Functional nano-fillers are commonly used to reduce bacterial colonization in dentistry. This study aimed to synthesize, characterize, and evaluate the biological effects of magnesium oxide (MgO) ...nanoparticles (NP) obtained by mechanosynthesis. XRD, TEM, FT-IR, and UV-Vis were used to characterize MgO-NP which were subsequently tested for their activity against Staphylococcus aureus, Enterococcus faecalis and Escherichia coli (E. coli). The effects of MgO-NP on osteoblast cells were also analyzed. Three variables were studied: microbial inhibition by optical density (OD; 570-nm), viability estimated by colony-forming-units, and cell proliferation. The characterization of NP is consistent with nanostructures, minimum inhibitory concentration between 1.5–5 mg/mL, and microbial inhibition at 9.75 ug/mL concentration for E. coli were determined. There were different concentration-dependent effects on cell proliferation. Results were observed with 0.156 mg/mL MgO-NP, which increased cell proliferation at 24 and 48 h. The results suggest the antibacterial suitability of MgO-NP, with tolerable viability of mammalian cells for dental applications.
(1) Dental caries, periodontitis, or peri-implantitis are commensal infections related to oral biofilm former bacteria. Likewise, magnesium oxide nanoparticles (MgO-NPs) were studied to introduce ...them to the antibacterial properties of a few microorganisms. Considering this, the purpose of the present investigation was to determine the antibacterial properties of MgO-NPs on representative oral strains. (2) Methods: MgO-NPs with a cubic crystal structure were obtained by magnesium hydroxide mechanical activation. After synthesis, the MgO-NPs product was annealed at 800 °C (2 h). The MgO-NPs obtained were tested against ten oral ATCC strains at ten serial concentrations (1:1 20.0-0.039 mg/mL per triplicate) using the micro-broth dilution method to determine the minimal inhibitory concentration (MIC) or minimal bactericidal concentration (MIB). Measures of OD595 were compared against each positive control with a Student's
-test. Viability was corroborated by colony-forming units. (3) Results: The polycrystalline structure had an average size of 21 nm as determined by X-ray diffraction and transmission electron microscopy (high resolution). Antimicrobial sensitivity was observed in
(MIB/MIC 10-5 mg/mL),
(MIB 10 mg/mL), and
(MIB 20 mg/mL) at high concentrations of the MgO-NPs and at lower concentrations of the MgO-NPs in
(MIB 0.039 mg/mL),
subsp.
(MIB/MIC 5-2.5 mg/mL),
(MIB 20 mg/mL/MIC 2.5 mg/mL),
(MIB 0.625 mg/mL),
(MIC 2.5 mg/mL),
(MIB 20 mg/mL/MIC 0.321 mg/mL), and
(MIB/MIC 5-2.5 mg/mL). (4) Conclusions: The MgO-NPs' reported antibacterial properties in all oral biofilm strains were evaluated for potential use in dental applications.
The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens;
E. coli
,
P. aeruginosa
,
S. aureus
, and
S. epidermidis
were determined. BSS ...nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of
E. coli
and
S. epidermidis
was dependant on the NPs size and/or concentration, meanwhile
P. aeruginosa
and
S. aureus
were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.
This work focuses on the obtaining and the bactericidal properties study, in vitro, of hybrid films as potential coating materials to inhibit bacteria proliferation. In consequence, hybrid films from ...nickel oxide (NiO) and nickel ferrite (NiFe
2
O
4
) nanoparticles (NPs) embedded in poly-3-hydroxybutyrate (P3HB) were obtained by the solvent casting method. P3HB@NiO and P3HB@NiFe
2
O
4
hybrid films and P3HB film were characterized by X-ray diffraction (XRD), Raman scattering, and scanning electron microscopy (SEM). The XRD of the hybrid films showed that NiO and NiFe
2
O
4
NPs incorporated in the P3HB conserved their nanometric size, and by Energy-dispersive X-ray spectroscopy (EDS) were observed that NPs are homogeneously distributed in the films. The bactericidal effect of the obtained films was evaluated in vitro from the broth surface method against two opportunistic and nosocomial pathogens,
Staphylococcus aureus
and
Pseudomonas aeruginosa
. The results showed that P3HB film, P3HB@NiO, and P3HB@NiFe
2
O
4
hybrid films reduced 90%, 98%, and 97% of the growth of
S. aureus
, respectively. For
P. aeruginosa,
their growth was reduced by 90%, 94%, and 96%, respectively. In addition, the cytotoxic effect of NiO and NiFe
2
O
4
NPs, as well as P3HB film, and P3HB@NiO, and P3HB@NiFe
2
O
4
hybrid films was evaluated using human skin cells; keratinocytes and fibroblast, being the NPs less cytotoxic than films. Although P3HB is known as a biocompatible polymer, here is demonstrated that in our work conditions, their films have bactericidal properties and are cytotoxic to keratinocytes and fibroblasts, the first barrier of the human skin. However, the P3HB@NiO and P3HB@NiFe
2
O
4
hybrid films synergize the bactericidal effect between the P3HB and the NPs. On the other hand, the NPs decrease the P3HB cytotoxicity to keratinocytes. The methodology used in this work is particularly suitable for producing hybrid films with antibacterial activity against Gram-positive and Gram-negative bacterial strains.
