Search results for: cell engineering

Authors: Adenike Adesanya, Nonthaphat Wong, Xiang-Yun Lan, Shea Ping Yip, Chien-Ling Huang

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Background: The most challenging mutation of the oncokinase BCR-ABL protein T315I, which is commonly known as the “gatekeeper” mutation and is notorious for its strong resistance to almost all tyrosine kinase inhibitors (TKIs), especially imatinib. Therefore, this study aims to identify T315I-dependent downstream microRNA (miRNA) pathways associated with drug resistance in chronic myeloid leukemia (CML) for prognostic and therapeutic purposes. Methods: T315I-carrying K562 cell clones (K562-T315I) were generated by the CRISPR-Cas9 system. Imatinib-treated K562-T315I cells were subjected to small RNA library preparation and next-generation sequencing. Putative lncRNA-miRNA-mRNA networks were analyzed with (i) DESeq2 to extract differentially expressed miRNAs, using Padj value of 0.05 as cut-off, (ii) STarMir to obtain potential miRNA response element (MRE) binding sites of selected miRNAs on lncRNA H19, (iii) miRDB, miRTarbase, and TargetScan to predict mRNA targets of selected miRNAs, (iv) IntaRNA to obtain putative interactions between H19 and the predicted mRNAs, (v) Cytoscape to visualize putative networks, and (vi) several pathway analysis platforms – Enrichr, PANTHER and ShinyGO for pathway enrichment analysis. Moreover, mitochondria isolation and transcript quantification were adopted to determine the new mechanism involved in T315I-mediated resistance of CML treatment. Results: Verification of the CRISPR-mediated mutagenesis with digital droplet PCR detected the mutation abundance of ≥80%. Further validation showed the viability of ≥90% by cell viability assay, and intense phosphorylated CRKL protein band being detected with no observable change for BCR-ABL and c-ABL protein expressions by Western blot. As reported by several investigations into hematological malignancies, we determined a 7-fold increase of H19 expression in K562-T315I cells. After imatinib treatment, a 9-fold increment was observed. DESeq2 revealed 171 miRNAs were differentially expressed K562-T315I, 112 out of these miRNAs were identified to have MRE binding regions on H19, and 26 out of the 112 miRNAs were significantly downregulated. Adopting the seed-sequence analysis of these identified miRNAs, we obtained 167 mRNAs. 6 hub miRNAs (hsa-let-7b-5p, hsa-let-7e-5p, hsa-miR-125a-5p, hsa-miR-129-5p, and hsa-miR-372-3p) and 25 predicted genes were identified after constructing hub miRNA-target gene network. These targets demonstrated putative interactions with H19 lncRNA and were mostly enriched in pathways related to cell proliferation, senescence, gene silencing, and pluripotency of stem cells. Further experimental findings have also shown the up-regulation of mitochondrial transcript and lncRNA MALAT1 contributing to the lncRNA-miRNA-mRNA networks induced by BCR-ABL T315I mutation. Conclusions: Our results have indicated that lncRNA-miRNA regulators play a crucial role not only in leukemogenesis but also in drug resistance, considering the significant dysregulation and interactions in the K562-T315I cell model generated by CRISPR-Cas9. In silico analysis has further shown that lncRNAs H19 and MALAT1 bear several complementary miRNA sites. This implies that they could serve as a sponge, hence sequestering the activity of the target miRNAs.

Keywords: chronic myeloid leukemia, imatinib resistance, lncRNA-miRNA-mRNA, T315I mutation

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Authors: Palak V. Patel, Jessica Pixley, Steven R. Feldman

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Introduction: Basal cell carcinoma (BCC) is the most common skin cancer worldwide and requires substantial resources to treat. When choosing between indicated therapies, providers consider their associated adverse effects, efficacy, cosmesis, and function preservation. The patient’s tumor burden, infiltrative risk, and risk of tumor recurrence are also considered. Treatment cost is often left out of these discussions. This can lead to financial toxicity, which describes the harm and quality of life reductions inflicted by high care costs. Methods: We studied the guidelines set forth by the American Academy of Dermatology for the treatment of BCC. A PubMed literature search was conducted to identify the costs of each recommended therapy. We discuss costs alongside treatment efficacy and side-effect profile. Results: Surgical treatment for BCC can be cost-effective if the appropriate treatment is selected for the presenting tumor. Curettage and electrodesiccation can be used in low-grade, low-recurrence tumors in aesthetically unimportant areas. The benefits of cost-conscious care are not likely to be outweighed by the risks of poor cosmesis or tumor return ($471 BCC of the cheek). When tumor burden is limited, MMS offers better cure rates and lower recurrence rates than surgical excision, and with comparable costs (MMS $1263; SE $949). Surgical excision with permanent sections may be indicated when tumor burden is more extensive or if molecular testing is necessary. The utility of surgical excision with frozen sections, which costs substantially more than MMS without comparable outcomes, is less clear (SE with frozen sections $2334-$3085). Less data exists on non-surgical treatments for BCC. These techniques cost less, but recurrence-risk is high. Side-effects of nonsurgical treatment are limited to local skin reactions, and cosmesis is good. Cryotherapy, 5-FU, and MAL-PDT are all more affordable than surgery, but high recurrence rates increase risk of secondary financial and psychosocial burden (recurrence rates 21-39%; cost $100-270). Radiation therapy offers better clearance rates than other nonsurgical treatments but is associated with similar recurrence rates and a significantly larger financial burden ($2591-$3460 BCC of the cheek). Treatments for advanced or metastatic BCC are extremely costly, but few patients require their use, and the societal cost burden remains low. Vismodegib and sonidegib have good response rates but substantial side effects, and therapy should be combined with multidisciplinary care and palliative measures. Expert-review has found sonidegib to be the less expensive and more efficacious option (vismodegib $128,358; sonidegib $122,579). Platinum therapy, while not FDA-approved, is also effective but expensive (~91,435). Immunotherapy offers a new line of treatment in patients intolerant of hedgehog inhibitors ($683,061). Conclusion: Dermatologists working within resource-compressed practices and with resource-limited patients must prudently manage the healthcare dollar. Surgical therapies for BCC offer the lowest risk of recurrence at the most reasonable cost. Non-surgical therapies are more affordable, but high recurrence rates increase the risk of secondary financial and psychosocial burdens. Treatments for advanced BCC are incredibly costly, but the low incidence means the overall cost to the system is low.

Keywords: nonmelanoma skin cancer, basal cell skin cancer, squamous cell skin cancer, cost of care

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Authors: Irene Carmagnola, Valeria Chiono, Sandra Pacharra, Jochen Salber, Sean McMahon, Chris Lovell, Pooja Basnett, Barbara Lukasiewicz, Ipsita Roy, Xiang Zhang, Gianluca Ciardelli

