Percorrer por autor "Biscaia, S."
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- Adhesion, proliferation and distribution of human mesenchymal stem/stromal cells (MSCs) in Poly(ɛ -caprolactone) (PCL) scaffolds with different pore sizesPublication . Moura, C. S.; Biscaia, S.; Viana, T.; Bártolo, P. J.; Silva, C. L. da; Cabral, J. S.; Ferreira, F. C.Tissue engineering, combining the use of biomaterials, mesenchymal stem/stromal cells (MSCs) and optimized culture medium formulations, is a very promising research field for tissue regeneration. This work is focused on the application of Poly(ε-caprolactone) scaffolds designed to have a spacing gradient between orthogonal fibres with diameters of 0.3mm with pore sizes ranging from 190 to 390 μm. Human bone marrow (BM)-derived MSCs, were used to evaluate cell adhesion, proliferation and distribution within the scaffolds. Specifically, we hypothesized if seeding MSC in scaffold regions with different pore sizes would influence cell proliferation. Therefore, MSC were seeded at the centre of scaffolds with either larger (390 μm) or smaller pores (190 μm). Results obtained showed similar levels of adhesion and proliferation in both configurations, with fold increase in total cell number of 5 after 13 days of cultivation; which indicates that no limitation for cell proliferation within the range of pore sizes studied is observed.
- Cork Plastic Composite Optimization for 3D Printing ApplicationsPublication . Brites, F.; Malça, C.; Gaspar, F.; Horta, J. F.; Franco, M. C.; Biscaia, S.; Mateus, A.Among natural fillers, cork has been acknowledged as a suitable alternative of other cellular materials that are widely employed in engineering applications due to their low conductivity to heat, noise and vibration, high abrasion resistance and flexibility, high compressibility ratio, among other characteristics [1]. The eco-friendly features of natural fillers based composites make them a very promising and sustainable solution to large markets mainly if additive manufacturing technologies, such as 3D printing, are used [2]. Through 3D printers, engineers, designers and architects can create design and decor products with a free complexity of geometry. In this research work, plastic matrices of HDPE – obtained from conventional suppliers – were reinforced with different ratios of cork waste and natural cork powders – obtained from cork transformation industries – to find the optimum mixture for 3D printing. The effects of cork powders content in the plastic on the morphological, physical and mechanical properties of the composites were investigated through the density, optical microscopy, wettability, thermal analysis and tensile testing. Cork-based composites were processed by an extrusion system, and the mixture of polymer, adhesive and fillers is discussed. The results show that the addition of pure cork and cork waste can be processed with polymers such as HDPE, having adequate physical and mechanical properties.
- Development of Heterogeneous Structures with Polycaprolactone-Alginate Using a New 3D Printing System – BioMED βeta : Design and ProcessingPublication . Biscaia, S.; Dabrowska, E; Tojeira, A.; Horta, J.; Carreira, P; Morouço. P; Mateus, A.; Alves, N.Direct Digital Manufacturing of implantable biomedical devices is the strategy for designing and constructing three dimensional (3D) structures. DDM (i.e., biomanufacturing) technologies have been widely used to construct complex 3D structures (scaffolds), where chemicals, biomaterials, and cells are deposited in a layer-by-layer fashion. These technologies control size, microarchitecture and pores interconnectivity in scaffolds, essential to transporting oxygen and nutrients for cell survival. As the Tissue engineering field progresses, new types of printers have been designed to accomplish functional engineered tissue constructs. However, the availability of innovative 3D biomanufacturing technologies for hard tissue and organ engineering is scarce and with several equipment limitations. In this work, a new biomanufacturing system, BioMEDBeta, composed of three different fabrication modules (thermoplastic micro-extrusion, multi-head deposition of hydrogels and electrospinning) was used to fabricate (3D) scaffolds using layer-by-layer alternated deposition of polycaprolactone and alginate hydrogel. The BioMEDBeta system demonstrates the possibility of obtaining scaffolds with well-defined architecture, using both natural and synthetic polymers. Nevertheless, there are still parameters to optimize related with the design of 3D constructs and materials processing.
- Fabrication of Poly(Glycerol Sebacate)-Poly(ε-Caprolactone) Extrusion-Based Scaffolds for Cartilage RegenerationPublication . Reis, D.; Biscaia, S.; Seabra, I. J.; Veloso, A.; Morouço, P.Cartilage related diseases are on the top list concerns of the World Health Organization, being the prevention of articular cartilage degeneration a major health matter for which there are few effective solutions. Using an extrusion-based approach and a polyester elastomer it was aimed to produce 3D structures with controlled architecture and with closer mimicry to cartilage native tissue. The obtained constructs demonstrated high reliability, being the addition of poly (glycerol sebacate) a procedure to enhance the properties of the constructs.
