Publications by authors named "Benjamín Valdez-Salas"

16 Publications

  • Page 1 of 1

Poly(-vinylcaprolactam) and Salicylic Acid Polymeric Prodrug Grafted onto Medical Silicone to Obtain a Novel Thermo- and pH-Responsive Drug Delivery System for Potential Medical Devices.

Materials (Basel) 2021 Feb 25;14(5). Epub 2021 Feb 25.

Faculty of Chemical Sciences and Engineering, Autonomous University of Baja California, University Boulevard No. 14418, Otay Mesa, Tijuana 22390, Mexico.

New medical devices with anti-inflammatory properties are critical to prevent inflammatory processes and infections in medical/surgical procedures. In this work, we present a novel functionalization of silicone for medical use with a polymeric prodrug and a thermosensitive polymer, by graft polymerization (gamma rays), for the localized release of salicylic acid, an analgesic, and anti-inflammatory drug. Silicone rubber (SR) films were functionalized in two stages using graft polymerization from ionizing radiation (Co). The first stage was grafting poly(-vinylcaprolactam) (PNVCL), a thermo-sensitive polymer, onto SR to obtain SR--PNVCL. In the second stage, poly(2-methacryloyloxy-benzoic acid) (P2MBA), a polymeric prodrug, was grafted to obtain (SR--PNVCL)--P2MBA. The degree of functionalization depended on the concentrations of monomers and the irradiation dose. The films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDX), thermogravimetric analysis (TGA), and contact angle. An upper critical solution temperature (UCST) of the films was demonstrated by the swelling degree as a temperature function. (SR--PNVCL)--P2MBA films demonstrated hydrolysis-mediated drug release from the polymeric prodrug, pH, and temperature sensitivity. GC-MS confirmed the presence of the drug (salicylic acid), after polymer hydrolysis. The concentration of the drug in the release media was quantified by HPLC. Cytocompatibility and thermo-/pH sensitivity of functionalized medical silicone were demonstrated in cancer and non-cancer cells.
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http://dx.doi.org/10.3390/ma14051065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7956192PMC
February 2021

Structure-activity relationship of diameter controlled Ag@Cu nanoparticles in broad-spectrum antibacterial mechanism.

Mater Sci Eng C Mater Biol Appl 2021 Feb 12;119:111501. Epub 2020 Sep 12.

Magna International Pte Ltd, Singapore.

Current outbreaks associated with drug-resistant clinical strains are demanding for the development of broad-spectrum antibacterial agents. The bactericidal materials should be eco-friendly, economical and effective to suppress bacterial growth. Thus, in this work, diameter controlled spherical Cu-Ag nanoparticles (Ag@CuNPs) with diameter ranging from 70 to 100 nm by one-step co-reduction approach were designed and synthesized. The Ag@CuNPs were homogenous, stable, and positively charged. The 70 nm Ag@CuNPs showed a consistent and regular Ag shielding. We observed the 100 nm Ag@CuNPs achieved symmetrical doped Ag clusters on the Cu core surface. We used Gram-positive and Gram-negative models strains to test the wide-spectrum antibacterial activity. The Ag@CuNPs showed detrimental microbial viability in a dose-dependent manner; however, 70 nm Ag@CuNPs were superior to those of 100 nm Ag@CuNPs. Initially, Ag@CuNPs attached and translocated the membrane surface resulting in bacterial eradication. Our analyses exhibited that antibacterial mechanism was not governed by the bacterial genre, nonetheless, by cell type, morphology, growing ability and the NPs uptake capability. The Ag@CuNPs were highly tolerated by human fibroblasts, mainly by the use of starch as glucosidic capper and stabilizer, suggesting optimal biocompatibility and activity. The Ag@CuNPs open up a novel platform to study the potential action of bimetallic nanoparticles and their molecular role for biomedical, clinical, hospital and industrial-chemical applications.
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http://dx.doi.org/10.1016/j.msec.2020.111501DOI Listing
February 2021

Changes in the physiological and biochemical state of peanut plants ( L.) induced by exposure to green metallic nanoparticles.

