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Dive into the research topics where Phaedra Silva-Bermudez is active.

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Featured researches published by Phaedra Silva-Bermudez.


Materials Science and Engineering: C | 2015

Bacterial adhesion on amorphous and crystalline metal oxide coatings.

Argelia Almaguer-Flores; Phaedra Silva-Bermudez; Rey Galicia; S.E. Rodil

Several studies have demonstrated the influence of surface properties (surface energy, composition and topography) of biocompatible materials on the adhesion of cells/bacteria on solid substrates; however, few have provided information about the effect of the atomic arrangement or crystallinity. Using magnetron sputtering deposition, we produced amorphous and crystalline TiO2 and ZrO2 coatings with controlled micro and nanoscale morphology. The effect of the structure on the physical-chemical surface properties was carefully analyzed. Then, we studied how these parameters affect the adhesion of Escherichia coli and Staphylococcus aureus. Our findings demonstrated that the nano-topography and the surface energy were significantly influenced by the coating structure. Bacterial adhesion at micro-rough (2.6 μm) surfaces was independent of the surface composition and structure, contrary to the observation in sub-micron (0.5 μm) rough surfaces, where the crystalline oxides (TiO2>ZrO2) surfaces exhibited higher numbers of attached bacteria. Particularly, crystalline TiO2, which presented a predominant acidic nature, was more attractive for the adhesion of the negatively charged bacteria. The information provided by this study, where surface modifications are introduced by means of the deposition of amorphous or crystalline oxide coatings, offers a route for the rational design of implant surfaces to control or inhibit bacterial adhesion.


Journal of Biomedical Materials Research Part A | 2017

Enhancing the osteoblastic differentiation through nanoscale surface modifications

Phaedra Silva-Bermudez; Argelia Almaguer-Flores; Victor Garcia; Rene Olivares-Navarrete; S.E. Rodil

Human mesenchymal stem cells (MSCs) showed larger differentiation into osteoblasts on nanoscale amorphous titanium oxide (TiO2 ) coatings in comparison to polycrystalline TiO2 coatings or native oxide layers. In this article, we showed that the subtle alterations in the surface properties due to a different atomic ordering of titanium oxide layers could substantially modify the osteoblastic differentiation of MSCs. Amorphous (a) and polycrystalline (c) TiO2 coatings were deposited on smooth (PT) and microstructured sandblasted/acid-etched (SLA) Ti substrates using a magnetron sputtering system. The surface roughness, water contact angle, structure, and composition were measured using confocal microscopy, drop sessile drop, X-ray diffraction, and X-ray photoelectron spectroscopy, respectively. The ∼70-nm-thick coatings presented a well-passivated and uniform TiO2 (Ti4+ ) surface composition, while the substrates (native oxide layer) showed the presence of Ti atoms in lower valence states. The polycrystalline TiO2 -coated surfaces (cPT and cSLA) showed the same cell attachment as the uncoated metallic surfaces (PT and SLA), and in both cases, it was lower on the rough than on the smooth surfaces. However, attachment and differentiation were significantly increased on the amorphous TiO2 -coated surfaces (aPT and aSLA). The amorphous coated Ti surfaces presented the highest expression of integrins and production of osteogenic proteins in comparison to the uncoated and crystalline-coated Ti surfaces.


Bio-Tribocorrosion in Biomaterials and Medical Implants | 2013

Corrosion resistant coatings for dental implants

Phaedra Silva-Bermudez; G. Ramírez; S.E. Rodil

Abstract: In this chapter, a general overview of current dental implants is presented, identifying weak points where improvements can be made. Particular importance is given to the surface properties of materials susceptible to modifications for improving the biological response for the specific application. Then, the concepts and techniques relevant for the evaluation of the physico-chemical properties and the protein adsorption, biocompatibility, bioactivity and biofilm formation are described. The chapter describes a particular method to modify the chemical and physical properties of materials, known as magnetron sputtering. Finally, an example using Nb2O5 coatings is presented, where also corrosion resistance and adhesion results are included.


Carbohydrate Polymers | 2018

Polyelectrolyte complex of Aloe vera, chitosan, and alginate produced fibroblast and lymphocyte viabilities and migration

Raquel Gallardo-Rivera; María de los Ángeles Aguilar-Santamaría; Phaedra Silva-Bermudez; Julieta García-López; Alberto Tecante; Cristina Velasquillo; Angélica Román-Guerrero; C. Pérez-Alonso; Humberto Vázquez-Torres; Keiko Shirai

Chitosan, sodium alginate and gel of Aloe vera (Aloe barbadensis Miller) were employed for the preparation of polyelectrolyte complexes at pH 4 and 6. FT-IR spectroscopy analysis showed evidence on complexes formation and incorporation of the Aloe vera gel. The ζ potential determination of the polyelectrolyte complexes revealed the presence of surface charges in the range of -20 to -24 mV, which results in stable systems. The dynamic moduli exhibited a high dependence on angular frequency, which is commonly found in solutions of macromolecules. The materials showed human fibroblast and lymphocyte viabilities up to 90% in agreement with null cytotoxicity. The polyelectrolyte complexes at pH 6 with Ca2+ were stable, showed high water absorption, satisfactory morphology, pore size and rigidity, characteristics that allowed significant human fibroblast migration in wound closure in vitro assays.


Surface & Coatings Technology | 2013

An overview of protein adsorption on metal oxide coatings for biomedical implants

Phaedra Silva-Bermudez; S.E. Rodil


Solid State Ionics | 2014

Stabilization of the delta-phase in Bi2O3 thin films

Celia L. Gomez; Osmary Depablos-Rivera; Juan C. Medina; Phaedra Silva-Bermudez; S. Muhl; A. Zeinert; S.E. Rodil


Applied Surface Science | 2011

Albumin adsorption on oxide thin films studied by spectroscopic ellipsometry

Phaedra Silva-Bermudez; S.E. Rodil; S. Muhl


Thin Solid Films | 2015

Opto-electronic properties of bismuth oxide films presenting different crystallographic phases

Celia L. Gomez; Osmary Depablos-Rivera; Phaedra Silva-Bermudez; S. Muhl; A. Zeinert; M. Lejeune; S. Charvet; P. R. J. Barroy; Enrique Camps; S.E. Rodil


Thin Solid Films | 2016

Photocatalytic discoloration of methyl orange dye by δ-Bi2O3 thin films

Juan C. Medina; Monserrat Bizarro; Phaedra Silva-Bermudez; Mauro Giorcelli; Alberto Tagliaferro; S.E. Rodil


Applied Surface Science | 2013

A comparative study of fibrinogen adsorption onto metal oxide thin films

Phaedra Silva-Bermudez; S. Muhl; S.E. Rodil

Collaboration


Dive into the Phaedra Silva-Bermudez's collaboration.

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S.E. Rodil

National Autonomous University of Mexico

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Argelia Almaguer-Flores

National Autonomous University of Mexico

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S. Muhl

National Autonomous University of Mexico

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Cristina Velasquillo

National Autonomous University of Mexico

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Clemente Ibarra

Instituto Politécnico Nacional

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Celia L. Gomez

National Autonomous University of Mexico

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Juan C. Medina

National Autonomous University of Mexico

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Keiko Shirai

Universidad Autónoma Metropolitana

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Osmary Depablos-Rivera

National Autonomous University of Mexico

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Victor Garcia

National Autonomous University of Mexico

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