78 results on '"Novoa Carballal R"'
Search Results
2. Antithrombotic and hemocompatible properties of nanostructured coatings assembled from block copolymers
- Author
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Fontelo, R., Soares da Costa, D., Reis, R.L., Novoa-Carballal, R., and Pashkuleva, I.
- Published
- 2022
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3. Bactericidal nanopatterns generated by block copolymer self-assembly
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Fontelo, R., primary, Soares da Costa, D., additional, Reis, R.L., additional, Novoa-Carballal, R., additional, and Pashkuleva, I., additional
- Published
- 2020
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4. Efficient Bactericidal Nanopatterns Generated by Block Copolymer Self-Assembly
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Fontelo, R., primary, da Costa, D. Soares, additional, Reis, R. L., additional, Novoa-Carballal, R., additional, and Pashkuleva, I., additional
- Published
- 2020
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5. Chitosan–PEG nanocapsules as new carriers for oral peptide delivery Effect of chitosan pegylation degree
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Prego, C., Torres, D., Fernandez-Megia, E., Novoa-Carballal, R., Quiñoá, E., and Alonso, M. J.
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- 2006
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6. Biomedical potential of fucoidan, a seaweed sulfated polysaccharide: from a anticancer agent to a building block of cell encapsulating systems for regenerative medicine
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Silva, Tiago José Quinteiros Lopes Henriques, Oliveira, Catarina, Reys, Lara Priscila Lopes, Costa, Diana Pereira Soares, Novoa-Carballal, R., Oliveira, Nuno M., Ferreira, Andreia S., Nunes, Cláudia, Silva, Simone Santos, Martins, Albino, Coimbra, Manuel A., Mano, J. F., Neves, N. M., Reis, R. L., and Universidade do Minho
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Biomacromolecule ,Biomimetic ,Tissue engineering ,Biomaterial - Abstract
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]Â 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:Â 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]Â (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:Â 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 fucoidanâ 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:Â Confocal microscopy images of 1.1B4 cells cultured in the presence of fucoidan-based particles and organized in pseudo-islets (red â actin; blue â nuclei). Conclusion:Â 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.
- Published
- 2016
7. Comparative in vitro studies on PBN loaded nanoparticles prepared by biodegradable chitosan, PLGA polymers and their PEGylated block copolymers
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Ozturk, K., Fernandez-Megia, E., Novoa-Carballal, R., Riguera, R., Yemisci, M., Gursoy-Ozdemir, Y., Dalkara, T., Couvreur, P., and Capan, Y.
- Published
- 2014
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8. An aquaporin 4 antisense oligonucleotide loaded, brain targeted nanoparticulate system design
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Kozlu S, Caban S, Yerlikaya F, Fernandez-Megia E, Novoa-Carballal R, Riguera R, Yemisci M, Gursoy-Ozdemir Y, Dalkara T, COUVREUR Patrick, Capan Y, Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares, and Universidade de Santiago de Compostela. Departamento de Química Orgánica
- Subjects
Aquaporin 4 ,Chitosan ,Drug Delivery Systems ,Surface Properties ,Chemistry, Pharmaceutical ,Drug Compounding ,Drug Design ,Electrochemistry ,Brain ,Nanoparticles ,Brain Edema ,Oligonucleotides, Antisense ,Particle Size - Abstract
Aquaporins (AQPs), members of the water-channel protein family, are highly expressed in brain tissue especially in astrocytic end-feet. They are important players for water hemostasis during development of cytotoxic as well as vasogenic edema. Increased expression of AQPs is important in pathophysiology of neurological diseases such as neuroinflammation and ischemia. Unfortunately, there are a few pharmacological inhibitors of AQP4 with several side effects limiting their translation as a drug for use in clinical conditions. Another therapeutic approach is using antisense oligonucleotides (ASOs) to block AQP4 activity. These are short, synthetic, modified nucleic acids that bind RNA to modulate its function. However, they cannot pass the blood brain barrier (BBB). To overcome this obstacle we designed a nanoparticulate system made up of chitosan nanoparticles surface modified with PEG and conjugated with monoclonal anti transferrin receptor-1 antibody via streptavidin-biotin binding. The nanocarrier system could be targeted to the transferrin receptor-1 at the brain endothelial capillaries through monoclonal antibodies. It is hypothesized that the nanoparticles could pass the BBB via receptor mediated transcytosis and reach brain parenchyma. Particle size, zeta potential, loading capacity and release profiles of nanoparticles were investigated. It was observed that all types of chitosau (CS) nanoparticles had positive zeta potential values and nanoparticle particle size distribution varied between 100 and 800 nm. The association efficiency of ASOs into the nanoparticles was between 80–97% and the release profiles of the nanoparticles exhibited an initial burst effect followed by a controlled release. The results showed that the designed chitosan based nanocarriers could be a promising carrier system to transport nucleic acid based drugs to brain parenchyma This study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Project Number: 110S460) SI
- Published
- 2014
9. Nanocarriers based on interpolyelectrolyte complexation of Sulphated polysaccharide-b- PEG diblock copolymers and PLL
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Novoa-Carballal, R., Reis, R. L., Pashkuleva, I., and Universidade do Minho
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Hyaluronic acid ,education ,Chondroitin sulphate ,health care economics and organizations ,humanities - Abstract
Publicado em "Journal of Tissue Engeneering and Regenerative Medicine", vol. 7, supp. 1 (2013), Glycosaminoglycans (GAGs) are integral part of the closest cellular environment: they can be found on the cells surface and in the extracellular matrix, where they interact with different proteins acting as local regulator of their activity. The use of GAGs in the preparation of protein delivery nanosystems is, therefore, prominent but so far, underexploited mainly because of the heterogeneity (composition and molecular weights) of natural glycans and the multistep procedures needed to obtain GAGs’ synthetic analogues and diblock copolymers.1 Recently, we have shown that oxime click reaction can be applied as a straightforward methodology for the synthesis of poly(ethylene glycol) (PEG)- hyaluronic acid (HA) diblock copolymers.2 These copolymers formed nanosized interpolyelectrolyte complexes (45 to 150 nm) by interaction with poly- L -lysine (PLL).3 Unfortunately, these complexes are not stable at physiological ionic strength. Herein, we describe a strategy to overcome this drawback; chondroitin sulphate-b-PEG diblock copolymers (CS-b-PEG) were obtained using the same oxime click reaction. The stronger negative charge of sulphate groups (versus the carboxilic groups present in HA) resulted in the complexes with higher stability: interpolyelectrolyte complexes between PLL and (CS-b-PEG) are stable up to 260 mM ionic strenght. Because carbohydrates do not activate Tcells, we believe that the reported herein complexes have an enormous potential in both drug delivery and vaccination fields.
- Published
- 2013
10. Preparation and evaluation of alpha-phenyl-n-tert-butyl nitrone (PBN)-encapsulated chitosan and PEGylated chitosan nanoparticles
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Pinarbasli O, Aktas Y, Dalkara T, Andrieux K, Maria Jose Alonso, Fernandez-Megia E, Novoa-Carballal R, Riguera R, Couvreur P, and Capan Y
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Cyclic N-Oxides ,Excipients ,Chitosan ,Chemistry, Pharmaceutical ,Drug Compounding ,Electrochemistry ,Nanoparticles ,Free Radical Scavengers ,Particle Size ,Polyethylene Glycols - Abstract
Alpha-phenyl-n-tert-butyl nitrone (PBN) shows its major effect by scavenging free radicals formed in the ischemia and it has the ability to penetrate through the blood brain barrier easily. The in vivo stability of PBN is very low and when administered systemically, it has a mean plasma half life of about three hours. Therefore, formulations which are able to prolong the plasma residence time of PBN are of major interest, because oxygen radicals are usually continuously formed under pathological conditions. In this study, PBN, a nitrone compound having neuroprotective properties, was encapsulated in chitosan (CS) and chitosan-poly(ethylene glycol) (CS-PEG) nanoparticles for treatment of diseases such as stroke, in which sustained free radical production is reported. The nanoparticles were characterized through particle size determination, zeta potential, encapsulation efficiency, surface morphology determinations and in vitro release studies. The surface morphologies were evaluated by transmission electron microscopy (TEM) and nanoparticles having spherical shapes were characterized. The particle size distribution was between approximately 97 nm and approximately 322 nm; and the zeta potentials varied between approximately 9 mV and approximately 33 mV. Size of the nanoparticle formulations was important for the release of PBN from nanoparticles. The quantitative determination of PBN has been evaluated by a validated analytical HPLC method. The presented chitosan-based nanotechnology opens new perspectives for testing antioxidant activity in vivo.
