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1.
Ecotoxicology ; 32(8): 1024-1049, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37878111

RESUMEN

Due to its persistence and potential ecological and health impacts, mercury (Hg) is a global pollutant of major concern that may reach high concentrations even in remote polar oceans. In contrast to the Arctic Ocean, studies documenting Hg contamination in the Southern Ocean are spatially restricted and large-scale monitoring is needed. Here, we present the first circumpolar assessment of Hg contamination in Antarctic marine ecosystems. Specifically, the Adélie penguin (Pygoscelis adeliae) was used as a bioindicator species, to examine regional variation across 24 colonies distributed across the entire Antarctic continent. Mercury was measured on body feathers collected from both adults (n = 485) and chicks (n = 48) between 2005 and 2021. Because penguins' diet represents the dominant source of Hg, feather δ13C and δ15N values were measured as proxies of feeding habitat and trophic position. As expected, chicks had lower Hg concentrations (mean ± SD: 0.22 ± 0.08 µg·g‒1) than adults (0.49 ± 0.23 µg·g‒1), likely because of their shorter bioaccumulation period. In adults, spatial variation in feather Hg concentrations was driven by both trophic ecology and colony location. The highest Hg concentrations were observed in the Ross Sea, possibly because of a higher consumption of fish in the diet compared to other sites (krill-dominated diet). Such large-scale assessments are critical to assess the effectiveness of the Minamata Convention on Mercury. Owing to their circumpolar distribution and their ecological role in Antarctic marine ecosystems, Adélie penguins could be valuable bioindicators for tracking spatial and temporal trends of Hg across Antarctic waters in the future.


Asunto(s)
Mercurio , Spheniscidae , Animales , Mercurio/análisis , Ecosistema , Biomarcadores Ambientales , Regiones Antárticas , Monitoreo del Ambiente
2.
J Pept Sci ; 28(1): e3362, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34545666

RESUMEN

Despite lacking cooperatively folded structures under native conditions, numerous intrinsically disordered proteins (IDPs) nevertheless have great functional importance. These IDPs are hybrids containing both ordered and intrinsically disordered protein regions (IDPRs), the structure of which is highly flexible in this unfolded state. The conformational flexibility of these disordered systems favors transitions between disordered and ordered states triggered by intrinsic and extrinsic factors, folding into different dynamic molecular assemblies to enable proper protein functions. Indeed, prokaryotic enzymes present less disorder than eukaryotic enzymes, thus showing that this disorder is related to functional and structural complexity. Protein-based polymers that mimic these IDPs include the so-called elastin-like polypeptides (ELPs), which are inspired by the composition of natural elastin. Elastin-like recombinamers (ELRs) are ELPs produced using recombinant techniques and which can therefore be tailored for a specific application. One of the most widely used and studied characteristic structures in this field is the pentapeptide (VPGXG)n . The structural disorder in ELRs probably arises due to the high content of proline and glycine in the ELR backbone, because both these amino acids help to keep the polypeptide structure of elastomers disordered and hydrated. Moreover, the recombinant nature of these systems means that different sequences can be designed, including bioactive domains, to obtain specific structures for each application. Some of these structures, along with their applications as IDPs that self-assemble into functional vesicles or micelles from diblock copolymer ELRs, will be studied in the following sections. The incorporation of additional order- and disorder-promoting peptide/protein domains, such as α-helical coils or ß-strands, in the ELR sequence, and their influence on self-assembly, will also be reviewed. In addition, chemically cross-linked systems with controllable order-disorder balance, and their role in biomineralization, will be discussed. Finally, we will review different multivalent IDPs-based coatings and films for different biomedical applications, such as spatially controlled cell adhesion, osseointegration, or biomaterial-associated infection (BAI).


