Browsing by Author "Fernandes, Maria H."
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- 3D-printed platform multi-loaded with bioactive, magnetic nanoparticles and an antibiotic for re-growing bone tissuePublication . Saraiva, Ana S.; Ribeiro, Isabel A. C.; Fernandes, Maria H.; Cerdeira, Ana Cláudia; Vieira, Bruno J.C.; Waerenborgh, João Carlos; Pereira, Laura C.J.; Cláudio, Ricardo; Carmezim, Maria João; Gomes, Pedro; Gonçalves, Lídia; Santos, Catarina F.; Bettencourt, AnaPolymeric platforms obtained by three-dimensional (3D) printing are becoming increasingly important as multifunctional therapeutic systems for bone treatment applications. In particularly, researchers aim to control bacterial biofilm on these 3D-platforms and enhance re-growing bone tissue, at the same time. This study aimed to fabricate a 3D-printed polylactic acid platform loaded with hydroxyapatite (HA), iron oxide nanoparticles (IONPs) and an antibiotic (minocycline) with tuneable properties and multistimuli response. IONPs were produced by a facile chemical co-precipitation method showing an average diameter between 11 and 15 nm and a superparamagnetic behaviour which was preserved when loaded into the 3D-platforms. The presence of two types of nanoparticles (IONPs and HA) modify the nanomorphological/nanotopographical feature of the 3D-platforms justifying their adequate bioactivity profile and in vitro cellular effects on immortalized and primary osteoblasts, including cytocompatibility and increased osteogenesis-related gene expression (RUNX2, BGLAP and SPP1). Disk diffusion assays and SEM analysis confirmed the effect of the 3D-platforms loaded with minocycline against Staphylococcus aureus. Altogether results showed that fabricated 3D-platforms combined the exact therapeutic antibiofilm dose of the antibiotic against S. aureus, with the enhanced osteogenic stimulation of the HA and IONPs nanoparticles which is a disruptive approach for bone targeting applications.
- Bonding antimicrobial rhamnolipids onto medical grade PDMS: A strategy to overcome multispecies vascular catheter-related infectionsPublication . Dardouri, Maïssa; Aljnadi, Israa M.; Deuermeier, Jonas; Santos, Catarina; Costa, Fabiola; Martin, Victor; Fernandes, Maria H.; Gonçalves, Lídia; Bettencourt, Ana; Gomes, Pedro Sousa; Ribeiro, Isabel A. C.In clinic there is a demand to solve the drawback of medical devices multispecies related infections. Consequently, different biomaterial surfaces, such as vascular catheters, urgently need improvement regarding their antifouling/antimicrobial properties. In this work, we covalently functionalized medical grade polydimethylsiloxane (PDMS) with antimicrobial rhamnolipids to investigate the biomaterial surface activity towards mono and dual species biofilms. Preparation of surfaces with “piranha” oxidation, followed by APTES bonding and carbodiimide reaction with rhamnolipids effectively bonded these compounds to PDMS surface as confirmed by FTIR-ATR and XPS analysis. Generated surfaces were active towards S. aureus biofilm formation showing a 4.2 log reduction while with S. epidermidis and C. albicans biofilms a reduction of 1.2 and 1.0 log reduction, respectively, was observed. Regarding dual-species testing the higher biofilm log reduction observed was 1.9. Additionally, biocompatibility was assessed by cytocompatibility towards human fibroblastic cells, low platelet activation and absence of vascular irritation. Our work not only sheds light on using covalently bonded rhamnolipids towards dual species biofilms but also highlights the biocompatibility of the obtained PDMS surfaces.
- Effect of high hydrostatic pressure challenge on biogenic amines, microbiota, and sensory profile in traditional poultry- and pork-based semidried fermented sausagePublication . Borges, Ana F.; Cozar, Almudena; Patarata, Luis; Gama, Luis; Alfaia, Cristina; Fernandes, Maria J.; Fernandes, Maria H.; Perez Vergara, Herminia; Fraqueza, M. J.The processing of traditional poultry- and pork-based semidried fermented smoked sausages needs to bemodernized to improve product quality and further extend its shelf life. The aim of the present study was to applydifferent combinations of high pressure (300 to 600 MPa) and time (154 to 1,800 s) on the sausages using an experimentaldesign based on response surface methodology. The chemical, microbial, and sensory characteristics of sausages treatedwith high-pressure processing (HPP) were investigated. HPP application to semidried fermented sausages resulted incolor changes, which could be dependent on the ingredients, formulation, and smoking conditions used. Nevertheless,none of the HPP treatments applied resulted in detectable changes in sensory properties, as tested in a triangle test andconfirmed by the analysis of focus groups assessment. Significant differences were detected for lactic acid bacteria (LAB)counts from 344 MPa and 1,530 s onward, with a marked decrease for the combination of 600 MPa and 960 s (P<0.05).Coagulase-negativestaphylococcishowed higher tolerance to the increase in pressure than LAB. HPP induced a microbialreduction onEnterobacteriaceae, molds, and yeasts, minimizing the production of the main biogenic amines. However,the polyamines (spermine and spermidine) increased since their metabolic use by microorganisms did not occur. Giventhe reduction of the main spoilage microbial indicators with no detectable sensory changes observed with the binomialcondition of 600 MPa and 960 s, this was chosen as the optimal combination to be further applied.
