Effects of diallyl trisulfide, an active substance from garlic essential oil, on structural chemistry of chitin in Sitotroga cerealella (Lepidoptera: Gelechiidae).

The environmental pollution, evolution of resistance, and risks to human and aquatic animal health associated with pesticide application have attracted much attention globally. Herein, we tested the capacity of diallyl trisulfide (DAT) from garlic essential oil to control the destructive stored-product pest, Sitotroga cerealella. The effects of DAT on the total content of cuticular chitin and structure of adults S. cerealella were evaluated. This study was the first to investigate changes in chitin structure in adults due to exposure to DAT through Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and differential scanning calorimetry. The results of these analyses revealed that the cuticular chitin content of pests decreased after DAT treatment. DAT treatment also reduced thermal stability and crystallinity of chitin. These findings indicate that DAT is a potent biopesticide that is active against the moth, and establishes the basis for its use as an IPM and alternative to chitin synthesis inhibitors.

The Pimpled Gold Nanosphere: A Superior Candidate for Plasmonic Photothermal Therapy.

BACKGROUND: The development of highly efficient nanoparticles to convert light to heat for anti-cancer applications is quite a challenging field of research. METHODS: In this study, we synthesized unique pimpled gold nanospheres (PGNSs) for plasmonic photothermal therapy (PPTT). The light-to-heat conversion capability of PGNSs and PPTT damage at the cellular level were investigated using a tissue phantom model. The ability of PGNSs to induce robust cellular damage was studied during cytotoxicity tests on colorectal adenocarcinoma (DLD-1) and fibroblast cell lines. Further, a numerical model of plasmonic (COMSOL Multiphysics) properties was used with the PPTT experimental assays. RESULTS: A low cytotoxic effect of thiolated polyethylene glycol (SH-PEG400-SH-) was observed which improved the biocompatibility of PGNSs to maintain 89.4% cell viability during cytometry assays (in terms of fibroblast cells for 24 hrs at a concentration of 300 µg/mL). The heat generated from the nanoparticle-mediated phantom models resulted in ΔT=30°C, ΔT=23.1°C and ΔT=21°C for the PGNSs, AuNRs, and AuNPs, respectively (at a 300 µg/mL concentration and for 325 sec). For the in vitro assays of PPTT on cancer cells, the PGNS group induced a 68.78% lethality (apoptosis) on DLD-1 cells. Fluorescence microscopy results showed the destruction of cell membranes and nuclei for the PPTT group. Experiments further revealed a penetration depth of sufficient PPTT damage in a physical tumor model after hematoxylin and eosin (H&E) staining through pathological studies (at depths of 2, 3 and 4 cm). Severe structural damages were observed in the tissue model through an 808-nm laser exposed to the PGNSs. CONCLUSION: Collectively, such results show much promise for the use of the present PGNSs and photothermal therapy for numerous anti-cancer applications.

Current advancements in chitosan-based film production for food technology; A review.

Chitosan is obtained from chitin, which could be considered to be the most abundant polymer after cellulose. Owing to these properties, chitosan alone or chitosan-based composite film production is attaining huge attention in terms of applications from researchers and industrialists coming from divergent fields. To enhance the biological (mainly antimicrobial and antioxidant) and physiological (mainly mechanical, thermal and barrier) attributes of the chitosan-based films, a vast medley of plant extracts and supporting polymers has been blended into chitosan films. Considering the up to date literature reports based on chitosan film production and applications, it can be stated that still, the research ratio is low in this field. Chitosan blend/composite films with specific properties (superhydrophobicity, excellent mechanical strength, acceptable barrier properties) can be produced only for specific applications in food technology. In the current review, we tried to summarize the advancements made in the last 5-7 years in the field of chitosan film technology for its application in the food industry.

A large electroencephalographic motor imagery dataset for electroencephalographic brain computer interfaces.

Recent advancements in brain computer interfaces (BCI) have demonstrated control of robotic systems by mental processes alone. Together with invasive BCI, electroencephalographic (EEG) BCI represent an important direction in the development of BCI systems. In the context of EEG BCI, the processing of EEG data is the key challenge. Unfortunately, advances in that direction have been complicated by a lack of large and uniform datasets that could be used to design and evaluate different data processing approaches. In this work, we release a large set of EEG BCI data collected during the development of a slow cortical potentials-based EEG BCI. The dataset contains 60 h of EEG recordings, 13 participants, 75 recording sessions, 201 individual EEG BCI interaction session-segments, and over 60 000 examples of motor imageries in 4 interaction paradigms. The current dataset presents one of the largest EEG BCI datasets publically available to date.

False flax (Camelina sativa) seed oil as suitable ingredient for the enhancement of physicochemical and biological properties of chitosan films.

