228 research outputs found

    Detecting glacial refugia in the Southern Ocean

    Get PDF
    Throughout the Quaternary, the continental‐based Antarctic ice sheets expanded and contracted repeatedly. Evidence suggests that during glacial maxima, grounded ice eliminated most benthic (bottom‐dwelling) fauna across the Antarctic continental shelf. However, paleontological and molecular evidence indicates most extant Antarctica benthic taxa have persisted in situ throughout the Quaternary. Where and how the Antarctic benthic fauna survived throughout repeated glacial maxima remain mostly hypothesised. If understood, this would provide valuable insights into the ecology and evolution of Southern Ocean biota over geological timescales. Here we synthesised and appraised recent studies and presented an approach to demonstrate how genetic data can be effective in identifying where and how Antarctic benthic fauna survived glacial periods. We first examined the geological and ecological evidence for how glacial periods influenced past species demography in order to provide testable frameworks for future studies. We outlined past ice‐free areas from Antarctic ice sheet reconstructions that could serve as glacial refugia and discussed how benthic fauna with pelagic or non‐pelagic dispersal strategies moved into and out of glacial refugia. We also reviewed current molecular studies and collated proposed locations of Southern Ocean glacial refugia on the continental shelf around Antarctica, in the deep sea, and around sub‐Antarctic islands. Interestingly, the proposed glacial refugia based on molecular data generally do not correspond to the ice‐free areas identified by Antarctic ice sheet reconstructions. The potential biases in sampling and in the choice of molecular markers in current literature are discussed, along with the future directions for employing testable frameworks and genomic methods in Southern Ocean molecular studies. Continued data syntheses will elucidate greater understanding of where and how Southern Ocean benthic fauna persisted throughout glacial periods and provide insights into their resilience against climate changes in the future

    Microfluidic-assisted electrospinning, an alternative to coaxial, as a controlled dual drug release system to treat inflammatory arthritic diseases

    Get PDF
    Inflammatory arthritic diseases are characterized by a persistent inflammation of the synovial tissues where tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) pro-inflammatory cytokines are over-expressed, leading to progressive musculoskeletal disability. Methotrexate (MTX), a disease-modifying-anti-rheumatic drug (DMARD) commonly applied in their treatment, can be used in combination with biological-DMARDs as anti-TNFα antibody to improve the treatments efficacy. However, their systemic administration comes with severe side-effects and limited therapeutic efficacy due to their off-target distribution and short half-life. To overcome such limitations, encapsulation of clinically relevant concentrations of MTX and anti-TNFα antibody into polycaprolactone (PCL) or poly(vinyl-alcohol) (PVA) microfluidic-assisted or coaxial electrospun fibrous meshes is proposed as local controlled dual drug release systems. Release studies show that microfluidic-assisted electrospinning meshes encapsulating both drugs achieved higher concentrations than coaxials. Biological assays using human articular chondrocytes (hACs) and monocytic cells (THP-1 cell line) demonstrate that fibrous meshes encapsulating the drugs are non-toxic. The systems' efficacy is proved by a significant decrease of TNFα and IL-6 concentrations in conditioned medium of lipopolysaccharide (LPS)-stimulated THP-1 cells, especially in the presence of microfluidic-assisted electrospun meshes, when compared with THP-1 conditioned medium (59.5% and 83.9% less, respectively). Therefore, microfluidic-assisted electrospinning fibrous meshes with encapsulating drugs represent an alternative to coaxial, as a local therapy for inflammatory arthritis diseases.This work was supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, for the Ph.D grant of Catarina Silva (UMINHO/BD/33/2016; NORTE-08-5369-FSE-000012), and by the Portuguese Science and Technology Foundation (FCT) for the cells project Cells4_ID (PTDC/BTM-SAL/28882/2017)

    Effective cytocompatible nanovectors based on serine-derived gemini surfactants and monoolein for small interfering RNA delivery

