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- Current Strategies to Produce 3D Electrospun-Based Wound Dressings for Skin RegenerationPublication . Ferreira, Carolina A. M.; Lemos, Marco F. L.; Maurício, Ana Colette; Dias, Juliana R.Tissue engineering-based wound dressings are a promising treatment approach that mimics the native skin microenvironment to promote effective healing and tissue regeneration. In fact, those advanced wound dressings can be made by electrospinning which has revolutionized the field of wound healing by developing biostructures that closely mimic the skin’s extracellular matrix (ECM). To date, most electrospinning research has focused on composition and materials rather than exploring advanced deposition strategies. Conventional electrospinning using random, aligned fibers, co-electrospinning, core-shell approaches, or redesigned collectors has achieved significant results in wound healing, which are discussed in this article. However, these approaches lack the development of realistic 3D structures. To achieve that, advancing approaches through the combination of electrospinning with different techniques such as gas foaming, short nanofiber assembly, or 3D printing significantly enhance skin regeneration of deep wounds (full-thickness and chronic wounds) compared to 2D structures. This review highlights the latest developments, design principles, and recent breakthroughs in electrospinning structures for skin regeneration and provides a fresh perspective for upcoming research in the field of 3D electrospun-based structures.
- Magnesium oxide coatings on thermoplastic polyurethane as a key approach to prevent catheter-associated infectionsPublication . Padrão, Tatiana; Monteiro, Fernando J.; Sousa, Susana R.; Dias, Juliana R.Central venous catheters (CVCs) are essential healthcare tools, but their use is often complicated by bacterial colonization on the catheter surface, leading to serious infections and life-threatening bloodstream complications. Current strategies, often reliant on antibiotics or antiseptics, are increasingly ineffective due to the rise of antimicrobial resistance. This study aimed to develop a novel antibacterial coating for CVCs by incorporating magnesium oxide (MgO) nanoparticles onto a thermoplastic polyurethane (TPU) film surface containing barium sulfate (BaSO4). The antibacterial efficacy of these coatings was evaluated against Staphylococcus epidermidis, a major pathogen in catheter-associated infections. The results showed that MgO coatings significantly inhibited bacterial growth in a concentration-dependent manner, with 0.50 % and 1.0 % MgO concentrations achieving complete eradication of both planktonic and adherent bacteria. Importantly, the coatings exhibited excellent cytocompatibility with fibroblasts and showed no significant impact on hemolysis or blood clotting. The 0.50 % MgO coating was identified as the optimal formulation, offering the best balance of potent antibacterial activity, cytocompatibility and hemocompatibility. This approach preserves the valuable physical and chemical properties of the TPU material while providing effective antibacterial protection. The straightforward and cost-effective coating process holds significant promise for industrial scale production, paving the way for a new generation of safer and more effective CVCs.
- Expanding the Potential of Self-Assembled Silk Fibroin as Aerogel Particles for Tissue RegenerationPublication . Bernardes, Beatriz G.; Baptista-Silva, Sara; Illanes-Bordomás, Carlos; Magalhães, Rui; Dias, Juliana Rosa; Alves, Nuno M. F.; Costa, Raquel; García-González, Carlos A.; Oliveira, Ana LeiteA newly produced silk fibroin (SF) aerogel particulate system using a supercritical carbon dioxide (scCO2)-assisted drying technology is herein proposed for biomedical applications. Different concentrations of silk fibroin (3%, 5%, and 7% (w/v)) were explored to investigate the potential of this technology to produce size- and porosity-controlled particles. Laser diffraction, helium pycnometry, nitrogen adsorption–desorption analysis and Fourier Transform Infrared with Attenuated Total Reflectance (FTIR-ATR) spectroscopy were performed to characterize the physicochemical properties of the material. The enzymatic degradation profile of the SF aerogel particles was evaluated by immersion in protease XIV solution, and the biological properties by cell viability and cell proliferation assays. The obtained aerogel particles were mesoporous with high and concentration dependent specific surface area (203–326 m2/g). They displayed significant antioxidant activity and sustained degradation in the presence of protease XIV enzyme. The in vitro assessment using human dermal fibroblasts (HDF) confirm the particles’ biocompatibility, as well as the enhancement in cell viability and proliferation.
