activity in the brain at this time. The uptake of all these ligands in the striatum could be blocked by cold SP showing the striatal uptake to be by the dopamine receptors.     

Effect of<Emphasis Type="Italic">Trichoderma</Emphasis> species on growth of Fusarium<Emphasis Type="Italic">proliferatiom</Emphasis> and production of fumonisins,fusaproliferin and beauvericin

Trichoderma species has been suggested as potential biocontrol agent forFusarium verticillioides on maize. In this cereal,F. verticillioides and F. proliferatum contributed to fumonisin accumulation. In addition,F. proliferatum could produce beauvericin and fusaproliferin. The aim of this work was to evaluate the effect ofTrichoderma spp. on growth and fumonisin B¹ fusaproliferin and beauvericin production byF. proliferatum. Dual cultures of F.proliferatum andT. harzianum ITEM 3636 andT. longibrachiatum ITEM 3635 on maize meal agar at 0.995 aw were done. The effect ofTrichoderma spp. on the lineal growth ofF. proliferatum was determined. The effect ofTrichoderma species on fumonisin B¹, fusaproliferin and beauvericin production byF. proliferatum was determined on co-inoculated maize kernels by HPLC.T. harzianum suppressedF. proliferatum growth once contact between the colonies occurred.T. longibrachiatum showed a less antagonistic effect againstF. proliferatum. A reduction on fumonisin B¹ production of 98% and 88% was observed in the co-incubation ofF. proliferatum withT. harzianum andT. longibrachiatum, respectively. The decrease of FB¹ production was significant even in maize kernels on whichF. proliferatum had been growing 7 days prior to the addition ofTrichoderma spp. The concentration of beauvericin and fusaproliferin produced during 30 days coincubation ofF. proliferatum with bothTrichoderma spp. did not differ to those produced byF. proliferatum alone. These mycotoxins might enter the food chain causing so far unknown consequences to the health of domestic animals and humans. For this reason it is important, when a potential biocontrol agent is under study, to test the effect on the fungal growth and on the putative mycotoxin produced. Part of the information was presented at the Mycotoxin Prevention Cluster Dissemination Day and Mycoglobe Launch Conference, Brussels, Belgium, Oct 20–21, 2004 Financial support: Agenda Córdoba Ciencia, grant N^o 0279–000431/00     

Preparation,structural characterization and <Emphasis Type="Italic">in vitro</Emphasis> antitumor activity of <Emphasis Type="Italic">kappa</Emphasis>-carrageenan oligosaccharide fraction from <Emphasis Type="Italic">Kappaphycus striatum</Emphasis>

Oligosaccharides were prepared through mild hydrochloric acid hydrolysis of kappa-carrageenan from Kappaphycus striatum to compare the antitumor activity with carrageenan polysaccharides. Oligosaccharide fractions were isolated by gel permeation chromatography and the structure of fraction 1 (F1) was studied by using negative-ion electrospray ionization-mass spectrometry (ESI-MS), and ¹H and ¹³C-NMR spectrometry. The in vitro antitumor effects in three human neoplastic cell lines (KB, BGC, and Hela) of polysaccharides and F1 were investigated. The bioassay results showed that F1 exhibited relatively higher antitumor activity against the three cancer cells than polysaccharides.     