- Engineering a multifunctional 3D-printed PLA-collagen-minocycline-nanoHydroxyapatite scaffold with combined antimicrobial and osteogenic effects for bone regenerationPublication . Martin, Victor; Ribeiro, Isabel A. C.; Alves, Marta M.; Gonçalves, Lídia; Claudio, Ricardo A.; Grenho, Liliana; Fernandes, Maria H.; Gomes, Pedro; Santos, Catarina F.; Bettencourt, Ana3D-printing and additive manufacturing can be powerful techniques to design customized structures and produce synthetic bone grafts with multifunctional effects suitable for bone repair. In our work we aimed the development of novel multifunctionalized 3D printed poly(lactic acid) (PLA) scaffolds with bioinspired surface coatings able to reduce bacterial biofilm formation while favoring human bone marrow-derived mesenchymal stem cells (hMSCs) activity. For that purpose, 3D printing was used to prepare PLA scaffolds that were further multifunctionalized with collagen (Col), minocycline (MH) and bioinspired citrate- hydroxyapatite nanoparticles (cHA). PLA-Col-MH-cHA scaffolds provide a closer structural support approximation to native bone architecture with uniform macroporous, adequate wettability and an excellent compressive strength. The addition of MH resulted in an adequate antibiotic release profile that by being compatible with local drug delivery therapy was translated into antibacterial activities against Staphylococcus aureus, a main pathogen associated to bone-related infections. Subsequently, the hMSCs response to these scaffolds revealed that the incorporation of cHA significantly stimulated the adhesion, proliferation and osteogenesis-related gene expression (RUNX2, OCN and OPN) of hMSCs. Furthermore, the association of a bioinspired material (cHA) with the antibiotic MH resulted in a combined effect of an enhanced osteogenic activity. These findings, together with the antibiofilm activity depicted strengthen the appropriateness of this 3D-printed PLA-Col-MH-cHA scaffold for future use in bone repair. By targeting bone repair while mitigating the typical infections associated to bone implants, our 3D scaffolds deliver an integrated strategy with the combined effects further envisaging an increase in the success rate of bone-implanted devices.
- Understanding intracellular trafficking and anti-inflammatory effects of minocycline chitosan-nanoparticles in human gingival fibroblasts for periodontal disease treatmentPublication . Martin, Victor; Ribeiro, Isabel A. C.; Alves, Marta M.; Gonçalves, Lídia; Almeida, António José; Grenho, Liliana; Fernandes, Maria H.; Santos, Catarina F.; Gomes, Pedro S.; Bettencourt, AnaPeriodontal diseases remain a challenge due to a complex interplay of factors involving a chronic inflammatory activation and bacteria internalization in periodontal cells. In this work, chitosan-nanoparticles loaded with minocycline (MH-NPs), a tetracycline with antimicrobial and anti-inflammatory effects, were developed for in situ delivery in the periodontal milieu aiming to improve drug effectiveness. A general cytocompatibility evaluation and a detailed approach to address the cellular uptake process, trafficking pathways and the modulation of relevant inflammatory gene expression was conducted using human gingival fibroblasts. Results show that MH-NPs with an adequate cytocompatible profile can be internalized by distinct endocytic processes (macropinocytosis and clathrin-mediated endocytosis). The ability to modulate autophagy with the delivery within the same endosomal/lysosomal pathway as periodontal pathogens was observed, which increases the intracellular drug effectiveness. Porphyromonas gingivalis LPS-stimulated cultures, grown in the presence of MH-NPs, were found to express significantly reduced levels of inflammation-related markers (IL-1b, TNFα, CXCL-8, NFKB1). These nanoparticles can be potentially used in periodontal disease treatment conjoining the ability of intracellular drug targeting with significant anti-inflammatory effects.