Asunto(s)
Elastina , Proteínas Intrínsecamente Desordenadas , Materiales Biocompatibles , Péptidos , Polímeros , Conformación Proteica , Pliegue de Proteína
3.
Biol Lett ; 13(8)2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28794274

RESUMEN

Identifying the at-sea distribution of wide-ranging marine predators is critical to understanding their ecology. Advances in electronic tracking devices and intrinsic biogeochemical markers have greatly improved our ability to track animal movements on ocean-wide scales. Here, we show that, in combination with direct tracking, stable carbon isotope analysis of essential amino acids in tail feathers provides the ability to track the movement patterns of two, wide-ranging penguin species over ocean basin scales. In addition, we use this isotopic approach across multiple breeding colonies in the Scotia Arc to evaluate migration trends at a regional scale that would be logistically challenging using direct tracking alone.


Asunto(s)
Spheniscidae , Aminoácidos , Migración Animal , Animales , Isótopos de Carbono , Plumas , Isótopos de Nitrógeno , Océanos y Mares
4.
Mol Pharm ; 13(3): 795-808, 2016 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-26815223

RESUMEN

The search for new and biocompatible materials with high potential for improvement is a challenge in gene delivery applications. A cell type specific vector made of elastin-like recombinamer (ELR) and aptamers has been specifically designed for the intracellular delivery of therapeutic material for breast cancer therapy. A lysine-enriched ELR was constructed and complexed with plasmid DNA to give positively charged and stable polyplexes. Physical characterization of these polyplexes showed a particle size of around 140 nm and a zeta potential of approximately +40 mV. The incorporation of MUC1-specific aptamers into the polyplexes resulted in a slight decrease in zeta potential but increased cell transfection specificity for MCF-7 breast cancer cells with respect to a MUC1-negative tumor line. After showing the transfection ability of this aptamer-ELR vector which is facilitated mainly by macropinocytosis uptake, we demonstrated its application for suicide gene therapy using a plasmid containing the gene of the toxin PAP-S. The strategy developed in this work about using ELR as polymeric vector and aptamers as supplier of specificity to deliver therapeutic material into MUC1-positive breast cancer cells shows promising potential and continues paving the way for ELRs in the biomedical field.


Asunto(s)
Aptámeros de Nucleótidos/química , Materiales Biocompatibles/farmacología , Neoplasias de la Mama/terapia , Elastina/química , Terapia Genética , Mucina-1/genética , Polímeros/química , Materiales Biocompatibles/química , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Supervivencia Celular , Células Cultivadas , Femenino , Técnicas de Transferencia de Gen , Humanos , Terapia Molecular Dirigida , Plásmidos/genética
5.
J Mater Sci Mater Med ; 26(2): 105, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25663022

RESUMEN

Elastin-like recombinamer click gels (ELR-CGs) for biomedical applications, such as drug delivery or tissue engineering, have been developed by taking advantage of the click reaction (CuAAC) in the absence of traditional crosslinking agents. ELRs are functionalized with alkyne and azide groups using conventional chemical techniques to introduce the reactivity required to carry out the 1,3-dipolar cycloaddition under mild biocompatible conditions, with no toxic by-products and in short reaction times. Hydrogels with moduli in the range 1,000-10,000 Pa have been synthesized, characterized, and tested in vitro against several cell types. The cells embedded into ELR-CGs possessed high viability and proliferation rate. The mechanical properties, porosity and swelling of the resulting ELR-CGs can easily be tuned by adjusting the ELR concentration. We also show that it is possible to replicate different patterns on the hydrogel surface, thus allowing the use of this type of hydrogel to improve applications that require cell guidance or even differentiation depending on the surface topography.


