RESUMEN
Tissue engineering scaffolds require complex networks for nutrient diffusion and cell attachment. They must have specific surface area and curvature, and often need a multimaterial composition, demanding advanced micro-fabrication methods. 3D extrusion bioprinting offers versatility to manufacture different scaffold, and strategies for multimaterial printing have been introduced. We propose a method to fabricate scaffolds based on gyroid-helical-patterned microfibers, providing a platform to study the effect of the gyroid minimum curvature on cellular processes, since the geometry wont be layer-by-layer approximated. The pattern is obtained by mixing inks using a gyroid-helix shaped rotational mixer, modifying the extruder of a conventional 3D printer. The mixer was simulated using computational fluid dynamics tools, varying the volumetric flow to obtain different gyroid-thickness. Due to its surface area minimization, it shows lower energy requirements than state-of-art fluid mixers, with a pressure drop of 1.7%, a power number of 39, and a rotation-induced shear stress of â¼400 Pa, enabling the use of cell-embedded bioinks.
Asunto(s)
Bioimpresión , Ingeniería de Tejidos , Ingeniería de Tejidos/métodos , Bioimpresión/métodos , Impresión Tridimensional , Andamios del Tejido/química , Estrés MecánicoRESUMEN
The relevance of affective information triggers cognitive prioritisation, dictated by both the attentional load of the relevant task, and socio-emotional abilities. This dataset provides electroencephalographic (EEG) signals related to implicit emotional speech perception under low, intermediate, and high attentional demands. Demographic and behavioural data are also provided. Specific social-emotional reciprocity and verbal communication characterise Autism Spectrum Disorder (ASD) and may influence the processing of affective prosodies. Therefore, 62 children and their parents or legal guardians participated in data collection, including 31 children with high autistic traits (xÌage=9.6-year-old, σage=1.5) who previously received a diagnosis of ASD by a medical specialist, and 31 typically developed children (xÌage=10.2-year-old, σage=1.2). Assessments of the scope of autistic behaviours using the Autism Spectrum Rating Scales (ASRS, parent report) are provided for every child. During the experiment, children listened to task-irrelevant affective prosodies (anger, disgust, fear, happiness, neutral and sadness) while answering three visual tasks: neutral image viewing (low attentional load), one-target 4-disc Multiple Object Tracking (MOT; intermediate), one-target 8-disc MOT (high). The EEG data recorded during all three tasks and the tracking capacity (behavioural data) from MOT conditions are included in the dataset. Particularly, the tracking capacity was computed as a standardised index of attentional abilities during MOT, corrected for guessing. Beforehand, children answered the Edinburgh Handedness Inventory, and resting-state EEG activity of children was recorded for 2 minutes with eyes open. Those data are also provided. The present dataset can be used to investigate the electrophysiological correlates of implicit emotion and speech perceptions and their interaction with attentional load and autistic traits. Besides, resting-state EEG data may be used to characterise inter-individual heterogeneity at rest and, in turn, associate it with attentional capacities during MOT and with autistic behavioural patterns. Finally, tracking capacity may be useful to explore dynamic and selective attentional mechanisms under emotional constraints.
RESUMEN
Porous scaffolds have been widely explored for tissue regeneration and engineering in vitro three-dimensional models. In this review, a comprehensive literature analysis is conducted to identify the steps involved in their generation. The advantages and disadvantages of the available techniques are discussed, highlighting the importance of considering pore geometrical parameters such as curvature and size, and summarizing the requirements to generate the porous scaffold according to the desired application. This paper considers the available design tools, mathematical models, materials, fabrication techniques, cell seeding methodologies, assessment methods, and the status of pore scaffolds in clinical applications. This review compiles the relevant research in the field in the past years. The trends, challenges, and future research directions are discussed in the search for the generation of a porous scaffold with improved mechanical and biological properties that can be reproducible, viable for long-term studies, and closer to being used in the clinical field.
Asunto(s)
Ingeniería de Tejidos , Andamios del Tejido , Ingeniería de Tejidos/métodos , PorosidadRESUMEN
Recently, the interest in porous scaffolds design for cell culture has increased. Because of the curvotaxis property of the cells, they can respond to the curvature of the substrate in which they are seeded, like changing their morphology, despite that, curvature is little explored within scaffold design. What is more, for bone regeneration, the scaffold should ideally have a porosity gradient corresponding to the transition between compact and cancellous bone. Various studies have focused on finding the best geometry to mimic it, being the triple periodic minimum structures (TPMS) the most promising ones. However, as they are mathematically complex, researchers have approximated them with implicit equations, no longer respecting their minimum curvature when they vary the pore size, deforming the original geometry. This work proposed to approach the TPMS with parametric equations, finding an exact fundamental patch. In this way showing its potential to make customized structures with a porous gradient, thanks to the acquisition of a constant of variation. This generates a friendly user interface for the design of scaffolds. The work also presents a comparison with the implicit structures, remarking the benefits of using the parametric approach. Finally, it presents examples of 3D printed designs.