    Get PDF
    Supplementary data to this article can be found online athttps://doi.org/10.1016/j.jcis.2020.09.077.Non-viral gene therapy based on gene silencing with small interfering RNA (siRNA) has attracted great interest over recent years. Among various types of cationic complexation agents, amino acid-based surfactants have been recently explored for nucleic acid delivery due to their low toxicity and high biocompatibility. Monoolein (MO), in turn, has been used as helper lipid in liposomal systems due to its ability to form inverted nonbilayer structures that enhance fusogenicity, thus contributing to higher transfection efficiency. In this work, we focused on the development of nanovectors for siRNA delivery based on three gemini amino acid-based surfactants derived from serine (12Ser)2N12, amine derivative; (12Ser)2COO12, ester derivative; and (12Ser)2CON12, amide derivative individually combined with MO as helper lipid. The inclusion of MO in the cationic surfactant system influences the morphology and size of the mixed aggregates. Furthermore, the gemini surfactant:MO systems showed the ability to efficiently complex siRNA, forming stable lipoplexes, in some cases clearly depending on the MO content, without inducing significant levels of cytotoxicity. High levels of gene silencing were achieved in comparison with a commercially available standard indicating that these gemini:MO systems are promising candidates as lipofection vectors for RNA interference (RNAi)-based therapies.The authors acknowledge Fundação para a CiĂȘncia e a Tecnolo-gia (FCT) for financial support through projects UIDB/00081/2020 and UIDB/50006/2020. This work was supported by the‘‘Contrato-Programa” UIDB/04050/2020 funded by national fundsthrough the FCT I.P. Dr. Marisa Passos is gratefully acknowledged for help with the statistical analysis of cytotoxicity data. Fundingby the CCDR-N/NORTE2020/Portugal2020 through project DESign-BIOtechHealth (ref. Norte-01-0145-FEDER-000024) is also acknowledged. I. S. Oliveira and S.G. Silva also acknowledge finan-cial support from FCT through PhD grant SFRH/BD/108629/2015 and Individual Call to Scientific Employment Stimulus - CEEC Indi-vidual grant CEECIND/01932/2017, respectivelyinfo:eu-repo/semantics/publishedVersio

    Advancing our understanding of the connectivity, evolution and management of marine lobsters through genetics

    Get PDF
    The genomic revolution has provided powerful insights into the biology and ecology of many non-model organisms. Genetic tools have been increasingly applied to marine lobster research in recent years and have improved our understanding of species delimitation and population connectivity. High resolution genomic markers are just beginning to be applied to lobsters and are now starting to revolutionise our understanding of fine spatial and temporal scales of population connectivity and adaptation to environmental conditions. Lobsters play an important role in the ecosystem and many species are commercially exploited but many aspects of their biology is still largely unknown. Genetics is a powerful tool that can further contribute to our understanding of their ecology and evolution and assist management. Here we illustrate how recent genetic advancements are (1) leading to a step change in our understanding of evolution and adaptation, (2) elucidating factors driving connectivity and recruitment, (3) revealing insights into ecological processes and can (4) potentially revolutionise management of this commercially important group. We discuss how improvements in sequencing technologies and statistical methods for genetic data analyses combined with increased sampling efforts and careful sampling design have transformed our understanding of lobsters biology in recent years. We also highlight possible future directions in the application of genomic tools to lobster research that can aid management, in particular, the close-kin-mark-recapture method. Finally, we identify gaps and challenges in lobster research, such as the lack of any reference genomes and predictions on how lobsters will respond to future environmental conditions

    Gross morphology and topography of the digestive apparatus in rheas (Rhea americana americana)