Non‐invasive imaging of allogeneic transplanted skin graft by 131I‐anti‐TLR5 mAb

Although ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG) uptake can be used for the non‐invasive detection and monitoring of allograft rejection by activated leucocytes, this non‐specific accumulation is easily impaired by immunosuppressants. Our aim was to evaluate a ¹³¹I‐radiolabelled anti‐Toll‐like receptor 5 (TLR5) mAb for non‐invasive in vivo graft visualization and quantification in allogeneic transplantation mice model, compared with the non‐specific radiotracer ¹⁸F‐FDG under using of immunosuppressant. Labelling, binding, and stability studies were performed. BALB/c mice transplanted with C57BL/6 skin grafts, with or without rapamycin treatment (named as allo‐treated group or allo‐rejection group), were injected with ¹³¹I‐anti‐TLR5 mAb, ¹⁸F‐FDG, or mouse isotype ¹³¹I‐IgG, respectively. Whole‐body phosphor‐autoradiography and ex vivo biodistribution studies were obtained. Whole‐body phosphor‐autoradiography showed ¹³¹I‐anti‐TLR5 mAb uptake into organs that were well perfused with blood at 1 hr and showed clear graft images from 12 hrs onwards. The ¹³¹I‐anti‐TLR5 mAb had significantly higher graft uptake and target‐to‐non‐target ratio in the allo‐treated group, as determined by semi‐quantification of phosphor‐autoradiography images; these results were consistent with ex vivo biodistribution studies. However, high ¹⁸F‐FDG uptake was not observed in the allo‐treated group. The highest allograft‐skin‐to‐native‐skin ratio (A:N) of ¹³¹I‐anti‐TLR5 mAb uptake was significantly higher than the ratio for ¹⁸F‐FDG (7.68 versus 1.16, respectively). ¹³¹I‐anti‐TLR5 mAb uptake in the grafts significantly correlated with TLR5 expression in the allograft area. The accumulation of ¹³¹I‐IgG was comparable in both groups. We conclude that radiolabelled anti‐TLR5 mAb is capable of detecting allograft with high target specificity after treatment with the immunosuppressive drug rapamycin.     

Approaches for the measurement of solvent exposure in proteins by <Superscript>19</Superscript>F NMR

Fluorine NMR is a useful tool to probe protein folding, conformation and local topology owing to the sensitivity of the chemical shift to the local electrostatic environment. As an example we make use of ¹⁹F NMR and 3-fluorotyrosine to evaluate the conformation and topology of the tyrosine residues (Tyr-99 and Tyr-138) within the EF-hand motif of the C-terminal domain of calmodulin (CaM) in both the calcium-loaded and calcium-free states. We critically compare approaches to assess topology and solvent exposure via solvent isotope shifts, ¹⁹F spin–lattice relaxation rates, ¹H–¹⁹F nuclear Overhauser effects, and paramagnetic shifts and relaxation rates from dissolved oxygen. Both the solvent isotope shifts and paramagnetic shifts from dissolved oxygen sensitively reflect solvent exposed surface areas.     

High efficiency transformation by electroporation of <Emphasis Type="Italic">Yarrowia lipolytica</Emphasis>

Yarrowia lipolytica was usually transformed by heat shock, but linearized integrative vectors always resulted in a low transformation efficiency when electroporation was used. To develop a high efficiency integrative transformation method by electroporation of F. lipolytica, we report here that pretreatment of F. lipolytica with 150 mM LiAc for 1 h before electroporation will approximately 30-fold of increase transformation efficiency. A cell concentration of 10¹⁰/ml and instrument settings of 1.5 kV will generate the highest transformation efficiencies. We have developed a procedure to transform F. lipolytica that will be able to yield an efficiency of 2.1 × 10⁴ transformants/ug for integrative linear DNA. With our modifications, the electroporation procedures became a very efficient and reliable tool for F. lipolytica transformation.     

Perfluoro‐tert‐butyl‐homoserine as a sensitive 19F NMR reporter for peptide–membrane interactions in solution

Fluorine (¹⁹F) NMR is a valuable tool for studying dynamic biological processes. However, increasing the sensitivity of fluorinated reporter molecules is a key to reducing acquisition times and accessing transient biological interactions. Here, we evaluate the utility a novel amino acid, l ‐O‐(perfluoro‐t‐butyl)‐homoserine (pFtBSer), that can easily be synthesized and incorporated into peptides and provides greatly enhanced sensitivity over currently used ¹⁹F biomolecular NMR probes. Incorporation of pFtBSer into the potent antimicrobial peptide MSI‐78 results in a sharp ¹⁹F NMR singlet that can be readily detected at concentrations of 5 µm and lower. We demonstrate that pFtBSer incorporation into MSI‐78 provides a sensitive tool to study binding through ¹⁹F NMR chemical shift and nuclear relaxation changes. These results establish future potential for pFtBSer to be incorporated into various proteins where NMR signal sensitivity is paramount, such as in‐cell investigations. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.     