- Published
- 2009
11. ¿Se realiza correctamente la punción lumbar en pediatría? Revisión de las recomendaciones actuales y análisis de la realidad
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Storch De Gracia Calvo, P., primary, De La Torre Espí, M., additional, Martín Díaz, M.J., additional, García Ruiz, S., additional, Domínguez Ortega, G., additional, and Novoa Carballal, R., additional
- Published
- 2012
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12. Estenosis pulmonar supravalvular como causa probable de muerte súbita en el lactante
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Mastro-Martinez, I., primary, Casco, F., additional, Novoa-Carballal, R., additional, and Serrano-Gonzalez, A., additional
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- 2012
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13. Hernia de hiato paraesofágica congénita como causa de anemia grave hiporregenerativa
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Storch de Gracia Calvo, P., primary, Novoa Carballal, R., additional, Fernández García, M., additional, and Albi Rodríguez, G., additional
- Published
- 2011
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14. Complicaciones del cateterismo vesical realizado en un servicio de urgencias para obtener una muestra de orina
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Hernangómez Vázquez, S., primary, Oñoro, G., additional, de la Torre Espí, M., additional, Martín Díaz, M.J., additional, Novoa-Carballal, R., additional, and Molina Cabañero, J.C., additional
- Published
- 2011
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15. CARTAS AL EDITOR.
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Mastro-Martinez, I., Casco, F., Novoa-Carballal, R., Serrano-Gonzalez, A., Sánchez, R. Ballester, De Unamuno Bustos, B., Mejías, A. Agustí, Bosch, M. I. Febrer, Mora, F.J. Caballero, Moreno, G. A. Martos, Gómez, M. J. Martínez, Argente, J., Álvarez, C. Álvarez, Pérez, M. J. Cabero, Díez, L. Guerra, Rodríguez, M. Saldaña, Perea, B. García-Montesinos, Sanz, A. Bercedo, Reija, M. F. García, and González, I. Cervigón
- Published
- 2012
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16. Development and Brain Delivery of Chitosan−PEG Nanoparticles Functionalized with the Monoclonal Antibody OX26
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Aktas, Y., Yemisci, M., Andrieux, K., Gursoy, R. N., Alonso, M. J., Fernandez-Megia, E., Novoa-Carballal, R., Quinoa, E., Riguera, R., Sargon, M. F., Celik, H. H., Demir, A. S., Hincal, A. A., Dalkara, T., Capan, Y., and Couvreur, P.
- Abstract
The inhibition of the caspase-3 enzyme is reported to increase neuronal cell survival following cerebral ischemia. The peptide Z-DEVD-FMK is a specific caspase inhibitor, which significantly reduces vulnerability to the neuronal cell death. However, this molecule is unable to cross the blood−brain barrier (BBB) and to diffuse into the brain tissue. Thus, the development of an effective delivery system is needed to provide sufficient drug concentration into the brain to prevent cell death. Using the avidin (SA)−biotin (BIO) technology, we describe here the design of chitosan (CS) nanospheres conjugated with poly(ethylene glycol) (PEG) bearing the OX26 monoclonal antibody whose affinity for the transferrin receptor (TfR) may trigger receptor-mediated transport across the BBB. These functionalized CS−PEG−BIO−SA/OX26 nanoparticles (NPs) were characterized for their particle size, zeta potential, drug loading capacity, and release properties. Fluorescently labeled CS−PEG−BIO−SA/OX26 nanoparticles were administered systemically to mice in order to evaluate their efficacy for brain translocation. The results showed that an important amount of nanoparticles were located in the brain, outside of the intravascular compartment. These findings, which were also confirmed by electron microscopic examination of the brain tissue indicate that this novel targeted nanoparticulate drug delivery system was able to translocate into the brain tissue after iv administration. Consequently, these novel nanoparticles are promising carriers for the transport of the anticaspase peptide Z-DEVD-FMK into the brain.
- Published
- 2005
17. Co-assembly of peptide and carbohydrate amphiphiles to generate proteoglycan mimics
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Brito, A., Abul-Haija, Y., Diana Soares da Costa, Novoa-Carballal, R., Reis, R. L., Ulijn, R., Pires, R., and Pashkuleva, I.
18. Hydrothermal extraction of ulvans from Ulva spp. in a biorefinery approach.
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Rodríguez-Iglesias P, Baltrusch KL, Díaz-Reinoso B, López-Álvarez M, Novoa-Carballal R, González P, González-Novoa A, Rodríguez-Montes A, Kennes C, Veiga MC, Torres MD, and Domínguez H
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- Polysaccharides chemistry, Biomass, Hot Temperature, Seaweed chemistry, Animals, Mice, Ulva
- Abstract
A simple cascade process based on the hydrothermal fractionation of Ulva spp. biomass was proposed. Considering the overall extraction yields (50 %), ulvan recovery (23 %), and ulvan composition, structural, mechanical and cytotoxic properties, the selected optimal final heating temperature was 160 °C. Ethanol precipitation provided the highest ulvan recovery yields but choline chloride precipitated ulvans showed stronger mechanical properties, G´ moduli 1.5·10
4 Pa and 3·104 Pa for ethanol and for choline chloride, respectively. Both products were safe on NCTC 929 mouse fibroblasts and after a cooling stage, formed films without requiring any additives. From the ulvan-free liquid fraction, one product with 43 % (wt, d.b.) phenolics and moderate antiradical properties and a byproduct containing nutrients and minerals were separated. The methane potential of the corresponding residual solids was influenced by the hydrothermal heating temperature and was doubled compared to than for the untreated seaweed biomass (60 mL/g VS). This scheme could be also applied to the wet algal biomass, in a chemical free alternative to provide ready to use ulvan biopolymers, bioactives, nutrients, salts and biogas, conforming a biorefinery approach., Competing Interests: Declaration of competing interest No conflict of interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
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19. Preparation, Properties, and Bioapplications of Block Copolymer Nanopatterns.
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Fontelo R, Reis RL, Novoa-Carballal R, and Pashkuleva I
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- Cell Membrane, Polymers, Anti-Bacterial Agents, Electronics
- Abstract
Block copolymer (BCP) self-assembly has emerged as a feasible method for large-scale fabrication with remarkable precision - features that are not common for most of the nanofabrication techniques. In this review, recent advancements in the molecular design of BCP along with state-of-the-art processing methodologies based on microphase separation alone or its combination with different lithography methods are presented. Furthermore, the bioapplications of the generated nanopatterns in the development of protein arrays, cell-selective surfaces, and antibacterial coatings are explored. Finally, the current challenges in the field are outlined and the potential breakthroughs that can be achieved by adopting BCP approaches already applied in the fabrication of electronic devices are discussed., (© 2023 Wiley-VCH GmbH.)
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- 2024
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20. End-on PEGylation of heparin: Effect on anticoagulant activity and complexation with protamine.
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Amaral S, Lozano-Fernández T, Sabin J, Gallego A, da Silva Morais A, Reis RL, González-Fernández Á, Pashkuleva I, and Novoa-Carballal R
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- Animals, Rats, Humans, Rats, Sprague-Dawley, Anticoagulants pharmacology, Anticoagulants chemistry, Heparin adverse effects, Protamines chemistry
- Abstract
Heparin is the most common anticoagulant used in clinical practice but shows some downsides such as short half-life (for the high molecular weight heparin) and secondary effects. On the other hand, its low molecular weight analogue cannot be neutralized with protamine, and therefore cannot be used in some treatments. To address these issues, we conjugated polyethylene glycol (PEG) to heparin reducing end (end-on) via oxime ligation and studied the interactions of the conjugate (Hep-b-PEG) with antithrombin III (AT) and protamine. Isothermal titration calorimetry showed that Hep-b-PEG maintains the affinity to AT. Dynamic light scattering demonstrated that the Hep-b-PEG formed colloidal stable nanocomplexes with protamine instead of large multi-molecular aggregates, associated with heparin side effects. The in vitro (human plasma) and in vivo experiments (Sprague Dawley rats) evidenced an extended half-life and higher anticoagulant activity of the conjugate when compared to unmodified heparin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sandra Amaral, Tamara Lozano-Fernández, Juan Sabin, Amanda Gallego, Alain da Silva Morais, Rui L. Reis, África González-Fernández., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2023
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21. Antibacterial nanopatterned coatings for dental implants.
