CBQF - Documentos de Conferências / Conference Objects
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- Sequential injection system for multiparametric determination of copper (II), zinc and manganese in water samplesPublication . Ferreira, Francisca T. S. M.; Ribas, Tânia C. F.; Mesquita, Raquel B. R.; Rangel, António O. S. S.Heavy metals such as copper, zinc, and manganese are commonly found in both natural and treated water sources. Although these metals are essential micronutrients, their accumulation even at low concentrations, can lead to serious health issues. Therefore, continuous and accurate monitoring of these elements in environmental and drinking water is crucial to ensure public safety. Solid Phase Extraction (SPE) is a widely used sample preparation technique that relies on sorbent materials to separate and concentrate specific analytes from complex matrices. In heavy metal analysis SPE offers several advantages, such as enhanced sensitivity, selectivity, and compatibility with automated systems. Ion-exchange resins selectively bind to ions based on their charge and therefore are one the most effective sorbents for metal ion separation. While cation-exchange resins retain positively charged metal ions like Cu²?, Zn²?, and Mn²?, anion-exchange resins bind to negatively charged species. This selectivity allows for cleaner separation and more accurate quantification in multi-parametric analysis. The objective of this work is to develop an automated sequential injection analysis (SIA) system integrated with an in-line cation-exchange resin column (Toyopearl) for the simultaneous determination of copper (II), zinc, and manganese in water samples. This system uses a cationic resin coupled with a colorimetric reagent (Zincon) whose selectivity varies with pH, enabling separation of target metal ions and consequent individual quantification. This method presents a reliable and reagent-efficient alternative to conventional techniques, with strong potential for real-time or on-site monitoring applications.
- Exploiting stimuli-responsiveness to patient-personalized smart patches for the advanced treatment of hard-to-heal skin woundsPublication . Laurano, Rossella; Boffito, Monica; Ribeiro, Viviana P.; Oliveira, Ana Leite; Ciardelli, Gianluca
- Detergent-free supercritical CO2–assisted protocol for the production of sustainable and highly preserved decellularized porcine meniscus for orthopedic applicationsPublication . Ho, Chou I.; Rodrigues, Francisco A. P.; Reis, Mariana S.; Ribeiro, Viviana P.; Oliveira, Ana Leite; Costa, João B.
- Detergent-free supercritical CO2–assisted protocol for the production of sustainable and highly preserved decellularized porcine meniscus for orthopedic applicationsPublication . Ho, Chou I.; Rodrigues, Francisco A. P.; Reis, Mariana S.; Ribeiro, Viviana P.; Oliveira, Ana L.; Costa, João B.
- Biohybrid solutions for burn care: merging silk medical textiles with decellularized matricesPublication . Sousa, Teresa; Vale, Inês; Rosadas, Marta; Silva, Inês V.; Ribeiro, Viviana P.; Oliveira, Ana L.
- Biohybrid solutions for burn care: merging silk medical textiles with decellularized matricesPublication . Sousa, Teresa; Vale, Inês; Rosadas, Marta; Silva, Inês V.; Ribeiro, Viviana P.; Oliveira, Ana L.
- Supercritical CO2-assisted decellularization: advanced pancreatic tissue platform for diabetes treatmentPublication . Sá, Simone C.; Pazmino, Carlos; Sá, Joana; Amorim, Sara; Ribeiro, Viviana P.; Costa, Raquel; Oliveira, Ana L.Introduction: Decellularization is a procedure that aims to remove the cellular and antigenic material of a tissue while preserving its extracellular matrix (ECM) and biological properties. Decellularized ECM offers a natural microenvironment with significant potential for use in cell-based therapies and tissue regeneration [1]. Different protocols have been employed to decellularize tissues and organs. However, many rely on solvents and detergents that compromise the bioactive signals inherent to the native tissue [2]. Thus, it is crucial to establish a method that achieves effective decellularization while maintaining the ECM biochemical integrity. Objectives: In this study, we focus on the pancreatic tissue decellularization to create a native-like matrix suitable for the delivery of functional, insulin-producing β-cells as a therapeutic approach for diabetes treatment [3]. We propose a decellularization protocol based on Supercritical CO₂ (scCO₂) technology as an innovative alternative to solvent-based methods, offering high transfer rates, diffusivity, chemical inertness, and non-toxicity [4]. Conclusions: Both decellularization protocols efficiently removed DNA and SEM confirmed ECM ultrastructure maintenance in both groups. Biochemical analysis revealed that scCO₂ decellularization slightly improves GAG’s preservation, while insoluble collagen is protocol-independent and soluble collagen remains similar in both methods. Proteomic analysis showed that traditional treatment retained more proteoglycans and SLRPs, whereas scCO₂ better preserved some basal membrane and especially elastic fiber proteins. Biocompatibility assays demonstrated that both scaffolds supported cell adhesion, viability, and proliferation. In conclusion, both protocols generate biocompatible scaffolds, with distinct ECM preservation profiles relevant for recellularization, but scCO₂ stands out for being a green technology, with a shorter effective decellularization time and reduced waste.