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Thrombosis and restenosis after stenting procedure can be prevented by promoting fast stent wall endothelialisation. It is well known that surface functionalisation with antifouling molecules combining with extracellular matrix proteins is a promising strategy to design biomimetic surfaces able to promote fast endothelialization. In particular, REDV has gained much attention for the ability to enhance rapid endothelialization due to its specific affinity with endothelial cells (ECs). In this work, a two-step plasma treatment was performed to polymerize a thin layer of acrylic acid, used to subsequently graft PEGylated-REDV and polyethylene glycol (PEG) at different molar ratio with the aim to selectively promote endothelial cell adhesion avoiding platelet activation. PEGylate-REDV was provided by Biomatik and it is formed by 6 PEG monomer repetitions (Chempep Inc.), with an NH2 terminal group. PEG polymers were purchased from Chempep Inc. with two different chain lengths: m-PEG6-NH2 (295.4 Da) with 6 monomer repetitions and m-PEG12-NH2 (559.7 Da) with 12 monomer repetitions. Plasma activation was obtained by operating at 50W power, 5 min of treatment and at an Ar flow rate of 20 sccm. Pure acrylic acid (99%, AAc) vapors were diluted in Ar (flow = 20 sccm) and polymerized by a pulsed plasma discharge applying a discharge RF power of 200 W, a duty cycle of 10% (on time = 10 ms, off time = 90 ms) for 10 min. After plasma treatment, samples were dipped into an 1-(3-dimethylaminopropyl)-3- ethylcarbodiimide (EDC)/N-hydroxysuccinimide (NHS) solution (ratio 4:1, pH 5.5) for 1 h at 4°C and subsequently dipped in PEGylate-REDV and PEGylate-REDV:PEG solutions at different molar ratio (100 μg/mL in PBS) for 20 h at room temperature. Surface modification was characterized through physico-chemical analyses and in vitro cell tests. PEGylated-REDV peptide and PEG were successfully bound to the carboxylic groups that are formed on the polymer surface after plasma reaction. FTIR-ATR spectroscopy, X -ray Photoelectron Spectroscopy (XPS) and contact angle measurement gave a clear indication of the presence of the grafted molecules. The use of PEG as a spacer allowed for an increase in wettability of the surface, and the effect was more evident by increasing the amount of PEG. Endothelial cells adhered and spread well on the surfaces functionalized with the REDV sequence. In conclusion, a selective coating able to promote a new endothelial cell layer on polymeric stent surface was developed. In particular, a thin AAc film was polymerised on the polymeric surface in order to expose –COOH groups, and PEGylate-REDV and PEG were successful grafted on the polymeric substrates. The REDV peptide demonstrated to encourage cell adhesion with a consequent, expected improvement of the hemocompatibility of these polymeric surfaces in vivo. Acknowledgements— This work was funded by the European Commission 7th Framework Programme under grant agreement number 604251- ReBioStent (Reinforced Bioresorbable Biomaterials for Therapeutic Drug Eluting Stents). The authors thank all the ReBioStent partners for their support in this work.

Keywords: endothelialisation, plasma treatment, stent, surface functionalisation

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Authors: Faraz Zarghami, Elham Anari, Nosratollah Zarghami, Yones Pilehvar-Soltanahmadi, Abolfazl Akbarzadeh, Sepideh Jalilzadeh-Tabrizi

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The development of nanotherapy has presented a new method of drug delivery targeted directly to the neoplasmic tissues, to maximize the action with fewer dose requirements. In the past two decades, poly(lactic-co-glycolic acid) (PLGA) has frequently been investigated by many researchers and is a popular polymeric candidate, due to its biocompatibility and biodegradability, exhibition of a wide range of erosion times, tunable mechanical properties, and most notably, because it is a FDA-approved polymer. Chrysin is a natural flavonoid which has been reported to have some significant biological effects on the processes of chemical defense, nitrogen fixation, inflammation, and oxidation. However, the low solubility in water decreases its bioavailability and consequently disrupts the biomedical benefits. Being loaded with PLGA-PEG increases chrysin solubility and drug tolerance, and decreases the discordant effects of the drug. The well-structured chrysin efficiently accumulates in the breast cancer cell line (T47D). In the present study, the structure and chrysin loading were delineated using proton nuclear magnetic resonance (HNMR), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM), and the in vitro cytotoxicity of pure and nanochrysin was studied by the MTT assay. Next, the RNA was exploited and the cytotoxic effects of chrysin were studied by real-time PCR. In conclusion, the nanochrysin therapy developed is a novel method that could increase cytotoxicity to cancer cells without damaging the normal cells, and would be promising in breast cancer therapy.

Keywords: MTT assay, chrysin, flavonoids, nanotherapy

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Authors: Saravanan Govindaraju, Kyusik Yun

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The purpose of this study is to develop the chitosan doped curcumin gold cluster nanofiber for wound healing and skin cancer drug delivery applications. Chitosan is a typical marine polysaccharide composed of glucosamine and n-acetyl glucosamine biodegradable and biocompatible polymer. Curcumin is a natural bioactive molecule obtained from Curcuma longo, it mostly occurs in some Asian countries like India and China. It has naturally antioxidant, antimicrobial, wound healing and anticancer property. Due to this advantage, we prepared a combination of natural polymer chitosan with Curcumin and gold nanocluster nanofiber (CH-CUR-AuNCs nanofibers). The prepared nanofiber was characterized by using Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Antibacterial studies were performed with E.coli and S.aureus. Antioxidant assay, drug release test, and cytotoxicity will be evaluated. Prepared nanofiber emits low intensity of red fluorescent. The FTIR confirm the presence of chitosan and Curcumin in the nanofiber. In vitro study clearly shows the antibacterial activity against the gram negative and gram positive bacteria. Particularly, synthesised nanofibers provide better antibacterial activity against gram negative than gram positive. Cytotoxicity study also provides better killing rate in cancer cell, biocompatible with normal cell. Prepared CH-CUR-AuNCs nanofibers provide the better killing rate to bacterial strains and cancer cells. Finally, prepared nanofiber can be possible to use for wound healing dressing, patch for skin cancer and other biomedical applications.

Keywords: curcumin, chitosan, gold clusters, nanofibers

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Authors: Ibrahim Rassoul, E-K. Si Ahmed

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The growth, deformation, and detachment of fluid droplets adherent to solid substrates is a problem of fundamental interest with numerous practical applications. Specific interest in this proposal is the problem of a droplet on a fibrous, hydrophobic substrate subjected to body or external forces (gravity, convection). The past decade has seen tremendous advances in proton exchange membrane fuel cell (PEMFC) technology. However, there remain many challenges to bring commercially viable stationary PEMFC products to the market. PEMFCs are increasingly emerging as a viable alternative clean power source for automobile and stationary applications. Before PEMFCs can be employed to power automobiles and homes, several key technical challenges must be properly addressed. One technical challenge is elucidating the mechanisms underlying water transport in and removal from PEMFCs. On the one hand, sufficient water is needed in the polymer electrolyte membrane or PEM to maintain sufficiently high proton conductivity. On the other hand, too much liquid water present in the cathode can cause 'flooding' (that is, pore space is filled with excessive liquid water) and hinder the transport of the oxygen reactant from the gas flow channel (GFC) to the three-phase reaction sites. The aim of this work is to investigate the stability of a liquid water droplet emerging form a GDL pore, to gain fundamental insight into the instability process leading to detachment. The approach will combine analytical and numerical modeling with experimental visualization and measurements.

Keywords: polymer electrolyte fuel cell, water droplet, gas diffusion layer, contact angle, surface tension

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Authors: Keundong Lee, Dongha Yoo, Youngbin Tchoe, Gyu-Chul Yi

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Light emitting diode (LED) array is an ideal optical stimulation tool for optogenetics, which controls inhibition and excitation of specific neurons with light-sensitive ion channels or pumps. Although a fiber-optic cable with an external light source, either a laser or LED mechanically connected to the end of the fiber-optic cable has widely been used for illumination on neural tissue, a new approach to use micro LEDs (µLEDs) has recently been demonstrated. The LEDs can be placed directly either on the cortical surface or within the deep brain using a penetrating depth probe. Accordingly, this method would not need a permanent opening in the skull if the LEDs are integrated with miniature electrical power source and wireless communication. In addition, multiple color generation from single µLED cell would enable to excite and/or inhibit neurons in localized regions. Here, we demonstrate flexible and color tunable µLEDs for the optogenetic device applications. The flexible and color tunable LEDs was fabricated using multifaceted gallium nitride (GaN) nanorod arrays with GaN nanorods grown on InxGa1−xN/GaN single quantum well structures (SQW) anisotropically formed on the nanorod tips and sidewalls. For various electroluminescence (EL) colors, current injection paths were controlled through a continuous p-GaN layer depending on the applied bias voltage. The electric current was injected through different thickness and composition, thus changing the color of light from red to blue that the LED emits. We believe that the flexible and color tunable µLEDs enable us to control activities of the neuron by emitting various colors from the single µLED cell.

