69 research outputs found

    Development and characterization of biointeractive gelatin wound dressing based on extract of Punica granatum Linn

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    Punica granatum Linn (pomegranate) extracts have been proposed for wound healing due to their antimicrobial, antioxidant, and anti-inflammatory properties. In this work, we designed biointeractive membranes that contain standard extracts of P. granatum for the purpose of wound healing. The used standard extract contained 32.24 mg/g of gallic acid and 41.67 mg/g of ellagic acid, and it showed high antioxidant activity (the concentration of the extract that produces 50% scavenging (IC50) 1.715 ”g/mL). Compared to the gelatin-based membranes (GEL), membranes containing P. granatum extracts (GELPG) presented a higher maximal tension (p=0.021) and swelling index (p=0.033) and lower water vapor permeability (p=0.003). However, no difference was observed in the elongation and elastic modulus of the two types of membranes (p > 0.05). Our wound-healing assay showed that a GELPG-treated group experienced a significant increase compared to that of the control group in their wound contraction rates on days 3 (p < 0.01), 7 (p < 0.001), and on day 14 (p < 0.001). The GELPG membranes promoted major histological changes in the dynamics of wound healing, such as improvements in the formation of granular tissue, better collagen deposition and arrangement, and earlier development of cutaneous appendages. Our results suggest that a biointeractive gelatin-based membrane containing P. granatum extracts has a promising potential application for dressings that are used to treat wounds.The research was funded by FAPITEC/SE (Fundação de Apoio à Pesquisa e Inovação Tecnológica do Estado de Sergipe) and by the Brazilian Bureau of Research. T. Pashirova received the financial support from the government assignment for the FRC Kazan Scientific Center of Russian Academy of Sciences. E.B. Souto received the support from the projects M-ERA-NET-0004/2015-PAIRED and UIDB/04469/2020, granted by the Portuguese Science and Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds and co-financed by FEDER under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

    Double membrane based on lidocaine-coated polymyxin-alginate nanoparticles for wound healing: in vitro characterization and in vivo tissue repair

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    The aim of this study was to develop and characterize a double layer biomembrane for dual drug delivery to be used for the treatment of wounds. The membrane was composed of chitosan, hydroxypropyl methylcellulose and lidocaine chloride (anesthetic drug) in the first layer, and of sodium alginate-polymyxin B sulphate (antibiotic) nanoparticles as the second layer. A product with excellent thickness (0.01-0.02 mm), adequate mechanical properties with respect to elasticity, stiffness, tension, and compatible pH for lesion application has been successfully obtained. The incorporation of the drugs was confirmed analysing the membrane cross-sections by scanning electron microscopy. A strong interaction between the drugs and the functional groups of respective polymers was confirmed by Fourier-Transform Infrared Spectroscopy, thermal analysis and X-ray diffraction. Microbiological assays showed a high antimicrobial activity when polymyxin B was present to act against the Staphylococcus aureus and Pseudomonas aeruginosa strains. Low cytotoxicity observed in a cell viability colorimetric assay and SEM analysis suggest biocompatibility between the developed biomembrane and the cell culture. The in vivo assay allowed visualizing the healing potential by calculating the wound retraction index and by histological analysis. Our results confirm the effectiveness of the developed innovative biomaterial for tissue repair and regeneration in an animal model.The authors acknowledge the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/Brazil), Fundação de Amparo a Pesquisa do Estado de Sergipe (FAPITEC, MS/CNPq/FAPITEC/SE/SES N◩06/2018) e do Conselho Nacional de Pesquisas (CNPq, Apoio a Projetos de Pesquisa/MCTI/CNPQ/Universal 14/2014) for supporting funds. EBS acknowledges the Portuguese Science and Technology Foundation (FCT) for the funded projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund) financed from national funds, and co-financed Education (FCT/MEC) from national funds and FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

    Cymbopogon winterianus essential oil attenuates bleomycin-induced pulmonary fibrosis in a murine model

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    The essential oil of Cymbopogon winterianus (EOCW) is a natural product with antioxidant, anti-inflammatory, and antifibrotic properties. We studied the effect of EOCW in the progression of histological changes of pulmonary fibrosis (PF) in a rodent model. The oil was obtained by hydrodistillation and characterized using gas chromatographymass spectrometry. Intratracheal instillation of bleomycin was performed in 30 rats to induce PF, while Sham animals were subjected to instillation of saline solution. The treatment was performed using daily oral administration of distilled water, EOCW at 50, 100, and 200 mg/kg, and deflazacort (DFC). After 28 days, hemogram and bronchoalveolar lavage fluid (BALF), tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were assayed. Histological grading of PF, immunohistochemical expression of -smooth muscle actin (-SMA), and transforming growth factor- (TGF-) were also analyzed. The EOCW major compounds were found to be citronellal, geraniol, and citronellol. EOCW significantly reduced inflammation in BALF, reduced MDA levels, and increased SOD activity. EOCW attenuated histological grading of PF and reduced immunohistochemical expression of -SMA and TGF- in a dose-dependent way, likely due to the reduction of oxidative stress, inflammation, and TGF--induced myofibroblast differentiation.This research was financed by the Coordenação Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de Sergipe (FAPITEC), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). EBS wishes to acknowledge the sponsorship of the project UIDB/04469/2020 (strategic fund) from the Portuguese Science and Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and was co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