Proteinuria is assumed to be less frequent in cats than in dogs and is mainly associated with chronic kidney disease (CKD).
The current study aimed to evaluate and compare urine protein-to-creatinine ...(UPC) values retrospectively in cats visited for comprehensive annual health check or for presenting systemic clinical signs related to CKD.
UPC ratio was retrospectively evaluated in 112 owned cats, out of which 51 (45.5%) were apparently healthy cats according to their owners who visited for comprehensive annual health checks and 61 (54.5%) sick cats, presenting systemic clinical signs suggesting CKD, such as weight loss or polyuria/polydipsia, among others.
Based on UPC, the present study found that 54.5% of all cats included were borderline proteinuric or proteinuric, having increased UPC (UPC ≥ 0.2), with 35.7% included in the sick group and 18.7% in the health-check group. Increased UPC was also statistically associated with azotemia and isosthenuria (urinary-specific gravity between 1,008 and 1,035) in both sick and health-check groups of cats.
Independent of the reason for their medical visit, it could be concluded that borderline proteinuria and proteinuria were statistically mainly related to CKD in cats. Furthermore, the measurement of UPC could be very useful in the detection and management of CKD in apparently healthy cats during a medical visit for annual health check irrespective of the age.
Esculetin (6,7-dihydroxycoumarin) and daphnetin (7,8-dihydroxycoumarin) are secondary metabolites of plants used in folk medicine. These compounds have showed great antiproliferative activity in ...several tumor cell lines and have been proposed as potential anticancer agents. However, the estrogenic potential of these two compounds has to date not been reported. The present study compared esculetin and daphnetin on the inhibition of cell proliferation and cell cycle progression of the MCF-7 estrogen-responsive human carcinoma cell line. In vivo and in vitro estrogenic activity for both compounds was also evaluated. Esculetin inhibited cell proliferation after 72h exposure (IC50=193±6.6μM), while daphnetin evidenced inhibiting effects starting at 24-h exposure (72h, IC50=73±4.1μM). Both effects showed changes in cyclin D1 gene expression. In non-estrogenic conditions (E-screening assay), esculetin produced biphasic response on proliferation of the MCF-7 cells; at 10−8–10−6M, concentrations induced proliferative effects as EC50=4.07×10−9M (E2=2.91×10−12M); at higher concentrations (10−5–10−4M), cell proliferation was inhibited. Relative proliferative effect at E2 was 52% (E2=100), relative proliferative potency was 0.072 (E2=100). Additionally, esculetin tested in vivo showed estrogenic effects at 50–100mg/kg doses; relative uterotrophic effect at E2 was 37%, with relative uterotrophic potency registered at 0.003. In contrast, daphnetin did not induce estrogenic effects in vitro or with in vivo models. The low estrogenic activity of esculetin could prove useful in postmenopausal therapy but not as a safe antitumor agent in estrogen-dependent tumors. Daphnetin-based antiproliferative selectivity with MCF-7 cells showed that daphnetin is a promising antitumoral agent also acting on estrogen dependent tumors.
This paper presents the synthesis of NiO and NiFe2O4 nanoparticles (NPs), with an average crystallite size of 7 ± 0.6 and 5 ± 0.4 nm respectively, by a simple, low-cost, and environmentally friendly ...mechanochemical method. X-ray diffraction (XRD) patterns and high-resolution transmission electron microscopy (HR-TEM) reveal that NiO and NiFe2O4 NPs possess a cubic crystal structure. Their corresponding Raman scattering spectra confirm the structure and composition of these nanoparticles, and the band gap energy was determined from their Tauc's plot, being 3.44 eV for NiO and 1.55 eV for NiFe2O4. A strong confinement was observed for NiFe2O4 NPs because it exhibits a superparamagnetic behavior at room temperature. Besides, the antibacterial activity of these NPs against two opportunistic pathogens Pseudomonas aeruginosa (ATCC 43,636) and Staphylococcus aureus (ATCC 23,235), was tested in vitro. The results obtained from the microbroth dilution method showed that NiO and NiFe2O4 NPs inhibit 100% and 70% of the P. aeruginosa growth, respectively, while both oxides, inhibit 100% of S. aureus growth. The methodology presented in this work allowed us to obtain NPs with small size, low polydispersity, defined morphology, and is particularly suitable to produce other NPs of metal oxides.