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Fontelo R, Soares da Costa D, Gomez-Florit M, Tiainen H, Reis RL, Novoa-Carballal R, and Pashkuleva I
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- Humans, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Surface Properties, Gram-Negative Bacteria, Gram-Positive Bacteria, Titanium pharmacology, Titanium chemistry, Dental Implants
- Abstract
Dental implants, usually made of titanium, are exposed to hostile oral microflora that facilitate bacterial infections and subsequent inflammation. To mitigate these processes, we coated titanium substrates with block copolymer nanopatterns and investigated the bactericidal effect of these coatings against Gram-positive and Gram-negative bacteria. We found that the bactericidal efficacy of the coatings depends on their morphology and surface chemistry as well as on the bacterial strain: an optimal combination can lead to significant bacterial death for a short time, i.e. 90% for 90 min. Human gingival fibroblasts in contact with the nanopatterned coatings showed similar cell attachment and morphology as on bare Ti. Immunostaining assays showed similar levels of CCR7 and CD206 in macrophages cultured over the nanopatterns and bare Ti, demonstrating adequate properties for tissue integration. The nanopatterns induced a small increase in macrophage aspect ratio, which might indicate early states of M2 polarization, given the absence of CD206.
- Published
- 2022
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22. Hyaluronan Brush-like Copolymers Promote CD44 Declustering in Breast Cancer Cells.
- Author
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Carvalho AM, Valcarcel J, Soares da Costa D, Gomes M, Vázquez JA, Reis RL, Novoa-Carballal R, and Pashkuleva I
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- Cell Line, Tumor, Female, Humans, Hyaluronan Receptors metabolism, Hyaluronoglucosaminidase metabolism, Methacrylates, Oximes, Polymers pharmacology, Breast Neoplasms drug therapy, Hyaluronic Acid chemistry
- Abstract
We report on the synthesis of hyaluronan (HA) brush-like copolymers and their application as antagonists of tumorigenic CD44-HA interactions. HA (4.8 kDa, ca. 24 saccharides) was grafted on 2-hydrohyethyl methacrylate (HEMA) by end-on oxime ligation. The obtained copolymers were compared with low and high molecular weight HA in terms of hydrolysis kinetics in the presence of hyaluronidase (isothermal titration calorimetry) and interactions with CD44 (surface plasmon resonance). The results evidenced that the high molecular weight HA and HA- g -HEMA have a much higher affinity to CD44 than low molecular weight HA. Additionally, slower enzymatic degradation was observed for the copolymer, making it an excellent candidate for active targeting of tumorigenic CD44-HA interactions. We, therefore, investigated the effect of the copolymer on cancer cell lines with different expression of CD44 and observed an efficient declustering of CD44 that is usually associated with reduction of metastasis and drug resistance.
- Published
- 2022
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23. Isolation and Characterization of Polysaccharides from the Ascidian Styela clava .
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Valcarcel J, Vázquez JA, Varela UR, Reis RL, and Novoa-Carballal R
- Abstract
Styela clava is an edible sea squirt farmed in Korea that has gradually invaded other seas, negatively impacting the ecology and economy of coastal areas. Extracts from S. clava have shown wide bioactivities, and ascidians have the unique capability among animals of biosynthesizing cellulose. Thus, S. clava is a relevant candidate for valorization. Herein, we aimed at surveying and characterizing polysaccharides in both tunic and flesh of this ascidian. To this end, we enzymatically hydrolyzed both tissues, recovering crystalline cellulose from the tunic with high aspect ratios, based on results from microscopy, X-ray diffraction, and infrared spectroscopy analyses. Alkaline hydroalcoholic precipitation was applied to isolate the polysaccharide fraction that was characterized by gel permeation chromatography (with light scattering detection) and NMR. These techniques allowed the identification of glycogen in the flesh with an estimated Mw of 7 MDa. Tunic polysaccharides consisted of two fractions of different Mw. Application of Diffusion-Ordered NMR allowed spectroscopically separating the low-molecular-weight fraction to analyze the major component of an estimated Mw of 40-66 kDa. We identified six different sugar residues, although its complexity prevented the determination of the complete structure and connectivities of the residues. The two more abundant residues were N-acetylated and possibly components of the glycosaminoglycan-like (GAG-like) family, showing the remaining similarities to sulfated galactans. Therefore, Styela clava appears as a source of nanocrystalline cellulose and GAG-like polysaccharides.
- Published
- 2021
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24. Unveiling an NMR-Invisible Fraction of Polymers in Solution by Saturation Transfer Difference.
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Novoa-Carballal R, Martin-Pastor M, and Fernandez-Megia E
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- Diffusion, Magnetic Resonance Spectroscopy methods, Nuclear Magnetic Resonance, Biomolecular methods, Protons, Magnetic Resonance Imaging, Polymers
- Abstract
The observation of signals in solution NMR requires nuclei with sufficiently large transverse relaxation times ( T
2 ). Otherwise, broad signals embedded in the baseline afford an invisible fraction of nuclei (IF). Based on the STD (saturation transfer difference) sequence, IF-STD is presented as a quick tool to unveil IF in the1 H NMR spectra of polymers. The saturation of a polymer in a region of the NMR spectrum with IF (very short1 H T2 ) results in an efficient propagation of the magnetization by spin diffusion through the network of protons to a visible-invisible interphase with larger1 H T2 (STDon ). Subtracting this spectrum from one recorded without saturation (STDoff ) produces a difference spectrum (STDoff-on ), with the nuclei at the visible-invisible interphase, that confirms the presence of an IF. Analysis of a wide collection of polymers by IF-STD reveals IF more common than previously thought, with relevant IF figures when STD > 0.4% at 750 MHz. A fundamental property of the IF-STD experiment is that the signal is generated within a single state comprising polymer domains with different dynamics, as opposed to several states in exchange with different degrees of aggregation. Contrary to a reductionist visible-invisible dichotomy, our results confirm a continuous distribution of nuclei with diverse dynamics. Since nuclei observed (edited) by IF-STD at the visible-invisible interphase are in close spatial proximity to the IF (tunable with the saturation time), they emerge as a privileged platform from which gaining an insight into the IF itself.- Published
- 2021
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25. Hyaluronic Acid Oligomer Immobilization as an Angiogenic Trigger for the Neovascularization of TE Constructs.
- Author
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Silva AL, Babo PS, Rodrigues MT, Gonçalves AI, Novoa-Carballal R, Pires RA, Rouwkema J, Reis RL, and Gomes ME
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- Gelatin metabolism, Human Umbilical Vein Endothelial Cells metabolism, Humans, Hydrogels metabolism, Hyaluronic Acid pharmacology, Tissue Engineering
- Abstract
Tissue engineered (TE) substitutes of clinically relevant sizes need an adequate vascular system to ensure function and proper tissue integration after implantation. However, the predictable vascularization of TE substitutes is yet to be achieved. Molecular weight variations in hyaluronic acid (HA) have been pointed to trigger angiogenesis. Thus, this study investigates HA oligomer immobilization as a promoter for TE construct vascularization. As a proof-of-concept, the surface of methacrylated gelatin (GelMA) hydrogels were functionalized with high molecular weight (HMW; 1.5 to 1.8 MDa) and low molecular weight (LMW; < 10 kDa) HA, previously modified with aldehyde groups to enable the immobilization through Schiff's base formation. The ability of A-HA to bind amine-presenting surfaces was confirmed by Surface Plasmon Resonance (SPR). Human Umbilical Vein Endothelial Cells (HUVECs) seeded over hydrogels functionalized with LMW HA showed higher proliferation and expression of angiogenic markers (KDR and CD31), than those grown in HMW HA conjugated- or plain surfaces, in line with the activation of HA ERK1/2 mediated downstream signaling. Moreover, when cocultured with human dental pulp cells (hDPCs) encapsulated into the GelMA, an increase in endothelial cell migration was observed for the LMW HA functionalized formulations. Overall LMW HA functionalization enhanced endothelial cell response showing potential as an angiogenesis inducer for TE applications.
- Published
- 2021
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26. [Differential clinic in children infected by SARS-CoV-2, traceability of contacts and cost-effectiveness of diagnostic tests: Cross-sectional observational study].
