This page has only limited features, please log in for full access.

Dr. Margarida M. Fernandes
Centro/Departamento de Física, Universidade do Minho, 4710-057 Braga, Portugal

Basic Info

Basic Info is private.

Research Keywords & Expertise

0 Microbiology
0 Nanotechnology
0 magnetoelectric materials
0 bone tissue engineering
0 Surface Functionalization

Fingerprints

Microbiology
bone tissue engineering
magnetoelectric materials
Surface Functionalization

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 03 August 2021 in Acta Biomaterialia
Reads 0
Downloads 0

The search for alternative antimicrobial strategies capable of avoiding resistance mechanisms in bacteria are highly needed due to the alarming emergence of antimicrobial resistance. The application of physical stimuli as a mean of sensitizing bacteria for the action of antimicrobials on otherwise resistant bacteria or by allowing the action of low quantity of antimicrobials may be seen as a breakthrough for such purpose. This work proposes the development of antibacterial nanocomposites using the synergy between the electrically active microenvironments, created by a piezoelectric polymer (poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE)), with green-synthesized silver nanoparticles (AgNPs). The electrical microenvironment is generated via mechanical stimulation of piezoelectric PVDF-TrFE/AgNPs films using a lab-made mechanical bioreactor. The generated material's electrical response further translates to bacterial cells, namely Escherichia coli and Staphylococcus epidermidis which in combination with AgNPs and the specific morphological features of the material induce important antibacterial and antibiofilm activity. Both porous and non-porous PVDF composites have shown antibacterial characteristics when stimulated at a mechanical frequency of 4 Hz being the effect boosted when AgNPs were incorporated in the nanocomposite, reducing in more than 80% the S. epidermidis bacterial growth in planktonic and biofilm form. The electroactive environments sensitize the bacteria allowing the action of a low dose of AgNPs (1.69% (w/w)). Importantly, the material did not compromise the viability of mammalian cells, thus being considered biocompatible. The piezoelectric stimulation of PVDF-based polymeric films may represent a breakthrough in the development of antibacterial coatings for devices used at hospital setting, taking advantage on the use of mechanical stimuli (pressure/touch) to exert antibacterial and antibiofilm activity. The application of physical methods in alternative to the common chemical ones is seen as a breakthrough for avoiding the emergence of antimicrobial resistance. Antimicrobial strategies that take advantage on the capability of bacteria to sense physical stimuli such as mechanical and electrical cues are scarce. Electroactive nanocomposites comprised of poly(vinylidene fluoride-co-trifluoroethylene (PVDF-TrFE) and green-synthesized silver nanoparticles (AgNPs) were developed to obtain material able to inhibit the colonization of microorganisms. By applying a mechanical stimuli to the nanocomposite, which ultimately mimics movements such as walking or touching, an antimicrobial effect is obtained, resulting from the synergy between the electroactive microenvironments created on the surface of the material and the AgNPs. Such environments sensitize the bacteria to low doses of antimicrobials.

ACS Style

Joana Moreira; Margarida M. Fernandes; Estela O. Carvalho; Ana Nicolau; Vesna Lazic; Jovan M. Nedeljković; Senentxu Lanceros-Mendez. Exploring electroactive microenvironments in polymer-based nanocomposites to sensitize bacterial cells to low-dose embedded silver nanoparticles. Acta Biomaterialia 2021, 1 .

AMA Style

Joana Moreira, Margarida M. Fernandes, Estela O. Carvalho, Ana Nicolau, Vesna Lazic, Jovan M. Nedeljković, Senentxu Lanceros-Mendez. Exploring electroactive microenvironments in polymer-based nanocomposites to sensitize bacterial cells to low-dose embedded silver nanoparticles. Acta Biomaterialia. 2021; ():1.

Chicago/Turabian Style

Joana Moreira; Margarida M. Fernandes; Estela O. Carvalho; Ana Nicolau; Vesna Lazic; Jovan M. Nedeljković; Senentxu Lanceros-Mendez. 2021. "Exploring electroactive microenvironments in polymer-based nanocomposites to sensitize bacterial cells to low-dose embedded silver nanoparticles." Acta Biomaterialia , no. : 1.

Research article
Published: 07 January 2021 in ACS Applied Bio Materials
Reads 0
Downloads 0

The emergence of antimicrobial resistance is considered a public health problem due to the overuse and misuse of antibiotics which are losing efficacy toward an increasing number of microorganisms. Advanced antimicrobial strategies via development of alternative drugs and materials able to control microbial infections, especially in clinical settings, are urgently needed. In this work, nanocomposite films were developed from the piezoelectric polyvinylidene fluoride (PVDF) polymer, filled with nickel nanowires (NiNws) in an attempt to control and enhance the antimicrobial activity of the materials via applying a magnetic stimulus. The material was achieved through crystallization of PVDF in the electroactive β-phase upon incorporation of anisotropic and negatively charged NiNws in the polymeric matrix at a concentration of 1.5 wt %. The nanocomposites have shown to possess certain antimicrobial properties, which could be considerably boosted through the application of a magnetic field. In fact, more than 55% of bacterial growth inhibition was obtained by employing controlled dynamic magnetic conditions for representative Gram-positive and Gram-negative bacteria, compared to only 25% inhibition obtained under static conditions, i.e., without magnetic stimuli application, with the antibiofilm activity clearly improved as well upon dynamic conditions. This work demonstrates a proof-of-concept for materials able to boost on demand their antimicrobial activity and opens the room for applications in novel medical devices with improved control of healthcare-associated infections.

ACS Style

Margarida M. Fernandes; Pedro Martins; Daniela M. Correia; Estela O. Carvalho; Francisco M. Gama; Manuel Vazquez; Cristina Bran; Senentxu Lanceros-Mendez. Magnetoelectric Polymer-Based Nanocomposites with Magnetically Controlled Antimicrobial Activity. ACS Applied Bio Materials 2021, 4, 559 -570.