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This study presents an in vitro analysis of the bactericidal and cytotoxic properties of hybrid films containing nickel oxide (NiO) and nickel ferrite (NiFe2O4) nanoparticles embedded in ...polypropylene (PP). The solvent casting method was used to synthesize films of PP, PP@NiO, and PP@NiFe2O4, which were characterized by different spectroscopic and microscopic techniques. The X-ray diffraction (XRD) patterns confirmed that the small crystallite sizes of NiO and NiFe2O4 NPs were maintained even after they were incorporated into the PP matrix. From the Raman scattering spectroscopy data, it was evident that there was a significant interaction between the NPs and the PP matrix. Additionally, the Scanning Electron Microscopy (SEM) analysis revealed a homogeneous dispersion of NiO and NiFe2O4 NPs throughout the PP matrix. The incorporation of the NPs was observed to alter the surface roughness of the films; this behavior was studied by atomic force microscopy (AFM). The antibacterial properties of all films were evaluated against Pseudomonas aeruginosa (ATCC®: 43636™) and Staphylococcus aureus (ATCC®: 23235™), two opportunistic and nosocomial pathogens. The PP@NiO and PP@ NiFe2O4 films showed over 90% bacterial growth inhibition for both strains. Additionally, the effects of the films on human skin cells, such as epidermal keratinocytes and dermal fibroblasts, were evaluated for cytotoxicity. The PP, PP@NiO, and PP@NiFe2O4 films were nontoxic to human keratinocytes. Furthermore, compared to the PP film, improved biocompatibility of the PP@NiFe2O4 film with human fibroblasts was observed. The methodology utilized in this study allows for the production of hybrid films that can inhibit the growth of Gram-positive bacteria, such as S. aureus, and Gram-negative bacteria, such as P. aeruginosa. These films have potential as coating materials to prevent bacterial proliferation on surfaces.
Actualmente existe un gran interés en Centro de Ciencias Aplicadas y Desarrollo Tecnológico (CCADET) de la UNAM, por el desarrollo de métodos innovadores que permitan obtener materiales ...nanoestructurados y en particular aquellos formados por óxidos metálicos, con actividad antimicrobiana. En este artículo se presenta lo que el grupo de investigación de la Dra. América Vázquez ha llevado a cabo sobre la mecanosíntesis de una serie de óxidos nanoestructurados formados por CuO, CuBi2O4, ZnO, Mn3O4, Fe2O3, CuFe2O4, ZnFe2O4 y MgO, así como una revisión sobre las aplicaciones de dichos óxidos, como agentes antimicrobianos.
La principal motivación de esta investigación radica en el hecho de que el desarrollo de nuevos antibióticos, a pesar de ser constante, resulta inútil cuando los microorganismos se vuelven multirresistentes. Por tal razón, se han buscado nuevas formas de combatir dichas infecciones y en este sentido, las nanopartículas (NPs) formadas por óxidos metálicos han resultado ser una nueva herramienta en la lucha contra las enfermedades causadas por microorganismos que cada vez se vuelven más resistentes a los tratamientos convencionales con diversos antibióticos.
MIA 2021, Manejo Integral del Asma. Lineamientos para México Larenas-Linnemann, Désirée; Salas-Hernández, Jorge; Del Río-Navarro, Blanca E. ...
Revista alergia Mexico (Tecamachalco, Pueblo, Mexico : 1993),
07/2021, Letnik:
68, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Antecedentes: El asma sigue siendo una patología respiratoria crónica frecuente en México. Se han descrito nuevos métodos para el diagnóstico y tratamiento conforme se renuevan las guías ...internacionales.
Objetivo: Crear la plataforma nacional Manejo Integral del Asma (MIA), para el desarrollo de lineamientos actualizados con base en evidencia.
Métodos: Se utilizó el método ADAPTE. El grupo de desarrollo de MIA estuvo integrado por expertos en neumología, alergología y metodología y representantes de 13 instituciones y sociedades de especialidades que manejan asma. Las guías internacionales de referencia (seleccionadas con AGREE-II) fueron GINA 2020, GEMA 5.0, BTS/SIGN 2019 y consenso ATS/ERS 2014-2019. En MIA se aborda sospecha de asma, diagnóstico, tratamiento y grupos especiales. Se formularon preguntas clínicas clave sobre tratamiento en los pasos 1 a 3, biomarcadores y asma grave.
Resultados: Con base en evidencia, seguridad, costo y realidad local, el grupo nuclear desarrolló respuestas. Mediante proceso Delphi, el grupo amplio de desarrollo sugirió ajustes hasta que se logró el consenso.
Conclusión: El documento generado contiene múltiples figuras y algoritmos, está sólidamente basado en evidencia acerca del manejo del asma y fue ajustado para México con participación de diferentes sociedades para su desarrollo; no se incluyeron lineamientos para la crisis asmática.
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