Percorrer por autor "Negut, Irina"
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- AgNP-Polyphenol synergy on cotton fabrics: antimicrobial and free-radical-scavenging activity for dermal applicationsPublication . Fernandes, Andreia; Negut, Irina; Melo, Adma; Pintado, Manuela; Tavaria, Freni K.; Oliveira, Cláudia S.The development of antimicrobial textiles has gained increasing attention due to rising concerns regarding infection control and material safety, Conventional antimicrobial textiles often depend on synthetic agents or metal-based compounds, which may promote environmental and biocompatibility concerns. Hybrid strategies combining nanotechnology with bioactive compounds (BCs) derived from agri-food by-products have emerged as promising alternatives. In this study, silver nanoparticles (AgNPs) were first applied to cotton fabrics to create a stable antimicrobial platform. The combination of AgNPs and BCs is expected to yield synergistic bioactivity, promoting both microbial inhibition and oxidative stress modulation [1]. This study evaluated the biological performance of extracts from acorn shell (AS) functionalized with AgNPs-cotton, focusing on antimicrobial efficacy against pathogenic microorganisms (S. aureus, E. coli, C. albicans, C. tropicalis), and antioxidant activity (ABTS and DPPH radical scavenging assays). The biocompatibility with human skin cells will be further assessed through in vitro assays using HaCaT keratinocytes, aiming to evaluate potential cytotoxic effects and ensure the safety of the fabrics. Antimicrobial activity was evaluated through CFU counts, expressed as log?? reductions. Fabrics functionalized with extracts showed a greater reduction (p? 0.001) in microbial load, particularly against Candida albicans and Candida tropicalis, when compared to AgNP-only treated samples. The functionalized fabrics showed significant radical scavenging activity in both assays. In the ABTS and DPPH assay, samples treated with AS extracts exhibited higher activity compared to AgNP-only treated fabrics with inhibition values of 36 (±4.4)% and 43 (±4.1)%, respectively. In contrast, AgNPs alone showed no measurable antioxidant activity. These compounds likely act synergistically with AgNPs, contributing not only to oxidative stability but also enhancing antimicrobial performance. Interestingly, fabrics with AgNPs alone exhibited minimal antioxidant activity and may have induced pro-oxidant effects, consistent with the known ROSgenerating mechanisms. The upcoming biocompatibility will provide further insights into their safety for skin-contact use.
- Bioactivities of cotton fabrics with silver nanoparticles and acorn shell extracts: antimicrobial and antioxidant Potential for dermal applicationsPublication . Fernandes, Andreia; Negut, Irina; Melo, Adma Nadja Ferreira de; Pintado, Manuela E.; Kekhasharú Tavaria, Freni; Oliveira, Cláudia
- From 1D microbiological assays to 3D advanced skin models: enhancing preclinical strategies to unravel the impact of bioactive textiles on the human skin microbiomePublication . Negut, Irina; Mazzanti, Camilla; Laurano, Rossella; Ciardelli, Gianluca; Bronco, Simona; Oliveira, Cláudia S.Bioactive textiles have emerged as multifunctional materials to actively interact with the human skin and its microbiome. By embedding natural or synthetic bioactive compounds, such as chitosan, essential oils, plant extracts, and metallic nanoparticles, these materials aim to prevent and target infections, modulate inflammation, and promote skin homeostasis. Given the critical role of the skin microbiome in maintaining barrier integrity and immune balance, strategies that selectively inhibit pathogenic microorganisms (e.g., Staphylococcus aureus, Cutibacterium acnes) while preserving beneficial commensals like Staphylococcus epidermidis are essential to avoid dysbiosis and associated dermatological disorders. This review highlights current trends in the design and functionalization of bioactive textiles, emphasizing sustainable and biocompatible approaches that leverage natural antimicrobial compounds and green synthesis techniques. It also examines conventional evaluation pipelines primarily based on 1D microbiological assays and 2D skin models, highlighting their limitations in predicting real-world performance. Advanced in vitro models, particularly 3D reconstructed human skin platforms incorporating both pathogenic and commensal microbiota members, are presented as indispensable tools to study fabric–skin–microbe interactions under physiologically relevant conditions. These models enable accurate assessment of antimicrobial efficacy, biocompatibility, and microbiome impact, providing a bridge between in vitro and clinical outcomes. Furthermore, the potential of bioactive textiles in managing microbiome-related skin conditions, such as atopic dermatitis and acne, is discussed alongside the importance of developing microbiome-safe materials. Despite encouraging clinical evidence demonstrating pathogen reduction and symptomatic improvement, the successful translation of these materials to clinical practice needs interdisciplinary research and the adoption of advanced preclinical strategies to ensure innovative solutions for personalized skin health.
- The use of calcium phosphate bioceramics for the treatment of osteomyelitisPublication . Oliveira, Cláudia Suellen Ferro; Negut, Irina; Bita, BogdanBone infections, particularly osteomyelitis, present significant clinical challenges due to their resistance to treatment and risk of progressing to chronic disease. Conventional therapies, including systemic antibiotics and surgical debridement, often prove insufficient, especially in cases where biofilms form or infection sites are difficult to access. As an alternative, calcium phosphate bioceramics have emerged as a promising strategy for treating bone infections. These materials offer key advantages such as biocompatibility, osteoconductivity, and the ability to be engineered for controlled drug delivery. Calcium phosphate bioceramics can serve as scaffolds for bone regeneration while simultaneously delivering antibiotics locally, thus addressing the limitations of systemic therapies and reducing infection recurrence. This review provides an overview of osteomyelitis, including its pathogenesis and conventional treatment approaches, while exploring the diverse therapeutic possibilities presented by calcium phosphate bioceramics. Special attention is given to hydroxyapatite, tricalcium phosphate, and their composites, with a focus on their therapeutic potential in the treatment of bone infections. The discussion highlights their mechanisms of action, integration with antimicrobial agents, and clinical efficacy. The dual capacity of calcium phosphate bioceramics to promote both bone healing and infection management is critically evaluated, highlighting opportunities for future research to address current challenges and enhance their clinical application in orthopedics and dentistry. Future research directions should focus on developing calcium phosphate bioceramic composites with enhanced antibacterial properties, optimizing drug-loading capacities, and advancing minimally invasive delivery methods to improve clinical outcomes. Further in vivo studies are essential to validate the long-term efficacy and safety of calcium phosphate bioceramic applications, with an emphasis on patient-specific formulations and rapid prototyping technologies that can personalize treatment for diverse osteomyelitis cases.