Keywords: light emitting diode, optogenetics, graphene, flexible optoelectronics

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Authors: Liang Ning, Chung Hau Yin

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Angiogenesis is the process of new blood vessel development. It has been recognized as a therapeutic target for blocking cancer growth four decades ago. Vascular sprouting is initiated by pro-angiogenic factors. Vascular endothelial cell growth factor (VEGF) plays a central role in angiogenic initiation, many patients with cancer or ocular neovascularization have been benefited from anti-VEGF therapy. Emerging approaches impacting in the later stages of vessel remodeling and maturation are expected to improve clinical efficacy. TIE receptor as well as the corresponding angiopoietin ligands, were identified as another endothelial cell specific receptor tyrosine kinase signaling system. Much efforts were made to reduce the activity of angiopoietin-TIE receptor axis. Two eudesmane-type sesquiterpenes from laggera alata, namely, 15-dihydrocostic acid and ilicic acid were found with strong anti-angiogenic properties in zebrafish model. Meanwhile, the mRNA expression levels of VEGFR2 and TIE2 pathway related genes were down-regulated in the sesquiterpenes treated zebrafish embryos. Besides, in human umbilical vein endothelial cells (HUVECs), the sesquiterpenes have the ability to inhibit VEGF-induced HUVECs proliferation and migration at non-toxic concentration. Moreover, angiopoietin-2 induced TIE2 phosphorylation was inhibited by the sesquiterpenes, the inhibitory effect was detected in angiopoietin-1 induced HUVECs proliferation as well. Thus, we hypothesized the anti-angiogenic activity of the compounds may via the inhibition of VEGF and TIE2 related pathways. How the compounds come into play as the pathways inhibitors need to be evaluated in the future.

Keywords: Laggera alata, eudesmane-type sesquiterpene, anti-angiogenesis, VEGF, angiopoietin, TIE2

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Authors: Rauza Sukma Rita, Katsuya Dezaki, Yuko Maejima, Toshihiko Yada

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Oxytocin is a nine-amino acid peptide synthesized in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus. Oxytocin promotes contraction of the uterus during birth and milk ejection during breast feeding. Although oxytocin receptors are found predominantly in the breasts and uterus of females, many tissues and organs express oxytocin receptors, including the pituitary, heart, kidney, thymus, vascular endothelium, adipocytes, osteoblasts, adrenal gland, pancreatic islets, and many cell lines. On the other hand, in pancreatic islets, oxytocin receptors are expressed in both α-cells and β-cells with stronger expression in α- cells. However, to our knowledge there are no reports yet about the effect of oxytocin on cytosolic calcium reaction on α and β-cell. This study aims to investigate the effect of oxytocin on α-cells and β-cells and its oscillation pattern. Islet of Langerhans from wild type mice were isolated by collagenase digestion. Isolated and dissociated single cells either α-cells or β-cells on coverslips were mounted in an open chamber and superfused in HKRB. Cytosolic concentration ([Ca2+]i) in single cells were measured by fura-2 microfluorimetry. After measurement of [Ca2+]i, α-cells were identified by subsequent immunocytochemical staining using an anti-glucagon antiserum. In β-cells, the [Ca2+]i increase in response to oxytocin was observed only under 8.3 mM glucose condition, whereas in α-cells, [Ca2+]i an increase induced by oxytocin was observed in both 2.8 mM and 8.3 mM glucose. The oscillation incidence was induced more frequently in β-cells compared to α-cells. In conclusion, the present study demonstrated that oxytocin directly interacts with both α-cells and β-cells and induces increase of [Ca2+]i and its specific patterns.

Keywords: α-cells, β-cells, cytosolic calcium concentration, oscillation, oxytocin

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Authors: Amber C. W. Vandepoele, Michael A. Marciano

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Biological analyses frequently focus on single organisms, however many times, the biological sample consists of more than the target organism; for example, human microbiome research targets bacterial DNA, yet most samples consist largely of human DNA. Therefore, there would be an advantage to removing these contaminating organisms. Conversely, some analyses focus on a single organism but would greatly benefit from the additional information regarding the other organismal components of the sample. Forensic analysis is one such example, wherein most forensic casework, human DNA is targeted; however, it typically exists in complex non-pristine sample substrates such as soil or unclean surfaces. These complex samples are commonly comprised of not just human tissue but also microbial and plant life, where these organisms may help gain more forensically relevant information about a specific location or interaction. This project aims to optimize a ‘phylogenetic’ differential extraction method that will separate mammalian, bacterial and plant cells in a mixed sample. This is accomplished through the use of size exclusion separation, whereby the different cell types are separated through multiple filtrations using 5 μm filters. The components are then lysed via differential enzymatic sensitivities among the cells and extracted with minimal contribution from the preceding component. This extraction method will then allow complex DNA samples to be more easily interpreted through non-targeting sequencing since the data will not be skewed toward the smaller and usually more numerous bacterial DNAs. This research project has demonstrated that this ‘phylogenetic’ differential extraction method successfully separated the epithelial and bacterial cells from each other with minimal cell loss. We will take this one step further, showing that when adding the plant cells into the mixture, they will be separated and extracted from the sample. Research is ongoing, and results are pending.

Keywords: DNA isolation, geolocation, non-human, phylogenetic separation

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Authors: Ahmed Gaber Abdel Raheem, Nashwa Ahmed Mohamed

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Introduction: Sensorineural hearing loss (SNHL) is largely caused by the degeneration of the cochlea. Therapeutic options for SNHL are limited to hearing aids and cochlear implants. The cell transplantation approach to the regeneration of hair cells has gained considerable attention because stem cells are believed to accumulate in the damaged sites and have the potential for the repair of damaged tissues. The aim of the work: was to assess the use of bone marrow transplantation in repair of damaged inner ear hair cells in rats after the damage had been inflicted by Amikacin injection. Material and Methods: Thirty albino rats were used in this study. They were divided into three groups. Each group ten rats. Group I: used as control. Group II: Were given Amikacin- intratympanic injection till complete loss of hearing function. This could be assessed by Distortion product Otoacoustic Emission (DPOAEs) and / or auditory brain stem evoked potential (ABR). GroupIII: were given intra-peritoneal injection of bone marrow stem cell after complete loss of hearing caused by Amikacin. Clinical assessment was done using DPOAEs and / or auditory brain stem evoked potential (ABR), before and after bone marrow injection. Histological assessment of the inner ear was done by light and electron microscope. Also, Detection of stem cells in the inner ear by immunohistochemistry. Results: Histological examination of the specimens showed promising improvement in the structure of cochlea that may be responsible for the improvement of hearing function in rats detected by DPOAEs and / or ABR. Conclusion: Bone marrow stem cells transplantation might be useful for the treatment of SNHL.