- Phase-specific force–time adaptations in basketball jump shots under environmental constraintsPublication . Amaro, Catarina M.; Mendes, Rui; Castro, Maria António; Rice, Hannah; Gomes, Beatriz B.This study examined whether task-related and environmental constraints influence the vertical ground reaction force (vGRF) waveform during the basketball jump shot, with a focus on phase-specific adaptations across shooting positions. Eighteen senior basketball players performed jump shots from three shooting positions (45° right, middle, 45° left) under three conditions: baseline, simulated defensive opposition, and simulated gym audience noise. vGRF signals were recorded using a force platform and time-normalized to 0–100% of the movement cycle. One-dimensional Statistical Parametric Mapping (SPM) was applied using a hierarchical region-of-interest (ROI) approach, focusing on the unweighting, braking, and propulsive phases. Group-level effects were tested using a two-way SPM{F} ANOVA (Constraint × Position). Exploratory intra-individual SPM{t} analyses were conducted to examine athlete-specific adaptations. No significant main effects of constraint or position, and no constraint × position interactions were observed at the group level in any ROI (α = 0.05). Exploratory intra-individual analyses revealed heterogeneous, athlete-specific adaptations to external constraints and shooting position, predominantly during the braking and propulsive phases, with substantial variability in the timing and presence of significant clusters across athletes. The results indicate that experienced basketball players preserve a stable force–time organization during the jump shot despite environmental and task-related constraints. While group-level mechanical patterns remain invariant, individual athletes may exhibit phase-specific adaptations that do not generalize across the population. These findings underscore the importance of hierarchical and individualized analytical approaches for understanding skilled performance and support the use of ROI-based SPM for the biomechanical analysis of complex movement tasks.
- EMG Activity of the Biceps and Triceps Brachii During Basketball Chest Pass and Reception: Group Differences Based on Age, Experience, and Limb DominancePublication . Amaro, Catarina M.; Castro, Maria António; Amaro, Ana M.Understanding muscle activation patterns during sport-specific skills is essential for optimizing performance and training strategies. In basketball, upper limb actions such as passing and receiving require precise coordination and effective neuromuscular control. The main goal of this study was to analyze and compare the muscle activity of the biceps brachii and triceps brachii during the execution and reception of the two-handed chest pass in basketball players with different levels of competitive experience. Surface electromyography (EMG) data were collected from 14 federated athletes, aged between 11 and 29 years, using the BioSignal Plux system. Participants were allocated into two groups according to their playing experience. Muscle activation was analysed in terms of activation time (AT) and percentage of muscle activation (%MA), normalised to maximum voluntary contraction (MVC). A linear mixed model was used to evaluate the effects of experience level, limb dominance, and their interaction while accounting for repeated measures within participants. No significant differences were observed between dominant and non-dominant limbs for any variable. Significant differences between experience/ age groups were identified mainly in the triceps brachii, particularly for activation time in the lateral head and %MA in the long head. In general, more experienced/aged athletes demonstrated higher levels of neuromuscular activation and shorter activation times, suggesting different motor control strategies. A significant positive association was found between years of practice and %MA of the long head of the triceps brachii. These findings provide novel insights into neuromuscular recruitment during both the execution and reception phases of the basketball chest pass and may inform training strategies aimed at enhancing technical efficiency across developmental stages.