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Fiel-Ozores A, González-Durán ML, Novoa-Carballal R, Portugués-de la Red MDM, Fernández-Pinilla I, Cabrera-Alvargonzález JJ, Martínez-Reglero C, Rey-Cao S, and Concheiro-Guisán A
- Subjects
- Adolescent, Age Factors, COVID-19 virology, Child, Child, Preschool, Contact Tracing, Cost-Benefit Analysis, Cross-Sectional Studies, Female, Fever epidemiology, Fever virology, Humans, Infant, Infant, Newborn, Male, Predictive Value of Tests, SARS-CoV-2 immunology, Sensitivity and Specificity, COVID-19 diagnosis, COVID-19 Testing methods, Reverse Transcriptase Polymerase Chain Reaction methods, SARS-CoV-2 isolation & purification
- Abstract
Introduction: Given the possible coexistence of infection by the SARS-CoV-2 with other seasonal infections, the aim is to identify differential symptoms. There has been studied the role of children in intrafamily contagion and the sensitivity of reverse transcriptase polymerase chain reaction (RT-PCR) in an area with low community transmission., Material and Methods: Cross-sectional observational study. Patients between 0-15 years studied by RT-PCR technique due to clinical suspicion of infection by SARS-CoV-2 virus in the months of March-May 2020. Survey on symptoms and contacts. Determination of Anti-SARS-CoV-2 antibodies at least 21 days after the RT-PCR test., Results: 126 patients were included, 33 with confirmed infection and mean age 8.4 years (95% CI 6.8-10,5), age higher than not infected. Fever was the most common symptom and with greater sensitivity. The differences found were a greater frequency of anosmia (P=0.029) and headache (P=.009) among children infected with a specificity of 96.7% and 81.5% respectively. There were no differences in the duration of the symptoms. 81.8% of those infected were probably infected in the family nucleus, 85.2% by a parent who worked outside the home. The sensitivity of RT-PCR was 70.9% and its negative predictive value 91.1%., Conclusions: The clinical picture is nonspecific and the more specific symptoms difficult to detect in younger children. Children had a reduced role in the intrafamily transmission. The sensitivity of RT-PCR could be related to a less contagiousness in children after one week of infection., (Copyright © 2020. Publicado por Elsevier España, S.L.U.)
- Published
- 2021
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27. Subtle olfactory dysfunction after SARS-CoV-2 virus infection in children.
- Author
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Concheiro-Guisan A, Fiel-Ozores A, Novoa-Carballal R, González-Duran ML, Portugués de la Red M, Martínez-Reglero C, Fernández-Pinilla I, and González-Guijarro I
- Subjects
- Adolescent, Case-Control Studies, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Olfaction Disorders epidemiology, Prevalence, SARS-CoV-2, Smell, COVID-19 complications, Olfaction Disorders etiology
- Abstract
Objectives: Anosmia/hyposomia have been described as early signs of COVID-19 infection in adults, including young asymptomatic patients who commonly refer olfactory disfunction as their only clinical manifestation. Very few studies involving paediatric age patients have been published until now. This study aims to determine the presence of olfactory dysfunction in children with COVID-19 infection through the use of a self-reported questionnaire and a new olfactory screening tool., Methods: Nested case-control study. All paediatric patients screened by reverse transcription polymerase chain reaction (RT-PCR) and Anti-SARS-CoV-2 antibodies for COVID-19 infection, during the study period (March-May 2020), were asked to respond to a questionnaire about symptoms of olfactory disfunction. Patients above six years old also performed an odor identification test based on seven odorants (Kradeo®). This test was designed based on our cultural context and eating habits., Results: 126 patients were recruited, including 33 with COVID-19 infection. 15% of the infected children referred anosmia and/or dysgeusia on the questionnaire, all of them were older than eleven years. The results of the odor test (69 patients) revealed subtle disturbances in the infected group (mostly misrecognition of odorants). Median odorant recognition was 3 odors [Interquartile range (IQR) 2-4] in case group and 4 [IQR 3-5] in controls. Male patients showed significantly larger disturbances than girls in both groups (p = 0.03)., Conclusion: Self-referred prevalence of olfactory disfunction in our sample of infected children is lower than that described in adults, especially among the youngest ones, maybe due to immature development of angiotensin-converting enzyme 2 (ACE2) receptors expressed in nasal mucosa. Nevertheless, one month after infection, subtle disturbances (misrecognition of odors) were identified among the infected children. This screening olfactory test provides a hygienic, user-friendly tool, suitable for screening children older than six years of age., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
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28. Novel amphiphilic chitosan micelles as carriers for hydrophobic anticancer drugs.
- Author
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Almeida A, Araújo M, Novoa-Carballal R, Andrade F, Gonçalves H, Reis RL, Lúcio M, Schwartz S Jr, and Sarmento B
- Subjects
- Antineoplastic Agents metabolism, Camptothecin chemistry, Camptothecin metabolism, Drug Liberation, Gastric Acid chemistry, Hydrophobic and Hydrophilic Interactions, Kinetics, Oleic Acid chemistry, Particle Size, Polyethylene Glycols chemistry, Thermodynamics, Antineoplastic Agents chemistry, Chitosan chemistry, Drug Carriers chemistry, Micelles
- Abstract
Chitosan was grafted with O-methyl-O'-succinylpolyethylene glycol and oleic acid after a two-step carbodiimide coupling. The structural and physicochemical characterization of the compounds confirmed the successful conjugation of the hydrophilic and hydrophobic moieties to the chitosan backbone. The amphiphilic chitosan derivative obtained allowed the formation of polymeric micelles with an average size of 140 nm, a polydispersity index <0.234, and a positive superficial charge. Camptothecin, used as a model hydrophobic drug, was successfully carried into the polymeric micelles with an encapsulation efficiency of 78%. The in vitro drug release was evaluated in simulated gastrointestinal fluids, exhibiting a low release of camptothecin in gastric media and a controlled release in intestinal fluids. Furthermore, it was demonstrated that chitosan micelles were able to stabilize camptothecin, protecting up to 75% of the drug from hydrolysis, preserving its active lactone form. This new chitosan amphiphilic system exhibits great potential to load hydrophobic drugs, acting as a promising delivery system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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29. Structure, rheology, and copper-complexation of a hyaluronan-like exopolysaccharide from Vibrio.
- Author
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Martin-Pastor M, Ferreira AS, Moppert X, Nunes C, Coimbra MA, Reis RL, Guezennec J, and Novoa-Carballal R
- Abstract
MO245 exopolysaccharide (EPS) was produced in laboratory conditions from Vibrio genus microorganism isolated from bacterial mats found in Moorea Island. Its structure consists of a linear tetrasaccharide repeating unit →4)-β-D-GlcpA-(1→4)-α-D-GalpNAc-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→ containing covalently-linked 5% of glucose, galactose, and rhamnose, determined by methylation analyses and NMR spectroscopy. The molecular weight, radius of gyration (R
g ) and intrinsic viscosity, [η], determined by gel permeation chromatography with light scattering and viscosity detection, were 513 ± 4 kDa (PDI, 1.42 ± 0.01), 6.7 ± 0.3 dl/g and 56 ± 0.3 nm respectively. The chelation of the EPS with copper divalent ions leads to the instantaneous formation of gels. The structural similitude proposed, based in an equal ratio of GlcA to N-acetylated sugars and in the same type of glyosidic linkages present in the repeating unit (alternated 1→3 and 1→4 linkages), is translated into analogous physicochemical properties: MO245 EPS is a flexible polyelectrolyte, with scaling exponents similar to that described for HA. This similitude opens opportunities in future drug delivery, tissue engineering, and cosmetic applications., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
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30. [Urethral prolapse: Diagnostic image of a rare pathology].
- Author
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Novoa-Carballal R, Cantero Rey R, García García I, and Valenzuela Besada O
- Subjects
- Child, Female, Humans, Prolapse, Urethral Diseases pathology, Urethral Diseases diagnosis
- Published
- 2019
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31. Optimal isolation and characterisation of chondroitin sulfate from rabbit fish (Chimaera monstrosa).