AMA Style

Margarida M. Fernandes, Pedro Martins, Daniela M. Correia, Estela O. Carvalho, Francisco M. Gama, Manuel Vazquez, Cristina Bran, Senentxu Lanceros-Mendez. Magnetoelectric Polymer-Based Nanocomposites with Magnetically Controlled Antimicrobial Activity. ACS Applied Bio Materials. 2021; 4 (1):559-570.

Chicago/Turabian Style

Margarida M. Fernandes; Pedro Martins; Daniela M. Correia; Estela O. Carvalho; Francisco M. Gama; Manuel Vazquez; Cristina Bran; Senentxu Lanceros-Mendez. 2021. "Magnetoelectric Polymer-Based Nanocomposites with Magnetically Controlled Antimicrobial Activity." ACS Applied Bio Materials 4, no. 1: 559-570.

Journal article
Published: 06 January 2021 in Fibers
Reads 0
Downloads 0

Fabric structures are prone to contamination with microorganisms, as their morphology and ability to retain moisture creates a proper environment for their growth. In this work, a novel, easily processed and cheap coating for a nylon fabric with antimicrobial characteristics was developed. After plasma treatment, made to render the fabric surface more reactive sites, the fabric was impregnated with chitosan and silver nanoparticles by simply dipping it into a mixture of different concentrations of both components. Silver nanoparticles were previously synthesized using the Lee–Meisel method, and their successful obtention was proven by UV–Vis, showing the presence of the surface plasmon resonance band at 410 nm. Nanoparticles with 25 nm average diameter observed by STEM were stable, mainly in the presence of chitosan, which acted as a surfactant for silver nanoparticles, avoiding their aggregation. The impregnated fabric possessed bactericidal activity higher for Gram-positive Staphylococcus aureus than for Gram-negative Pseudomonas aeruginosa bacteria for all combinations. The percentage of live S. aureus and P. aeruginosa CFU was reduced to less than 20% and 60%, respectively, when exposed to each of the coating combinations. The effect was more pronounced when both chitosan and silver were present in the coating, suggesting an effective synergy between these components. After a washing process, the antimicrobial effect was highly reduced, suggesting that the coating is unstable after washing, being almost completely removed from the fabric. Nevertheless, the new-coated fabric can be successfully used in single-use face masks. To our knowledge, the coating of nylon fabrics intended for face-mask material with both agents has never been reported.

ACS Style

Cláudia M. Botelho; Margarida M. Fernandes; Jefferson M. Souza; Nicolina Dias; Ana M. Sousa; José A. Teixeira; Raul Fangueiro; Andrea Zille. New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric. Fibers 2021, 9, 3 .

AMA Style

Cláudia M. Botelho, Margarida M. Fernandes, Jefferson M. Souza, Nicolina Dias, Ana M. Sousa, José A. Teixeira, Raul Fangueiro, Andrea Zille. New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric. Fibers. 2021; 9 (1):3.

Chicago/Turabian Style

Cláudia M. Botelho; Margarida M. Fernandes; Jefferson M. Souza; Nicolina Dias; Ana M. Sousa; José A. Teixeira; Raul Fangueiro; Andrea Zille. 2021. "New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric." Fibers 9, no. 1: 3.

Journal article
Published: 16 December 2020 in Coatings
Reads 0
Downloads 0

A previously developed fiber-based polyester (PES) stent, with mechanical properties comparable to commercial nitinol stents, was coated with metallic silver (Ag0) and silver oxides (AgxO) thin films through direct current (DC) magnetron sputtering. Ag0 and AgxO coatings provide antimicrobial properties to the stents to minimize the occurrence of coronary stent infections. Nevertheless, the stent interacts with the atmosphere and then with the biological fluids and may lead to the generation of silver species with diminished antimicrobial efficiency and/or prone to induce cytotoxicity. Therefore, stent coating nanostructures aged 3 months were thoroughly analyzed by X-ray photoelectron spectroscopy (XPS) and their antimicrobial and cytotoxicity properties were assessed. Aging led to the presence of silver carbonate and bicarbonate as well as chemisorbed oxygen species in Ag0 and AgxO coatings. Bactericidal efficacy was tested against an important nosocomial bacterium, particularly associated to indwelling devices: Staphylococcus epidermidis. Aged Ag0 and AgxO coating presented a Log reduction of 1 and 2 at their surface; respectively. However, aged stents were able to induce a Log reduction of 2 (Ag0) and 4 (AgxO) on the surrounding medium. Only aged AgxO stent was able to provide a mild reduction of the bacterium at its surface and a clear antimicrobial effect (Log reduction >3) within its vicinity. More importantly, both aged Ag0 and AgxO stents were shown to be compatible with fibroblasts cells indicating that they can be safely used as indwelling devices, despite the aging effect.

ACS Style

Rita Rebelo; Jorge Padrão; Margarida M. Fernandes; Sandra Carvalho; Mariana Henriques; Andrea Zille; Raul Fangueiro. Aging Effect on Functionalized Silver-Based Nanocoating Braided Coronary Stents. Coatings 2020, 10, 1234 .

AMA Style

Rita Rebelo, Jorge Padrão, Margarida M. Fernandes, Sandra Carvalho, Mariana Henriques, Andrea Zille, Raul Fangueiro. Aging Effect on Functionalized Silver-Based Nanocoating Braided Coronary Stents. Coatings. 2020; 10 (12):1234.

Chicago/Turabian Style

Rita Rebelo; Jorge Padrão; Margarida M. Fernandes; Sandra Carvalho; Mariana Henriques; Andrea Zille; Raul Fangueiro. 2020. "Aging Effect on Functionalized Silver-Based Nanocoating Braided Coronary Stents." Coatings 10, no. 12: 1234.