Biochemical,Pharmacological and Structural Characterization of a New PLA<Subscript>2</Subscript> from <Emphasis Type="Italic">Crotalus durissus terrificus</Emphasis> (South American Rattlesnake) Venom

A new PLA₂ (F16) was purified from Crotalus durissus terrificus venom by molecular exclusion chromatography followed by analytical reverse phase HPLC. The PLA₂ (14.86 kDa by MALDI-TOF mass spectrometry) had an amino acid sequence of SLLQFNKMIKFETRKNAVPFYAFYGCYCGWGGRRRPKDATDRCCFVHDCCYEKVTKCNTKWDIYRYSLKSGYITCGKGTWCKEQICECDRVAAECLRRSLSTYKNGYMFYPDSRCRGPSETC, and showed highly conserved Ca²⁺-binding and catalytic sites. F16 showed allosteric behavior with 10 mM Ca²⁺ and had temperature and pH optima of 25°C and 7.9, respectively. F16 (10 μg/ml) produced neuromuscular blockade in chick biventer cervicis preparations in the absence and presence of crotapotin, indicating that crotapotin was not essential for neuromuscular action in this preparation. In contrast, in mouse phrenic nerve-diaphragm preparations, the neuromuscular blockade produced by the same concentration of toxin was dependent on crotapotin. Pre-incubation with heparin markedly reduced the neurotoxicity of F16. These results show that the biochemical and structural properties of F16 are similar to those of the PLA₂ isoforms F15 and F17, but that the neurotoxicity and the requirement for crotapotin to form the crotoxin complex varies according to the neuromuscular preparation.     

<Emphasis Type="Italic">Novosphingobium profundi</Emphasis> sp. nov. isolated from a deep-sea seamount

A marine bacterial strain, F72^T, was isolated from a solitary scleractinian coral, collected in Yap seamounts in the Pacific Ocean. Strain F72^T is a Gram-negative, light-yellow-pigmented, motile, rod-shaped bacterium. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain F72^T is related to the genus Novosphingobium and has high 16S rRNA gene sequence similarities with the type strains of Novosphingobium pentaromativorans US6-1^T (97.7 %), Novosphingobium panipatense SM16^T (97.6 %), Novosphingobium mathurense SM117^T (97.2 %) and Novosphingobium barchaimii LL02^T (97.1 %). Ubiquinone Q-10 was detected as the dominant quinone. The predominant cellular fatty acids were C_18:1ω7c and C_17:1ω6c. The genomic DNA G+C content of strain F72^T was 63.4 mol %. The polar lipids profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylcholine, sphingoglycolipid and one uncharacterized lipid. Strain F72^T shared DNA relatedness of 25 % with N. pentaromativorans JCM 12182^T, 31 % with N. panipatense DSM 22890^T, 21 % with N. mathurense DSM 23374^T and 26 % with N. barchaimii DSM 25411^T. Combined data from phenotypic, phylogenetic and DNA–DNA relatedness studies demonstrated that the strain F72^T is a representative of a novel species of the genus Novosphingobium, for which we propose the name Novosphingobium profundi sp. nov. (type strain F72^T = KACC 18566^T = CGMCC 1.15390^T).     