    Get PDF
    Rodrigues M.N., Oliveira G.B., Silva R.S.S, Tivane C.T., Albuquerque J.F.G., Miglino M.A. & Oliveira M.F. 2012. [Gross morphology and topography of the digestive apparatus in rheas (Rhea americana americana).] Macroscopia e topografia do aparelho digestorio de emas (Rhea americana americana). Pesquisa Veterinaria Brasileira 32(7):681-686. Departamento de Cirurgia, Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, Cidade Universitaria, Av. Prof. Dr. Orlando Marques de Paiva 87, Sao Paulo, SP 05508270, Brazil. E-mail: [email protected] Rheas are birds belonging to the ratites group and, among ostriches and emus, are the largest birds currently alive. In this work we studied the macroscopic aspects of rheas' digestive tract in order to provide important information to a better understanding of these birds' eating habits as well their anatomy. Twenty young animals aging between two and six months from the Centre for Wild Animals Multiplication (Cemas, scientific breeding license form Ibama no.1478912) were used. After dissection it was observed that their tongue was small and presented a rhomboid form, being disposed on the oral cavity floor, and inserted in its base by a frenulum. The esophagus was a rectilinear tube with elastic aspect and longitudinal elastic fibers, without dilation, which gives it an absence of crop. The proventriculus presented a fusiform form and the gastric ventricle showed and slightly oval form when filled, and was internally coated with a thick gastric cuticle. The small intestine was composed of three distinct regions: duodenum, jejunum and ileum. The duodenum had a light gray color and showed a "U" curved shaped. The jejunum was dark green, long and composed of several short loops arranged above each other. The ileum had a gray color and was connected with the jejunum. In ventral line to the rectum and cloaca, the ileum extended cranially, dorsally to the ascending duodenum. The large intestine was composed of two caeca, one right and one left, and colon-rectum and ileum were continuous with the cloaca. The structures of the rhea digestive tract resemble those described in the literature regarding to its shape and topography, even though rhea's caeca are well developed and relatively long

    Nanocellulose toxicity in vitro models: contributing to its safety assessment to human health

    Get PDF
    As nanoceluloses sĂŁo nanomateriais inovadores com potencial para uma vasta gama de aplicaçÔes industriais e biomĂ©dicas. No entanto, a expansĂŁo da sua produção tem vindo a suscitar preocupaçÔes quanto aos possĂ­veis efeitos, a longo prazo, na saĂșde humana. Este estudo teve como objetivo avaliar a segurança de algumas nanoceluloses produzidas a partir de matĂ©ria-prima nacional, atravĂ©s da caracterização da sua potencial toxicidade em cĂ©lulas de mamĂ­fero. Para tal, testaram-se duas celuloses nano /microfibrilares (CNF e CMF ) e uma celulose nanocristalina (CNC). Analisou-se a citotoxicidade usando ensaios colorimĂ©tricos e o ensaio clonogĂ©nico, e a genotoxicidade pelo ensaio do micronĂșcleo in vitro em cĂ©lulas pulmonares de mamĂ­fero (A549 e V79 ) e em osteoblastos humanos ( MG-63 ). A indução de espĂ©cies reativas de oxigĂ©nio (ROS) e a internalização celular foram tambĂ©m estudadas nas cĂ©lulas A549. Observou- -se citotoxicidade no ensaio clonogĂ©nico, principalmente no caso da CNC, mas nĂŁo nos restantes ensaios, nĂŁo havendo tambĂ©m indução de ROS. Todas as nanoceluloses revelaram efeitos genotĂłxicos nalgumas concentraçÔes, uma vez que induziram micronĂșcleos e /ou pontes nucleoplĂĄsmicas num dos modelos celulares. Para alĂ©m disso, visualizou-se a internalização da CNF e CMF, mas nĂŁo da CNC, em cĂ©lulas A549. Esta primeira avaliação toxicolĂłgica veio contribuir para prevenir a exposição a materiais celulĂłsicos potencialmente perigosos, procurando impulsionar o desenvolvimento de materiais inovadores e mais seguros.Nanocelluloses are innovative nanomaterials with potential for a wide range of industrial and biomedical applications. However, the expansion of its production has raised concerns about their possible long-term effects on human health. This study aimed to evaluate the safety of various nanocelluloses through the characterization of their potential toxicity in mammalian cells. Two samples of nano/microfibrillar celluloses with different pre-treatments (CNF and CMF) and a nanocrystalline cellulose (CNC) were tested. The cytotoxicity of the nanocelluloses was analyzed using colorimetric assays and the clonogenic assay, and genotoxicity by the in vitro micronucleus assay in human alveolar epithelial cells (A549), human osteoblasts (MG-63) and Chinese hamster fibroblasts (V79). Induction of reactive oxygen species (ROS) and cellular internalization were also studied in A549 cells. Cytotoxicity was observed through the clonogenic assay, mainly in the case of CNC, but not in the remaining assays, with no induction of ROS. All nanocelluloses, at some of the concentrations tested, induced micronuclei and/or nucleoplasmic bridges in one of the cellular models. Furthermore, the internalization of CNF and CMF, but not of CNC was visualized in A549 cells. These results aim to contribute to preventing exposure to potentially hazardous cellulosic materials, seeking to boost the development of innovative and safer materials.Projeto ToxApp4NanoCELFI – Uma abordagem de toxicologia preditiva para a caracterização dos potenciais efeitos respiratĂłrios de fibras de nanocelulose funcionalizadas num sistema de co-cultura (PTDC/SAU-PUB/32587/2017).info:eu-repo/semantics/publishedVersio