Research article
Published: 29 September 2020 in ACS Applied Polymer Materials
Reads 0
Downloads 0

Environmentally resilient antimicrobial coatings are becoming increasingly required for a wide range of applications. For this purpose, nanocomposite thin films of poly(vinylidene fluoride) (PVDF) filled with several types of functionalized nanodiamonds (NDs) were processed by solvent casting. The effects of ND inclusion and functionalization in their morphological, structural, optical, thermal and electrical properties were evaluated taking into account the type of the nanofiller and a concentration up to 2 wt.%. The morphology, structure and thermal features of the polymer matrix are governed by the processing conditions and no noticeable changes occurred due to the presence of the ND fillers. The polymer crystallized mainly in the α phase with a crystallinity of ≈60 %. In turn, the optical transmittance from 200 to 800 nm and the dielectric constant effectively depended on the ND type and content. The inclusion of the ND particles effectively provided antimicrobial properties to the films, which depended on the ND functionalization. This study thus shows that the incorporation of functionalized NDs into PVDF allows the development of antimicrobial coatings with tailorable optical and dielectric properties, which could be of great importance to face nowadays pandemic crisis scenario.

ACS Style

João Nunes-Pereira; Pedro Costa; Liliana Fernandes; Estela O. Carvalho; Margarida M. Fernandes; Sónia A. C. Carabineiro; Josephus Gerardus Buijnsters; Carmen R. Tubio; Senentxu Lanceros-Mendez. Antimicrobial and Antibiofilm Properties of Fluorinated Polymers with Embedded Functionalized Nanodiamonds. ACS Applied Polymer Materials 2020, 2, 5014 -5024.

AMA Style

João Nunes-Pereira, Pedro Costa, Liliana Fernandes, Estela O. Carvalho, Margarida M. Fernandes, Sónia A. C. Carabineiro, Josephus Gerardus Buijnsters, Carmen R. Tubio, Senentxu Lanceros-Mendez. Antimicrobial and Antibiofilm Properties of Fluorinated Polymers with Embedded Functionalized Nanodiamonds. ACS Applied Polymer Materials. 2020; 2 (11):5014-5024.

Chicago/Turabian Style

João Nunes-Pereira; Pedro Costa; Liliana Fernandes; Estela O. Carvalho; Margarida M. Fernandes; Sónia A. C. Carabineiro; Josephus Gerardus Buijnsters; Carmen R. Tubio; Senentxu Lanceros-Mendez. 2020. "Antimicrobial and Antibiofilm Properties of Fluorinated Polymers with Embedded Functionalized Nanodiamonds." ACS Applied Polymer Materials 2, no. 11: 5014-5024.

Research article
Published: 30 July 2020 in Langmuir
Reads 0
Downloads 0

Cerium dioxide (CeO2) finds applications in areas such as corrosion protection, solar cells, or catalysis, finding increasing applications in biomedicine. This work reports on surface-modified CeO2 particles in order to tune their applicability in the biomedical field. Stable aqueous cerium dioxide (CeO2) sol, consisting of 3-4 nm in size crystallites, was synthesized using forced hydrolysis. The coordination of catecholate-type of ligands (catechol, caffeic acid, tiron, and dopamine) to the surface-Ce atoms is followed with the appearance of absorption in the visible spectral range as a consequence of interfacial charge transfer complex formation. The spectroscopic observations are complemented with the density functional theory calculations using a cluster model. The synthesized samples were characterized by X-ray diffraction analysis, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. The zeta-potential measurements indicated that the stability of CeO2 sol is preserved upon surface modification. The pristine CeO2 nanoparticles are non-toxic against pre-osteoblast cells in the entire studied concentration range (up to 1.5 mM). Hybrid CeO2 nanoparticles, caped with dopamine or caffeic acid, display toxic behavior for concentrations ≥ 0.17 and 1.5 mM, respectively. On the other hand, surface-modified CeO2 NPs with catechol and tiron promote the proliferation of pre-osteoblast cells.

ACS Style

Vesna Lazić; Ljiljana S. Živković; Dušan Sredojević; Margarida M. Fernandes; Senentxu Lanceros-Mendez; S. Phillip Ahrenkiel; Jovan M. Nedeljković. Tuning Properties of Cerium Dioxide Nanoparticles by Surface Modification with Catecholate-type of Ligands. Langmuir 2020, 36, 1 .

AMA Style

Vesna Lazić, Ljiljana S. Živković, Dušan Sredojević, Margarida M. Fernandes, Senentxu Lanceros-Mendez, S. Phillip Ahrenkiel, Jovan M. Nedeljković. Tuning Properties of Cerium Dioxide Nanoparticles by Surface Modification with Catecholate-type of Ligands. Langmuir. 2020; 36 (33):1.

Chicago/Turabian Style

Vesna Lazić; Ljiljana S. Živković; Dušan Sredojević; Margarida M. Fernandes; Senentxu Lanceros-Mendez; S. Phillip Ahrenkiel; Jovan M. Nedeljković. 2020. "Tuning Properties of Cerium Dioxide Nanoparticles by Surface Modification with Catecholate-type of Ligands." Langmuir 36, no. 33: 1.

Journal article
Published: 12 June 2020 in Sensors
Reads 0
Downloads 0

Biomimetic bioreactor systems are increasingly being developed for tissue engineering applications, due to their ability to recreate the native cell/tissue microenvironment. Regarding bone-related diseases and considering the piezoelectric nature of bone, piezoelectric scaffolds electromechanically stimulated by a bioreactor, providing the stimuli to the cells, allows a biomimetic approach and thus, mimicking the required microenvironment for effective growth and differentiation of bone cells. In this work, a bioreactor has been designed and built allowing to magnetically stimulate magnetoelectric scaffolds and therefore provide mechanical and electrical stimuli to the cells through magnetomechanical or magnetoelectrical effects, depending on the piezoelectric nature of the scaffold. While mechanical bioreactors need direct application of the stimuli on the scaffolds, the herein proposed magnetic bioreactors allow for a remote stimulation without direct contact with the material. Thus, the stimuli application (23 mT at a frequency of 0.3 Hz) to cells seeded on the magnetoelectric, leads to an increase in cell viability of almost 30% with respect to cell culture under static conditions. This could be valuable to mimic what occurs in the human body and for application in immobilized patients. Thus, special emphasis has been placed on the control, design and modeling parameters governing the bioreactor as well as its functional mechanism.