    Bean tissue culture for introduction of foreign genes

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    O objetivo deste trabalho foi determinar parĂąmetros da cultura de tecidos de feijoeiro necessĂĄrios para a aplicação da tĂ©cnica de transformação via Agrobacterium. Diversos genĂłtipos de feijoeiro (Phaseolus vulgaris L.) foram cultivados in vitro. Alguns parĂąmetros visando Ă  infecção de ĂĄpices caulinares com Agrobacterium tumefaciens foram otimizados, como a eliminação da agrobactĂ©ria apĂłs a co-cultura e a concentração de kanamicina suficiente para a seleção dos ĂĄpices infectados. MultibrotaçÔes em nĂłs cotiledonares foram obtidas com freqĂŒĂȘncia de atĂ© 55,7%, dependendo do genĂłtipo utilizado. Estes nĂłs foram infectados com A. tumefaciens contendo em seu plasmĂ­deo Ti o gene da ÎČ-glucuronidase (GUS) sob regulação de promotor eucariĂłtico. Entre as multibrotaçÔes obtidas, 30% apresentaram regiĂŁo onde foi detectada atividade do gene GUS. Demonstrou-se tambĂ©m a susceptibilidade de feijoeiro a Agrobacterium rhizogenes. RaĂ­zes transgĂȘnicas foram obtidas apĂłs infecção de epicĂłtilos.The objective of this work was to determine different bean tissue culture parameters necessary to the application of Agrobacterium-mediated transformation technique. Several bean (Phaseolus vulgaris L.) genotypes were cultured in vitro. The protocols for Agrobacterium elimination, after infection of the apical meristems with Agrobacterium tumefaciens and the selective kanamycin concentration were determined. Depending on the genotype, multiple buds were obtained from cotiledonary nodes in a frequency up to 55.7%. The cotiledonary nodes were infected with A. tumefaciens carrying in the Ti plasmid the gene for ÎČ-glucuronidase (GUS) under the control of an eucariotic promoter. Regions with GUS activity were detected in 30% of the shoots. The susceptibility of bean to Agrobacterium rhizogenes was also shown. Transgenic roots were obtained after infection of epicotyls with A. rhizogenes

    Antimicrobial Photodynamic Therapy: Study of Bacterial Recovery Viability and Potential Development of Resistance after Treatment

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    Antimicrobial photodynamic therapy (aPDT) has emerged in the clinical field as a potential alternative to antibiotics to treat microbial infections. No cases of microbial viability recovery or any resistance mechanisms against it are yet known. 5,10,15-tris(1-Methylpyridinium-4-yl)-20-(pentafluorophenyl)-porphyrin triiodide (Tri-Py+-Me-PF) was used as photosensitizer. Vibrio fischeri and recombinant Escherichia coli were the studied bacteria. To determine the bacterial recovery after treatment, Tri-Py+-Me-PF (5.0 ÎŒM) was added to bacterial suspensions and the samples were irradiated with white light (40 W m−2) for 270 minutes. Then, the samples were protected from light, aliquots collected at different intervals and the bioluminescence measured. To assess the development of resistance after treatment, bacterial suspensions were exposed to white light (25 minutes), in presence of 5.0 ÎŒM of Tri-Py+-Me-PF (99.99% of inactivation) and plated. After the first irradiation period, surviving colonies were collected from the plate and resuspended in PBS. Then, an identical protocol was used and repeated ten times for each bacterium. The results suggest that aPDT using Tri-Py+-Me-PF represents a promising approach to efficiently destroy bacteria since after a single treatment these microorganisms do not recover their viability and after ten generations of partially photosensitized cells neither of the bacteria develop resistance to the photodynamic process

    Photodynamic Antimicrobial Chemotherapy in Aquaculture: Photoinactivation Studies of Vibrio fischeri

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    BACKGROUND: Photodynamic antimicrobial chemotherapy (PACT) combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1) with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2) with aquaculture water, to reproduce photoinactivation (PI) conditions in situ. METHODOLOGY/PRINCIPAL FINDINGS: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+)-Me-PF) was used as photosensitizer (5 ”M in the studies with buffer solution and 10-50 ”M in the studies with aquaculture water); artificial white light (4 mW cm(-2)) and solar irradiation (40 mW cm(-2)) were used as light sources; and the bacterial concentration used for all experiments was ≈10(7) CFU mL(-1) (corresponding to a bioluminescence level of 10(5) relative light units--RLU). The variations in pH (6.5-8.5), temperature (10-25°C), salinity (20-40 g L(-1)) and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction). The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 ”M of Tri-Py(+)-Me-PF. CONCLUSIONS/SIGNIFICANCE: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to treat aquaculture water makes this technology cost-effective and attractive

    Personality Traits of an Entrepreneur, Determinants of Successful Microenterprise in Ireland

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    Why do certain individuals become entrepreneur and are successful, whereas others do not? The researchers in the entrepreneurship field attempt to answer that question by studying the personality traits of entrepreneurs for decades. Many confirm that the personality traits have a positive correlation with entrepreneurial intention and performance. Various studies suggest that the main entrepreneurial characteristics are risk attitudes, need for achievement, internal locus of control, innovativeness, and self-efficacy. However, debate exist if the personality traits are born or inherited and if the entrepreneurs’ actions are influenced by factors such as family, culture, education and market conditions. Although these aspects will be reviewed the focus of this study is on entrepreneurs’ personality traits only. Consequently, the aim of this study is to identify which of the personality traits, and whether there are traits, that are associated with operating successful microenterprise, from a perspective of an owner-manager of an established business in Ireland. The findings of this research revealed that the participants perceive themselves as individuals who possess indirectly four out of five most cited traits in the literature, which are need for achievement, locus of control, innovativeness and self-efficacy. In addition, they mentioned ability to relate to others, being organized and perform a quality work as the most important characteristics of a successful business owner. Also, other factors of environment influenced the participants’ decision to become an entrepreneur and Ireland was perceived as an attractive country to set up a business. Still, most of the participants do not perceive themselves as a successful entrepreneur. In summary, the inconclusiveness of this study generate more questions than it provide answers, coupled with this study limitations it is suggested that additional and more extensive research is desired

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016
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