Aldehyde oxidase carrying an unusual subunit structure from Pseudomonas sp. MX‐058

Pseudomonas sp. MX‐058 produces aldehyde oxidase catalysing glyoxal to glyoxylic acid. Two aldehyde oxidases (F10 and F13) were purified to homogeneity from Pseudomonas sp. MX‐058. F10 and F13 had subunit structures, a heterotetramer and heteropentamer respectively. The N‐terminal amino acid sequences of all subunits were highly homologous to amino acid sequences of the putative oxidoreductases of Pseudomonas strains. All of these homologous oxidoreductases have a heterotrimer structure consisting of 85‐88 (α), 37‐39 (β) and 18‐23 (γ) kDa subunits. However, the α‐subunits of F10 and F13 might have decomposed into two [80 (α¹) and 9 kDa (α²)] and three [58 (α^1′), 22 (α^1″) and 9 (α²) kDa] subunits, respectively, while the β‐ and γ‐subunits remained intact. Both F10 and F13 show high activity toward several aliphatic and aromatic aldehydes. The aldehyde oxidases of Pseudomonas sp. MX‐058 has unique protein structures, α¹α²βγ for F10 and α^1′α^1″α²βγ for F13, a heterotetramer and heteropentamer respectively. The enzymes exhibit significantly low activity toward glyoxylic acid compared with glyoxal, which is an advantageous property for glyoxylic acid production from glyoxal.     

Optimization of <Emphasis Type="Italic">Curcuma</Emphasis> Oil/Quinine-Loaded Nanocapsules for Malaria Treatment

Quinine, a treatment used in chloroquine-resistant falciparum malaria, was loaded into poly(?-caprolactone) or Eudragit^® RS100 nanocapsules using Curcuma oil as the oil-based core. Until now, the effect of cationic nanocapsules on malaria has not been reported. A 2⁴ factorial design was adopted using, as independent variables, the concentration of Curcuma oil, presence of quinine, type of polymer, and aqueous surfactant. Diameter, zeta potential, and pH were the responses studied. The formulations were also evaluated for drug content, encapsulation efficiency, photostability, and antimalarial activity against Plasmodium berghei-infected mice. The type of polymer influenced all of the responses studied. Quinine-loaded Eudragit^® RS100 (F13) and PCL nanocapsules (F9), both with polysorbate 80 coating, showed nanometric particle size, positive zeta potential, neutral pH, high drug content, and quinine photoprotection ability; thus, these nanocapsules were selected for in vivo tests. Both formulations showed lower levels of parasitemia from the beginning of the experiment (5.78 ± 3.60 and 4.76 ± 3.46% for F9 and F13, respectively) and highest survival mean time (15.3 ± 2.0 and 14.9 ± 5.6 days for F9 and F13, respectively). F9 and F13 showed significant survival curve compared to saline, thus demonstrating that nanoencapsulation improved bioefficacy of QN and co-encapsulated curcuminoids, regardless of the surface charge.     

Paper‐Based Energy‐Storage Devices Comprising Carbon Fiber‐Reinforced Polypyrrole‐Cladophora Nanocellulose Composite Electrodes

Composites of polypyrrole (PPy) and Cladophora nanocellulose, reinforced with 8 μm‐thick chopped carbon filaments, can be used as electrode materials to obtain paper‐based energy‐storage devices with unprecedented performance at high charge and discharge rates. Charge capacities of more than 200 C g^?1 (PPy) are obtained for paper‐based electrodes at potential scan rates as high as 500 mV s^?1, whereas cell capacitances of ～60–70 F g^?1 (PPy) are reached for symmetric supercapacitor cells with capacitances up to 3.0 F (i.e.,0.48 F cm^?2) when charged to 0.6 V using current densities as high as 31 A g^?1 based on the PPy weight (i.e., 99 mA cm^?2). Energy and power densities of 1.75 Wh kg^?1 and 2.7 kW kg^?1, respectively, are obtained when normalized with respect to twice the PPy weight of the smaller electrode. No loss in cell capacitance is seen during charging/discharging at 7.7 A g^?1 (PPy) over 1500 cycles. It is proposed that the nonelectroactive carbon filaments decrease the contact resistances and the resistance of the reduced PPy composite. The present straightforward approach represents significant progress in the development of low‐cost and environmentally friendly paper‐based energy‐storage devices for high‐power applications.