ACS Style

Nelson Castro; Margarida M. Fernandes; Clarisse Ribeiro; Vítor Correia; Rikardo Minguez; Senentxu Lanceros-Méndez. Magnetic Bioreactor for Magneto-, Mechano- and Electroactive Tissue Engineering Strategies. Sensors 2020, 20, 1 .

AMA Style

Nelson Castro, Margarida M. Fernandes, Clarisse Ribeiro, Vítor Correia, Rikardo Minguez, Senentxu Lanceros-Méndez. Magnetic Bioreactor for Magneto-, Mechano- and Electroactive Tissue Engineering Strategies. Sensors. 2020; 20 (12):1.

Chicago/Turabian Style

Nelson Castro; Margarida M. Fernandes; Clarisse Ribeiro; Vítor Correia; Rikardo Minguez; Senentxu Lanceros-Méndez. 2020. "Magnetic Bioreactor for Magneto-, Mechano- and Electroactive Tissue Engineering Strategies." Sensors 20, no. 12: 1.

Journal article
Published: 19 May 2020 in Materialia
Reads 0
Downloads 0

Bone-related diseases are one of the most common health conditions that limit the quality of life of elderly. Novel materials for bone tissue engineering that actively assist on the regeneration of bone tissue are thus needed. In this work, magnetoactive scaffolds comprised of silk fibroin (SF) with different content of filler- cobalt ferrite nanoparticles- were produced by solvent-casting and electrospinning technique and further evaluated for bone cells growth under static and dynamic magnetic stimulation. The materials were evaluated for their enhanced electric properties, analyzed through the silk fibroin β-sheet content, an important factor for the envisaged cell stimulation strategy, which are in much higher content in films (∼50%) than in electrospun fibres (∼25%). Cell culture experiments under varying magnetic field, induced a magneto-mechanical stimulation on the materials, hence on cells, promoting improved cell viability after 4 days of culture. The scaffold morphology was found to play an important role in pre-osteoblast proliferation rate, being larger for cells growing on films, which is related to the topography of the material but also to the increased β-sheet content. It is shown that the use of magnetic cues on magnetoactive biocompatible scaffolds is a promising strategy for remote stimulation of bone for its regeneration.

ACS Style

A. Reizabal; R Brito-Pereira; M.M. Fernandes; Nélson Castro; Vítor Manuel Gomes Correia; Clarisse Ribeiro; C.M. Costa; L. Perez; Jose Luis Vilas; S. Lanceros-Méndez. Silk fibroin magnetoactive nanocomposite films and membranes for dynamic bone tissue engineering strategies. Materialia 2020, 12, 100709 .

AMA Style

A. Reizabal, R Brito-Pereira, M.M. Fernandes, Nélson Castro, Vítor Manuel Gomes Correia, Clarisse Ribeiro, C.M. Costa, L. Perez, Jose Luis Vilas, S. Lanceros-Méndez. Silk fibroin magnetoactive nanocomposite films and membranes for dynamic bone tissue engineering strategies. Materialia. 2020; 12 ():100709.

Chicago/Turabian Style

A. Reizabal; R Brito-Pereira; M.M. Fernandes; Nélson Castro; Vítor Manuel Gomes Correia; Clarisse Ribeiro; C.M. Costa; L. Perez; Jose Luis Vilas; S. Lanceros-Méndez. 2020. "Silk fibroin magnetoactive nanocomposite films and membranes for dynamic bone tissue engineering strategies." Materialia 12, no. : 100709.

Journal article
Published: 21 February 2020 in Chemosphere
Reads 0
Downloads 0

Emerging pollutants represent a new global problem for water quality. As these compounds get into the environment, they cause severe threats to aquatic environments and human health and are typically resistant to conventional wastewater treatments. In this work, TiO2 nanoparticles surface was functionalized with silver (Ag) nanoparticles, and solvent cast and electrospun membranes of poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were prepared with different concentrations of TiO2 and Ag–TiO2 to produce a multifunctional material. The photocatalytic activity of the nanocomposites was evaluated through the degradation of norfloxacin under ultraviolet (UV) and visible radiation. It is shown that nanocomposites with Ag–TiO2 show the highest degradation efficiencies: 64.2% under UV and 80.7% under visible radiation, for 90 and 300 min, respectively. Furthermore, the recyclability of the membranes has also been demonstrated. Finally, it is shown the antimicrobial activity of the nanocomposite membranes, demonstrating the suitability of the Ag–TiO2/PVDF-HFP nanocomposites as multifunctional photocatalytic and antimicrobial membranes for water remediation applications.

ACS Style

Hugo Salazar; P.M. Martins; Bruno Santos; Margarida Fernandes; Ander Reizabal; Víctor Sebastián; Gabriela Botelho; Carlos Jose Tavares; Jose Luis Vilas; S. Lanceros-Mendez. Photocatalytic and antimicrobial multifunctional nanocomposite membranes for emerging pollutants water treatment applications. Chemosphere 2020, 250, 126299 .

AMA Style

Hugo Salazar, P.M. Martins, Bruno Santos, Margarida Fernandes, Ander Reizabal, Víctor Sebastián, Gabriela Botelho, Carlos Jose Tavares, Jose Luis Vilas, S. Lanceros-Mendez. Photocatalytic and antimicrobial multifunctional nanocomposite membranes for emerging pollutants water treatment applications. Chemosphere. 2020; 250 ():126299.

Chicago/Turabian Style

Hugo Salazar; P.M. Martins; Bruno Santos; Margarida Fernandes; Ander Reizabal; Víctor Sebastián; Gabriela Botelho; Carlos Jose Tavares; Jose Luis Vilas; S. Lanceros-Mendez. 2020. "Photocatalytic and antimicrobial multifunctional nanocomposite membranes for emerging pollutants water treatment applications." Chemosphere 250, no. : 126299.