Asunto(s)
Materiales Biocompatibles/síntesis química , Química Clic/métodos , Elastina/química , Hidrogeles/síntesis química , Células Madre Mesenquimatosas/fisiología , Ingeniería de Proteínas/métodos , Materiales Biomiméticos/síntesis química , Línea Celular , Proliferación Celular/fisiología , Supervivencia Celular/fisiología , Elastina/genética , Elastina/ultraestructura , Humanos , Ensayo de Materiales , Células Madre Mesenquimatosas/citología
6.
Parasitol Res ; 113(11): 3947-51, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25082018

RESUMEN

As a part of an ongoing long-term study on the biology of pack-ice seals in Antarctica, we had the opportunity to collect lice from Weddell seals (Leptonychotes weddelli). We did not find the original description of this host-parasite association. Antarctophthirus ogmorhini had previously been reported as a parasite for the Weddell seal, but the information is, to a certain extent, confusing. During the development of the present study, we had access to literature concerning the presence of A. ogmorhini on this host, which, to our knowledge, was not determined in any of the previous works on this species. We compared lice collected from Weddell seals with A. ogmorhini obtained from the type host, the leopard seal (Hydrurga leptonyx), and we found that both species can be distinguished. The main differences are the characteristic pattern of chaetotaxy in the dorsal side of the head in lice from Weddell seals, the size and form of the pseudopenis, and the distribution and size of the fringe of setae surrounding the genital opening. Considering the conservative morphology, and ecological and evolutionary features of sucking lice, we proposed that lice from Weddell seals constitute a new species. In the present work, we described and illustrated adults of this new species collected from Weddell seals during the austral summer of 2014 at the Danco Coast, Antarctic Peninsula.


Asunto(s)
Anoplura/anatomía & histología , Anoplura/clasificación , Phocidae/parasitología , Animales , Regiones Antárticas , Femenino , Masculino
7.
Mater Today Bio ; 25: 100999, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38379933

RESUMEN

Despite the remarkable progress in the generation of recombinant elastin-like (ELR) hydrogels, further improvements are still required to enhance and control their viscoelasticity, as well as limit the use of expensive chemical reagents, time-consuming processes and several purification steps. To alleviate this issue, the reactivity of carboxylic groups from glutamic (E) acid distributed along the hydrophilic block of an amphiphilic ELR (coded as E50I60) with amine groups has been studied through a one-pot amidation reaction in aqueous solutions, for the first time. By means of this approach, immediate conjugation of E50I60 with molecules containing amine groups has been performed with a high yield, as demonstrated by the 1H NMR and MALDI-TOF spectroscopies. This has resulted in the preparation of viscoelastic irreversible hydrogels through the "in-situ" cross-linking of E50I60 with another ELR (coded as VKV24) containing amine groups from lysines (K). The rheology analysis demonstrated that the gelation process takes place following a dual mechanism dependent on the ELR concentration: physical cross-linking of I60 block through the hydrophobic interactions, and covalent cross-linking of E50I60 with VKV24 through the amidation reaction. While the chemical network formed between the hydrophilic E50 block and VKV24 ELR preserves the elasticity of ELR hydrogels, the self-assembly of the I60 block through the hydrophobic interactions provides a tunable physical network. The presented investigation serves as a basis for generating ELR hydrogels with tunable viscoelastic properties promising for tissue regeneration, through an ''in-situ", rapid, scalable, economically and feasible one-pot method.

8.
Biomacromolecules ; 14(6): 1893-903, 2013 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-23614455

RESUMEN

A wide range of smart surfaces with novel properties relevant for biomedical applications have been developed recently. Herein we focus on thermoresponsive surfaces that switch between cell-adherent and nonadherent states and their applications for cell harvesting. These smart surfaces are obtained by covalently coupling a tailored elastin-like recombinamer onto glass surfaces by means of the well-known and widely applied Click Chemistry methodology. The resulting recombinamer-functionalized surfaces have been characterized by means of water contact angle measurements, XPS and TOF-SIMS. A cell-based analysis of these surfaces with human fibroblasts showed a high degree of adhesion to the surface in its adherent state (37 °C), thus, promoting cell viability and proliferation. A temperature decrease triggers reorganization of the recombinamer, thus, markedly increasing the number of nonadherent domains and masking the adherent ones. This process allows a specific and efficient temporal control of cell adhesion and cell detachment. After determination of the properties required for a suitable cell-harvesting system, optimization of the process allows single cells or cell sheets from at least two types of cells (HFF-1 and ADSCs) to be rapidly harvested.


