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BACKGROUND: The ideal blood pressure target level for preventing cognitive decline or dementia in patients with systemic arterial hypertension (SAH) remains unclear. PURPOSE: This study aims to investigate whether intensive blood pressure reduction compared to standard treatment is associated with a reduced risk of cognitive decline or dementia in adults with SAH. METHODS: PubMed, Scopus and Cochrane databases were searched for randomized clinical trials (RCTs) comparing intensive treatment versus standard treatment for blood pressure reduction in patients with SAH. A random-effects model was used for analyzing the results, which were presented as relative risk (RR) with a 95% confidence interval (CI). Heterogeneity was examined using the I² statistic. Statistical analysis was performed using R software version 4.2.3. RESULTS: A total of 5 RCTs and 46,658 patients were included, of whom 23,726 (50,85%) underwent intensive therapy for SAH treatment. The mean age of participants ranged from 62.8 to 80.9 years in the intensive treatment group while it ranged from 63.3 to 80.3 years in the standard treatment group. Occurrence of dementia or probable dementia was significantly lower in the intensive treatment group (3.8% vs. 4,3%; RR 0.88; 95% CI: 0.80 - 0.96; p= 0.0049; I²=0%). Dementia or Cognitive decline (16.4% vs. 18.8%; RR 0.87; 95% CI 0.83 - 0.90; p < 0.000001; I²=0%), and cognitive decline (13.2% vs. 15.2%; RR 0.88; 95% CI 0.80 - 0.98; p= 0.014; I²=53%) also tended towards the intensive treatment group. Additionally, no significant association was found in mortality (6.4% vs. 7.3%; RR 0.87; 95% CI 0.75 - 1.02; p= 0.09; I²=28%) and serious adverse effects (34.4% vs. 35.5%; RR 0.99; 95% CI 0.92 - 1.06; p=0.73; I²=63%). CONCLUSION: Our study shows that intensive blood pressure treatment is associated with a fewer occurrence of dementia, probable dementia and cognitive decline in comparison to the standard blood pressure target.
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Humanos , Anciano , Anciano de 80 o más Años , Terapéutica , Presión Sanguínea , Demencia , Disfunción Cognitiva , HipertensiónRESUMEN
Hybrid diamond-like carbon (DLC) with incorporated titanium dioxide (TiO2) nanoparticle coatings have low friction coefficient, high wear resistance, high hardness, biocompatibility, and high chemical stability. They could be employed to modify biomedical alloys surfaces for numerous applications in biomedical engineering. Here we investigate for the first time the in vivo inflammatory process of DLC coatings with incorporated TiO2 nanoparticles. TiO2-DLC films were grown on AISI 316 stainless-steel substrates using plasma-enhanced chemical vapor deposition. The coated substrates were implanted in CF1 mice peritoneum. The in vivo cytotoxicity and biocompatibility of the samples were analyzed from macrophage lavage. Analysis in the first weeks after implantation could be helpful to evaluate the acute cytotoxicity generated after a possible inflammatory process. The in vivo results showed no inflammatory process. A significant increase in nitric oxide production on the uncoated substrates was confirmed through cytometry, and the coated substrates demonstrated biocompatibility. The presence of TiO2 nanoparticles enhanced the wound healing activity, due to their astringent and antimicrobial properties. DLC and TiO2-DLC coatings were considered biocompatible, and the presence of TiO2 nanoparticles reduced the inflammatory reactions, increasing DLC biocompatibility.