- Experimentally driven atomistic model of 1,2 polybutadienePublication . Gkourmpis, Thomas; Mitchell, Geoffrey R.We present an efficient method of combining wide angle neutron scattering data with detailed atomistic models, allowing us to perform a quantitative and qualitative mapping of the organisation of the chain conformation in both glass and liquid phases. The structural refinement method presented in this work is based on the exploitation of the intrachain features of the diffraction pattern and its intimate linkage with atomistic models by the use of internal coordinates for bond lengths, valence angles, and torsion rotations. Atomic connectivity is defined through these coordinates that are in turn assigned by pre-defined probability distributions, thus allowing for the models in question to be built stochastically. Incremental variation of these coordinates allows for the construction of models that minimise the differences between the observed and calculated structure factors. We present a series of neutron scattering data of 1,2 polybutadiene at the region 120–400 K. Analysis of the experimental data yields bond lengths for CC and C C of 1.54 Å and 1.35 Å, respectively. Valence angles of the backbone were found to be at 112° and the torsion distributions are characterised by five rotational states, a three-fold trans-skew± for the backbone and gauche± for the vinyl group. Rotational states of the vinyl group were found to be equally populated, indicating a largely atactic chan. The two backbone torsion angles exhibit different behaviour with respect to temperature of their trans population, with one of them adopting an almost all trans sequence. Consequently, the resulting configuration leads to a rather persistent chain, something indicated by the value of the characteristic ratio extrapolated from the model. We compare our results with theoretical predictions, computer simulations, RIS models and previously reported experimental results.
- Influence of commensal bacteria on the proteolytic and antigenic profiles of INFOGEST-like digested wheat gliadinPublication . Pereira-Costa, Flávio; Domingues, Vanessa S.; Roque, Ana; Almeida, Zaida L.; Cruz, Pedro F.; Cordeiro, Rachel; Trindade, Daniela; Moura, Carla; Melo, Joana B.; Pereira, Sónia G.; Vaz, Daniela C.Introduction: Celiac disease (CeD) is a chronic autoimmune enteropathy developed by genetically predisposed individuals when exposed to gluten. Gluten gliadins, along with gut microbiota, may influence CeD onset and progression through mechanisms that remain unclear. Methods: Gliadin-degrading bacterial isolates obtained from CeD patients, and their 1st-degree relatives’ stool and blood were identified (Bacillus tropicus, Enterococcus faecalis, Micrococcus sp., Cronobacter sakazakii, Pseudomonas aeruginosa, and Serratia marcescens) and used in an INFOGEST-like protocol to simulate gliadin digestion after 4 h (digested gliadin, d-gliadin). The d-gliadin digesta were analyzed by fast protein liquid chromatography (FPLC), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), fluorescence spectroscopy, and polyclonal and monoclonal (R5 and G12) enzyme-linked immunosorbent assays (ELISA). Results and discussion: In the absence of the bacterial isolates, gliadin is poorly digested and self-assembles within 1 day into intermediate and large protein oligomers/aggregates, enriched in β-sheet structure (FTIR amide I band between 1,600 and 1,700 cm−1) and able to bind thioflavin T and Congo red. Conversely, in the presence of the bacterial isolates, gliadin is further digested, leading to an increase in protein fragments. After 4 h, the P. aeruginosa, C. sakazakii, and B. tropicus d-gliadin digesta presented a mixture of d-gliadin peptides and aggregates that showed higher antigenicity (associated with the exposure of the 5-amino acid QQPFP and 6-amino acid QPQLPY epitopes, present in the 25-mer and 33-mer, respectively) than control digestions (without bacteria), while E. faecalis led to lower antigenicity. In turn, within 24 h of incubation, all bacterial isolates led to the formation of undigested material with lower antigenicity, either due to fewer 33-mers and 25-mers in solution, or to fragment aggregation into amorphous material, not exposing antigenic sequences. Hence, intestinal flora may enhance or diminish the antigenicity of gliadin, thereby modulating the immunogenic response to gliadin/gluten.