- Author
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Vázquez JA, Fraguas J, Novoa-Carballal R, Reis RL, Pérez-Martín RI, and Valcarcel J
- Subjects
- Animals, Cartilage chemistry, Disaccharides analysis, Hydrolysis, Membranes, Artificial, Molecular Weight, Proteolysis, Chemical Fractionation methods, Chondroitin Sulfates chemistry, Chondroitin Sulfates isolation & purification, Fishes
- Abstract
Chondroitin sulfate (CS) is a glycosaminoglycan widely explored for cartilage regeneration. Its bioactivity is influenced by sulfation degree and pattern, and distinct sulfation in marine CS may open new therapeutic possibilities. In this context, we studied for the first time the isolation and characterisation of CS from Rabbit Fish (Chimaera monstrosa). We propose an efficient process starting with enzymatic hydrolysis, followed by chemical treatments and ending in membrane purification. All steps were optimised by response surface methodology. Chemical treatment by alkaline-hydroalcoholic precipitation led to 99% purity CS suitable for biomedical and pharmaceutical applications, and treatment by alkaline hydrolysis yielded CS adequate for nutraceutical formulations (89% purity). Molecular weight and sulfation profiles were similar for both materials. Gel permeation chromatography analyses resulted in molecular weights (Mn) of 51-55 kDa. NMR and SAX-HPLC revealed dominant 6S-GalNAc sulfation (4S/6S ratio of 0.4), 17% of GlcA 2S-GalNAc 6S and minor quantities of other disaccharides., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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32. A multifunctional drug nanocarrier for efficient anticancer therapy.
- Author
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Teijeiro-Valiño C, Novoa-Carballal R, Borrajo E, Vidal A, Alonso-Nocelo M, de la Fuente Freire M, Lopez-Casas PP, Hidalgo M, Csaba N, and Alonso MJ
- Subjects
- A549 Cells, Animals, Antineoplastic Agents pharmacokinetics, Coculture Techniques, Docetaxel pharmacokinetics, Drug Carriers pharmacokinetics, Female, Humans, Hyaluronic Acid pharmacokinetics, Jurkat Cells, Lung Neoplasms metabolism, Mice, Nude, Tissue Distribution, Antineoplastic Agents administration & dosage, Docetaxel administration & dosage, Drug Carriers administration & dosage, Hyaluronic Acid administration & dosage, Lung Neoplasms drug therapy
- Abstract
So far, the success of anticancer nanomedicines has been moderate due to their lack of adequate targeting properties and/or to their difficulties for penetrating tumors. Here we report a multifunctional drug nanocarrier consisting of hyaluronic acid nanocapsules conjugated with the tumor homing peptide tLyp1, which exhibits both, dual targeting properties (to the tumor and to the lymphatics), and enhanced tumor penetration. Data from a 3D co-culture in vitro model showed the capacity of these nanocapsules to interact with the NRP1 receptors over-expressed in cancer cells. The targeting capacity of the nanocapsules was evidenced in orthotopic lung cancer-bearing mice, using docetaxel as a standard drug. The results showed a dramatic accumulation of docetaxel in the tumor (37-fold the one achieved with Taxotere®). This biodistribution profile correlated with the high efficacy shown in terms of tumor growth regression and drastic reduction of metastasis in the lymphatics. When efficacy was validated in a pancreatic patient-derived tumor, the nanocapsule's activity was comparable to that of a dose ten times higher of Abraxane®. Multi-functionality was found to be the key to the success of this new therapy., (Copyright © 2018. Published by Elsevier B.V.)
- Published
- 2019
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33. Minimalistic supramolecular proteoglycan mimics by co-assembly of aromatic peptide and carbohydrate amphiphiles.
- Author
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Brito A, Abul-Haija YM, da Costa DS, Novoa-Carballal R, Reis RL, Ulijn RV, Pires RA, and Pashkuleva I
- Abstract
We report the co-assembly of aromatic carbohydrate and dipeptide amphiphiles under physiological conditions as a strategy to generate minimalistic proteoglycan mimics. The resulting nanofibers present a structural, fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) core and a functional carbohydrate (Fmoc-glucosamine-6-sulfate or -phosphate) shell. The size, degree of bundling and mechanical properties of the assembled structures depend on the chemical nature of the carbohydrate amphiphile used. In cell culture medium, these nanofibers can further organize into supramolecular hydrogels. We demonstrate that, similar to proteoglycans, the assembled gels prolong the stability of growth factors and preserve the viability of cultured cells. Our results demonstrate that this approach can be applied to the design of extracellular matrix (ECM) substitutes for future regenerative therapies.
- Published
- 2018
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34. Star-Like Glycosaminoglycans with Superior Bioactivity Assemble with Proteins into Microfibers.
- Author
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Novoa-Carballal R, Carretero A, Pacheco R, Reis RL, and Pashkuleva I
- Subjects
- Chondroitin Sulfates chemistry, Fibroblast Growth Factor 2 chemistry, Heparin chemistry, Hyaluronic Acid chemistry, Microtechnology, Molecular Weight, Nanostructures chemistry, Oximes chemistry, Protein Multimerization, Proteoglycans chemistry, Thermodynamics, Glycosaminoglycans chemistry
- Abstract
Here it is shown that glycosaminoglycans (GAGs) with high molecular weight can be grafted via their reducing end on hyperbranched synthetic cores by oxime condensation without the need of any previous functionalisation of the polysaccharide. The versatility of this reaction is demonstrated by the use of hyaluronan, chondroitin sulfate and heparin with up to 60 sugar units. The isothermal calorimetry analysis demonstrated that the generated star-like glycopolymers have superior bioactivity. Moreover, when mixed with positively charged proteins (e.g., fibroblast growth factor-2, FGF-2) they form microfiber structures instead of the spherical nanocomplexes described for linear GAGs. The results suggest that the described star-like GAG are closer mimics of the proteoglycans at the structural and functional level and therefore have huge potential in the development of tissue engineering platforms and therapeutics by modulating the activity and presentation of various proteins such as growth factors., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2018
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35. Redox-Responsive Micellar Nanoparticles from Glycosaminoglycans for CD44 Targeted Drug Delivery.
- Author
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Carvalho AM, Teixeira R, Novoa-Carballal R, Pires RA, Reis RL, and Pashkuleva I
- Subjects
- Cell Line, Tumor, Humans, Oxidation-Reduction, Surface-Active Agents chemistry, Drug Carriers chemistry, Glycosaminoglycans chemistry, Hyaluronan Receptors metabolism, Micelles, Nanoparticles chemistry
- Abstract
Cancer progression is associated with overexpression of various receptors at the cell surface. Among these, CD44 is known to recognize and bind specifically hyaluronan (HA) and interact with less affinity to other glycosaminoglycans (GAGs), such as chondroitin sulfate (CS). In this study, we describe a simple method to obtain micellar nanoparticles with a GAG shell (HA or CS) as potential drug delivery systems that target cancer cells overexpressing CD44. Alkanethiol was conjugated at the reducing end of the respective GAG using highly efficient oxime chemistry. The alkane moiety confers amphiphilic behavior to the obtained conjugates and triggers their self-assembly into micellar nanoparticles, while the thiol group adds redox-responsiveness to the system. The properties of the particles depend on the used GAG: HA amphiphiles form more dense, smaller assemblies that are redox sensitive. Both systems allow encapsulation of either hydrophobic or hydrophilic cargos with high efficiency. We demonstrate that the GAGs exposed on the surface of the nanoparticles are with preserved bioactivity and recognized by the cellular receptors: the particles were internalized via CD44 dependent pathways.
- Published
- 2018
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36. Glycosaminoglycans from marine sources as therapeutic agents.