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Carbono/química , Membranas Artificiales , Nanopartículas del Metal/química , Prótesis e Implantes , Titanio/química , Aleaciones , Animales , Carbono/farmacología , Materiales Biocompatibles Revestidos/síntesis química , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Diamante/química , Dureza , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/fisiología , Ensayo de Materiales , Nanopartículas del Metal/uso terapéutico , Ratones , Acero Inoxidable/química , Acero Inoxidable/farmacología , Propiedades de Superficie , Titanio/farmacologíaRESUMEN
Recently, the development of coatings to protect biomedical alloys from oxidation, passivation and to reduce the ability for a bacterial biofilm to form after implantation has emerged. Diamond-like carbon films are commonly used for implanted medical due to their physical and chemical characteristics, showing good interactions with the biological environment. However, these properties can be significantly improved when titanium dioxide nanoparticles are included, especially to enhance the bactericidal properties of the films. So far, the deposition of hydroxyapatite on the film surface has been studied in order to improve biocompatibility and bioactive behavior. Herein, we developed a new route to obtain a homogeneous and crystalline apatite coating on diamond-like carbon films grown on 304 biomedical stainless steel and evaluated its antibacterial effect. For this purpose, films containing two different concentrations of titanium dioxide (0.1 and 0.3g/L) were obtained by chemical vapor deposition. To obtain the apatite layer, the samples were soaked in simulated body fluid solution for up to 21days. The antibacterial activity of the films was evaluated by bacterial eradication tests using Staphylococcus aureus biofilm. Scanning electron microscopy, X-ray diffraction, Raman scattering spectroscopy, and goniometry showed that homogeneous, crystalline, and hydrophilic apatite films were formed independently of the titanium dioxide concentration. Interestingly, the diamond-like films containing titanium dioxide and hydroxyapatite reduced the biofilm formation compared to controls. A synergism between hydroxyapatite and titanium dioxide that provided an antimicrobial effect against opportunistic pathogens was clearly observed.
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Biopelículas , Carbono , Materiales Biocompatibles Revestidos , Diamante , Nanopartículas del Metal , Staphylococcus aureus , Propiedades de Superficie , TitanioRESUMEN
Graphene oxide nanoribbons (O-GNR) surges as an interesting nanomaterial for biomedical applications due to feasibility to incorporate functional groups and possible bactericidal properties. Herein, high concentrations of O-GNR were biologically evaluated using human osteoblast cells and gram positive and negative bacteria. Briefly, our goal were to evaluate: (1) synthetic pathway, (2) characterization and (3) effects of O-GNR composition and structural factors as a new approach for biomedical applications. For this, O-GNR were produced combining chemical vapor deposition and oxygen plasma treatment of multiwalled carbon nanotubes. Then, we analyzed the bioactivity, cell viability, osteogenic differentiation, matrix mineralization, mRNA levels of the five genes related direct to bone repair and bactericidal effect of high concentrations of O-GNR (10µgmL-1, 100µgmL-1, 200µgmL-1 and 300µgmL-1). Impressively, O-GNR showed no cytotoxic effects up to a concentration of 100µgmL-1 and no gene expression alteration when used in its dose. We also observed that S. aureus and E. coli bacteria are susceptible to damage when incubated with 100µgmL-1 of O-GNR, showing approximately 50% of bacterial death. We consider that O-GNR displays attractive properties when used at a suitable dose, displaying bactericidal effect and apparently lacking to cause damages in the bone repair process.
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Nanotubos de Carbono , Regeneración Ósea , Escherichia coli , Grafito , Humanos , Nanoestructuras , Osteogénesis , Óxidos , Staphylococcus aureusRESUMEN
Researchers have been looking for modifying surfaces of polymeric biomaterials approved by FDA to obtain nanofeatures and bactericidal properties. If modified, it would be very interesting because the antibiotic administration could be reduced and, therefore, the bacterial resistance. Here, we report the electrospinning of poly (lactic acid) (PLA) with high loadings of titanium dioxide nanoparticles (TiO2, 1-5wt%) and their bactericidal properties. TiO2 nanoparticles have been recognized for a long time for their antibacterial, low cost and self-cleaning properties. However, their ability to reduce bacteria functions when used in polymers has not been well studied to date. In this context, we aimed here to generate nanostructured PLA electrospun fiber-TiO2 nanoparticle composites for further evaluation of their bactericidal activity and cell viability. TEM and SEM micrographs revealed the successful electrospinning of PLA/TiO2 and the generation of polymer-TiO2 nanostructures. When increasing the TiO2 concentration, we observed a proportional increase in the nanoparticle density along the fiber and surface. The nanostructured PLA/TiO2 nanofibers showed no mammalian cell toxicity and, most importantly, possessed bactericidal activity with higher TiO2 loads. Such results suggest that the present PLA electrospun fiber-TiO2 nanoparticle composites should be further studied for a wide range of biomedical applications.