Asunto(s)
Elastina/química , Adhesión Celular , Células Cultivadas , Citometría de Flujo , Humanos , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
9.
Biomater Adv ; 154: 213595, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37639856

RESUMEN

New strategies to develop drug-loaded nanocarriers with improved therapeutic efficacy are needed for cancer treatment. Herein we report a novel drug-delivery nanosystem comprising encapsulation of the chemotherapeutic drug docetaxel (DTX) and recombinant fusion of a small peptide inhibitor of Akt kinase within an elastin-like recombinamer (ELR) vehicle. This combined approach is also precisely targeted to colorectal cancer cells by means of a chemically conjugated DNA aptamer specific for the CD44 tumor marker. This 53 nm dual-approach nanosystem was found to selectively affect cell viability (2.5 % survival) and proliferation of colorectal cancer cells in vitro compared to endothelial cells (50 % survival), and to trigger both apoptosis- and necrosis-mediated cell death. Our findings also show that the nanohybrid particles remain stable under physiological conditions, trigger sustained drug release and possess an adequate pharmacokinetic profile after systemic intravenous administration. In vivo assays showed that these dual-approach nanohybrids significantly reduced the number of tumor polyps along the colorectal tract in a murine colorectal cancer model. Furthermore, systemic administration of advanced nanohybrids induced tissue recovery by improving the morphology of gastrointestinal crypts and the tissue architecture. Taken together, these findings indicate that our strategy of an advanced dual-approach nanosystem allows us to achieve successful controlled release of chemotherapeutics in cancer cells and may have a promising potential for colorectal cancer treatment.


Asunto(s)
Antineoplásicos , Neoplasias Colorrectales , Nanopartículas , Ratones , Animales , Docetaxel/farmacología , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Proteínas Proto-Oncogénicas c-akt , Células Endoteliales , Portadores de Fármacos , Inhibidores de la Angiogénesis , Neoplasias Colorrectales/tratamiento farmacológico
10.
Adv Healthc Mater ; 11(22): e2201646, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36099430

RESUMEN

Spatiotemporal control of vascularization and innervation is a desired hallmark in advanced tissue regeneration. For this purpose, we design a 3D model scaffold, based on elastin-like recombinamer (ELR) hydrogels. This contains two interior and well-defined areas, small cylinders, with differentiated bioactivities with respect to the bulk. Both are constructed on a protease sensitive ELR with a fast-proteolyzed domain, but one bears a VEGF-mimetic peptide (QK) and the other a laminin-derived pentapeptide (IKVAV), to promote angiogenesis and neurogenesis, respectively. The outer bulk is based on a slow proteolytic sequence and RGD cell adhesion domains. In vitro studies show the effect of QK and IKVAV peptides on the promotion of endothelial cell and axon spreading, respectively. The subcutaneous implantation of the final 3D scaffold demonstrates the ability to spatiotemporally control angiogenesis and neurogenesis in vivo. Specifically, the inner small cylinder containing the QK peptide promotes fast endothelialization, whereas the one with IKVAV peptide promotes fast neurogenesis. Both, vascularization and innervation take place in advance of the bulk scaffold infiltration. This scaffold shows that it is possible to induce vascularization and innervation in predetermined areas of the scaffold well ahead to the bulk infiltration. That significantly increases the efficiency of the regenerative activity.