Keywords: amikacin, hair cells, sensorineural hearing loss, stem cells

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Authors: Alessio Giovannelli, Claudia Cocozza, Enrico Marchi, Valerio Giorgio Muzzini, Eleftherios Touloupakis, Raffaella Margherita Zampieri

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In Mediterranean countries, forest fires are recurrent events that need to be considered as a central component of regional and global forest management strategies and biodiversity restoration programmes. The response of tree function to fire damage can vary widely, also taking into account species, season, age of the tree, etc. Trees that survive fire may have different levels of physiological functionality, which may result in reduced growth or increased susceptibility to delayed mortality. An approach to assessing irreversible physiological injury in trees could help to inform management decisions at burned sites for biodiversity restoration, environmental safety and understanding of ecosystem functional adaptations. Physiological proxies for latent tree mortality, such as cambial cell death, reduced or absent starch and soluble sugar content in C sinks, and ethanol accumulation in the phloem, are considered proxies for cell death. However, their determination requires time-consuming laboratory protocols, making the approach unfeasible as a practical option in the field, but recent findings have shown that biosensors could be usefully applied to overcome these limitations. The study will focus on the development of amperometric biosensors capable of detecting a few target molecules in the phloem and xylem (such as ethanol and glucose) that have recently been identified as proxies for latent tree mortality. The results of a specific experiment on a stand of Pinus pinaster subjected to prescribed fire are reported.

Keywords: enzymes, glucose, ethanol, prescribed fires

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Authors: S. Sushma, S. Balasubramanian, K. C. Latha

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The mammographic image of breast cancer compressed and synthesized to get co-efficient values which will be converted (5x5) matrix to get ROI image where we get the highest value of effected region and with the same ideology the technique has been extended to differentiate between Calcification and normal cell image using mean value derived from 5x5 matrix values

Keywords: texture analysis, mammographic image, partitioned gray scale co-oocurance matrix, co-efficient

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Authors: Moreblessings Shoko

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Polymersomes are materials which are considered as artificial counterparts of natural vesicles. The nanotechnology of such smart nanovesicles is very useful to enhance the efficiency of many therapeutic and diagnostic drugs. Those compounds show a higher stability, flexibility, and mechanical strength to the membrane compared to natural liposomes. Also, they can be designed in detail, the permeability of the membrane can be controlled by different stimuli, and the surface can be functionalized with different biological molecules to facilitate monitoring and target. For this purpose, this study demonstrates the formation of multifunctional and pH sensitive polymersomes and their functionalization with different reactive groups or biomolecules inside and outside of polymersomes´ membrane providing by crossing the membrane and docking/undocking processes for biomedical applications. Overall, they are highly versatile and thus present new opportunities for the design of targeted and selective recognition systems, for example, in mimicking cell functions and in synthetic biology.

Keywords: women, geomatics, challenges, capacity building

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Authors: A. Taoufyq, B. Bakiz, A. Benlhachemi, L. Patout, D. V. Chokouadeua, F. Guinneton, G. Nolibe, A. Lyoussi, J-R. Gavarri

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Currently, the photo catalytic reactions occurring under solar illumination have attracted worldwide attentions due to a tremendous set of environmental problems. Taking the sunlight into account, it is indispensable to develop highly effective visible-light-driver photo catalysts. Nano structured materials such as MxM’1-xWO6 system are widely studied due to its interesting piezoelectric, dielectric and catalytic properties. These materials can be used in photo catalysis technique for environmental applications, such as waste water treatments. The aim of this study was to investigate the photo catalytic activity of polycrystalline phases of bismuth tungstate of formula Bi2WO6. Polycrystalline samples were elaborated using a coprecipitation technique followed by a calcination process at different temperatures (300, 400, 600 and 900°C). The obtained polycrystalline phases have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Crystal cell parameters and cell volume depend on elaboration temperature. High-resolution electron microscopy images and image simulations, associated with X-ray diffraction data, allowed confirming the lattices and space groups Pca21. The photo catalytic activity of the as-prepared samples was studied by irradiating aqueous solutions of Rhodamine B, associated with Bi2WO6 additives having variable crystallite sizes. The photo catalytic activity of such bismuth tungstates increased as the crystallite sizes decreased. The high specific area of the photo catalytic particles obtained at 300°C seems to condition the degradation kinetics of RhB.

Keywords: Bismuth tungstate, crystallite sizes, electron microscopy, photocatalytic activity, X-ray diffraction.

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Authors: Dace Grauda, Inta Belogrudova, Alexei Katashev, Linda Lancere, Isaak Rashal

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The goal of study was the elaboration of easy applicable flow cytometry method for detection of influence of abiotic stress factors on plants, which could be useful for detection of environmental stresses in urban areas. The lime tree Tillia vulgaris H. is a popular tree species used for urban landscaping in Europe and is one of the main species of street greenery in Riga, Latvia. Tree decline and low vitality has observed in the central part of Riga. For this reason lime trees were select as a model object for the investigation. During the period of end of June and beginning of July 12 samples from different urban environment locations as well as plant material from a greenhouse were collected. BD FACSJazz® cell sorter (BD Biosciences, USA) with flow cytometer function was used to test viability of plant cells. The method was based on changes of relative fluorescence intensity of cells in blue laser (488 nm) after influence of stress factors. SpheroTM rainbow calibration particles (3.0–3.4 μm, BD Biosciences, USA) in phosphate buffered saline (PBS) were used for calibration of flow cytometer. BD PharmingenTM PBS (BD Biosciences, USA) was used for flow cytometry assays. The mean fluorescence intensity information from the purified cell suspension samples was recorded. Preliminary, multiple gate sizes and shapes were tested to find one with the lowest CV. It was found that low CV can be obtained if only the densest part of plant cells forward scatter/side scatter profile is analysed because in this case plant cells are most similar in size and shape. The young pollen cells in one nucleus stage were found as the best for detection of influence of abiotic stress. For experiments only fresh plant material was used– the buds of Tillia vulgaris with diameter 2 mm. For the cell suspension (in vitro culture) establishment modified protocol of microspore culture was applied. The cells were suspended in the MS (Murashige and Skoog) medium. For imitation of dust of urban area SiO2 nanoparticles with concentration 0.001 g/ml were dissolved in distilled water. Into 10 ml of cell suspension 1 ml of SiO2 nanoparticles suspension was added, then cells were incubated in speed shaking regime for 1 and 3 hours. As a stress factor the irradiation of cells for 20 min by UV was used (Hamamatsu light source L9566-02A, L10852 lamp, A10014-50-0110), maximum relative intensity (100%) at 365 nm and at ~310 nm (75%). Before UV irradiation the suspension of cells were placed onto a thin layer on a filter paper disk (diameter 45 mm) in a Petri dish with solid MS media. Cells without treatment were used as a control. Experiments were performed at room temperature (23-25 °C). Using flow cytometer BS FACS Software cells plot was created to determine the densest part, which was later gated using oval-shaped gate. Gate included from 95 to 99% of all cells. To determine relative fluorescence of cells logarithmic fluorescence scale in arbitrary fluorescence units were used. 3x103 gated cells were analysed from the each sample. The significant differences were found among relative fluorescence of cells from different trees after treatment with SiO2 nanoparticles and UV irradiation in comparison with the control.

Keywords: flow cytometry, fluorescence, SiO2 nanoparticles, UV irradiation

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Authors: F. Bosca, F. Foglietta, F. Turci, E. Calcio Gaudino, S. Mana, F. Dosio, R. Canaparo, L. Serpe, A. Barge

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In recent years, medical science has improved chemotherapy, radiation therapy and adjuvant therapy and has developed newer targeted therapies as well as refining surgical techniques for removing cancer. However, the chances of surviving the disease depend greatly on the type and location of the cancer and the extent of the disease at the start of treatment. Moreover, mainstream forms of cancer treatment have side effects which range from the unpleasant to the fatal. Therefore, the continuation of progress in anti-cancer therapy may depend on placing emphasis on other existing but less thoroughly investigated therapeutic approaches such as Sonodynamic Therapy (SDT). SDT is based on the local activation of a so called 'sonosensitizer', a molecule able to be excited by ultrasound, the radical production as a consequence of its relaxation processes and cell death due to different mechanisms induced by radical production. The present work deals with synthesis, characterization and preliminary in vitro test of Single Walled Carbon Nanotubes (SWCNT) decorated with porphyrins and biological vectors. The SWCNT’s surface was modified exploiting 1, 3-dipolar cycloaddition or Dies Alder reactions. For this purpose, different porphyrins scaffolds were ad-hoc synthesized using also non-conventional techniques. To increase cellular specificity of porphyrin-conjugated SWCNTs and to improve their ability to be suspended in aqueous solution, the modified nano-tubes were grafted with suitable glutamine or hyaluronic acid derivatives. These nano-sized sonosensitizers were characterized by several methodologies and tested in vitro on different cancer cell lines.