- Author
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Valcarcel J, Novoa-Carballal R, Pérez-Martín RI, Reis RL, and Vázquez JA
- Subjects
- Animals, Anti-Inflammatory Agents chemistry, Anti-Inflammatory Agents therapeutic use, Antineoplastic Agents chemistry, Antineoplastic Agents therapeutic use, Antiviral Agents chemistry, Antiviral Agents therapeutic use, Glycosaminoglycans chemistry, Humans, Aquatic Organisms chemistry, Chondroitin Sulfates therapeutic use, Glycosaminoglycans therapeutic use
- Abstract
Glycosaminoglycans (GAGs) in marine animals are different to those of terrestrial organisms, mainly in terms of molecular weight and sulfation. The therapeutic properties of GAGs are related to their ability to interact with proteins, which is very much influenced by sulfation position and patterns. Since currently GAGs cannot be chemically synthesized, they are sourced from natural products, with high intra- but also inter-species variability, in terms of chain length, disaccharide composition and sulfation pattern. Consequently, sulfated GAGs are the most interesting molecules in the marine environment and constitute the focus of the present review. In particular, chondroitin sulfate (CS) appears as the most promising compound. CS-E chains [GlcA-GalNAc(4S,6S)] extracted from squid possess antiviral and anti-metastatic activities and seem to impart signalling properties and improve the mechanical performance of cartilage engineering constructs; Squid CS-E and octopus CS-K [GlcA(3S)-GalNAc(4S)], dermatan sulfate (DS) from sea squirts [-iK units, IdoA(3S)-GalNAc(4S)] and sea urchins [-iE units, IdoA-GalNAc(4S,6S)] and hybrids CS/DS from sharks (-B/iB [GlcA/IdoA(2S)-GalNAc(4S)], -D/iD [GlcA/IdoA(2S)-GalNAc(6S)] and -E/iE units [GlcA/IdoA-GalNAc(4S,6S)]) promote neurite outgrowth and could be valuable materials for nerve regeneration. Also displaying antiviral and anti-metastatic properties, a rare CS with fucosylated branches isolated from sea cucumbers is an anticoagulant and anti-inflammatory agent. In this same line, marine heparin extracted from shrimp and sea squirt has proven anti-inflammatory properties, with the added advantage of decreased risk of bleeding because of its low anticoagulant activity., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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37. Design of protein delivery systems by mimicking extracellular mechanisms for protection of growth factors.
- Author
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Silva C, Carretero A, Soares da Costa D, Reis RL, Novoa-Carballal R, and Pashkuleva I
- Subjects
- Animals, Cell Line, Click Chemistry, Drug Liberation, Dynamic Light Scattering, Heparin analogs & derivatives, Heparin chemical synthesis, Heparin chemistry, Humans, Mice, Osmolar Concentration, Particle Size, Polyelectrolytes chemistry, Polyethylene Glycols chemical synthesis, Polyethylene Glycols chemistry, Proteoglycans chemical synthesis, Proteoglycans chemistry, Drug Delivery Systems, Extracellular Space chemistry, Fibroblast Growth Factor 2 pharmacology
- Abstract
Heparin sulfate proteoglycans (HSPGs) are responsible for the storage and stabilization of numerous growth factors in the extracellular matrix. In this complex native environment, the efficient binding of the growth factors is determined by multivalent, specific and reversible electrostatic interactions between the sulfate groups of HSPGs and the positively charged amino acids of the growth factor. Inspired by this naturally occurring stabilization process, we propose the use of diblock copolymers of heparin and polyethylene glycol (Hep-b-PEG) for protection and delivery of FGF-2. We describe the encapsulation of FGF-2 into spontaneously assembling polyelectrolyte complexes (PECs) with Hep-b-PEG in which the Hep block ensures the formation of the PECs, while the PEG moiety confers stability of the generated complex by a stealth corona. Our results demonstrate that by this method we can generate homogeneous complexes (ca. 400nm diameter, PDI 0.29±0.07) with a very high encapsulation efficiency (about 99% encapsulated FGF-2). The release of the growth factor in response to different stimuli such as pH, ionic strength or presence of heparinase was also studied. We report a sustained release of up to 80% during 28days which is not influenced by the presence of heparinase - a result that clearly demonstrates the protective effect of the stealth corona. We also show that FGF-2 remains bioactive as it influences the morphology of bone marrow mesenchymal stem cells., Statement of Significance: We describe a biopolymer that uses the way the cells shield a type of proteins (growth factors) to simultaneously assemble, slowly deliver and shield the protein in a "nanocarrier". Growth factors are essential for the regeneration of cartilage, bones by stem cell therapies but have a short life time as when added directly to tissues. Our design makes use of the heparin bioactivity towards such proteins in combination with a polyethylene glycol moiety (PEG) that makes a protecting shell. PEG, is biocompatible and used in approved medicines and countless cosmetic products. The highest novelty is the reaction (oxime click) used to bound these molecules that does not require modification of heparin and allows preservation of its bioactivity., (Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2017
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38. Optimization of high purity chitin and chitosan production from Illex argentinus pens by a combination of enzymatic and chemical processes.
- Author
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Vázquez JA, Noriega D, Ramos P, Valcarcel J, Novoa-Carballal R, Pastrana L, Reis RL, and Pérez-Martín RI
- Abstract
The present report illustrates the optimisation of the experimental conditions for the chemical and enzymatic production of chitin and chitosan from Illex argentinus pen by-products. Optima conditions for chitin isolation were established at 0.82M NaOH/36.4°C, 57.5°C/pH=9.29, 59.6°C/pH=9.30 and 49.6°C/pH=5.91 for chemical, alcalase, esperase and neutrase deproteinization, respectively. Chitin samples were subsequently deacetylated by alkaline treatment reaching the highest degrees of deacetylation (DD>93%) at 61.0-63.7% of NaOH and 14.9-16.4h of hydrolysis depending on the type of process previously performed to the squid pens. Molecular weight (as number average molecular weight, Mn) of chitosan produced in the experimental designs ranged from 143kDa (PDI 2.37) to 339kDa (PDI 2.38)., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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39. The Key Role of Sulfation and Branching on Fucoidan Antitumor Activity.
- Author
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Oliveira C, Ferreira AS, Novoa-Carballal R, Nunes C, Pashkuleva I, Neves NM, Coimbra MA, Reis RL, Martins A, and Silva TH
- Subjects
- Cell Line, Cell Line, Tumor, Drug Screening Assays, Antitumor, Humans, Polysaccharides chemistry, Polysaccharides pharmacology, Sulfates chemistry
- Abstract
There is an urgent need for antitumor bioactive agents with minimal or no side effects over normal adjacent cells. Fucoidan is a marine-origin polymer with known antitumor activity. However, there are still some concerns about its application due to the inconsistent experimental results, specifically its toxicity over normal cells and the mechanism behind its action. Herein, three fucoidan extracts (FEs) have been tested over normal and breast cancer cell lines. From cytotoxicity results, only one of the extracts shows selective antitumor behavior (at 0.2 mg mL
-1 ), despite similarities in sulfation degree and carbohydrates composition. Although the three FEs present different molecular weights, depolymerization of selected samples discarded Mw as the key factor in the antitumor activity. Significant differences in sulfates position and branching are observed, presenting FE 2 the higher branching degree. Based on all these experimental data, it is believed that these last two properties are the ones that influence the cytotoxic effects of fucoidan extracts., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2017
- Full Text
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40. By-products of Scyliorhinus canicula, Prionace glauca and Raja clavata: A valuable source of predominantly 6S sulfated chondroitin sulfate.
- Author
-
Novoa-Carballal R, Pérez-Martín R, Blanco M, Sotelo CG, Fassini D, Nunes C, Coimbra MA, Silva TH, Reis RL, and Vázquez JA
- Subjects
- Animals, Chromatography, Gel, Chondroitin Sulfates isolation & purification, Sharks, Skates, Fish
- Abstract
Chondroitin sulfate (CS) was isolated from Scyliorhinus canicula (fin, head and skeleton), Prionace glauca (head), and Raja clavata (skeleton) by-products from fish processing industry using environmentally friendly processes. The molecular weight was determined by gel permeation chromatography and the sugar composition and sulfation position by NMR and SAX-HPLC after enzymatic digestion. The CSs showed a prevalent 6S GalNAc sulfation for the 3 species (4S/6S ratio lower than 1). A higher 6S sulfation was observed for P. glauca head and R. clavata skeleton (4S/6S ratio below 0.20) than for S. canicula (4S/6S ratio ca. 0.6). The existence of CS samples with such low 4S/6S ratio has only been observed before in a rare species of shark (Mitsukutina owatoni, globin shark). The good extraction yields achieved make S. canicula, P. glauca and R. clavata fish industry by-products a useful source of 6-sulfated chondroitin sulfate., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
