CDRsp - Comunicações em conferências internacionais
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Percorrer CDRsp - Comunicações em conferências internacionais por Domínios Científicos e Tecnológicos (FOS) "Ciências Médicas::Biotecnologia Médica"
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- Alginate/Aloe Vera Hydrogel Films for Biomedical ApplicationsPublication . Pereira, Rúben F.; Mendes, Ausenda; Bártolo, PauloThis paper describes a methodology to produce hydrogel films, composed of alginate and Aloe vera, for wound healing and drug delivery applications. The films were prepared through the solvent-casting method and subsequently submitted to an additional cross-linking step to improve their properties. Alginate films with different Aloe vera contents (5, 15 and 25%) were prepared and its properties evaluated in terms of thickness, transparency, swelling behavior and in vitro degradation. Results show a positive influence of Aloe vera on the transparency of the films, in both dry and wet state. Films were immersed in acetate buffer at pH 5.5 simulating the value of the skin, to evaluate its water absorption capacity. It was found that water absorption increases as the Aloe vera content increases, suggesting that Aloe vera enhances the hydrophilic properties of the films. The in vitro degradation tests were performed through the incubation of the films, for 10 weeks, in a simulated body fluid at 37°C. After this period, films kept its structure integrity exhibiting a weight loss in the range of 14.1-18.6%.
- Characterisation of PCL and PCL/PLA Scaffolds for Tissue EngineeringPublication . Patrício, T.; Domingos, M.; A. Gloria; Bártolo, P.This paper investigates the use of PCL and PCL/PLA scaffolds produced using a novel additive biomanufacturing system called BioCell Printing. PCL/PLA blends were prepared using melt blend and solvent casting techniques. Scaffolds with 0/90° architecture and 350 μm of pore size were morphologically evaluated using scanning electron microscopy and atomic force microscopy. Biological tests, using osteosarcoma cell line G-63, were performed using the Alamar Blue Assay and Alkaline Phosphatase Activity. Results show that the BioCell Printing system produces scaffolds with regular and reproducible architecture, presenting no toxicity and enhancing cell attachment and proliferation. It was also possible to observe that the addition of PLA to PCL scaffolds strongly improves the biomechanical performance of the constructs.
- Influence of Hydroxyapatite on Extruded 3D ScaffoldsPublication . Rodriguez, Geraldine; Dias, Juliana; d’Ávila, Marcos Akira; Bártolo, PauloIdeal scaffolds for tissue engineering must mimic the complex characteristics of natural tissues and their mechanical performance. In this work, Polycaprolactone (PCL) and composite Polycaprolactone/Hydroxyapatite (PCL/HA) (75/25) scaffolds were produced by using an extrusion-based process called BioExtruder. The structures were characterized regarding the chemical, thermal, morphological and mechanical properties, in order to investigate the effect of HA addition in the polymeric scaffolds. Results show that the incorporation of HA in the 3D structures improve both the thermal and mechanical properties.
- Levodopa Incorporation in Alginate Membranes for Drug Delivery StudiesPublication . Franco, Margarida Rosa; Viana, Tânia Filipa; Biscaia, Sara; Bártolo, PauloParkinsons Disease (PD) is the second most common progressive neurodegenerative disorder and is referred as a leading cause of neurologic disability. The symptoms and signs of PD result from a decrease of dopamines level in the basal ganglia. Accordingly to this, exogenous substitution with dopamine agonists like levodopa, is used to correct the mechanical disorders at the early stages of the disease. Levodopa is referred as a standard in the treatment of PD. The modern studies of PD drug development and experimental therapeutics focuses on the concept of slowing and targeting the release of levodopa to prolong the therapeutic effect and reduce the number of administrations. The transdermal route was thought to be the best route for providing a progressive supply of levodopa to the systemic circulation. Alginate was chosen as a drug carrier because of its biocompatible and biodegradable properties and also because it has been widely used in drug delivery systems (DDS). The aim of this research work was to produce alginate membranes with and without levodopa. A solvent casting based methodology was used. Calcium chloride was assayed as crosslinking agent. Membranes were characterized using Differential Scanning Calorimetry (DSC) techniques. Drug release was evaluated using UV Spectrophotometry.