- A Novel Biomanufacturing System to Produce Multi-Material Scaffolds for Tissue Engineering: Concept and Preliminary ResultsPublication . Viana, T.; Biscaia, S.; Dabrowska, E.; Franco, M.; Carreira, P.; Morouço, P.; Alves, N.This research work aims to validate a new system that enables the fabrication of multimaterial 3D structures using poly(e-caprolactone) and sodium alginate for potential use in Tissue Engineering applications. To produce multi-material scaffolds for Tissue Engineering, accurate techniques are needed to obtain three-dimensional constructs with clinically appropriate size and structural integrity. This paper presents a novel biomanufacturing system which can fabricate 3D scaffolds with precise shape and porosity, through the control of all fabrication modules by an integrated computational platform. The incorporation of a clean flow unit and a camera makes it possible to produce scaffolds in a clean environment and provides a monitoring tool to analyse constructs during the production, respectively.
- Structure development during additive manufacturingPublication . Tojeira, A.; Biscaia, S.; Viana, T.; Bártolo, P. J.; Mitchell, G. R.Additive manufacturing involves the shaping of a product through the use of a liquid phase which is subsequently transformed to the solid state by cooling or through the use of chemical cross-linking reactions. Of particular note is the fused deposition modeling which utilizes semi-crystalline polymers such as poly(ε-caprolactone) or poly(lactic acid) and has been employed in CDRsp to prepare highly porous scaffolds for Tissue Engineering. We show that the crystallization process amplifies small levels of molecular anisotropy introduced in the additive writing process. We show that the level of anisotropy is significantly dependent on the process parameters such as temperature, write speed, and flow rate. The differences in the crystalline morphology introduced by changing these process parameters will have a marked impact on the mechanical properties. This in turn will alter the growth of tissue on such scaffold structures. As with other polymer processing procedures, tuning the process parameters provides a route to controlling and defining the structure and morphology of the scaffold and the properties exhibited by that scaffold.
- The Use of Polypropylene and High-Density Polyethylene on Cork Plastic Composites for Large Scale 3D PrintingPublication . Brites, Fernando; Malça, Cândida; Gaspar, F.; Horta, J. F.; Franco, M. C.; Biscaia, S.; Mateus, A.This work focuses on studying the possibility of 3D printing of composite materials composed by cork and a polymer matrix (CPC). Initially the cork was mixed with two types of polymers (HDPE and PP) in different proportions and later processed using extrusion and injection. The composites were tested to study the physical, chemical and mechanical properties. The material was then tested on a large-scale 3D printer to study its feasibility and the ability to produce new products through 3D printing. Attention was focused on the use of pure cork, varying the concentration of cork and coupling agent in thermoplastic matrix composites of PP and HDPE. It was demonstrated that the increase of 5wt.% of coupling agent in the two types of polymers significantly improved the mechanical properties and adhesion between the phases but the increase in cork concentration decreased mechanical properties and crystallinity. The CPCs with PP showed to have better mechanical properties, better aesthetic and internal structural quality, and easier processability than those with HDPE matrix. Nevertheless, the HDPE CPCs showed a high degree of crystallization. Concerning 3D printing, it was demonstrated the possibility of making new products based on natural cork fibers, showing promising results, although additional research is still needed to optimize the process.
- Traffic Vertical Signposting: Materials Characterization and Structural Numerical SimulationPublication . Franco, M.; Fonseca, R.; Gomes, S.; Biscaia, S.; Brites, F.; Pascoal-Faria, P.; Mateus, A.The existing metallic solutions used for vertical traffic signs are associated with higher costs and environmental issues due to their manufacturing and degradation, when compared with polymeric solutions. Thus, the development of vertical signs considering the injection from polymeric materials in order to overcome problems related with sustainability, maintenance costs, and to achieve higher resistance to corrosion assumes nowadays an important role. The use of ecofriendly and innovative products considering the industrial waste combined with synthetic polymers performing the appropriate mechanical properties, can also be studied to find out new solutions that allow to solve the aforementioned problems. Additionally, these innovative vertical signs can contribute to avoid vandalism events related with theft and graffiti activities. This work presents the prior materials investigation and the structural design of vertical signs that are intended to be produced through polymer injection. Three main steps were considered: i) materials research, ii) materials characterisation through the analysis of polycarbonate resin isolated and in different sets of mixtures with different concentrations through tensile testing and static water contact angle measurements to find the optimal material composition; and iii) structural numerical simulation considering polycarbonate resin and using the current standard EN 12899-1 [1] to compute wind resistance, temporary and permanent deflections. Both experimental and numerical results led to an optimized proposal of the vertical signposting structural design.