13 documents found, page 1 of 2
Preparation, properties and bioapplications of block copolymer nanopatterns
Fontelo, R.; Reis, R. L.; Novoa-Carballal, Ramon; Pashkuleva, I.Block copolymer (BCP) self-assembly has emerged as a feasible method for large-scale fabrication with remarkable precision â features that are not common for most of the nanofabrication techniques. In this review, we present 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 me...
End-on PEGylation of heparin: Effect on anticoagulant activity and complexation...
Amaral, S.; Lozano-Fernández, T.; Sabin, J.; Gallego, A.; da Silva Morais, Alain; Reis, R. L.; Gonzalez-Fernández, A.; Pashkuleva, I.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-...
Block copolymer nanopatterns affect cell spreading: stem versus cancer bone cells
Fontelo, R.; Costa, Diana Pereira Soares; Reis, R. L.; Novoa-Carballal, Ramon; Pashkuleva, I.Bone healing after a tumor removal can be promoted by biomaterials that enhance the bone regeneration and prevent the tumor relapse. Herein, we obtained several nanopatterns by self-assembly of polystyrene-block-poly 2-vinyl pyridine (PS-b-P2VP) with different molecular weight and investigated the adhesion and morphology of human bone marrow mesenchymal stem cells (BMMSC) and osteosarcoma cell line (SaOS-2) on ...
Antibacterial nanopatterned coatings for dental implants
Fontelo, Raul; Costa, Diana Pereira Soares; Gómez-Florit, Manuel; Tiainen, Hanna; Reis, R. L.; Novoa-Carballal, Ramon; Pashkuleva, I.Dental implants, usually made of titanium, are exposed to hostile oral microflora that facilitates 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...
Antithrombotic and hemocompatible properties of nanostructured coatings assembl...
Fontelo, R.; Soares da Costa, D.; Reis, R. L.; Novoa-Carballal, Ramon; Pashkuleva, I.We describe the antithrombotic properties of nanopatterned coatings created by self-assembly of poly(styrene-block-2-vinylpyridine) (PS-b-P2VP) with different molecular weights. By changing the assembly conditions, we obtained nanopatterns that differ by their morphology (size and shape of the nanopattern) and chemistry. The surface exposition of P2VP block allowed quaternization, i.e. introduction of positive ...
Hyaluronan brush-like copolymers promote CD44 declustering in breast cancer cells
Carvalho, A. M.; Valcarcel, J.; Costa, Diana Pereira Soares; Gomes, M.; Vázquez, J. A.; Reis, R. L.; Novoa-Carballal, Ramon; Pashkuleva, I.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 ...
Isolation and characterization of polysaccharides from the ascidian Styela clava
Valcarcel, Jesus; Vázquez, José Antonio; Varela, Uxía R.; Reis, R. L.; Novoa-Carballal, Ramon<i>Styela clava</i> 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 <i>S. clava</i> have shown wide bioactivities, and ascidians have the unique capability among animals of biosynthesizing cellulose. Thus, <i>S. clava</i> is a relevant candidate for valorization. Herein, we aimed at surveying and characte...
Hyaluronic acid oligomer immobilization as an angiogenic trigger for the neovas...
Silva, A. L.; Babo, Pedro Miguel Sousa; Rodrigues, Márcia T.; Gonçalves, A I; Novoa-Carballal, Ramon; Pires, R. A.; Rouwkema, J.; Reis, R. L.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 ...
Optimal isolation and characterisation of chondroitin sulfate from Rabbit fish ...
Vázquez, José A.; Fraguas, J.; Novoa-Carballal, Ramon; Reis, R. L.; Pérez-Martín, Ricardo I.; Valcarcel, J.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 ...
Structure, rheology, and copper-complexation of a hyaluronan-like exopolysaccha...
Martin-Pastor, M.; Ferreira, A. S.; Moppert, X.; Nunes, C.; Coimbra, M. A.; Reis, R. L.; Guezennec, J.; Novoa-Carballal, RamonMO245 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 â 4)-β-D-GlcpA-(1â 4)-α-D-GalpNAc-(1â 3)-β-D-GlcpNAc-(1â 4)-β-D-GlcpA-(1â containing covalently-linked 5% of glucose, galactose, and rhamnose, determined by methylation analyses and NMR spe...