Int J Phytoremediation 2020 Dec 7:1-8. Epub 2020 Dec 7.

National Technology of Mexico, Technology Institute of Tuxtla Gutierrez, Tuxtla Gutierrez, Mexico.

Different types of nanoparticles (NPs) are increasingly used in multiple sectors such as industry, medicine and agriculture. This application has increased the possibility of NPs accumulating and contaminating the environment. Plants are one of the essential building blocks of all ecosystems and the interaction between NPs and plants is an indispensable aspect of risk assessment. To understand the effects of NPs in agricultural systems, in the present study we investigated the effects of exposure of Ag, Cu and Cu/Ag phytonanoparticles in L. plants at a physiological and biochemical level, for which NPs solutions were applied foliarly at concentrations of 250, 500, 750 and 1000 ppm for 48 days. Parameters such as leaf length, chlorophyll and concentration of phytohormones showed that phytonanoparticles could cause serious damage to plant growth and development. Plants exposed to phytonanoparticles showed an increase in total phenols, proline, PAL activity and antioxidant enzymes, this to mitigate the stress caused. The alteration in the composition and content of fatty acids in the peanut kernels after exposure to different NPs indicated that they could affect the yield and quality of crop. Therefore, it is necessary to investigate its potential impact on food quality. Statement of novelty In this manuscript, we report for the first time that green nanoparticles induced a lower degree of toxicity in plants compared to commercial nanoparticles. Our results indicate that the mechanisms by which peanut plants respond to the application of nanoparticles were an increase in the activity of phenylalanine ammonia-lyase and antioxidant enzymes. So far there are few studies on the effect of nanoparticles on plant hormones, our results revealed a significant decrease in indole-3 acetic acid and induced the synthesis of gibberellins. The modification in the composition and content of fatty acids in the peanut kernels indicated that the nanoparticles could affect the quality of the crop.
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http://dx.doi.org/10.1080/15226514.2020.1856037DOI Listing
December 2020

Nutritional assessment, phytochemical composition and antioxidant analysis of the pulp and seed of medjool date grown in Mexico.

PeerJ 2019 17;7:e6821. Epub 2019 Jul 17.

National Clonal Germplasm Repository for Citrus and Dates, USDA-ARS, Riverside, CA, United States of America.

The aim of this study was the characterization of fatty acids, antioxidant activity, some physical properties, nutrient content, sugars, and minerals in the pulp and seeds of the date cultivar 'Medjool' ( L.) grown in Mexico. The samples were obtained at maturity (Tamar) in the 2017 harvest season in the valleys of San Luis Rio Colorado and Mexicali, Mexico. The following average values were obtained on a % dry weight basis for pulp and seeds, respectively: protein, 3.14% and 4.84%; lipids, 0.75% and 9.94%; fiber, 6.34% and 66.79%; total sugars, 75.32% and 5.88%; reducing sugars, 70.26% and 4.40%; and sucrose, 5.06% and 1.46%. Analysis of the minerals revealed that the most abundant elements for the pulp were: potassium, 851.98 mg/100 g; magnesium, 142.97 mg/100 g; and phosphorus, 139.40 mg/100 g, whereas for the seeds, they were potassium, 413.36 mg/100 g; sulfur, 151.36 mg/100 g; and phosphorus, 92.42 mg/100 g. Gas chromatography-mass spectrometry analysis revealed that the major unsaturated fatty acid was oleic acid, at 52.34% and 45.92%, respectively, for pulp and seeds. The main saturated fatty acids were palmitic acid (6.75%) and lauric acid (17.24%) in pulp and seeds, respectively. The total phenolic content was 1.16 and 13.73 mg GAE/100 g for pulp and seeds, respectively. Finally, the antioxidant activities were: b-carotene, 65.50% and 47.75%; DPPH, 0.079 IC g/L and 0.0046 IC g/L; and ABTS, 13.72 IC g/L and 0.238 IC g/L, respectively. The results obtained in this study confirm that the 'Medjool' cultivar grown in Mexico has the same quality of nutrients and antioxidants as those grown in the other main date-producing countries.
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http://dx.doi.org/10.7717/peerj.6821DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6648623PMC
July 2019

, an Endophyte That Establishes a Nutrient-Transfer Symbiosis With Banana Plants and Protects Against the Black Sigatoka Pathogen.