41. Neovascularization Induced by the Hyaluronic Acid-Based Spongy-Like Hydrogels Degradation Products.
- Author
-
Silva LP, Pirraco RP, Santos TC, Novoa-Carballal R, Cerqueira MT, Reis RL, Correlo VM, and Marques AP
- Subjects
- Animals, Human Umbilical Vein Endothelial Cells, Humans, Hyaluronic Acid, Mice, Neovascularization, Physiologic, Regenerative Medicine, Tissue Engineering, Hydrogels chemistry
- Abstract
Neovascularization has been a major challenge in many tissue regeneration strategies. Hyaluronic acid (HA) of 3-25 disaccharides is known to be angiogenic due to its interaction with endothelial cell receptors. This effect has been explored with HA-based structures but a transitory response is observed due to HA burst biodegradation. Herein we developed gellan gum (GG)-HA spongy-like hydrogels from semi-interpenetrating network hydrogels with different HA amounts. Enzymatic degradation was more evident in the GG-HA with high HA amount due to their lower mechanical stability, also resulting from the degradation itself, which facilitated the access of the enzyme to the HA in the bulk. GG-HA spongy-like hydrogels hyaluronidase-mediated degradation lead to the release of HA oligosaccharides of different amounts and sizes in a HA content-dependent manner which promoted in vitro proliferation of human umbilical cord vein endothelial cells (HUVECs) but not their migration. Although no effect was observed in human dermal microvascular endothelial cells (hDMECs) in vitro, the implantation of GG-HA spongy-like hydrogels in an ischemic hind limb mice model promoted neovascularization in a material-dependent manner, consistent with the in vitro degradation profile. Overall, GG-HA spongy-like hydrogels with a sustained release of HA oligomers are valuable options to improve tissue vascularization, a critical issue in several applications in the tissue engineering and regenerative medicine field.
- Published
- 2016
- Full Text
- View/download PDF
42. Following the enzymatic digestion of chondroitin sulfate by a simple GPC analysis.
- Author
-
Silva C, Novoa-Carballal R, Reis RL, and Pashkuleva I
- Subjects
- Animals, Cattle, Models, Molecular, Proton Magnetic Resonance Spectroscopy, Sharks, Chondroitin ABC Lyase metabolism, Chondroitin Sulfates chemistry, Chondroitin Sulfates metabolism, Chromatography, Gel methods, Hyaluronoglucosaminidase metabolism, Proteus vulgaris enzymology
- Abstract
We describe the use of gel permeation chromatography (GPC) setup with four size exclusion columns for analysis of enzymatically digested glycosaminoglycans (GAGs). This setup provides information about the molecular weight (Mw) and concentration of all species (low and high Mw) present in the digests in a single measurement. The data about the fraction with high Mw (often omitted in the analysis of GAG digests) provide direct evidence about the mechanisms of action of the enzymes. We proved the feasibility of this methodology by applying it to chondroitin sulfate (CS) substrates with different molecular weight and sulfation pattern and using different enzymes (hyaluronidase and chondroitinase). NMR analysis of the obtained digests fractionated by ultrafiltration confirmed the results obtained by GPC setup and reveal further details about the degradation mechanisms: (i) both enzymes preferentially attack 4-sulfated chondroitin and (ii) additionally to the well documented endolytic activity of hyaluronidase we also observed a low lyase activity for this enzyme reflected in the detected minor exolytic breakage. Finally, we demonstrate that CS with medium molecular weight (12-60kDa) which is sulfated mainly at 6-position can be obtained in good yields by enzymatic digestion and following ultrafiltration., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
43. Systemically administered brain-targeted nanoparticles transport peptides across the blood-brain barrier and provide neuroprotection.
- Author
-
Yemisci M, Caban S, Gursoy-Ozdemir Y, Lule S, Novoa-Carballal R, Riguera R, Fernandez-Megia E, Andrieux K, Couvreur P, Capan Y, and Dalkara T
- Subjects
- Animals, Blood-Brain Barrier, Male, Mice, Fibroblast Growth Factor 2 administration & dosage, Nanoconjugates administration & dosage, Neuroprotective Agents administration & dosage, Oligopeptides administration & dosage, Stroke pathology
- Abstract
Although growth factors and anti-apoptotic peptides have been shown to be neuroprotective in stroke models, translation of these experimental findings to clinic is hampered by limited penetration of peptides to the brain. Here, we show that a large peptide like the basic fibroblast growth factor (bFGF) and a small peptide inhibitor of caspase-3 (z-DEVD-FMK) can effectively be transported to the brain after systemic administration by incorporating these peptides to brain-targeted nanoparticles (NPs). Chitosan NPs were loaded with peptides and then functionalized by conjugating with antibodies directed against the transferrin receptor-1 on brain endothelia to induce receptor-mediated transcytosis across the blood-brain barrier (BBB). Pre-ischemic systemic administration of bFGF- or z-DEVD-FMK-loaded NPs significantly decreased the infarct volume after 2-hour middle cerebral artery occlusion and 22-hour reperfusion in mice. Co-administration of bFGF- or z-DEVD-FMK-loaded NPs reduced the infarct volume further and provided a 3-hour therapeutic window. bFGF-loaded NPs were histologically detected in the brain parenchyma and also restored ischemia-induced Akt dephosphorylation. The neuroprotection was not observed when receptor-mediated transcytosis was inhibited with imatinib or when bFGF-loaded NPs were not conjugated with the targeting antibody, which enables them to cross the BBB. Nanoparticles targeted to brain are promising drug carriers to transport large as well as small BBB-impermeable therapeutics for neuroprotection against stroke.
- Published
- 2015
- Full Text
- View/download PDF
44. Controlling cancer cell fate using localized biocatalytic self-assembly of an aromatic carbohydrate amphiphile.
- Author
-
Pires RA, Abul-Haija YM, Costa DS, Novoa-Carballal R, Reis RL, Ulijn RV, and Pashkuleva I
- Subjects
- Alkaline Phosphatase chemistry, Alkaline Phosphatase metabolism, Cell Line, Tumor, Humans, Models, Molecular, Nanofibers chemistry, Phosphorylation, Protein Conformation, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Biocatalysis, Glucosamine chemistry, Glucosamine pharmacology, Hydrophobic and Hydrophilic Interactions, Osteosarcoma pathology
- Abstract
We report on a simple carbohydrate amphiphile able to self-assemble into nanofibers upon enzymatic dephosphorylation. The self-assembly can be triggered by alkaline phosphatase (ALP) in solution or in situ by the ALP produced by osteosarcoma cell line, SaOs2. In the latter case, assembly and localized gelation occurs mainly on the cell surface. The gelation of the pericellular environment induces a reduction of the SaOs2 metabolic activity at an initial stage (≤7 h) that results in cell death at longer exposure periods (≥24 h). We show that this effect depends on the phosphatase concentration, and thus, it is cell-selective with prechondrocytes ATDC5 (that express ∼15-20 times lower ALP activity compared to SaOs2) not being affected at concentrations ≤1 mM. These results demonstrate that simple carbohydrate derivatives can be used in an antiosteosarcoma strategy with limited impact on the surrounding healthy cells/tissues.
- Published
- 2015
- Full Text
- View/download PDF
45. GATG dendrimers and PEGylated block copolymers: from synthesis to bioapplications.
- Author
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Sousa-Herves A, Novoa-Carballal R, Riguera R, and Fernandez-Megia E
- Subjects
- Active Transport, Cell Nucleus, Animals, Chemistry, Pharmaceutical, Dendrimers metabolism, Gallic Acid analogs & derivatives, Gallic Acid metabolism, Humans, Ligands, Models, Molecular, Molecular Structure, Nanoparticles, Nanotechnology, Polyethylene Glycols metabolism, Structure-Activity Relationship, Contrast Media chemistry, Dendrimers chemistry, Drug Carriers, Gallic Acid chemistry, Gene Transfer Techniques, Magnetic Resonance Imaging methods, Polyethylene Glycols chemistry, Technology, Pharmaceutical methods
- Abstract
Dendrimers are synthetic macromolecules composed of repetitive layers of branching units that emerge from a central core. They are characterized by a tunable size and precise number of peripheral groups which determine their physicochemical properties and function. Their high multivalency, functional surface, and globular architecture with diameters in the nanometer scale makes them ideal candidates for a wide range of applications. Gallic acid-triethylene glycol (GATG) dendrimers have attracted our attention as a promising platform in the biomedical field because of their high tunability and versatility. The presence of terminal azides in GATG dendrimers and poly(ethylene glycol) (PEG)-dendritic block copolymers allows their efficient functionalization with a variety of ligands of biomedical relevance including anionic and cationic groups, carbohydrates, peptides, or imaging agents. The resulting functionalized dendrimers have found application in drug and gene delivery, as antiviral agents and for the treatment of neurodegenerative diseases, in diagnosis and as tools to study multivalent carbohydrate recognition and dendrimer dynamics. Herein, we present an account on the preparation and recent applications of GATG dendrimers in these fields.