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Antibacterianos , Nanofibras/química , Nanopartículas/química , Poliésteres , Staphylococcus aureus/crecimiento & desarrollo , Titanio , Animales , Antibacterianos/química , Antibacterianos/farmacología , Línea Celular , Humanos , Poliésteres/química , Poliésteres/farmacología , Ratas , Titanio/química , Titanio/farmacologíaRESUMEN
Electrospinning is a simple and low-cost way to fabricate fibers. Among the various polymers used in electrospinning process, the poly (lactic acid) (PLA) stands out due to its excellent biodegradability and biocompatibility. Calcium phosphate ceramics has been recognized as an attractive biomaterial because their chemical composition is similar to the mineral component of the hard tissue in the body. Furthermore, they are bioactive and osteoinductive and some are even quite biodegradable. The beta-tricalcium phosphate (ß-TCP) particles were synthesized by solid state reaction. Different contents of ß-TCP particles were incorporated in polymer matrices to form fibers of PLA/ß-TCP composites by electrospinning aiming a possible application as a scaffold for tissue engineering. The fibers were characterized by scanning electron microscopy (SEM), infrared (FTIR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The average diameter of the fibers varied in the range of 260-519.6 ± 50 nm. The presence of ß-TCP particles promoted changes on thermal properties of the fibers. The composite with 8 wt-% of ß-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. The cell viability was analyzed by reduction of the methyl tetrazolium salt by the pyruvate dehydrogenase enzymatic complex present in the matrix of mitochondria (MTT test). All PLA fiber groups, with different contents of ß-TCP, showed cytocompatibility ability with non-cytotoxicity effect and bioactive properties using SBF assay.
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Materiales Biocompatibles/química , Fosfatos de Calcio/química , Ácido Láctico/química , Polímeros/química , Ingeniería de Tejidos/métodos , Materiales Biocompatibles/farmacología , Fosfatos de Calcio/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Ensayo de Materiales , Microscopía Electroquímica de Rastreo , PoliésteresRESUMEN
Graphene and carbon nanotube nanocomposite (GCN) was synthesised and applied in gene transfection of pIRES plasmid conjugated with green fluorescent protein (GFP) in NIH-3T3 and NG97 cell lines. The tips of the multi-walled carbon nanotubes (MWCNTs) were exfoliated by oxygen plasma etching, which is also known to attach oxygen content groups on the MWCNT surfaces, changing their hydrophobicity. The nanocomposite was characterised by high resolution scanning electron microscopy; energy-dispersive X-ray, Fourier transform infrared and Raman spectroscopies, as well as zeta potential and particle size analyses using dynamic light scattering. BET adsorption isotherms showed the GCN to have an effective surface area of 38.5m(2)/g. The GCN and pIRES plasmid conjugated with the GFP gene, forming π-stacking when dispersed in water by magnetic stirring, resulting in a helical wrap. The measured zeta potential confirmed that the plasmid was connected to the nanocomposite. The NIH-3T3 and NG97 cell lines could phagocytize this wrap. The gene transfection was characterised by fluorescent protein produced in the cells and pictured by fluorescent microscopy. Before application, we studied GCN cell viability in NIH-3T3 and NG97 line cells using both MTT and Neutral Red uptake assays. Our results suggest that GCN has moderate stability behaviour as colloid solution and has great potential as a gene carrier agent in non-viral based therapy, with low cytotoxicity and good transfection efficiency.