Front Microbiol 2019 7;10:804. Epub 2019 May 7.

Department of Chemistry, Universidad Autónoma de Guadalajara, Zapopan, Mexico.

Banana ( spp.) is an important crop worldwide, but black Sigatoka disease caused by the fungus threatens fruit production. In this work, we examined the potential of the endophytes of banana plants and , as antagonists of and support plant growth in nutrient limited soils by N-transfer. The two bacterial isolates were identified by MALDI-TOF mass spectrometry and corroborated by 16S rRNA sequence analysis. Both bacteria were positive for beneficial traits such as N-fixation, indole acetic acid production, phosphate solubilization, negative for 1-aminocyclopropane 1-carboxylic acid deaminase and were antagonistic to . To measure the effects on plant growth, the two plant bacteria and an strain (as non-endophyte), were inoculated weekly for 60 days as active cells (AC) and heat-killed cells (HKC) into plant microcosms without nutrients and compared to a water only treatment, and a mineral nutrients solution (MMN) treatment. Bacterial treatments increased growth parameters and prevented accelerated senescence, which was observed for water and mineral nutrients solution (MMN) treatments used as controls. Plants died after the first 20 days of being irrigated with water; irrigation with MMN enabled plants to develop some new leaves, but plants lost weight (-30%) during the same period. Plants treated with bacteria showed good growth, but AC treated plants had significantly greater biomass than the HKC. After 60 days, plants inoculated with AC showed intracellular bacteria within root cells, suggesting that a stable symbiosis was established. To evaluate the transference of organic N from bacteria into the plants, the 3 bacteria were grown with NHCl or NaNO as the nitrogen source. The N transferred from bacteria to plant tissues was measured by pheophytin isotopomer abundance. The relative abundance of the isotopomers 872.57, 873.57, 874.57, 875.57, 876.57 unequivocally demonstrated that plants acquired N atoms directly from bacterial cells, using them as a source of N, to support plant growth in restricted nutrient soils. might be a new alternative to promote growth and health of banana crops.
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http://dx.doi.org/10.3389/fmicb.2019.00804DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513882PMC
May 2019

Influence of Monometallic and Bimetallic Phytonanoparticles on Physiological Status of Mezquite.

Open Life Sci 2019 Jan 20;14:62-68. Epub 2019 Mar 20.

Universidad Veracruzana. Facultad de Ciencias Agrícolas. Circuito Gonzalo Aguirre Beltrán s/n. Universidad Veracruzana. Xalapa, Veracruz, México.

The present study was conducted to evaluate the impact of monometallic and bimetallic nanoparticles (NPs) of copper (Cu) and silver (Ag) from on the photochemical efficiency and phenol pattern of . In this study, the existence of localized surface plasmon resonance absorption associated with the nano-sized nature of Ag, Cu and Cu/Ag particles was confirmed by the presence of a single peak around 487, 585, and 487/580 nm respectively. Zeta potential and electrophoretic mobility were found to be 0.2 mV and 0.02 μmcm/(Vs) for synthesized NPs indicating less stability and thus tendency to agglomerate, and broad distribution of particles. Cu-NPs and Cu/Ag-NPs demonstrate that the dispersed phase is stable and has a minimum particle size at zeta potentials above -30 mV. Changes in phenolic compounds, total chlorophyll, and photochemical efficiency in leaves exposed to Ag, Cu and Cu/Ag phyto-nanoparticles were evaluated up to 72 hours. The results revealed that Ag-NP and Cu-NP from at 100 mg/L showed significant reduction in chlorophyll, epidermal polyphenol content and photochemical efficiency of . In contrast, the application of bimetallic Cu/Ag-NP from showed a positive impact on physiological parameters of after 72 h of exposure.
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http://dx.doi.org/10.1515/biol-2019-0008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7874825PMC
January 2019

Correction: Ungson, Y. et al. Filling of Irregular Channels with Round Cross-Section: Modeling Aspects to Study the Properties of Porous Materials. 2018, , 1901.