- Fabrication and characterisation of PCL and PCL/PLA scaffolds for tissue engineeringPublication . Patrício, T.; Domingos, M.; Gloria, A.; D'Amora, U.; Coelho, J. F.; Bartolo, P.J.Purpose – The main purpose of this research work is to study the effect of poly lactic acid (PLA) addition into poly (e-caprolactone) (PCL) matrices, as well the influence of the mixing process on the morphological, thermal, chemical, mechanical and biological performance of the 3D constructs produced with a novel biomanufacturing device (BioCell Printing). Design/methodology/approach – Two mixing processes are used to prepare PCL/PLA blends, namely melt blending and solvent casting. PCL and PCL/PLA scaffolds are produced via BioCell Printing using a 300-mm nozzle, 0/908 lay down pattern and 350-mm pore size. Several techniques such as scanning electron microscopy (SEM), simultaneous thermal analyzer (STA), nuclear magnetic resonance (NMR), static compression analysis and Alamar BlueTM are used to evaluate scaffold’s morphological, thermal, chemical, mechanical and biological properties. Findings – Results show that the addition of PLA to PCL scaffolds strongly improves the biomechanical performance of the constructs. Additionally, polymer blends obtained by solvent casting present better mechanical and biological properties, compared to blends prepared by melt blending. Originality/value – This paper undertakes a detailed study on the effect of the mixing process on the biomechanical properties of PCL/PLA scaffolds. Results will enable to prepare customized PCL/PLA scaffolds for tissue engineering applications with improved biological and mechanical properties, compared to PCL scaffolds alone. Additionally, the accuracy and reproducibility of by the BioCell Printing enables to modulate the micro/macro architecture of the scaffolds enhancing tissue regeneration.
- MSCs Conditioned Media and Umbilical Cord Blood Plasma Metabolomics and CompositionPublication . Pereira, Tiago; Ivanova, Galya; Caseiro, Ana Rita; Barbosa, Paula; Bártolo, Paulo Jorge; Santos, José Domingos; Luís, Ana Lúcia; Maurício, Ana Colette; Ivanovic, ZoranHuman mesenchymal stem cells (hMSCs) from umbilical cord (UC) blood (UCB) and matrix are tested clinically for a variety of pathologies but in vitro expansion using culture media containing fetal bovine serum (FBS) is essential to achieve appropriate cell numbers for clinical use. Human UCB plasma (hUCBP) can be used as a supplement for hMSCs culture, since UCB is rich in soluble growth factors and due to worldwide increased number of cryopreserved UCB units in public and private banks, without the disadvantages listed for FBS. On the other hand, the culture media enriched in growth factors produced by these hMSCs in expansion (Conditioned medium - CM) can be an alternative to hMSCs application. The CM of the hMSCs from the UC might be a better therapeutic option compared to cell transplantation, as it can benefit from the local tissue response to the secreted molecules without the difficulties and complications associated to the engraftment of the allo- or xeno-transplanted cells. These facts drove us to know the detailed composition of the hUCBP and CM, by 1H-NMR and Multiplexing LASER Bead Technology. hUCBP is an adequate alternative for the FBS and the CM and hUCBP are important sources of growth factors, which can be used in MSCs-based therapies. Some of the major proliferative, chemotactic and immunomodulatory soluble factors (TGF-β, G-CSF, GM-CSF, MCP-1, IL-6, IL-8) were detected in high concentrations in CM and even higher in hUCBP. The results from 1H-NMR spectroscopic analysis of CM endorsed a better understanding of hMSCs metabolism during in vitro culture, and the relative composition of several metabolites present in CM and hUCBP was obtained. The data reinforces the potential use of hUCBP and CM in tissue regeneration and focus the possible use of hUCBP as a substitute for the FBS used in hMSCs in vitro culture.
- Semidirect Products and Split Short Five Lemma in Normal CategoriesPublication . Martins-Ferreira, Nelson; Montoli, Andrea; Sobral, ManuelaIn this paper we study a generalization of the notion of categorical semidirect product, as defined in [6], to a non-protomodular context of categories where internal actions are induced by points, like in any pointed variety. There we define semidirect products only for regular points, in the sense we explain below, provided the Split Short Five Lemma between such points holds, and we show that this is the case if the category is normal, as defined in [12]. Finally, we give an example of a category that is neither protomodular nor Mal’tsev where such generalized semidirect products exist.