Article
Published: 04 December 2019 in Journal of Inorganic and Organometallic Polymers and Materials
Reads 0
Downloads 0

The aim of this study was the development of a non-toxic, biosynthetic antimicrobial agent which selectively acts on only one type of microorganism, and preserves the microbiota. Antimicrobial performance of biosynthesized silver nanoparticles (Ag NPs) by horsetail (Equisetum arvense L.) extract was examined against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus, as well as yeasts Candida albicans and Saccharomyces boulardii. Also, the cytotoxicity of Ag NPs was examined toward pre-osteoblast cells. The synthetic conditions—concentration of extract, temperature, and pH—were optimized to prepare silver colloids with different particle size distributions and long-term stability. The obtained samples were characterized using transmission electron microscopy, X-ray diffraction analysis, and absorption spectroscopy. The smaller-sized Ag NPs (~ 10–20 nm), prepared at a lower temperature (20 °C), showed better antimicrobial performance against E. coli compared to larger ones (~ 40–60 nm), prepared at high temperature (100 °C). On the other hand, both samples did not display any toxic action against bacteria S. aureus, or yeasts C. albicans and S. boulardii. Non-cytotoxic behavior of Ag NPs toward pre-osteoblast cells was observed for the concentrations of silver ≤ 2.25 and ≤ 4.5 mg L−1 for 10–20 and 40–60 nm-sized Ag NPs, respectively. Biosynthesized Ag NPs by horsetail extract display selective toxic action against E. coli at the ecologically acceptable concentration level.

ACS Style

Miona Miljković; Vesna Lazić; Slađana Davidović; Ana Milivojević; Jelena Papan; Margarida Fernandes; Senentxu Lanceros-Mendez; S. Phillip Ahrenkiel; Jovan M. Nedeljković. Selective Antimicrobial Performance of Biosynthesized Silver Nanoparticles by Horsetail Extract Against E. coli. Journal of Inorganic and Organometallic Polymers and Materials 2019, 30, 2598 -2607.

AMA Style

Miona Miljković, Vesna Lazić, Slađana Davidović, Ana Milivojević, Jelena Papan, Margarida Fernandes, Senentxu Lanceros-Mendez, S. Phillip Ahrenkiel, Jovan M. Nedeljković. Selective Antimicrobial Performance of Biosynthesized Silver Nanoparticles by Horsetail Extract Against E. coli. Journal of Inorganic and Organometallic Polymers and Materials. 2019; 30 (7):2598-2607.

Chicago/Turabian Style

Miona Miljković; Vesna Lazić; Slađana Davidović; Ana Milivojević; Jelena Papan; Margarida Fernandes; Senentxu Lanceros-Mendez; S. Phillip Ahrenkiel; Jovan M. Nedeljković. 2019. "Selective Antimicrobial Performance of Biosynthesized Silver Nanoparticles by Horsetail Extract Against E. coli." Journal of Inorganic and Organometallic Polymers and Materials 30, no. 7: 2598-2607.

Research article
Published: 04 November 2019 in ACS Applied Materials & Interfaces
Reads 0
Downloads 0

Bone tissue repair strategies are gaining increasing relevance due to the growing incidence of bone disorders worldwide. Biochemical stimulation is the most commonly used strategy for cell regeneration while the application of physical stimuli such as magnetic, mechanical or electrical fields is a promising, however scarcely investigated field. This work reports on novel magneto-active 3D porous scaffolds, suitable for effective proliferation of osteoblasts in a biomimetic microenvironment. This physically active microenvironment is developed through the bone mimicking structure of the scaffold combined with the physical stimuli provided by a magnetic custom-made bioreactor on a magneto-responsive scaffold. Scaffolds are obtained through the development of nanocomposites comprised of a piezoelectric polymer, poly(vinylidene fluoride) (PVDF), and magnetostrictive particles of CoFe2O4 using a solvent casting method guided by the overlapping of nylon template structures with three different fibre diameter sizes (60, 80 and 120 µm), thus generating 3D scaffolds with different pore sizes. The magneto-active composites show a structure very similar to trabecular bone with pore sizes ranging from 5 µm to 20 µm, owed to the inherent process of crystallization of PVDF with the NPs, interconnected with bigger pores, formed after removing the nylon templates. It is found that the materials crystallize mainly in the electroactive β-phase of PVDF and that promote the proliferation of pre-osteoblasts through the application of magnetic stimuli. This phenomenon is attributed to both local magnetomechanical and magnetoelectric response of the scaffolds, which induce a proper cellular mechano- and electro-transduction process.

ACS Style

Margarida M. Fernandes; Daniela M. Correia; Clarisse Ribeiro; Nélson Castro; Vítor Manuel Gomes Correia; Senentxu Lanceros-Mendez. Bioinspired Three-Dimensional Magnetoactive Scaffolds for Bone Tissue Engineering. ACS Applied Materials & Interfaces 2019, 11, 45265 -45275.

AMA Style

Margarida M. Fernandes, Daniela M. Correia, Clarisse Ribeiro, Nélson Castro, Vítor Manuel Gomes Correia, Senentxu Lanceros-Mendez. Bioinspired Three-Dimensional Magnetoactive Scaffolds for Bone Tissue Engineering. ACS Applied Materials & Interfaces. 2019; 11 (48):45265-45275.

Chicago/Turabian Style

Margarida M. Fernandes; Daniela M. Correia; Clarisse Ribeiro; Nélson Castro; Vítor Manuel Gomes Correia; Senentxu Lanceros-Mendez. 2019. "Bioinspired Three-Dimensional Magnetoactive Scaffolds for Bone Tissue Engineering." ACS Applied Materials & Interfaces 11, no. 48: 45265-45275.