To overcome the drawbacks of synthetic films in food packaging industry, researchers are turned to natural bio-based edible films enriched with various plant additives. In current study chitosan blend films were produced by incorporating Camelina sativa seed oil at varying concentrations to chitosan matrix. The chitosan blend films were characterized both physicochemically (structural, morphological, thermal, optical and mechanical) and biologically (antimicrobial and antioxidant activity). The incorporation of C. sativa seed oil notably enhanced thermal stability, antioxidative, anti-quorum sensing and antimicrobial activity. Except elongation at break, other mechanical properties of the blend films were not affected by incorporation of C. sativa seed oil. The surface morphology of blend films was recorded as slightly rough, non-porous and fibre-free surface. As it was expected the optical transmittance in visible region was gradually decreased with increasing fraction of seed oil. Interestingly the hydrophilicity of the blend films revealed a swift increase which can be explained by the formation of micelle between glycerol and Tween 40 in blend films. This study provides valuable information for C. sativa seed oil to be used as a blending ingredient in chitosan film technology.

Effect of different animal fat and plant oil additives on physicochemical, mechanical, antimicrobial and antioxidant properties of chitosan films.

Practical application of chitosan-essential oil blend films is limited due to the uneconomical extraction procedure of essential oils from plants. This study aimed to produce chitosan films blended with low cost and commercially available oils and fats consumed in daily human diet (olive, corn and sunflower oils, butter and animal fats). The study also focused on how physicochemical, biological and mechanical properties of chitosan blend films were influenced by the incorporation of oils and fats with varying unsaturation degrees. Possible interactions of chitosan film matrix with incorporated oils or fats were investigated. Chitosan-olive oil film showed better surface morphology and higher thermal stability than the films with other unsaturated oils. Tensile strength, Young's modulus and elongation at break were improved by 57.2%, 25.1% and 31.7% for chitosan-olive oil film, respectively. Chitosan-olive oil blend film had the highest antibacterial activity (almost equal to that of commercial antibiotic gentamicin). Edible films obtained from by incorporation of natural oils and fats into chitosan can help produce an environmentally friendly packaging material that is low cost and easily manufactured.

Controlled release and anti-proliferative effect of imatinib mesylate loaded sporopollenin microcapsules extracted from pollens of Betula pendula.

Sporopollenin is a promising material for drug encapsulation due to its excellent properties; uniformity in size, non-toxicity, chemically and thermally resilient nature. Herein, morphologically intact sporopollenin microcapsules were extracted from Betula pendula pollens. Cancer therapeutic agent (imatinib mesylate) was loaded into the microcapsules. The encapsulation efficiency by passive loading technique was found to be 21.46%. Release behaviour of the drug from microcapsules was found to be biphasic, with an initial fast release followed by a slower rate of release. Imatinib mesylate release from the drug itself (control) was faster than from imatinib mesylate-loaded sporopollenin microcapsules. The release profiles for both free and entrapped drug samples were significantly slower and more controlled in PBS buffer (pH 7.4) than in HCl (pH 1.2) buffer. Cumulative drug release from IM-MES-loaded sporopollenin microcapsules was found to be 65% within 24h for PBS, whereas release from the control was completed within 1h. Also, a complete dissolution of control in HCl buffer was observed within first 30min. MTT assay revealed that drug-loaded microcapsules were effective on WiDr human colon carcinoma cell line. B. pendula sporopollenin can be suggested as an effective carrier for oral delivery of imatinib mesylate.

Newly isolated sporopollenin microcages from Platanus orientalis pollens as a vehicle for controlled drug delivery.

Sporopollenin microcages were produced from the pollens of Platanus orientalis. Paracetamol was loaded into the microcages. Pollen, sporopollenin, paracetamol and paracetamol-loaded sporopollenin microcages were characterized with FT-IR, TGA and SEM. The analytical analyses demonstrated that sporopollenin microcages were structurally intact, highly reticulated and thermally stable. The loading efficiency of the sporopollenin microcages was found to be 8.2% using the passive loading technique and 23.7% via evaporating loading technique. In vitro release and kinetics studies were performed to test the suitability of sporopollenin microcages for loading. These studies revealed that sporopollenin from P. orientalis can be suggested as a suitable carrier for drug loading and controlled release studies.

A new pollen-derived microcarrier for pantoprazole delivery.

Plant-derived carriers have emerged as promising materials for drug encapsulation. Especially, sporopollenin microcapsules extracted from diverse pollen species have been proved to be effective drug carriers due to their biocompatibility, homogeneity in size, resistance to harsh chemical conditions and high thermal stability. Here in this study, sporopollenin microcapsules were isolated successfully from the pollens of a common tree (Corylus avellana, the European hazelnut) and used as a carrier for pantoprazole (PaNa) (a proton pump inhibitor). The drug entrapment efficiency was recorded as 29.81%. SEM micrographs clearly showed the drug was loaded into the microcapsules through the apertures of microcapsule and also some drugs were adsorbed on the surface of microcapsules. FT-IR spectra analysis confirmed the drug loading. Thermogravimetric analysis revealed that thermal stability of PaNa was enhanced by encapsulation. In vitro release studies showed that PaNa-loaded sporopollenin microcapsules exhibited better release performance than the control. C. avellana sporopollenin microcapsules can make an efficient carrier for delivery of PaNa.