Keywords: sonodynamic therapy, porphyrins synthesis and modification, SWNCT grafting, hyaluronic acid, anti-cancer treatment

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Authors: Ahmed Samy Elnoby

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Ailanthus altissima native to Asia which belongs to the family Simaroubaceae was subjected to phytochemical screening and biological investigations. Phytochemical screening revealed the presence of carbohydrates, tannins, sterols, flavonoids and traces of saponins. In addition, quantitative determination of phenolics and flavonoid content were performed. The antimicrobial activity of methanolic extract of the leaves was determined against gram-positive, gram-negative bacteria in addition to fungi using a modified Kirby-Bauer disc diffusion method that was compared with standard discs ampicillin which acts as an antibacterial agent and amphotericin B which acts as an antifungal agent. A high potency was observed against gram-positive bacteria mainly staphylococcus aureus, gram-negative bacteria mainly Escherichia coli and showed no potency against fungi mainly Aspergillus flavus and candida albicans. On the other hand, the antioxidant activity of the extract was determined by 1, 1-diphenyl-2- diphenyl-2-picryl-hydrazil (DPPH). A very low potency was shown by using DPPH for the antioxidant effect so IC50 = 0 ug/ml, IC90 =0 ug /ml and remark gave 47.2 % at 100 ug/ml which is very weak. Cytotoxic activity was determined by using MTT assay (3-4, 5-Dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium Bromide) against MCF7 (Human Caucasian breast adenocarcinoma) cell line. A moderate potency was shown by using MCF7 cell line for cytotoxic effect so LC50= 90.2 ug/ml, LC90=139.9 ug/ml and the remark gave 55.2% at 100 ug/ml which is of moderate activity so, Ailanthus altissima can be considered to be a promising antimicrobial agent from natural origin.

Keywords: Ailanthus altissima, TLC, HPLC, anti-microbial activity, antifungal activity, antioxidant, cytotoxic activity

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Authors: Rony Tawk, Boutros Ghannam, Maroun Nemer

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Topology optimization technique presents a potential tool for the design and optimization of structures involved in mass and heat transfer. The method starts with an initial intermediate domain and should be able to progressively distribute the solid and the two fluids exchanging heat. The multi-objective function of the problem takes into account minimization of total pressure loss and maximization of heat transfer between solid and fluid subdomains. Existing methods account for the presence of only one fluid, while the actual work extends optimization distribution of solid and two different fluids. This requires to separate the channels of both fluids and to ensure a minimum solid thickness between them. This is done by adding a third objective function to the multi-objective optimization problem. This article uses density approach where each cell holds two local design parameters ranging from 0 to 1, where the combination of their extremums defines the presence of solid, cold fluid or hot fluid in this cell. Finite volume method is used for direct solver coupled with a discrete adjoint approach for sensitivity analysis and method of moving asymptotes for numerical optimization. Several examples are presented to show the ability of the method to find a trade-off between minimization of power dissipation and maximization of heat transfer while ensuring the separation and continuity of the channel of each fluid without crossing or mixing the fluids. The main conclusion is the possibility to find an optimal bi-fluid domain using topology optimization, defining a fluid to fluid heat exchanger device.

Keywords: topology optimization, density approach, bi-fluid domain, laminar steady state regime, fluid-to-fluid heat exchanger

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Authors: Mansa Radhakrishnan, Anwar Ali, Muhammad Rizwan Mughal

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Many universities around the world are working on modular and low budget architecture of small spacecraft to reduce the development cost of the overall system. This paper focuses on the design of a modular solar power harvesting system for a hexagonal-shaped small satellite. The designed solar power harvesting systems are composed of solar panels and power converter subsystems. The solar panel is composed of solar cells mounted on the external face of the printed circuit board (PCB), while the electronic components of power conversion are mounted on the interior side of the same PCB. The solar panel with dimensions 16.5cm × 99cm is composed of 36 solar cells (each solar cell is 4cm × 7cm) divided into four parallel banks where each bank consists of 9 solar cells. The output voltage of a single solar cell is 2.14V, and the combined output voltage of 9 series connected solar cells is around 19.3V. The output voltage of the solar panel is boosted to the satellite power distribution bus voltage level (28V) by a boost converter working on a constant voltage maximum power point tracking (MPPT) technique. The solar panel module is an eight-layer PCB having embedded coil in 4 internal layers. This coil is used to control the attitude of the spacecraft, which consumes power to generate a magnetic field and rotate the spacecraft. As power converter and distribution subsystem components are mounted on the PCB internal layer, therefore it is mandatory to do thermal analysis in order to ensure that the overall module temperature is within thermal safety limits. The main focus of the overall design is on compactness, miniaturization, and efficiency enhancement.

Keywords: small satellites, power subsystem, efficiency, MPPT

Procedia PDF Downloads 74

Authors: Imdad Ullah Khan, Yongseok Yoon, Kyeung Uk Choi, Kwang Rae Jo, Namyul Kim, Eunbee Lee, Wan Hee Kim, Oh-Kyeong Kweon

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The primary spinal cord injury (SCI) causes mechanical damage to the neurons and blood vessels. It leads to secondary SCI, which activates multiple pathological pathways, which expand neuronal damage at the injury site. It is characterized by vascular disruption, ischemia, excitotoxicity, oxidation, inflammation, and apoptotic cell death. It causes nerve demyelination and disruption of axons, which perpetuate a loss of impulse conduction through the injured spinal cord. It also leads to the production of myelin inhibitory molecules, which with a concomitant formation of an astroglial scar, impede axonal regeneration. The pivotal role regarding the neuronal necrosis is played by oxidation and inflammation. During an early stage of spinal cord injury, there occurs an abundant expression of reactive oxygen species (ROS) due to defective mitochondrial metabolism and abundant migration of phagocytes (macrophages, neutrophils). ROS cause lipid peroxidation of the cell membrane, and cell death. Abundant migration of neutrophils, macrophages, and lymphocytes collectively produce pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1beta (IL-1β), matrix metalloproteinase, superoxide dismutase, and myeloperoxidases which synergize neuronal apoptosis. Therefore, it is crucial to control inflammation and oxidation injury to minimize the nerve cell death during secondary spinal cord injury. Therefore, in response to oxidation and inflammation, heme oxygenase-1 (HO-1) is induced by the resident cells to ameliorate the milieu. In the meanwhile, neurotrophic factors are induced to promote neuroregeneration. However, it seems that anti-stress enzyme (HO-1) and neurotrophic factor (BDNF) do not significantly combat the pathological events during secondary spinal cord injury. Therefore, optimum healing can be induced if anti-inflammatory and neurotrophic factors are administered in a higher amount through an exogenous source. During the first experiment, the inflammation and neuroregeneration were selectively targeted. HO-1 expressing MSCs (HO-1 MSCs) and BDNF expressing MSCs (BDNF MSC) were co-transplanted in one group (combination group) of dogs with subacute spinal cord injury to selectively control the expression of inflammatory cytokines by HO-1 and induce neuroregeneration by BDNF. We compared the combination group with the HO-1 MSCs group, BDNF MSCs group, and GFP MSCs group. We found that the combination group showed significant improvement in functional recovery. It showed increased expression of neural markers and growth-associated proteins (GAP-43) than in other groups, which depicts enhanced neuroregeneration/neural sparing due to reduced expression of pro-inflammatory cytokines such as TNF-alpha, IL-6 and COX-2; and increased expression of anti-inflammatory markers such as IL-10 and HO-1. Histopathological study revealed reduced intra-parenchymal fibrosis in the injured spinal cord segment in the combination group than in other groups. Thus it was concluded that selectively targeting the inflammation and neuronal growth with the combined use of HO-1 MSCs and BDNF MSCs more favorably promote healing of the SCI. HO-1 MSCs play a role in controlling the inflammation, which favors the BDNF induced neuroregeneration at the injured spinal cord segment of dogs.