Review article
Published: 18 October 2019 in Frontiers in Bioengineering and Biotechnology
Reads 0
Downloads 0

Despite being very simple organisms, bacteria possess an outstanding ability to adapt to different environments. Their long evolutionary history, being exposed to vastly different physicochemical surroundings, allowed them to detect and respond to a wide range of signals including biochemical, mechanical, electrical, and magnetic ones. Taking into consideration their adapting mechanisms, it is expected that novel materials able to provide bacteria with specific stimuli in a biomimetic context may tailor their behavior and make them suitable for specific applications in terms of anti-microbial and pro-microbial approaches. This review maintains that electroactive smart materials will be a future approach to be explored in microbiology to obtain novel strategies for fighting the emergence of live threatening antibiotic resistance.

ACS Style

Margarida M. Fernandes; Estela O. Carvalho; Senentxu Lanceros-Mendez. Electroactive Smart Materials: Novel Tools for Tailoring Bacteria Behavior and Fight Antimicrobial Resistance. Frontiers in Bioengineering and Biotechnology 2019, 7, 277 .

AMA Style

Margarida M. Fernandes, Estela O. Carvalho, Senentxu Lanceros-Mendez. Electroactive Smart Materials: Novel Tools for Tailoring Bacteria Behavior and Fight Antimicrobial Resistance. Frontiers in Bioengineering and Biotechnology. 2019; 7 ():277.

Chicago/Turabian Style

Margarida M. Fernandes; Estela O. Carvalho; Senentxu Lanceros-Mendez. 2019. "Electroactive Smart Materials: Novel Tools for Tailoring Bacteria Behavior and Fight Antimicrobial Resistance." Frontiers in Bioengineering and Biotechnology 7, no. : 277.

Research article
Published: 03 July 2019 in ACS Applied Materials & Interfaces
Reads 0
Downloads 0

Bacteria are simple organisms with a remarkable capacity of survival by adapting to different environments, which is a result of their long evolutionary history. Taking into consideration these adapting mechanisms, this work now investigates the effect of electrically active microenvironments on bacteria and on how this stimulation may trigger bacteria growth inhibition or proliferation. Electrical microenvironments are generated via stimulation of a piezoelectric polymer with a mechanical cue, thus developing an electrical response and a variation on the surface charge of the polymeric material. Specifically, Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli were grown overnight under static and dynamic conditions on piezoelectric poly(vinylidene) fluoride (PVDF) films, to further study bacteria behaviour under: i) the effect of the material surface charge in static conditions, ii) the mechanical effect and iii) the piezoelectric effect, the last two performed under dynamic conditions. Bacteria viability in planktonic and biofilm form was measured and the microorganism morphology was characterized. While Escherichia coli respond little to any of the stimuli application, Staphylococcus epidermidis growth can be regulated through the material surface charge and by the applied frequency. Positively charged PVDF induce bacterial growth inhibition in planktonic and adhered cells in static conditions while antifouling properties is obtained when a mechanical or piezoelectric effect at 4 Hz stimuli is applied. By increasing the stimuli to 40 Hz, however, the adhesion of bacteria is promoted. In conclusion, the behaviour of certain bacteria species is tailored through the application of piezoelectric materials, which provide sufficient mechanoelectrical stimuli for growth or inhibition of bacteria, allowing for the design of suitable anti- and pro-microbial strategies. Such strategies are only found in studies related to mammalian cells while in bacterial cells these type of stimuli are still unknown. Thus this work provides one of the first insights on the effect of piezoelectric stimuli on bacterial cells.

ACS Style

Estela O. Carvalho; Margarida M. Fernandes; Jorge Padrão; Ana Nicolau; Jorge Marqués-Marchán; Agustina Asenjo; Francisco M. Gama; Clarisse Ribeiro; Senentxu Lanceros-Mendez. Tailoring Bacteria Response by Piezoelectric Stimulation. ACS Applied Materials & Interfaces 2019, 11, 27297 -27305.

AMA Style

Estela O. Carvalho, Margarida M. Fernandes, Jorge Padrão, Ana Nicolau, Jorge Marqués-Marchán, Agustina Asenjo, Francisco M. Gama, Clarisse Ribeiro, Senentxu Lanceros-Mendez. Tailoring Bacteria Response by Piezoelectric Stimulation. ACS Applied Materials & Interfaces. 2019; 11 (30):27297-27305.

Chicago/Turabian Style

Estela O. Carvalho; Margarida M. Fernandes; Jorge Padrão; Ana Nicolau; Jorge Marqués-Marchán; Agustina Asenjo; Francisco M. Gama; Clarisse Ribeiro; Senentxu Lanceros-Mendez. 2019. "Tailoring Bacteria Response by Piezoelectric Stimulation." ACS Applied Materials & Interfaces 11, no. 30: 27297-27305.

Article
Published: 27 May 2019 in Fibers and Polymers
Reads 0
Downloads 0

The aim of this study was to evaluate the thermo-physiological comfort properties of surgical cotton gauze coated with chitosan (CH) and its effectiveness for the prevention of bacterial colonization. Gauze was coated with CH at mass fractions of 0.50, 0.25, 0.125, 0.10, 0.063 wt% and the friction, flexibility, thermal, moisture management and mechanical properties were evaluated. The best performing gauze in terms of comfort (0.125 wt%) was further evaluated for its ability to inhibit the growth of microorganisms such as bacteria and yeast. Results indicate that the functionalized medical gauze could induce low friction on the wound bed allowing a good degree of moisture and high absorption capacity of wound exudates. Moreover, it shows antimicrobial properties against medical-relevant pathogens. This biofunctional medical gauze demonstrates to deliver an efficient antimicrobial coating and promote the best conditions for maintenance of the wound microenvironment.

ACS Style

Jefferson M. Souza; Mariana Henriques; Pilar Teixeira; Margarida Fernandes; Raul Fangueiro; Andrea Zille. Comfort and Infection Control of Chitosan-impregnated Cotton Gauze as Wound Dressing. Fibers and Polymers 2019, 20, 922 -932.

AMA Style

Jefferson M. Souza, Mariana Henriques, Pilar Teixeira, Margarida Fernandes, Raul Fangueiro, Andrea Zille. Comfort and Infection Control of Chitosan-impregnated Cotton Gauze as Wound Dressing. Fibers and Polymers. 2019; 20 (5):922-932.