Design and application of sporopollenin microcapsule supported palladium catalyst: Remarkably high turnover frequency and reusability in catalysis of biaryls.

Bio-based catalyst support materials with high thermal and structural stability are desired for catalysts systems requiring harsh conditions. In this study, a thermally stable palladium catalyst (up to 440°C) was designed from sporopollenin, which occurs naturally in the outer exine layer of pollens and is widely acknowledged as chemically very stable and inert biological material. Catalyst design procedure included (1) extraction of sporopollenin microcapsules from Betula pendula pollens (∼25µm), (2) amino-functionalisation of the microcapsules, (3) Schiff base modification and (4) preparation of Pd(II) catalyst. The catalytic activity of the sporopollenin microcapsule supported palladium catalyst was tested in catalysis of biaryls by following a fast, simple and green microwave-assisted method. We recorded outstanding turnover number (TON: 40,000) and frequency (TOF: 400,000) for the catalyst in Suzuki coupling reactions. The catalyst proved to be reusable at least in eight cycles. The catalyst can be suggested for different catalyst systems due to its thermal and structural durability, reusability, inertness to air and its eco-friendly nature.

Comparison of chitin structures isolated from seven Orthoptera species.

Differences in the physichochemical properties of the chitin structure of the exoskeleton of seven species from four genera were investigated in this study. The same method was used to isolate the chitin structure of the seven species. The physicochemical properties of the isolated chitins were revealed by ESEM, FTIR, TGA and XRD analyses. The FTIR, TGA and XRD results from the chitin samples were similar. The surface morphologies of the chitins were investigated by ESEM and interesting results were noted. While the surface morphologies of the chitins isolated from two species within the same genus were quite different, the surface morphologies of chitins isolated from species belonging to different genera showed similarity. It was determined that the dry weight chitin contents of the grasshopper species varied between 5.3% and 8.9%. The results of molecular analysis showed that the chitins from seven Orthoptera species (between 5.2 and 6.8 kDa) have low molecular weights. Considering that these invasive and harmful species are killed with insecticides and go to waste in large amounts, this study suggests that they should be collected and evaluated as an alternative chitin source.

Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal.

Biosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55 mg g(-1)) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40 mg g(-1)) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal.

Levels of circulating homocysteine, vitamin B6, vitamin B12, and folate in different types of open-angle glaucoma.

OBJECTIVE: To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG). STUDY DESIGN: A prospective controlled trial. PARTICIPANTS AND METHODS: Forty healthy subjects, 48 patients with NTG, 38 patients with PXG, and 34 patients with POAG were included in the study. Those who used vitamin supplements or medications affecting Hcy and vitamin levels were excluded from the study. The levels of Hcy and vit-B6 were measured by High Performance Liquid Chromatography (HPLC). The levels of serum vit-B12 and folic acid were measured by competitive chemiluminescent enzyme immunoassay (CEI). One-way analysis if variance (ANOVA), analysis of covariance (ANCOVA), and the Tukey honestly significant difference test were used for statistical analysis. RESULTS: The mean Hcy level of the PXG group was 15.46+/-9.27 micromol/L which was significantly higher (P=0.03) than that of the control group. There were no statistical differences in serum vit-B12 and folate levels among control subjects and NTG, PXG and POAG groups (P>0.05). It was found that the mean plasma vit-B6 level was significantly higher in subjects with NTG (P=0.03) and POAG (P=0.025) versus controls. Mean vit-B6 levels in NTG and POAG were 30.50+/-11.29 microg/L and 30+/-12.15 microg/L, respectively. CONCLUSIONS: The plasma level of Hcy was found to be increased only in PXG patients and the plasma levels of vit-B6 were found to increase in the NTG and POAG sample groups. Using homocysteine and vit-B6 levels as the determinants of hyperhomocysteinemia still needs further research.

Calcium antagonists in N-methyl d-aspartate-induced retinal injury.

PURPOSE: To detect the neuroprotective role of nimodipine and dantrolene in N-methyl- d-aspartate (NMDA)-induced retinal injury. METHODS: In this study we used two calcium antagonists which have two different modes of action, nimodipine and dantrolene, to prevent NMDA-induced retinal ischemia in guinea pigs. In 40 animals we injected nimodipine (n=10), dantrolene (n=10), a combination of both (n=10) or sterile 0.9% NaCl solution as a placebo (n=10) before intravitreal injection of NMDA. We enucleated one eye of each animal after 48 hours and performed histopathologic examination. We also measured malondialdehyde (MDA) levels in retinal homogenates as a marker of ischemic injury. RESULTS: Our results indicate that ganglion cells of the retina were preserved mostly by nimodipine, followed by combined nimodipine-dantrolene, and dantrolene respectively. The ganglion cell count was statistically significantly higher in cases where we used calcium antagonists than in the control group (p<0.05). We also found that MDA was significantly reduced by calcium antagonists compared to the control group (p<0.05). CONCLUSION: Our data show that nimodipine and dantrolene both have potential neuroprotective effects; nimodipine preserved retinal ganglion cells to a greater extent than dantrolene from NMDA-induced retinal injury.