    Biomedical potential of fucoidan, a seaweed sulfated polysaccharide: from a anticancer agent to a building block of cell encapsulating systems for regenerative medicine

    Get PDF
    Marine macroalgae or seaweeds synthesize a wide variety of polymers and smaller compounds with several bioactivities, among which the sulfated polysaccharides acquire greater relevance not only due to the reported antioxidant, antiviral and anticancer[1] activities, but also to the resemblance of extracellular matrix glycosaminoglycans found in the human body[2]. In this study, the potential of fucoidan (Fu) isolated from brown seaweed Fucus vesiculosus for therapeutical use has been evaluated, focusing in its performance as antitumoral agent (bioactive role) or as building block of cell encapsulating systems (structural role). Materials and Methods: The anticancer activity of Fu extracts was assessed by evaluating the cytotoxic behavior over two human breast cancer cell lines (MCF-7 and MDA-MB-231) in in-vitro culture, using human fibroblasts and endothelial cells (HPMEC-ST1 and MRC-5, respectively) as reference. Regarding the structural role, Fu was modified by methacrylation reaction (MFu) using methacrylic acid and further crosslinked using visible radiation and triethanolamine and eosin-y as photoinitiators. The photocrosslinking was performed on MFu solution droplets placed in a silica-based superhydrophobic surface[3], allowing the formation of particles[4] (since natural Fu is highly soluble in water and ion gelation is not effective). Biological performance of the developed particles was assessed by in vitro culture of fibroblasts and pancreatic cells (L929 and 1.1B4, respectively) in contact with MFu particles, up to 7 days. The ability of the developed materials to support adhesion and proliferation of cells was evaluated for both types of cells. Results and Discussion: The tested anticancer activity is not ubiquitous on Fu extracts, being dependent on its chemical features, with molecular weight (Mw) representing a particular role. Specifically, Mw values around 60 kDa exhibited cytotoxic effects to human breast cancer cell lines, while not affecting normal fibroblasts or endothelial cells (which represent the cells of the healthy tissue that would be closer to the tumor in a real situation). A concentration range of 0.2 to 0.3 mg mL-1 from the selected Fu extract could be considered as the therapeutic window for further studies. Regarding fucoidanñ s role on innovative biomaterials, the developed MFu particles could support the proliferation of fibroblasts (L929), but also of human pancreatic beta cells (1.1B4), which tend to form pseudo-islets after 7 days in culture (Fig. 1). This pancreatic cells could be also successfully encapsulated, opening a new route for a diabetes mellitus type 1 therapeutic approach. Fig. 1: Confocal microscopy images of 1.1B4 cells cultured in the presence of fucoidan-based particles and organized in pseudo-islets (red ñ actin; blue ñ nuclei). Conclusion: The present work establishes fucoidan as a high performance building block for the development of advanced therapies for cancer (targeted therapy) or tissue and organ regeneration. It shed light on the relation between chemical structure and biological activity towards anti-cancer effect and proposes novel beta cell laden particles as injectable insulin producing systems to tackle diabetes.Funding from projects 0687_NOVOMAR_1_P (co-funded by INTERREG 2007-2013 / POCTEP), CarbPol_u_Algae (EXPL/MAR-BIO/0165/2013, funded by the Portuguese Foundation for Science and Technology, FCT), POLARIS (FP7-REGPOT-CT2012-316331) and ComplexiTE (ERC-2012-ADG 20120216-321266), funded by the European Union’s Seventh Framework Programme for Research and Development is acknowledged. ASF, SSS, NMO and DSC are also thankful to FCT for their individual fellowships
    • 

    corecore