Materials (Basel) 2019 03 11;12(5). Epub 2019 Mar 11.

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Carretera Tijuana-Ensenada km107, Playitas, 22860 Ensenada, Mexico.

The authors have found two errors in the paper published in [...].
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http://dx.doi.org/10.3390/ma12050818DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6427339PMC
March 2019

Controlled antifungal behavior on Ti6Al4V nanostructured by chemical nanopatterning.

Mater Sci Eng C Mater Biol Appl 2019 Mar 3;96:677-683. Epub 2018 Dec 3.

Facultad de Odontología Mexicali, Universidad Autónoma de Baja California, Av. Zotoluca y Chinampas s/n, Mexicali C.P. 21040, Baja California, Mexico.

Infections associated with bone implant prostheses are mainly related to bacterial contaminations. Recent investigations have suggested an important role of opportunistic fungal cells associated with non-responding antibacterial treatments. Thus, in order to evaluate the early Candida albicans (C. albicans) behavior; we built on Ti6Al4V surfaces nanopores (NPs) with controlled diameters applying oxidative nanopatterning for 30 (NP30) and 60 min (NP60). As a result of nanopatterning NPs with diameters of 12 and 24 nm were synthesized. Physicochemical differences were observed between both types of NPs, the most highlighting of which are anatase phase formation and improved hydrophilicity of NP60. C. albicans adhesion and colonization was assessed using scanning electron microscopy and by yeast counting for viability evaluation. The fungal behavior on the substrates was significantly different, showing an initial exopolysaccharide secretion stimulated by the nanopatterned surfaces. Larger NPs led to an important reduction in viability with decreased cell-surface contact bonds. The obtained results demonstrate that special control in the fabrication of nanostructured TiO materials can improve the early fungal resistance, especially for dental implants.
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http://dx.doi.org/10.1016/j.msec.2018.11.086DOI Listing
March 2019

Filling of Irregular Channels with Round Cross-Section: Modeling Aspects to Study the Properties of Porous Materials.

Materials (Basel) 2018 Oct 5;11(10). Epub 2018 Oct 5.

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Carretera Tijuana-Ensenada km107, Playitas, Ensenada 22860, Mexico.

The filling of channels in porous media with particles of a material can be interpreted in a first approximation as a packing of spheres in cylindrical recipients. Numerous studies on micro- and nanoscopic scales show that they are, as a rule, not ideal cylinders. In this paper, the channels, which have an irregular shape and a circular cross-section, as well as the packing algorithms are investigated. Five patterns of channel shapes are detected to represent any irregular porous structures. A novel heuristic packing algorithm for monosized spheres and different irregularities is proposed. It begins with an initial configuration based on an unit cell and the subsequent densification of the obtained structure by shaking and gravity procedures. A verification of the algorithm was carried out for nine sinusoidal axisymmetric channels with different ratio by MATLAB simulations, reaching a packing fraction of at least 0.67 (for sphere diameters of 5% or less), superior to a random close packing density. The maximum packing fraction was 73.01% for a channel with a ratio of = 0.1 and a sphere size of 5%. For sphere diameters of 50% or larger, it was possible to increase the packing factor after applying shaking and gravity movements.
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http://dx.doi.org/10.3390/ma11101901DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6213190PMC
October 2018

Silver nanoparticles from Justicia spicigera and their antimicrobial potentialities in the biocontrol of foodborne bacteria and phytopathogenic fungi.