Keywords: HO-1 MSCs, BDNF MSCs, neuroregeneration, inflammation, anti-inflammation, spinal cord injury, dogs

Procedia PDF Downloads 118

Authors: Martyna Chotomska, Aleksandra Studzinska, Marta Lisowska, Justyna Szubert, Aleksandra Tabis, Jacek Bania, Arkadiusz Miazek

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Objectives: Assessing antigen-specific T cell responses is of utmost importance for the pre-clinical testing of prototype vaccines against intracellular pathogens and tumor antigens. Mainly two types of in vitro assays are used for this purpose 1) enzyme-linked immunospot (ELISpot) and 2) intracellular cytokine staining (ICS). Both are time-consuming, relatively expensive, and require manual dexterity. Here, we assess if a straightforward detection of luciferase activity in blood samples of transgenic reporter mice expressing a secreted Lucia luciferase under the transcriptional control of IFN-γ promoter parallels the sensitivity of IFNγ ELISpot assay. Methods: IFN-γ-LUCIA mouse strain carrying multiple copies of Lucia luciferase transgene under the transcriptional control of IFNγ minimal promoter were generated by pronuclear injection of linear DNA. The specificity of transgene expression and mobilization was assessed in vitro using transgenic splenocytes exposed to various mitogens. The IFN-γ-LUCIA mice were immunized with 50mg of ovalbumin (OVA) emulsified in incomplete Freund’s adjuvant three times every two weeks by subcutaneous injections. Blood samples were collected before and five days after each immunization. Luciferase activity was assessed in blood serum. Peripheral blood mononuclear cells were separated and assessed for frequencies of OVA-specific IFNγ-secreting T cells. Results: We show that in vitro cultured splenocytes of IFN-γ-LUCIA mice respond by 2 and 3 fold increase in secreted luciferase activity to T cell mitogens concanavalin A and phorbol myristate acetate, respectively but fail to respond to B cell-stimulating E.coli lipopolysaccharide. Immunization of IFN-γ-LUCIA mice with OVA leads to over 4 fold increase in luciferase activity in blood serum five days post-immunization with a barely detectable increase in OVA-specific, IFNγ-secreting T cells by ELISpot. Second and third immunizations, further increase the luciferase activity and coincidently also increase the frequencies of OVA-specific T cells by ELISpot. Conclusions: We conclude that minimally invasive monitoring of luciferase secretions in blood serum of IFN-γ-LUCIA mice constitutes a sensitive method for evaluating primary and memory Th1 responses to protein antigens. As such, this method may complement existing methods for rapid immunogenicity assessment of prototype vaccines.

Keywords: ELISpot, immunogenicity, interferon-gamma, reporter mice, vaccines

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Authors: A. Monika, Manu Sharma, Hong Boo Lee, Richa Dhingra, Neelima Dhingra

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Nuclear factor-κappa B serve as a molecular lynchpin that links persistent infections and chronic inflammation to increased cancer risk. Inflammation has been recognized as a hallmark and cause of cancer. Natural products present a privileged source of inspiration for chemical probe and drug design. Herbal remedies were the first medicines used by humans due to the many pharmacologically active secondary metabolites produced by plants. Some of the metabolites like Lantadene (pentacyclic triterpenoids) from the weed Lantana camara has been known to inhibit cell division and showed anti-antitumor potential. The C-3 aromatic esters of lantadenes were synthesized, characterized and evaluated for cytotoxicity and inhibitory potential against Tumor necrosis factor alpha-induced activation of Nuclear factor-κappa B in lung cancer cell line A549. The 3-methoxybenzoyloxy substituted lead analogue inhibited kinase activity of the inhibitor of nuclear factor-kappa B kinase in a single-digit micromolar concentration. At the same time, the lead compound showed promising cytotoxicity against A549 lung cancer cells with IC50 ( half maximal inhibitory concentration) of 0.98l µM. Further, molecular docking of 3-methoxybenzoyloxy substituted analogue against Inhibitor of nuclear factor-kappa B kinase (Protein data bank ID: 3QA8) showed hydrogen bonding interaction involving oxygen atom of 3-methoxybenzoyloxy with the Arginine-31 and Glutamine-110. Encouraging results indicate the Lantadene’s potential to be developed as anticancer agents.

Keywords: anticancer, lantadenes, pentacyclic triterpenoids, weed

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Authors: Cigdem Karaaslan, Yalcin Duydu, Aylin Ustundag, Can Ozgur Yalcın, Hakan Goker

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Benzazole nucleus is found in the structure of many compounds as anticancer agents. Bendamustine (Alkylating agent), Nocodazole (Mitotic inhibitor), Veliparib (PARP inhibitor), Glasdegib (SMO inhibitor) are clinically used as anticancer therapeutics which bearing benzimidazole moiety. Based on the principle of bioisosterism in the present work, 23 compounds belonging to 2-(3,4-dimethoxy-phenyl) benzazoles and imidazopyridine series were synthesized and evaluated for their anticancer activities. N-(5-Chloro-2-hydroxyphenyl)-3,4-dimethoxybenzamide, was obtained by the amidation of 2-hydroxy-5-chloroaniline with 3,4-dimethoxybenzoic acid by using 1,1'-carbonyldiimidazole. Cyclization of benzamide derivative to benzoxazole, was achieved by p-toluenesulfonic acid. Other 1H-benz (or pyrido) azoles were prepared by the reaction between 2-aminothiophenol, o-phenylenediamine, o-pyridinediamine with sodium metabisulfite adduct of 3,4-dimethoxybenzaldehyde. The NMR assignments of the dimethoxy groups were established by the Nuclear Overhauser Effect Spectroscopy. A compound named, 5(4),7(6)-Dichloro-2-(3,4-dimethoxy) phenyl-1H-benzimidazole, bearing two chlorine atoms at the 5(4) and 7(6) positions of the benzene moiety of benzimidazole was found the most potent analogue, against A549 cells with the GI50 value of 1.5 µg/mL. In addition, 2-(3,4-Dimethoxyphenyl)-5,6-dimethyl-1H-benzimi-dazole showed remarkable cell growth inhibition against MCF-7 and HeLa cells with the GI₅₀ values of 7 and 5.5 µg/mL, respectively. It could be concluded that introduction of di-chloro atoms at the phenyl ring of 2-(3,4-dimethoxyphenyl)-1H-benzimidazoles increase significant cytotoxicity to selected human tumor cell lines in comparison to other all benzazoles synthesized in this study. Unsubstituted 2-(3,4-dimethoxyphenyl) imidazopyridines also gave the good inhibitory profile against A549 and HeLa cells.

