12 documents found, page 1 of 2
Long term performance evaluation of small-diameter vascular grafts based on pol...
Alexandre, Nuno; Amorim, Irina; Caseiro, Ana Rita; Pereira, Tiago; Alvites, Rui; Rêma, Alexandra; Gonçalves, Ana; Costa, Elisio; Santos-Silva, AliceThe functional and structural performance of a 5 cm synthetic small diameter vascular graft (SDVG) produced by the copolymerization of polyvinyl alcohol hydrogel with low molecular weight dextran (PVA/Dx graft) associated to mesenchymal stem cells (MSCs)-based therapies and anticoagulant treatment with heparin, clopidogrel and warfarin was tested using the ovine model during the healing period of 24 weeks. The ...
Evaluation of PVA biodegradable electric conductive membranes for nerve regener...
Ribeiro, Jorge; Caseiro, Ana Rita; Pereira, Tiago; Armada‐da‐Silva, Paulo Alexandre; Pires, Isabel; Prada, Justina; Irina, Amorim; Reis, Inês LealThe therapeutic effect of three polyvinyl alcohol (PVA) membranes loaded with electrically conductive materials - carbon nanotubes (PVA-CNTs) and polypyrrole (PVA-PPy) - were tested in vivo for neuro-muscular regeneration after an axonotmesis injury in the rat sciatic nerve. The membranes electrical conductivity measured was 1.5 ± 0.5 × 10-6 S/m, 579 ± 0.6 × 10-6 S/m, and 1837.5 ± 0.7 × 10-6 S/m, respectively. ...
Rússia : economia emergente ou reemergente?
Luís, Ana LúciaO objetivo do presente trabalho é problematizar o papel da Rússia enquanto economia emergente. É nossa opinião que a Rússia não é uma economia emergente, no sentido tradicional do conceito, normalmente associado aos BRICS (Brasil, Rússia, India, China e África do Sul), mas antes uma economia reemergente. Existem vários elementos de dissociação da visão tradicional que se tem dos países emergentes, elementos ess...
Biocompatibility and hemocompatibility of polyvinyl alcohol hydrogel used for v...
Alexandre, Nuno; Ribeiro, Jorge; Gärtner, Andrea; Pereira, Tiago; Amorim, Irina; Fragoso, João; Lopes, Ascensão; Fernandes, João; Costa, ElísioPolyvinyl alcohol hydrogel (PVA) is a synthetic polymer with an increasing application in the biomedical field that can potentially be used for vascular grafting. However, the tissue and blood–material interactions of such gels and membranesare unknown in detail. The objectives of this study were to: (a) assess the biocompatibility and (b) hemocompatibility of PVA-based membranes in order to get some insight in...
In vitro and in vivo evaluation of blood coagulation activation of polyvinyl al...
Alexandre, Nuno; Costa, Elísio; Coimbra, Susana; Silva, Alice; Lopes, Ascensão; Rodrigues, Miguel; Santos, Marta; Maurício, Ana ColettePolyvinyl alcohol hydrogel (PVA) is a water-soluble synthetic polymer with an increasingly use in biomedical applications including vascular grafting. It was argued that the copolymerization of PVA with dextran (Dx) can result in an improvement of blood/biomaterial interactions. The focus of this experimental work is to assess that interaction through an in vivo and in vitro evaluation of the coagulation system...
Neuro-muscular Regeneration Using Scaffolds with Mesenchymal Stem Cells (MSCs) ...
Caseiro, Ana Rita; Pereira, Tiago; Ribeiro, Jorge; Amorim, Irina; Faria, Fátima; Bártolo, Paulo Jorge; Armada, Paulo; Luís, Ana LúciaPeripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent of regeneration is often poor and may benefit from exogenous factors that enhance growth. Neonatal tissues are routinely discarded at parturition so little ethical controversy attends the harvest of the Mesenchymal Stem Cells (MSCs) which may play an important therapeutic role through the secretion of soluble troph...
The in vitro mechanical properties of small diameter Poly(vinyl) alcohol hydrog...
Alexandre, Nuno; Nunes, Natacha; Rodrigues, Miguel; Maurício, Ana Colette; Luís, Ana Lúcia; Lopes, Ascensão; Santos, José DomingosIntroduction The production of artificial vascular grafts of small diameter is a fluorescing line of investigation. PVA is a biomaterial that has been used for several biomedical applications and nowadays as a vascular graft. However the mechanical properties were never characterized in vitro. It was our objective to produce small diameter PVA grafts and characterize their physical and mechanical properties for...
In vivo evaluation of the potencial of mesenchymal stem cells (MSCs) from whart...
Alexandre, Nuno; Lopes, Ascensão; Rodrigues, Miguel; Amorim, Irina; Pereira, Tiaho; Gärtner, Andrea; Maurício, Ana Colette; Santos, José DomingosIntroduction: The use of cellular systems for improving biointegration of medical devices is a current trend of tissue engineering. The biocompatibility is a key aspect that can influence the performance of medical devices, for that reason inflammatory and foreign body reaction must be evaluated in pre-clinical studies. MSCs can modify the interaction of biomaterials with tissues by several mechanisms through t...
Application of Vascular grafts od Polyvinyl alcohol hydrogel associated to mese...
Alexandre, Nuno; Lopes, Ascensão; Nunes, Natacha; Amorim, Irina; Maurício, Ana Colette; Santos, José Domingos; Luís, Ana LúciaApplication of vascular grafts of the polyvinyl alcohol hydrogel (PVA) associated with MSCs from Wharton jelly in an animal model (sheep). N Alexandre, MA Lopes, N Fernandes, M Rodrigues, I Amorim, AC Mauricio, AL Luís Introduction: There is a great demand for new artificial vascular grafts of small diameter (< 6 mm) due to the functional limitations of the currently used biomaterials (ePTFE and Dacron). Polyvi...
Studies on the biocompatibility of bacterial cellulose.
Alexandre, Nuno; Andrade, Fábia; Amorim, Irina; Gartner, Fátima; Maurício, Ana Colette; Luís, Ana Lúcia; Gama, MiguelBacterial cellulose was functionalized with a chimeric protein containing a cellulose-binding module and the adhesion peptide Arg-Gly-Asp. Small-diameter bacterial cellulose membranes were produced and subcutaneously implanted in sheep for 1–32 weeks. The implants triggered a biological response similar to other high surface-to-volume implants. There were no significant differences in the inflammation degree be...