Asunto(s)
Elastina , Laminina , Elastina/farmacología , Elastina/química , Laminina/farmacología , Laminina/química , Factor A de Crecimiento Endotelial Vascular/farmacología , Péptido Hidrolasas , Péptidos/farmacología , Péptidos/química , Hidrogeles/farmacología , Hidrogeles/química , Neurogénesis
11.
Work ; 73(3): 991-1000, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35988245

RESUMEN

BACKGROUND: Although pulmonary rehabilitation programmes (PRPs) benefit patients with chronic obstructive pulmonary disease (COPD), poor adherence to these programmes is common. OBJECTIVE: This study aimed to analyse the factors associated with poor long-term adherence after completing a PRP. METHOD: We conducted a retrospective study of 70 patients with COPD who performed an 8-week outpatient PRP that included 24 sessions of aerobic training, skeletal muscle resistance exercises, physiotherapy and COPD education. The study classified the patients into 2 groups: (1) long-term adherence and (2) long-term non-adherence to the PRP. We considered long-term non-adherence when the patient did not attend the 32 weeks follow-up visit after beginning the PRP. We measured the degree of dyspnoea, quality of life, physical activity, anxiety-depression status, submaximal exercise capacity and COPD exacerbations in both groups. RESULTS: The patients' median age was 69.6 [63.8-75.0] years, and 71.4% were men. The median forced expiratory volume in 1 second was 60.0 [47.7-68.0] % of that predicted. We observed total COPD exacerbations and severe COPD exacerbations in the last year in 32 (45.7%) and 22 (31.4%) patients, respectively. Dyspnoea, physical activity and quality of life significantly improved after completing the PRP. Long-term non-adherence to the PRP was observed in 32 (45.7%) patients. In the single regression model, severe COPD exacerbations (p = 0.04) and dyspnoea (p = 0.03) were associated with long-term non-adherence to the PRP. In the multiple regression model, only severe COPD exacerbations remained as an associated factor (OR 2.7; 95% CI 1.1-8,1; p = 0.04). CONCLUSION: Approximately half of patients who complete PRPs present long-term non-adherence to the programme. Severe COPD exacerbations are associated with long-term non-adherence.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Calidad de Vida , Masculino , Humanos , Anciano , Femenino , Estudios Retrospectivos , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Disnea/rehabilitación , Volumen Espiratorio Forzado
12.
Macromol Rapid Commun ; 31(6): 568-73, 2010 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-21590944

RESUMEN

Here, we describe a procedure to manufacture smart hybrid probes that exhibit tunable optical properties as a function of multiple environmental variations. Initially, we achieved a one-pot synthesis of gold-PREP (photo-responsive elastin-like polymer) conjugate Gold-AzoGlu15 via reduction of auric acid in the presence of PREP AzoGlu15. Outstandingly, Gold-AzoGlu15 exhibited pH and temperature sensitiveness. However, Gold-AzoGlu15 was not UV-vis sensitive. We noticed that photo-isomerisation of azobenzene moieties in Gold-AzoGlu15 could not be detected by UV-vis spectroscopy. In a subsequent step, we explored the use of cyclodextrins and the formation of alkanethiol mixed-monolayers over mother Gold-AzoGlu15 by thiol-place exchange reactions in order to decouple photo-isomerisation of azobenzene from the bulk phase absorption. In this sense we achieved the synthesis of ß-cyclodextrin capped Gold-CD-AzoGlu15. Notable was that cis-trans photo-conversion of azobenzene groups in Gold-CD-AzoGlu15 could be successfully detected. Finally, we present the optical properties exhibited by multi-sensitive probe Gold-CD-AzoGlu15 as a function of pH, temperature and UV-vis irradiation. We think that gold-PREP hybrids could be of great interest in the design of multi-functional chromophore-metal nanocomposites that operate in aqueous media for the development of multi-stimuli sensitive detectors for biosensing applications.