Rev Argent Microbiol 2019 Apr - Jun;51(2):103-109. Epub 2018 Jul 17.

Instituto Tecnológico de Tuxtla Gutiérrez Carretera panamericana km 1080, Chiapas, Mexico.

In the present work, the biosynthesis of silver-nanoparticles (AgNP) was evaluated using the aqueous extract from Justicia spicigera. The obtained silver nanoparticles were characterized using UV-visible spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The antimicrobial activity of biosynthesized AgNP was tested against foodborne bacteria (Bacillus cereus, Klebsiella pneumoniae and Enterobacter aerogenes) and phytopathogenic fungi (Colletotrichum sp., Fusarium solani, Alternaria alternata and Macrophomina phaseolina). The elemental profile of synthesized nanoparticles using J. spicigera shows higher counts at 3keV due to silver, confirming the formation of silver nanoparticles. Scanning electron microscopy (SEM) analysis showed a particle size between 86 and 100nm with spherical morphology. AgNP showed effective antibacterial and antifungal activity against the tested organisms principally with B. cereus, K. pneumoniae, E. aerogenes, A. alternata and M. phaseolina. Therefore, further studies are needed to confirm the potential of AgNP from J. spicigera in the control of indicator organisms under field conditions.
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http://dx.doi.org/10.1016/j.ram.2018.05.002DOI Listing
January 2020

Antifungal Effects of Silver Phytonanoparticles from Against Strawberry Soil-Borne Pathogens: and .

Mycobiology 2018 29;46(1):47-51. Epub 2018 Mar 29.

Instituto de Ingeniería de la Universidad Autónoma de Baja California, Mexicali, Baja California, Mexico.

In the present study, the characterization and properties of silver nanoparticles from leaf extract (AgNPs) were investigated using UV-visible spectroscopic techniques, zeta potential, and dynamic light scattering. The UV-visible spectroscopic analysis showed the absorbance peaked at 460 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had -average diameter of 729 nm with lower stability (195.1 mV). Additionally, our dates revealed that AgNPs showed broad spectrum antagonism ( ≤ .05) against (83.05%) and (67.05%) when compared to the control after nine days of incubation. Finally, AgNPs from leaf extracts of may be used as an agent of biocontrol of microorganism of importance. However, further studies will be needed to fully understand the agronanotechnological potentialities of AgNPs from .
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http://dx.doi.org/10.1080/12298093.2018.1454011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6037081PMC
March 2018

In Vitro Assessment of Early Bacterial Activity on Micro/Nanostructured Ti6Al4V Surfaces.

Molecules 2017 May 18;22(5). Epub 2017 May 18.

Facultad de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P., 21040 Baja California, Mexico.

It is imperative to understand and systematically compare the initial interactions between bacteria genre and surface properties. Thus, we fabricated a flat, anodized with 80 nm TiO₂ nanotubes (NTs), and a rough Ti6Al4V surface. The materials were characterized using field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM). We cultured in vitro () and () to evaluate the bacterial-surface behavior by FE-SEM and viability calculation. In addition, the initial effects of human osteoblasts were tested on the materials. Gram-negative bacteria showed promoted adherence and viability over the flat and rough surface, while NTs displayed opposite activity with altered morphology. Gram-positive bacteria illustrated similar cellular architecture over the surfaces but with promoted surface adhesion bonds on the flat alloy. Rough surfaces supported viability, whilst NTs exhibited lower vitality. NTs advocated promoted better osteoblast organization with enhanced vitality. Gram-positive bacteria suggested preferred adhesion capability over flat and carbon-rich surfaces. Gram-negative bacteria were strongly disturbed by NTs but largely stimulated by flat and rough materials. Our work proposed that the chemical profile of the material surface and the bacterial cell wall characteristics might play an important role in the bacteria-surface interactions.
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http://dx.doi.org/10.3390/molecules22050832DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6154628PMC
May 2017

Enhanced antifungal activity by disinfected titanium dioxide nanotubes via reduced nano-adhesion bonds.