Chicago/Turabian Style

Jefferson M. Souza; Mariana Henriques; Pilar Teixeira; Margarida Fernandes; Raul Fangueiro; Andrea Zille. 2019. "Comfort and Infection Control of Chitosan-impregnated Cotton Gauze as Wound Dressing." Fibers and Polymers 20, no. 5: 922-932.

Book chapter
Published: 01 January 2019 in Advances in Biomechanics and Tissue Regeneration
Reads 0
Downloads 0
ACS Style

S. Ribeiro; C. Garcia-Astrain; M.M. Fernandes; S. Lanceros-Mendez. Multidimensional Biomechanics Approaches Though Electrically and Magnetically Active Microenvironments. Advances in Biomechanics and Tissue Regeneration 2019, 253 -267.

AMA Style

S. Ribeiro, C. Garcia-Astrain, M.M. Fernandes, S. Lanceros-Mendez. Multidimensional Biomechanics Approaches Though Electrically and Magnetically Active Microenvironments. Advances in Biomechanics and Tissue Regeneration. 2019; ():253-267.

Chicago/Turabian Style

S. Ribeiro; C. Garcia-Astrain; M.M. Fernandes; S. Lanceros-Mendez. 2019. "Multidimensional Biomechanics Approaches Though Electrically and Magnetically Active Microenvironments." Advances in Biomechanics and Tissue Regeneration , no. : 253-267.

Journal article
Published: 11 September 2018 in Composites Part B: Engineering
Reads 0
Downloads 0

Magnetic nanocomposite films, comprised of a genetically engineered silk-elastin-like protein (SELP) and CoFe2O4 nanoparticles (CFO NPs) with concentrations varying between 5 and 20 wt%, were produced by solvent casting. The obtained materials were analysed regarding their morphology, physical-chemical, thermal, mechanical and magnetic properties. It was found that the magnetic NPs are homogenously distributed among the film and do not induce any significant alterations in their physical-chemical properties. Regarding the thermal properties, the onset degradation temperature of the SELP-59-A films was also not significantly altered by the inclusion of the NPs. Further, strongly bound water is present in the material, which decreases with increasing NPs concentration. Likewise, the mechanical properties of the films were affected by the presence of NPs. Finally, it was demonstrated that the magnetization saturation increases with increasing CFO NPs content, showing the magnetic responsivity of the materials and opening new perspectives in the development of a new generation of multifunctional biocomposites suitable for a wide range of applications, from sensors to tissue engineering.

ACS Style

M.M. Fernandes; Daniela Maria Correia; A. da Costa; S. Ribeiro; Margarida Casal; Senentxu Lanceros-Mendez; R. Machado. Multifunctional magnetically responsive biocomposites based on genetically engineered silk-elastin-like protein. Composites Part B: Engineering 2018, 153, 413 -419.

AMA Style

M.M. Fernandes, Daniela Maria Correia, A. da Costa, S. Ribeiro, Margarida Casal, Senentxu Lanceros-Mendez, R. Machado. Multifunctional magnetically responsive biocomposites based on genetically engineered silk-elastin-like protein. Composites Part B: Engineering. 2018; 153 ():413-419.

Chicago/Turabian Style

M.M. Fernandes; Daniela Maria Correia; A. da Costa; S. Ribeiro; Margarida Casal; Senentxu Lanceros-Mendez; R. Machado. 2018. "Multifunctional magnetically responsive biocomposites based on genetically engineered silk-elastin-like protein." Composites Part B: Engineering 153, no. : 413-419.

Research article
Published: 27 July 2018 in Biomacromolecules
Reads 0
Downloads 0

In this study, freestanding nanobiocomposite films were obtained by the sequential deposition of biopolymer-capped silver nanoparticles (AgNPs) and hyaluronic acid (HA). At first, dispersions of AgNPs decorated with chitosan (CS) or aminocellulose (AC) were synthesized by applying high intensity ultrasound. These polycationic nanoentities were layer-by-layer assembled with the HA polyanion to generate stable 3D supramolecular constructs, where the biopolymer-capped AgNPs play the dual role of active agent and structural element. SEM images of the assemblies revealed gradual increase of thickness with the number of deposited bilayers. The composites of ≥50 bilayers were safe to human cells and demonstrated 100% antibacterial activity against Staphylococcus aureus and Escherichia coli. Moreover, the films containing CSAgNPs brought about the total prevention of biofilm formation reducing the cells surface adherence by up to 6 logs. Such nanobiocomposites could serve as an effective barrier to control bacterial growth on injured skin, burns, and chronic wounds.

ACS Style

Antonio Francesko; Kristina Ivanova; Javier Hoyo; Sílvia Pérez-Rafael; Petya Petkova; Margarida Fernandes; Thomas Heinze; Ernest Mendoza; Tzanko Tzanov. Bottom-up Layer-by-Layer Assembling of Antibacterial Freestanding Nanobiocomposite Films. Biomacromolecules 2018, 19, 3628 -3636.

AMA Style

Antonio Francesko, Kristina Ivanova, Javier Hoyo, Sílvia Pérez-Rafael, Petya Petkova, Margarida Fernandes, Thomas Heinze, Ernest Mendoza, Tzanko Tzanov. Bottom-up Layer-by-Layer Assembling of Antibacterial Freestanding Nanobiocomposite Films. Biomacromolecules. 2018; 19 (9):3628-3636.

Chicago/Turabian Style

Antonio Francesko; Kristina Ivanova; Javier Hoyo; Sílvia Pérez-Rafael; Petya Petkova; Margarida Fernandes; Thomas Heinze; Ernest Mendoza; Tzanko Tzanov. 2018. "Bottom-up Layer-by-Layer Assembling of Antibacterial Freestanding Nanobiocomposite Films." Biomacromolecules 19, no. 9: 3628-3636.