13.
Int J Biol Macromol ; 164: 1640-1648, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32758602

RESUMEN

One of the main goals in both tissue engineering and regenerative medicine is to design innovative synthetic scaffolds that can simulate and control the communication pathways between cells and the extracellular matrix (ECM). In this context, we describe herein the characterization of protein polymer, a recombinant elastin-like recombinamer (ELR) designed for developing tissue-engineered devices for use in vascular regeneration. This ELR is composed of an elastin-like backbone that contains a fibronectin domain, which provides specific, endothelial cell adhesion, and a protease target domain directed towards specific proteases involved in ECM remodeling. We also compare the specific response of endothelial and fibroblast cells to ELR scaffolds and show that cell adhesion and spreading on this ELR is significantly higher for endothelial cells than for fibroblasts. The reactivity of this polymer and its hydrogels to specific enzymatic degradation is demonstrated in vitro. As with natural elastin, enzymatic hydrolysis of the ELR produces elastin-derived peptides, or "matrikines", which, in turn, are potentially able to regulate important cell activities.


Asunto(s)
Elastina/química , Receptores de Superficie Celular/química , Adhesión Celular/efectos de los fármacos , Células Cultivadas , Células Endoteliales/efectos de los fármacos , Matriz Extracelular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana , Humanos , Hidrogeles/química , Polímeros/química , Medicina Regenerativa/métodos , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
14.
Acta Biomater ; 115: 264-274, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32771595

RESUMEN

Coronary artery disease (CAD) is the most common cardiovascular disorder. Vascular surgery strategies for coronary revascularization (either percutaneous or open) show a high rate of failure because of restenosis of the vessel, due to phenotypic switch of vascular smooth muscle cells (VSMCs) leading to proliferation and migration. We have previously reported that the inhibition of Kv1.3 channel function with selective blockers represents an effective strategy for the prevention of restenosis in human vessels used for coronary angioplasty procedures. However, delivery systems for controlled release of these drugs have not been investigated. Here we tested the efficacy of several formulations of elastin like recombinamers (ELRs) hydrogels to deliver the Kv1.3 blocker PAP-1 in various restenosis models. The dose and time course of PAP-1 release from ELRs click hydrogels was able to inhibit human VSMC proliferation in vitro as well as remodeling of human vessels in organ culture and restenosis in in vivo models. We conclude that this combination of active compound and advanced delivery method could improve the outcomes of vascular surgery in patients. STATEMENT OF SIGNIFICANCE: Vascular surgery strategies for coronary revascularization show a high rate of failure, because of occlusion (restenosis) of the vessel, due to vascular smooth muscle cells proliferation and migration. We have previously reported that blockers of Kv1.3 channels represent an effective anti-restenosis therapy, but delivery systems for their controlled release have not being explored. Here we tested the efficacy of several formulations of elastin like recombinamers (ELRs) hydrogels to deliver the Kv1.3 blocker PAP-1 in various restenosis models, both in vivo and in vitro, and also in human vessels. We demonstrated that combination of active compound and advanced delivery method could improve the outcomes of vascular surgery in patients.


Asunto(s)
Elastina , Músculo Liso Vascular , Proliferación Celular , Células Cultivadas , Humanos , Hiperplasia/tratamiento farmacológico , Hiperplasia/patología , Hiperplasia/prevención & control , Músculo Liso Vascular/patología
15.
PLoS One ; 15(10): e0239895, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33002046