Keywords: 3, 4-Dimethoxyphenyl, 1H-benzimidazole, benzazole, imidazopyridine

Procedia PDF Downloads 122

Authors: Dalita G. S. M. Cavalcante, Elton A. P. dos Reis, Andressa S. Gomes, Caroline S. Danna, Leandra Ernest Kerche-Silva, Eidi Yoshihara, Aldo E. Job

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In order to minimize environmental impacts, a composite was developed from mixture of leather shavings (LE) with natural rubber (NR), which patent is already deposited. The new material created can be used in applications such as floors e heels for shoes. Besides these applications, the aim is to use this new material for the production of products for the textile industry, such as boots, gloves and bags. But the question arises, as to biocompatibility of this new material. This is justified because the structure of the leather shavings has chrome. The trivalent chromium is usually not toxic, but the hexavalent chromium can be highly toxic and genotoxic for living beings, causing damage to the DNA molecule and contributing to the formation of cancer. Based on this, the objective of this study is evaluate the possible genotoxic effects of the new composite, using as system - test two cell lines (MRC-5 and CHO-K1) by comet assay. For this, the production of the composite was performed in three proportions: for every 100 grams of NR was added 40 (E40), 50 (E50) or 60 (E60) grams of LE. The latex was collected from the rubber tree (Hevea brasiliensis). For vulcanization of the NR, activators and accelerators were used. The two cell lines were exposed to the new composite in its three proportions using elution method, that is, cells exposed to liquid extracts obtained from the composite for 24 hours. For obtaining the liquid extract, each sample of the composite was crushed into pieces and mixed with an extraction solution. The quantification of total chromium and hexavalent chromium in the extracts were performed by Optical Emission Spectrometry by Inductively Coupled Plasma (ICP-OES). The levels of DNA damage in cells exposed to both extracts were monitored by alkaline version of the comet assay. The results of the quantification of metals in ICP-OES indicated the presence of total chromium in different extracts, but were not detected presence of hexavalent chromium in any extract. Through the comet assay were not found DNA damage of the CHO-K1 cells exposed to both extracts. As for MRC-5, was found a significant increase in DNA damage in cells exposed to E50 and E60. Based on the above data, it can be asserted that the extracts obtained from the composite were highly genotoxic for MRC-5 cells. These biological responses do not appear to be related to chromium metal, since there was a predominance of trivalent chromium in the extracts, indicating that during the production process of the new composite, there was no formation of hexavalent chromium. In conclusion it can infer that the leather shavings containing chromium can be reused, thereby reducing the environmental impacts of this waste. Already on the composite indicates to its incorporation in applications that do not aim at direct contact with the human skin, and it is suggested the chain of composite production be studied, in an attempt to make it biocompatible so that it may be safely used by the textile industry.

Keywords: cell line, chrome, genotoxicity, leather, natural rubber

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Authors: Maksudur Rahman Khan, Kar Min Chan, Huei Ruey Ong, Chin Kui Cheng, Wasikur Rahman

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Microbial fuel cells (MFCs) represent a promising technology for simultaneous bioelectricity generation and wastewater treatment. Catalysts are significant portions of the cost of microbial fuel cell cathodes. Many materials have been tested as aqueous cathodes, but air-cathodes are needed to avoid energy demands for water aeration. The sluggish oxygen reduction reaction (ORR) rate at air cathode necessitates efficient electrocatalyst such as carbon supported platinum catalyst (Pt/C) which is very costly. Manganese oxide (MnO2) was a representative metal oxide which has been studied as a promising alternative electrocatalyst for ORR and has been tested in air-cathode MFCs. However, the single MnO2 has poor electric conductivity and low stability. In the present work, the MnO2 catalyst has been modified by doping Pt nanoparticle. The goal of the work was to improve the performance of the MFC with minimum Pt loading. MnO2 and Pt nanoparticles were prepared by hydrothermal and sol-gel methods, respectively. Wet impregnation method was used to synthesize Pt/MnO2 catalyst. The catalysts were further used as cathode catalysts in air-cathode cubic MFCs, in which anaerobic sludge was inoculated as biocatalysts and palm oil mill effluent (POME) was used as the substrate in the anode chamber. The as-prepared Pt/MnO2 was characterized comprehensively through field emission scanning electron microscope (FESEM), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) where its surface morphology, crystallinity, oxidation state and electrochemical activity were examined, respectively. XPS revealed Mn (IV) oxidation state and Pt (0) nanoparticle metal, indicating the presence of MnO2 and Pt. Morphology of Pt/MnO2 observed from FESEM shows that the doping of Pt did not cause change in needle-like shape of MnO2 which provides large contacting surface area. The electrochemical active area of the Pt/MnO2 catalysts has been increased from 276 to 617 m2/g with the increase in Pt loading from 0.2 to 0.8 wt%. The CV results in O2 saturated neutral Na2SO4 solution showed that MnO2 and Pt/MnO2 catalysts could catalyze ORR with different catalytic activities. MFC with Pt/MnO2 (0.4 wt% Pt) as air cathode catalyst generates a maximum power density of 165 mW/m3, which is higher than that of MFC with MnO2 catalyst (95 mW/m3). The open circuit voltage (OCV) of the MFC operated with MnO2 cathode gradually decreased during 14 days of operation, whereas the MFC with Pt/MnO2 cathode remained almost constant throughout the operation suggesting the higher stability of the Pt/MnO2 catalyst. Therefore, Pt/MnO2 with 0.4 wt% Pt successfully demonstrated as an efficient and low cost electrocatalyst for ORR in air cathode MFC with higher electrochemical activity, stability and hence enhanced performance.

Keywords: microbial fuel cell, oxygen reduction reaction, Pt/MnO2, palm oil mill effluent, polarization curve

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Authors: Mazaher Yarmohamadi-Vasel, Ali Reza Modarresi-Alama, Sahar Shabzendedara

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Purpose/Objectives: The first purpose was synthesize Poly(N-(sulfophenyl)aniline) nanoflowers (PSANFLs) and Poly(N-(sulfophenyl)aniline) nanofibers/titanium dioxide nanoparticles ((PSANFs/TiO2NPs) by a solid-state mechano-chemical reaction and template-free method and use them in hybrid solar cell. Also, our second aim was to increase the solubility and the processability of conjugated nanomaterials in water through polar functionalized materials. poly[N-(4-sulfophenyl)aniline] is easily soluble in water because of the presence of polar groups of sulfonic acid in the polymer chain. Materials/Methods: Iron (III) chloride hexahydrate (FeCl3∙6H2O) were bought from Merck Millipore Company. Titanium oxide nanoparticles (TiO2, <20 nm, anatase) and Sodium diphenylamine-4-sulfonate (99%) were bought from Sigma-Aldrich Company. Titanium dioxide nanoparticles paste (PST-20T) was prepared from Sharifsolar Co. Conductive glasses coated with indium tin oxide (ITO) were bought from Xinyan Technology Co (China). For the first time we used the solid-state mechano-chemical reaction and template-free method to synthesize Poly(N-(sulfophenyl)aniline) nanoflowers. Moreover, for the first time we used the same technique to synthesize nanocomposite of Poly(N-(sulfophenyl)aniline) nanofibers and titanium dioxide nanoparticles (PSANFs/TiO2NPs) also for the first time this nanocomposite was synthesized. Examining the results of electrochemical calculations energy gap obtained by CV curves and UV–vis spectra demonstrate that PSANFs/TiO2NPs nanocomposite is a p-n type material that can be used in photovoltaic cells. Doctor blade method was used to creat films for three kinds of hybrid solar cells in terms of different patterns like ITO│TiO2NPs│Semiconductor sample│Al. In the following, hybrid photovoltaic cells in bilayer and bulk heterojunction structures were fabricated as ITO│TiO2NPs│PSANFLs│Al and ITO│TiO2NPs│PSANFs /TiO2NPs│Al, respectively. Fourier-transform infrared spectra, field emission scanning electron microscopy (FE-SEM), ultraviolet-visible spectra, cyclic voltammetry (CV) and electrical conductivity were the analysis that used to characterize the synthesized samples. Results and Conclusions: FE-SEM images clearly demonstrate that the morphology of the synthesized samples are nanostructured (nanoflowers and nanofibers). Electrochemical calculations of band gap from CV curves demonstrated that the forbidden band gap of the PSANFLs and PSANFs/TiO2NPs nanocomposite are 2.95 and 2.23 eV, respectively. I–V characteristics of hybrid solar cells and their power conversion efficiency (PCE) under 100 mWcm−2 irradiation (AM 1.5 global conditions) were measured that The PCE of the samples were 0.30 and 0.62%, respectively. At the end, all the results of solar cell analysis were discussed. To sum up, PSANFLs and PSANFLs/TiO2NPs were successfully synthesized by an affordable and straightforward mechanochemical reaction in solid-state under the green condition. The solubility and processability of the synthesized compounds have been improved compared to the previous work. We successfully fabricated hybrid photovoltaic cells of synthesized semiconductor nanostructured polymers and TiO2NPs as different architectures. We believe that the synthesized compounds can open inventive pathways for the development of other Poly(N-(sulfophenyl)aniline based hybrid materials (nanocomposites) proper for preparing new generation solar cells.