- Is decellularized rabbit dermis a viable option for skin wound healing and regeneration?Publication . Rosadas, Marta; Sousa, Teresa; Sousa, Alda; Ribeiro, Viviana P.; Oliveira, Ana L.Burn wounds remain a major clinical challenge, requiring effective coverage to restore the skin barrier and support healing. Autologous grafts are the standard treatment but are limited in deep or extensive burns [1]. Decellularized allografts and xenografts offer alternatives by removing immunogenic material while preserving ECM components [2]. Considering that xenografts source availability is significantly higher and free of ethical concerns, this study describes for the first time a protocol for decellularizing rabbit dermis, leveraging a valuable agro-food by-product that exceeds 5000 skins/day at the world-leading company Cortadoria Nacional de Pêlo, and studies its potential for skin regeneration.
- Is decellularized rabbit dermis a viable option for skin wound healing and regeneration?Publication . Rosadas, Marta; Sousa, Teresa; Sousa, Alda; Ribeiro, Viviana P.; Oliveira, Ana L.Burn wounds remain a significant challenge in medical care, requiring effective wound coverage to restore the skin barrier and promote healing or support skin reconstruction. The use of autologous grafts as substitutes is still the standard treatment, however, it is not suitable for deep and extensive burns (1). Decellularized skin allografts and xenografts have emerged as suitable options, using decellularization to remove the immunogenic material present in the tissue while preserving the ECM components and interesting biomolecules (3). Considering that xenografts source availability is significantly higher and free of ethical concerns, this study describes for the first time a protocol for decellularizing rabbit dermis, leveraging a valuable agro-food by-product which exceeds 5000 skins/day at the world-leading company Cortadoria Nacional de Pêlo, and studies its potential for skin regeneration.
- Effect of digestion on solid lipid nanoparticles loaded with rosmarinic acidPublication . Campos, Débora; Madureira, Ana Raquel; Gomes, Ana Maria; Sarmento, Bruno; Pintado, ManuelaThe incorporation of bioactive nanoparticles in food matrices as a way to improve and diversify functional and nutritional properties has been the aim of several research efforts. Solid lipid nanoparticles (SLNs) loaded with rosmarinic acid (RA) were produced using as lipid matrices the waxes Witepsol H15 and Carnauba (Campos et al., 2013). Since these nanoparticles will be further incorporated in food matrices, the effect of digestion on the stability and bioactivity of such systems was studied. Hence, nanoparticles were subject to simulated digestion conditions. Stomach was simulated by adjusting the pH of each solution to 2.0 (HCl, 1 M), and adding pepsin (25 mg/mL) at a ratio of 0.05 mL/mL of sample. Samples were incubated and digested during 60 min, at 37 ˚C, with continuous homogenization (130 rpm). Duodenum conditions were simulated by increasing pH of the digested samples to 6.0 (NaHCO3, 1M) and adding simulated intestinal juice comprising pancreatin (2 g/L) and bile salts (12 g/L) to a rate of 0.25 mL/mL of sample. All samples were incubated during 2 h, at 37 ˚C with continuous homogenization (45 rpm). Evolution of the physical properties was followed by Dynamic Light Scattering (DLS); polyphenol release % was obtained by High Performance Liquid Chromatography (HPLC). A release of 50% of RA from the SLNs was observed when SLNs were subjected to the duodenum phase. Concentration of free RA decreased along digestion simulation. Particle size was maintained along the simulation of digestion, viz. witepsol SLNs with sizes of ca. 220 nm and carnauba wax SLNs with ca. 350 nm. The polydispersion indexes of the initial SLNs were indicative of monodispersed solutions (0.150), but after digestion these exhibited an increase (0.300). Zeta potential values, for both types of SLNs, demonstrated the maintenance of a good stability, with values of charges between -20 and -30 mV.