RESUMEN

Knowledge of continental shelf faunal biodiversity of Antarctica is patchy and as such, the ecology of this unique ecosystem is not fully understood. To this end, we deployed baited cameras at 20 locations along ~ 500 km of the Western Antarctic Peninsula (WAP) at depths from 90 to 797 m. We identified 111 unique taxa, with mud bottom accounting for 90% of the dominant (≥ 50% cover) habitat sampled. Amphipoda comprised 41% of the total maximum number of individuals per camera deployment (MaxN) and occurred on 75% of deployments. Excluding this taxon, the highest MaxN occurred around King George/25 de Mayo Island and was driven primarily by the abundance of krill (Euphausiidae), which accounted for 36% of total average MaxN among deployments around this island. In comparison, krill comprised 22% of total average MaxN at Deception Island and only 10% along the peninsula. Taxa richness, diversity, and evenness all increased with depth and depth explained 18.2% of the variation in community structure among locations, which may be explained by decreasing ice scour with depth. We identified a number of Vulnerable Marine Ecosystem taxa, including habitat-forming species of cold-water corals and sponge fields. Channichthyidae was the most common fish family, occurring on 80% of all deployments. The Antarctic jonasfish (Notolepis coatsorum) was the most frequently encountered fish taxa, occurring on 70% of all deployments and comprising 25% of total MaxN among all deployments. Nototheniidae was the most numerically abundant fish family, accounting for 36% of total MaxN and was present on 70% of the deployments. The WAP is among the fastest warming regions on Earth and mitigating the impacts of warming, along with more direct impacts such as those from fishing, is critical in providing opportunities for species to adapt to environmental change and to preserve this unique ecosystem.


Asunto(s)
Biodiversidad , Ambientes Extremos , Animales , Regiones Antárticas , Antozoos/fisiología , Peces/fisiología , Poríferos/fisiología , Agua de Mar
16.
Curr Med Chem ; 26(40): 7117-7146, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-29737250

RESUMEN

Protein-based polymers are some of the most promising candidates for a new generation of innovative biomaterials as recent advances in genetic-engineering and biotechnological techniques mean that protein-based biomaterials can be designed and constructed with a higher degree of complexity and accuracy. Moreover, their sequences, which are derived from structural protein-based modules, can easily be modified to include bioactive motifs that improve their functions and material-host interactions, thereby satisfying fundamental biological requirements. The accuracy with which these advanced polypeptides can be produced, and their versatility, self-assembly behavior, stimuli-responsiveness and biocompatibility, means that they have attracted increasing attention for use in biomedical applications such as cell culture, tissue engineering, protein purification, surface engineering and controlled drug delivery. The biopolymers discussed in this review are elastin-derived protein-based polymers which are biologically inspired and biomimetic materials. This review will also focus on the design, synthesis and characterization of these genetically encoded polymers and their potential utility for controlled drug and gene delivery, as well as in tissue engineering and regenerative medicine.


Asunto(s)
Materiales Biocompatibles/química , Investigación Biomédica , Elastina/genética , Ingeniería Genética , Animales , Elastina/química , Humanos
17.
Int J Biol Macromol ; 121: 752-759, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30312699

RESUMEN

Herein we present a novel one-pot method for the chemical modification of elastin-like recombinamers (ELRs) in a mild and efficient manner involving enzymatic catalysis with Candida antarctica lipase B. The introduction of different functionalities into such ELRs could open up new possibilities for the development of advanced biomaterials for regenerative medicine and, specifically, for controlled drug delivery given their additional ability to respond to stimuli other than pH or temperature, such as glucose concentration or electromagnetic radiation. Candida antarctica lipase B immobilized on a macroporous acrylic resin (Novozym 435) was used to enzymatically couple different aminated substrates to a recombinamer containing carboxylic groups along its amino acid chain by way of an amidation reaction. A preliminary study of the kinetics of this amidation in response to different reaction conditions, such as solvent, temperature or reagent ratio, was carried out using a phenylazobenzene derivative (azo-NH2) as a model. The optimal amidation conditions were used to couple other amine reagents, such as phenylboronic acid (FB-NH2) or polyethylene glycol (PEG-NH2), thus allowing us to obtain photoresponsive, glucose-responsive or PEGylated ELRs that could potentially be useful as sensors in devices for controlled drug delivery.