Mater Sci Eng C Mater Biol Appl 2017 Jul 28;76:59-65. Epub 2017 Feb 28.

Department of Corrosion and Materials, Engineering Institute, Autonomous University of Baja California, Blvd. Benito Juarez and Normal St., 21280 Mexicali, Baja California, Mexico.

We have provided evidence that the beneficial effect of super-oxidized water (SOW) disinfected Ti6Al4V-TiO nanotubes (NTs) can reduce bacterial adhesion and biofilm formation. However, the need of antifungal nanostructured surfaces with osteoactive capabilities is an important goal that has been arising for dental implants (DI) applications. Thus, in the present study we isolated and tested the effects of Candida albicans (C. albicans) on disinfected, wetter and nanoroughness NTs compared to a non-modified control. Moreover, we elucidated part of the fungal adhesion mechanism by studying and relating the mycotic adhesion kinetics and the formation of fungal nanoadhesion bonds among the experimental materials, to gain new insight of the fungal-material-interface. Similarly, the initial behavior of human alveolar bone osteoblasts (HAOb) was microscopically evaluated. NTs significantly reduced the yeasts adhesion and viability with non-outcomes of biofilm than the non-modified surface. Cross-sectioning of the fungal cells revealed promoted nano-contact bonds with superior fungal spread on the control alloy interface; meanwhile NTs evidenced decreased tendency along time; suggesting, down-regulation by the nanostructured morphology and the SOW treatment. Importantly, the initial performance of HAOb demonstrated strikingly promoted anchorage with effects of filopodia formation and increased vital cell on NTs with SOW. The present study proposes SOW treatment as an active protocol for synthesis and disinfection of NTs with potent antifungal capability, acting in part by the reduction of nano-adhesion bonds at the surface-fungal interface; opening up a novel route for the investigation of mycotic-adhesion processes at the nanoscale for bone implants applications.
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http://dx.doi.org/10.1016/j.msec.2017.02.153DOI Listing
July 2017

Improved in vitro angiogenic behavior on anodized titanium dioxide nanotubes.

J Nanobiotechnology 2017 Jan 31;15(1):10. Epub 2017 Jan 31.

National Centre for Metallurgical Research (CENIM), CSIC, Ave. Gregorio del Amo 8, 28040, Madrid, Spain.

Background: Neovascularization over dental implants is an imperative requisite to achieve successful osseointegration onto implanted materials. The aim of this study was to investigate the effects on in vitro angiogenesis of anodized 70 nm diameter TiO nanotubes (NTs) on Ti6Al4V alloy synthesized and disinfected by means of a novel, facile, antibacterial and cost-effective method using super oxidized water (SOW). We also evaluated the role of the surface roughness and chemical composition of materials of materials on angiogenesis.

Methods: The Ti6Al4V alloy and a commercially pure Ti were anodized using a solution constituted by SOW and fluoride as electrolyte. An acid-etched Ti6Al4V was evaluated to compare the effect of micro-surface roughness. Mirror-polished materials were used as control. Morphology, roughness, chemistry and wettability were assessed by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy (EDX) and using a professional digital camera. Bovine coronary artery endothelial cells (BCAECs) were seeded over the experimental surfaces for several incubation times. Cellular adhesion, proliferation and monolayer formation were evaluated by means of SEM. BCAEC viability, actin stress fibers and vinculin cellular organization, as well as the angiogenic receptors vascular endothelial growth factor 2 (VEGFR2) and endothelial nitric oxide synthase (eNOS) were measured using fluorescence microscopy.

Results: The anodization process significantly increased the roughness, wettability and thickness of the oxidized coating. EDX analysis demonstrated an increased oxygen (O) and decreased carbon (C) content on the NTs of both materials. Endothelial behavior was solidly supported and improved by the NTs (without significant differences between Ti and alloy), showing that endothelial viability, adhesion, proliferation, actin arrangement with vinculin expression and monolayer development were evidently stimulated on the nanostructured surface, also leading to increased activation of VEGFR2 and eNOS on Ti6Al4V-NTs compared to the control Ti6Al4V alloy. Although the rougher alloy promoted BCAECs viability and proliferation, filopodia formation was poor.