Research article
Published: 25 July 2018 in The Journal of Physical Chemistry C
Reads 0
Downloads 0

Flexible polymer based magnetoelectric (ME) materials are developed based on novel CoFO nanoellipsoids and poly[(vinylidenefluoride-co-trifluoroethylene] [P(VDF-TrFE)]. The synthesized non-cytotoxic CoFO nanoellipsoids (270 nmx50nm) show high magnetization, ≈170 emu.g-1, high magnetostriction, ≈300 ppm, and magnetic anisotropy that, coupled to the piezoelectric response of P(VDF-TrFE), |d33|=22±1 pC.N-1, lead to an interfacial ME coupling (α) of 1.50 mV.cm-1.Oe-1. Further, nanoellipsoids orientation within the polymer matrix allow an anisotropic ME response of the CoFO/P(VDF-TrFE) composite. Such response is dependent on the angle between the DC magnetic field direction and the nanoellipsoids length direction. The proposed mechanism for the anisotropic behavior allows the tailoring of the ME response to contactless sensing applications.

ACS Style

Margarida M. Fernandes; Henrique Mora; E. D. Barriga-Castro; Carlos Luna; Raquel Mendoza-Reséndez; Clarisse Ribeiro; Senentxu Lanceros-Mendez; Pedro Martins. Improving Magnetoelectric Contactless Sensing and Actuation through Anisotropic Nanostructures. The Journal of Physical Chemistry C 2018, 122, 19189 -19196.

AMA Style

Margarida M. Fernandes, Henrique Mora, E. D. Barriga-Castro, Carlos Luna, Raquel Mendoza-Reséndez, Clarisse Ribeiro, Senentxu Lanceros-Mendez, Pedro Martins. Improving Magnetoelectric Contactless Sensing and Actuation through Anisotropic Nanostructures. The Journal of Physical Chemistry C. 2018; 122 (33):19189-19196.

Chicago/Turabian Style

Margarida M. Fernandes; Henrique Mora; E. D. Barriga-Castro; Carlos Luna; Raquel Mendoza-Reséndez; Clarisse Ribeiro; Senentxu Lanceros-Mendez; Pedro Martins. 2018. "Improving Magnetoelectric Contactless Sensing and Actuation through Anisotropic Nanostructures." The Journal of Physical Chemistry C 122, no. 33: 19189-19196.

Journal article
Published: 20 February 2018 in MRS Advances
Reads 0
Downloads 0

Tissue engineering and regenerative medicine are increasingly taking advantage of active materials, allowing to provide specific clues to the cells. In particular, the use of electroactive polymers that deliver an electrical signal to the cells upon mechanical solicitation, open new scientific and technological opportunities, as they in fact mimic signals and effects that occur in living tissues, allowing the development of suitable microenvironments for tissue regeneration. Thus, a novel overall strategy for bone and muscle tissue engineering was developed based on the fact that these cells type are subjected to mechano-electrical stimuli in their in vivo microenvironment and that piezo- and magnetoelectric polymers, used as scaffolds, are suitable for delivering those cues. The processing and functional characterizations of piezoelectric and magnetoelectric polymers based on poly(vinylindene fluoride) and poly-L-lactic acid in a variety of shapes, from microspheres to electrospun mats and three dimensional scaffolds, are shown as well as their performance in the development of novel bone and muscle tissue engineering.

ACS Style

Sylvie Ribeiro; Daniela Maria Correia; Margarida Fernandes; Senentxu Lanceros-Mendez. Piezo- and Magnetoelectric Polymers as Biomaterials for Novel Tissue Engineering Strategies. MRS Advances 2018, 3, 1671 -1676.

AMA Style

Sylvie Ribeiro, Daniela Maria Correia, Margarida Fernandes, Senentxu Lanceros-Mendez. Piezo- and Magnetoelectric Polymers as Biomaterials for Novel Tissue Engineering Strategies. MRS Advances. 2018; 3 (30):1671-1676.

Chicago/Turabian Style

Sylvie Ribeiro; Daniela Maria Correia; Margarida Fernandes; Senentxu Lanceros-Mendez. 2018. "Piezo- and Magnetoelectric Polymers as Biomaterials for Novel Tissue Engineering Strategies." MRS Advances 3, no. 30: 1671-1676.

Review
Published: 08 February 2018 in Polymers
Reads 0
Downloads 0

Fluorinated polymers constitute a unique class of materials that exhibit a combination of suitable properties for a wide range of applications, which mainly arise from their outstanding chemical resistance, thermal stability, low friction coefficients and electrical properties. Furthermore, those presenting stimuli-responsive properties have found widespread industrial and commercial applications, based on their ability to change in a controlled fashion one or more of their physicochemical properties, in response to single or multiple external stimuli such as light, temperature, electrical and magnetic fields, pH and/or biological signals. In particular, some fluorinated polymers have been intensively investigated and applied due to their piezoelectric, pyroelectric and ferroelectric properties in biomedical applications including controlled drug delivery systems, tissue engineering, microfluidic and artificial muscle actuators, among others. This review summarizes the main characteristics, microstructures and biomedical applications of electroactive fluorinated polymers.

ACS Style

Vanessa F. Cardoso; Daniela M. Correia; Clarisse Ribeiro; Margarida M. Fernandes; Senentxu Lanceros-Méndez. Fluorinated Polymers as Smart Materials for Advanced Biomedical Applications. Polymers 2018, 10, 161 .

AMA Style

Vanessa F. Cardoso, Daniela M. Correia, Clarisse Ribeiro, Margarida M. Fernandes, Senentxu Lanceros-Méndez. Fluorinated Polymers as Smart Materials for Advanced Biomedical Applications. Polymers. 2018; 10 (2):161.

Chicago/Turabian Style

Vanessa F. Cardoso; Daniela M. Correia; Clarisse Ribeiro; Margarida M. Fernandes; Senentxu Lanceros-Méndez. 2018. "Fluorinated Polymers as Smart Materials for Advanced Biomedical Applications." Polymers 10, no. 2: 161.