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Projeto de investigação
Centre for Textile Science and Technology
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Publicações
Chitosan/nanocellulose electrospun fibers with enhanced antibacterial and antifungal activity for wound dressing applications
Publication . Ribeiro, Ana S.; Costa, Sofia M.; Ferreira, Diana P.; Calhelha, Ricardo C.; Barros, Lillian; Stojković, Dejan; Soković, Marina; Ferreira, Isabel C.F.R.; Fangueiro, Raul
The combination of biodegradable fibers at nanoscale with plant-based extracts is attracting increasing attention to produce wound dressing systems. In this work, nanofibers based on chitosan (CS), poly(ethylene oxide) (PEO), cellulose nanocrystals (CNC) and acacia plant-based extract were developed by electrospinning. Firstly, the polymeric formulations and electrospinning parameters were optimized, resulting in nanofibers with average diameters of 80 nm. CNC were successfully introduced into the optimized CS/PEO blend and the membranes were characterized by FESEM, ATR-FTIR, TGA, XRD, WVTR and WCA. The CNC incorporation improved the nanofibers' physical integrity, morphology, diameters, water vapor transmission rate and thermal properties. After acacia introduction into the best CS/PEO/CNC system, the antibacterial effect was relatively maintained while the antifungal activity was enhanced for some fungi, demonstrating its great effect against a wide range of microorganisms, which is crucial to prevent or treat infections. All the developed systems exhibited absence of cytotoxicity in non-tumor cells, suggesting their biocompatibility. Finally, a continuous release of the acacia extract was observed for 24 h, showing its prolonged action, which contributes to the healing process while reduces the frequency of dressing's replacement. Overall, the developed nanofibers are very promising to act as localized drug delivery systems for wound care applications.
Electrospun Fibrous Architectures for Localized Delivery of Photosensitizers in Cancer Therapy
Publication . Gomes, Cátia V.; Costa, Sofia M.; Oliveira, João S.; Calhelha, Ricardo C.; Lourenço, Leandro M. O.; Fangueiro, Raul; Ferreira, Diana P.
Photodynamic therapy (PDT) is a promising localized strategy for the treatment of cervical cancer, ranking as the fourth most common cancer among women worldwide. The integration of photosensitizers (PSs) in localized drug delivery systems (DDSs), particularly in electrospun nanofibers, holds tremendous potential to overcome the drawbacks of their systemic administration. Exploring multilayer fibrous architectures provides a versatile therapeutic platform to design the next generation of localized DDS. In this work, localized implants for cancer treatment using PDT were developed using polyhydroxyalkanoate (PHA), chitosan (CS) and polyethylene oxide (PEO) as biopolymers and a porphyrin (Por) as PS, following two approaches: blended PHA/Por electrospun microfibers and multilayered membranes (PHA–Por/CS/PEO) produced by sequential electrospinning. The synthesized Por displayed higher cytotoxicity in light compared to dark against tumor cells. All the developed membranes were characterized regarding their morphology, wettability, absorption and fluorescence properties. PHA–Por membranes exhibited overall uniform fibrous morphologies with successful Por incorporation. Nonetheless, they presented a highly hydrophobic surface, compromising the Por release and cell–material interactions. In contrast, multilayer PHA–Por/CS/PEO membranes demonstrated enhanced hydrophilicity and enabled sustained Por release. Upon light irradiation, these membranes induced a significantly greater inhibition of HeLa cell proliferation (29.61%) compared to dark conditions (6.21%), confirming their photodynamic activity.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UID/CTM/00264/2019