Conclusion: The in vitro results suggest that 70 nm diameter NTs manufactured by anodization and cleaned using SOW promotes in vitro endothelial activity, which may improve in vivo angiogenesis supporting a faster clinical osseointegration process.
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http://dx.doi.org/10.1186/s12951-017-0247-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5282661PMC
January 2017

Disinfection of titanium dioxide nanotubes using super-oxidized water decrease bacterial viability without disrupting osteoblast behavior.

Mater Sci Eng C Mater Biol Appl 2016 Mar 17;60:239-245. Epub 2015 Nov 17.

National Centre for Metallurgical Research, CSIC, Av. Gregorio del Amo 8, 28040 Madrid, Spain.

Amorphous titanium dioxide (TiO2) nanotubes (NTs) on Ti6Al4V alloy were synthesized by anodization using a commercially available super-oxidized water (SOW). The NT surfaces were sterilized by ultraviolet (UV) irradiation and disinfected using SOW. The adhesion and cellular morphology of pig periosteal osteoblast (PPO) cells and the behavior of Staphylococcus aureus (S. aureus) cultured on the sterilized and disinfected surfaces were investigated. A non-anodized Ti6Al4V disc sterilized by UV irradiation (without SOW) was used as control. The results of this study reveal that the adhesion, morphology and filopodia development of PPO cells in NTs are dramatically improved, suggesting that SOW cleaning may not disrupt the benefits obtained by NTs. Significantly decreased bacterial viability in NTs after cleaning with SOW and comparing with non-cleaned NTs was seen. The results suggest that UV and SOW could be a recommendable method for implant sterilization and disinfection without altering osteoblast behavior while decreasing bacterial viability.
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http://dx.doi.org/10.1016/j.msec.2015.11.042DOI Listing
March 2016

Improved Osteoblast and Chondrocyte Adhesion and Viability by Surface-Modified Ti6Al4V Alloy with Anodized TiO₂ Nanotubes Using a Super-Oxidative Solution.

Materials (Basel) 2015 Mar 2;8(3):867-883. Epub 2015 Mar 2.

School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.

Titanium (Ti) and its alloys are amongst the most commonly-used biomaterials in orthopedic and dental applications. The Ti-aluminum-vanadium alloy (Ti6Al4V) is widely used as a biomaterial for these applications by virtue of its favorable properties, such as high tensile strength, good biocompatibility and excellent corrosion resistance. TiO₂ nanotube (NTs) layers formed by anodization on Ti6Al4V alloy have been shown to improve osteoblast adhesion and function when compared to non-anodized material. In his study, NTs were grown on a Ti6Al4V alloy by anodic oxidation for 5 min using a super-oxidative aqueous solution, and their biocompatibility was investigated in pig periosteal osteoblasts and cartilage chondrocytes. Scanning electron microscopy (SEM), energy dispersion X-ray analysis (EDX) and atomic force microscopy (AFM) were used to characterize the materials. Cell morphology was analyzed by SEM and AFM. Cell viability was examined by fluorescence microscopy. Cell adhesion was evaluated by nuclei staining and cell number quantification by fluorescence microscopy. The average diameter of the NTs was 80 nm. The results demonstrate improved cell adhesion and viability at Day 1 and Day 3 of cell growth on the nanostructured material as compared to the non-anodized alloy. In conclusion, this study evidences the suitability of NTs grown on Ti6Al4V alloy using a super-oxidative water and a short anodization process to enhance the adhesion and viability of osteoblasts and chondrocytes. The results warrant further investigation for its use as medical implant materials.
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http://dx.doi.org/10.3390/ma8030867DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5455429PMC
March 2015