- Published
- 2014
- Full Text
- View/download PDF
46. Tunable nano-carriers from clicked glycosaminoglycan block copolymers.
- Author
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Novoa-Carballal R, Silva C, Möller S, Schnabelrauch M, Reis RL, and Pashkuleva I
- Abstract
Oxime click reaction is used for the synthesis of diblock copolymers of polyethylene glycol (PEG) and glycosaminoglycans (GAGs) with different molecular weights (M
w ) and sulfation degrees. The ability of these copolymers to carry positively charged proteins is evidenced by their assembly with poly-l-lysine as a model: interpolyelectrolyte complexes with tunable size at the nanometric scale (radius of 25-90 nm) and narrow distribution are described. We demonstrate that there is a critical Mw of GAGs for the formation of stable complexes and that the sulfation degree determines the size of the nano-assemblies. Highly sulfated GAGs form the smallest complexes that are stable to at least 500 mM ionic strength: a property that is not usual for GAG interpolyelectrolyte complexes. The feasibility of the synthesised block copolymers as protein carriers is further evidenced by their complexation with fibroblast growth factor (FGF-2). The described assets of GAG block copolymers together with the intrinsic GAG properties such as biorecognition and biodegradability open up new opportunities in the design of selective encapsulation/release nanosystems with a stealth PEG corona.- Published
- 2014
- Full Text
- View/download PDF
47. Disclosing an NMR-invisible fraction in chitosan and PEGylated copolymers and its role on the determination of degrees of substitution.
- Author
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Novoa-Carballal R, Riguera R, and Fernandez-Megia E
- Subjects
- Chitosan chemistry, Magnetic Resonance Imaging, Polyethylene Glycols chemistry, Polymers chemistry
- Abstract
An unexpected (1)H NMR invisible fraction (IF) for chitosan (CS) and CS-g-PEG is reported. The presence of this IF is remarkable considering that solution NMR is recognized as the method of choice for studying structural modifications in CS, including the degrees of acetylation (DA) and substitution (DS). In spite of IF figures as high as 50%, this IF does not interfere in the correct determination of the DA by (1)H NMR, pointing to a homogeneous distribution of acetyl groups along the visible and invisible fractions. Quite in contrast, the IF negatively biases the determination of the DS in CS-g-PEG, with relative errors as high as 150% in a broad range of temperatures, pH values, and concentrations. This fact raises concerns about the accuracy of previously reported DS data for CS-g-PEG and many other CS copolymers. Efficient user-friendly conditions have been developed for the correct determination of the DS of CS-g-PEG by depolymerization by nitrous acid.
- Published
- 2013
- Full Text
- View/download PDF
48. Anti-tumor efficacy of chitosan-g-poly(ethylene glycol) nanocapsules containing docetaxel: anti-TMEFF-2 functionalized nanocapsules vs. non-functionalized nanocapsules.
- Author
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Torrecilla D, Lozano MV, Lallana E, Neissa JI, Novoa-Carballal R, Vidal A, Fernandez-Megia E, Torres D, Riguera R, Alonso MJ, and Dominguez F
- Subjects
- Animals, Antineoplastic Agents chemistry, Cell Line, Tumor, Docetaxel, Doublecortin Protein, Humans, Magnetic Resonance Spectroscopy, Mice, Mice, SCID, Taxoids chemistry, Xenograft Model Antitumor Assays, Antineoplastic Agents pharmacology, Chitosan chemistry, Membrane Proteins antagonists & inhibitors, Nanocapsules, Neoplasm Proteins antagonists & inhibitors, Polyethylene Glycols chemistry, Taxoids pharmacology
- Abstract
The development and evaluation of PEGylated chitosan (CS) nanocapsules (NCs) conjugated to a monoclonal antibody anti-TMEFF-2 (CS-PEG-anti-TMEFF-2 mAb NCs) for targeted delivery of docetaxel (DCX) is presented. CS-PEG-Biotin NCs, displaying biotin tags at their surface, were obtained and efficiently functionalized with an anti-TMEFF-2 mAb through a convenient avidin-biotin approach. Cell cycle analysis after treatment with different DCX-loaded CS-PEG NC formulations indicated that the encapsulated drug remained fully active, showing a similar functional behavior to free DCX. In vivo efficacy studies using a non-small cell lung carcinoma xenograft revealed that CS-PEG-anti-TMEFF-2 NCs resulted as effective as free DCX (Taxotere®). Interestingly, differences on the pharmacodynamic behavior among the different DCX formulations were observed. Thus, while free DCX exhibited a fast and short effect on tumor volume reduction, CS-PEG-anti-TMEFF-2 mAb NCs showed a delayed and prolonged action, with no significant side effects of treatments., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
49. Structural analysis of fructans produced by acetic acid bacteria reveals a relation to hydrocolloid function.
- Author
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Jakob F, Pfaff A, Novoa-Carballal R, Rübsam H, Becker T, and Vogel RF
- Subjects
- Colloids, Food Handling, Fructans isolation & purification, Molecular Conformation, Molecular Weight, Structure-Activity Relationship, Acetic Acid metabolism, Acetobacteraceae metabolism, Fructans biosynthesis, Fructans chemistry
- Abstract
Some strains of acetic acid bacteria (Gluconobacter frateurii TMW 2.767, Gluconobacter cerinus DSM 9533T, Neoasaia chiangmaiensis NBRC 101099, Kozakia baliensis DSM 14400) produce high amounts of fructans, which can be exploited in food applications as previously demonstrated empirically for dough systems. In order to get insight into the structure and functionality of these polymers, we investigated the fructans isolated from these strains with respect to their linkage types and molecular weights/shapes using NMR spectroscopy and AF4-MALS-RI. Each fructan was identified as levan. The isolated levan fractions were highly similar according to their basic linearity and linkage types, but differed significantly in terms of their individual molecular weight distributions. In aqueous solutions the size of levan molecules present in all isolated levans continuously increased with their molecular weight and they tended to adopt a more compact molecular shape. Our data suggest that the increasing molecular weight of a levan particle enforces intramolecular interactions to reach the structural compactness of a microgel with hydrocolloid properties., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
50. [Do paediatricians perform lumbar puncture correctly? Review of recommendations and analysis the technique in Spain].
- Author
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Storch De Gracia Calvo P, De La Torre Espí M, Martín Díaz MJ, García Ruiz S, Domínguez Ortega G, and Novoa Carballal R
- Subjects
- Adult, Child, Cross-Sectional Studies, Humans, Infant, Newborn, Middle Aged, Practice Guidelines as Topic, Spain, Surveys and Questionnaires, Clinical Competence, Guideline Adherence statistics & numerical data, Pediatrics, Spinal Puncture methods, Spinal Puncture standards
- Abstract
Introduction: Lumbar puncture (LP) is a commonly performed procedure in paediatrics. Performing this technique properly can avoid the most common associated complications., Objective: To assess whether paediatricians and paediatric residents in Spain follow current recommendations for the LP technique., Material and Methods: A cross-sectional study was conducted by sending a questionnaire by mail through the Spanish Society of Paediatric Emergencies, collecting demographic information and responses to multiple choice questions about LP technique., Results: A total of 206 questionnaires were analysed, of which 143 (69.5%) were answered by paediatricians, and 63 (30.5%) by paediatric residents. The majority (128; 62.1%) of physicians did not allow parents to be present during LP, 198 (96.1%) routinely use analgesia and sedation; 84 (42%) only used local anaesthesia. The majority of respondents used standard Quincke needles (126; 62.7%). The bevel was correctly positioned when puncturing the dura mater by 22 residents (36.1%) and 21 paediatricians (15.1%), a variation that was statistically significant (P=.001). For neonatal lumbar punctures, 63 paediatricians (46%) and 19 paediatric residents used a butterfly needle which did not contain a stylet, and this difference was also statistically significant (P=.035). Of those surveyed, 190 (92.2%) re-inserted the stylet when re-orientating the needle, and 186 (93%) re-oriented this when removing it. The recommendation of bed rest was made by 195 (94.7%) physicians., Conclusions: The majority of paediatricians orient the bevel wrongly when inserting the needle during LP, and still use "butterfly" needles in newborns, despite warnings to the contrary. Paediatric residents and less experienced paediatricians follow the recommendations more frequently., (Copyright © 2011 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
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