Keywords: mechanochemical synthesis, PSANFLs, PSANFs/TiO2NPs, solar cell

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Authors: Hoo Cheol Lee, Dae Seung Kim, Sang Myung Jung, Gwang Heum Yoon, Hwa Sung Shin

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Loss of bone tissue can occur due to a bone tissue disease and aging or fracture. Renewable formation of bone is mainly made by its differentiation and metabolism. For this reason, osteoblasts have been studied for regeneration of bone tissue. So, tissue engineering has attracted attention as a recovery means. In tissue engineering, a particularly important factor is a scaffold that supports cell growth. For osteoblast scaffold, we used the cellulose nanowhisker (CNW) extracted from marine organism. CNW is one of an abundant material obtained from a number of plants and animals. CNW is polymer consisting of monomer cellulose and this composition offers biodegradability and biocompatibility to CNW. Mechanical strength of CNW is superior to the existing natural polymers. In addition, substances of marine origin have a low risk of secondary infection by bacteria and pathogen in contrast with those of land-derived. For evaluating its suitability as an osteoblast scaffold, we fabricate CNW film for osteoblast culture and performed the MTT assay and ALP assay to confirm its cytotoxicity and effect on differentiation. Taking together these results, we assessed CNW is a potential candidate of a material for bone tissue regeneration.

Keywords: bone regeneration, cellulose nanowhisker, marine derived material, osteoblast

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Authors: Kyriaki Hatziagapiou, Konstantinos Bethanis, Olti Nikola, Elias Christoforides, Eleni Koniari, Eleni Kakouri, George Lambrou, Christina Kanaka-Gantenbein

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Glioblastoma multiforme (GBM) remains a serious health challenge, as current therapeutic modalities continue to yield unsatisfactory results, with the average survival rarely exceeding 1-2 years. Natural compounds still provide some of the most promising approaches for discovering new drugs. The non-psychotropic cannabidiol (CBD) deriving from Cannabis sativa L. provides such promise. CBD is endowed with anticancer, antioxidant, and genoprotective properties as established in vitro and in in vivo experiments. CBD’s selectivity towards cancer cells and its safe profile suggest its usage in cancer therapies. However, the bioavailability of oral CBD is low due to poor aqueous solubility, erratic gastrointestinal absorption, and significant first-pass metabolism, hampering its therapeutic potential and resulting in a variable pharmacokinetic profile. In this context, CBD can take great advantage of nanomedicine-based formulation strategies. Cyclodextrins (CDs) are cyclic oligosaccharides used in the pharmaceutical industry to incorporate apolar molecules inside their hydrophobic cavity, increasing their stability, water solubility, and bioavailability or decreasing their side effects. CBD-inclusion complexes with CDs could be a good strategy to improve its properties, like solubility and stability to harness its full therapeutic potential. The current research aims to study the potential cytotoxic effect of CBD and CBD-CDs complexes CBD-RMβCD (randomly methylated β-cyclodextrin) and CBD-HPβCD (hydroxypropyl-b-CD) on the A172 glioblastoma cell line. CBD is diluted in 10% DMSO, and CBD/CDs solutions are prepared by mixing solid CBD, solid CDs, and dH2O. For the biological assays, A172 cells are incubated at a range of concentrations of CBD, CBD-RMβCD and CBD-HPβCD, RMβCD, and HPβCD (0,03125-4 mg/ml) at 24, 48, and 72 hours. Analysis of cell viability after incubation with the compounds is performed with Alamar Blue viability assay. CBD’s dilution to DMSO 10% was inadequate, as crystals are observed; thus cytotoxicity experiments are not assessed. CBD’s solubility is enhanced in the presence of both CDs. CBD/CDs exert significant cytotoxicity in a dose and time-dependent manner (p < 0.005 for exposed cells to any concentration at 48, 72, and 96 hours versus cells not exposed); as their concentration and time of exposure increases, the reduction of resazurin to resofurin decreases, indicating a reduction in cell viability. The cytotoxic effect is more pronounced in cells exposed to CBD-HPβCD for all concentrations and time-points. RMβCD and HPβCD at the highest concentration of 4 mg/ml also exerted antitumor action per se since manifesting cell growth inhibition. The results of our study could afford the basis of research regarding the use of natural products and their inclusion complexes as anticancer agents and the shift to targeted therapy with higher efficacy and limited toxicity. Acknowledgments: The research is partly funded by ΙΚΥ (State Scholarships Foundation) – Post-doc Scholarships-Partnership Agreement 2014-2020.

Keywords: cannabidiol, cyclodextrins, glioblastoma, hydroxypropyl-b-Cyclodextrin, randomly-methylated-β-cyclodextrin

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Authors: Nijole Savickiene, Antonella Di Sotto, Gabriela Mazzanti, Rasa Starselskyte, Silvia Di Giacomo, Annabella Vitalone

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Plant lectins are non-enzymic and non-immune origin proteins that specifically recognize and bind to various sugar structures and possess the activity to agglutinate cells and/or precipitate polysaccharides and glycoconjugates. The emerging evidences showed that plant lectins contribute not only to tumour cell recognition but also to cell adhesion and localization, to signal transduction, to mitogenic cytotoxicity and apoptosis. Among chitin-binding lectins, the Urtica dioica agglutinin (UDA), which is a complex of different isoforms, has been poorly studied for its biological activity. In this context and according to the increasing interest for lectins as novel antitumor drugs, present paper aimed at evaluating the potential antimutagenic activity of a lectin-like glycoprotein-enriched fraction from aerial part of Urtica dioica L. Aim: to evaluate the potential chemopreventive properties of a protein - lectin fraction from the aerial part of Urtica dioica. Materials and methods: Protein – lectin fraction has been tested for the antimutagenic activity in bacteria (50–800 mg/plate; Ames test by the preincubation method) and for the cytotoxicity on human hepatoma HepG2 cells (0.06–2 mg/mL; 24 and 48 h incubation). Results: Protein – lectin fraction from stinging nettle was not cytotoxic on HepG2 cells up to 2 mg/mL; conversely, it exhibited a strong antimutagenic activity against the mutagen 2-aminoanthracene (2AA) in all strains tested (maximum inhibition of 56.78 and 61% in TA98, TA100, and WP2uvrA strains, respectively, at 800 mg/plate). Discussion and conclusions: Protein – lectin fraction from Urtica dioica L. possesses antimutagenic and radical scavenging properties. Being 2AA a pro-carcinogenic agent, we hypothesize that the antimutagenicity of it can be due to the inhibition of CYP450-isoenzymes, involved in the mutagen bioactivation.

Keywords: lectins, antimutagenicity, chemoprevention, Urtica dioica

Procedia PDF Downloads 426