Asunto(s)
Biocatálisis , Elastina/metabolismo , Proteínas Fúngicas/metabolismo , Lipasa/metabolismo , Resinas Acrílicas/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Proteínas Fúngicas/química , Lipasa/química , Porosidad , Solventes/química , Temperatura
18.
Curr Drug Targets ; 19(4): 360-379, 2018 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-26844559

RESUMEN

BACKGROUND: Drug delivery systems that are able to control the release of bioactive molecules and designed to carry drugs to target sites are of particular interest for tissue therapy. Moreover, systems comprising materials that can respond to environmental stimuli and promote self-assembly and higher order supramolecular organization are especially useful in the biomedical field. Objetive: This review focuses on biomaterials suitable for this purpose and that include elastin-like recombinamers (ELRs), a class of proteinaceous polymers bioinspired by natural elastin, designed using recombinant technologies. The self-assembly and thermoresponsive behaviour of these systems, along with their biodegradability, biocompatibility and well-defined composition as a result of their tailormade design, make them particularly attractive for controlled drug delivery. RESULTS: ELR-based delivery systems that allow targeted delivery are reviewed, especially ELR-drug recombinant fusion constructs, ELR-drug systems chemically bioconjugated in their monomeric and soluble forms, and drug encapsulation by nanoparticle-forming ELRs. Subsequently, the review focuses on those drug carriers in which smart release is triggered by pH or temperature with a particular focus on cancer treatments. Systems for controlled drug release based on depots and hydrogels that act as both a support and reservoir in which drugs can be stored will be described, and their applications in drug delivery discussed. Finally, smart drug-delivery systems not based on ELRs, including those comprising proteins, synthetic polymers and non-polymeric systems, will also be briefly discussed. CONCLUSION: Several different constructions based on ELRs are potential candidates for controlled drug delivery to be applied in advanced biomedical treatments.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Elastina/química , Polímeros/química , Materiales Biocompatibles/química , Portadores de Fármacos/química , Humanos , Nanopartículas/química
19.
Cienc. Salud (St. Domingo) ; 7(3): [14], 2023. tab, map
Artículo en Español | LILACS | ID: biblio-1525413

RESUMEN

Esta investigación pretende cuantificar las diferencias en la razón de mortalidad materna en las provincias de la República Dominicana, considerando las distintas condiciones sociales a la que estas mujeres están expuestas. Se utilizó la información proveniente de registro de estadísticas vitales. Se calculó la asociación entre la razón de mortalidad materna y ciertos indicadores socioeconómicos seleccionados. Se calcularon las métricas de desigualdad tomando en cuenta los indicadores socioeconómicos que se hallaron significativamente asociados con la razón de mortalidad materna, resultando esta dos veces mayor en los territorios más desfavorecidos socialmente, comparados con los territorios que se encontraron en mejores condiciones sociales.


This research aims to quantify the differences in the ma-ternal mortality rate in the provinces of the Dominican Republic, considering the different social conditions to which these women are exposed. Information from the vital statistics registry was used. The association be-tween the maternal mortality rate and certain selected socioeconomic indicators was calculated. The inequality metrics were calculated considering the socioeconomic indicators that were found to be significantly associated with the maternal mortality rate, resulting in two times higher in the most socially disadvantaged territories, compared to the territories that were found in better social conditions.


Asunto(s)
Humanos , Femenino , Niño , Adolescente , Adulto , Persona de Mediana Edad , Embarazo , Mortalidad Materna , Factores Socioeconómicos , República Dominicana , Estudios Ecológicos
20.
Bol. pediatr ; 63(265): 175-177, 2023. tab
Artículo en Español | IBECS (España) | ID: ibc-231600

RESUMEN

El trastorno de evitación y/o restricción de la ingesta de alimentos (ARFID) fue incluido como nuevo diagnóstico dentro de los trastornos de la conducta alimentaria en el manual DSM-V en el año 2013. Se lo define como un fracaso persistente para cumplir las necesidades nutricionales y/o energéticas adecuadas, lo que puede dar lugar a pérdida de peso, deficiencias nutricionales y necesidad de nutrición enteral. No presenta alteración de la constitución corporal o patología mental.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Ingestión de Alimentos , Nutrición del Lactante , Nutrición del Niño , Estado Nutricional , Salud Infantil
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