Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 168
Filtrar
1.
J Hazard Mater ; 470: 134190, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38593659

RESUMO

Organophosphorus compounds (OPs), such as VX, pose a significant threat due to their neurotoxic and hazardous properties. Skin decontamination is essential to avoid irreversible effects. Fuller's earth (FE), a phyllosilicate conventionally employed in powder form, has demonstrated decontamination capacity against OPs. The aim of this study was to develop a formulation that forms a film on the skin, with a significant OP removal capacity (>95 %) coupled with sequestration capabilities, favorable drying time and mechanical properties to allow for easy application and removal, particularly in emergency context. Various formulations were prepared using different concentrations of polyvinyl alcohol (PVA), FE and surfactants. Their removal and sequestration capacity was tested using paraoxon-ethyl (POX), a chemical that simulates the behavior of VX. Formulations with removal capacity levels surpassing 95 % were mechanically characterized and cell viability assays were performed on Normal Human Dermal Fibroblast (NHDF). The four most promising formulations were used to assess decontamination efficacy on pig ear skin explants. These formulations showed decontamination levels ranging from 84.4 ± 4.7 % to 96.5 ± 1.3 %, which is equivalent to current decontamination methods. These results suggest that this technology could be a novel and effective tool for skin decontamination following exposure to OPs.


Assuntos
Descontaminação , Paraoxon , Pele , Descontaminação/métodos , Animais , Pele/efeitos dos fármacos , Humanos , Suínos , Paraoxon/toxicidade , Paraoxon/química , Compostos de Alumínio/química , Sobrevivência Celular/efeitos dos fármacos , Silicatos/química , Álcool de Polivinil/química , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Tensoativos/química , Fibroblastos/efeitos dos fármacos
2.
Int J Biol Macromol ; 267(Pt 2): 131412, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38593894

RESUMO

The synthesis of ideal bioceramics to guide the fate of cells and subsequent bone regeneration within the chemical, biological, and physical microenvironment is a challenging long-term task. This study developed amorphous calcium magnesium phosphate (ACMP) bioceramics via a simple co-precipitation method. The role of Mg2+ in the formation of ACMP is investigated using physicochemical and biological characterization at different Ca/Mg molar ratio of the initial reaction solution. Additionally, ACMP bioceramics show superior cytocompatibility and improved osteogenic differentiation of co-cultured MC3T3-E1 cells. Regulation of the microenvironment with Mg2+ can promote early-stage bone regeneration. For this, bioprinting technology is employed to prepare ACMP-modified 3D porous structures. Our hypothesis is that the incorporation of ACMP into methacrylated gelatin (GelMA) bioink can trigger the osteogenic differentiation of encapsulated preosteoblast and stimulate bone regeneration. The cell-laden ACMP composite structures display stable printability and superior cell viability and cell proliferation. Also, constructs loading the appropriate amount of ACMP bioceramic showed significant osteogenic differentiation activity compared to the pure GelMA. We demonstrate that the dissolved Mg2+ cation microenvironment in ACMP-modified composite constructs plays an effective biochemical role, and can regulate cell fate. Our results predict that GelMA/ACMP bioink has significant potential in patient-specific bone tissue regeneration.


Assuntos
Bioimpressão , Regeneração Óssea , Fosfatos de Cálcio , Diferenciação Celular , Osteogênese , Impressão Tridimensional , Alicerces Teciduais , Regeneração Óssea/efeitos dos fármacos , Camundongos , Animais , Osteogênese/efeitos dos fármacos , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Diferenciação Celular/efeitos dos fármacos , Bioimpressão/métodos , Alicerces Teciduais/química , Proliferação de Células/efeitos dos fármacos , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Linhagem Celular , Engenharia Tecidual/métodos , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Fosfatos/química , Fosfatos/farmacologia
3.
ACS Appl Mater Interfaces ; 16(17): 21672-21688, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38637290

RESUMO

Titanium (Ti) and its alloys are widely used as hard tissue substitutes in dentistry and orthopedics, but their low bioactivity leads to undesirable osseointegration defects in the early osteogenic phase. Surface modification is an important approach to overcome these problems. In the present study, novel magnesium phosphate (MgP) coatings with controllable structures were fabricated on the surface of Ti using the phosphate chemical conversion (PCC) method. The effects of the microstructure on the physicochemical and biological properties of the coatings on Ti were researched. The results indicated that accelerators in PCC solution were important factors affecting the microstructure and properties of the MgP coatings. In addition, the coated Ti exhibited excellent hydrophilicity, high bonding strength, and good corrosion resistance. Moreover, the biological results showed that the MgP coatings could improve the spread, proliferation, and osteogenic differentiation of mouse osteoblast cells (MC3T3-E1) and vascular differentiation of human umbilical vein endothelial cells (HUVECs), indicating that the coated Ti samples had a great effect on promoting osteogenesis and angiogenesis. Overall, this study provided a new research idea for the surface modification of conventional Ti to enhance osteogenesis and angiogenesis in different bone types for potential biomedical applications.


Assuntos
Diferenciação Celular , Proliferação de Células , Materiais Revestidos Biocompatíveis , Células Endoteliais da Veia Umbilical Humana , Compostos de Magnésio , Neovascularização Fisiológica , Osteogênese , Fosfatos , Titânio , Titânio/química , Titânio/farmacologia , Osteogênese/efeitos dos fármacos , Animais , Camundongos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Fosfatos/química , Fosfatos/farmacologia , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Propriedades de Superfície , Linhagem Celular , Angiogênese
4.
Int J Biol Macromol ; 266(Pt 1): 130998, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38521332

RESUMO

Although calcium­magnesium phosphate cements (CMPCs) have been widely applied to treating critical-size bone defects, their repair efficiency is unsatisfactory owing to their weak surface bioactivity and uncontrolled ion release. In this study, we lyophilized alginate sodium (AS) as a coating onto HAp/K-struvite (H@KSv) to develop AS/HAp/K-struvite (AH@KSv), which promotes bone regeneration. The compressive strength and hydrophilicity of AH@KSv significantly improved, leading to enhanced cell adhesion in vitro. Importantly, the SA coating enables continuous ions release of Mg2+ and Ca2+, finally leading to enhanced osteogenesis in vitro/vivo and different patterns of new bone ingrowth in vivo. Furthermore, these composites increased the expression levels of biomarkers of the TRPM7/PI3K/Akt signaling pathway via an equilibrium effect of Mg2+ to Ca2+. In conclusion, our study provides novel insights into the mechanisms of Mg-based biomaterials for bone regeneration.


Assuntos
Alginatos , Cimentos Ósseos , Regeneração Óssea , Fosfatos , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Canais de Cátion TRPM , Regeneração Óssea/efeitos dos fármacos , Canais de Cátion TRPM/metabolismo , Alginatos/química , Alginatos/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Fosfatos/química , Fosfatos/farmacologia , Cimentos Ósseos/química , Cimentos Ósseos/farmacologia , Osteogênese/efeitos dos fármacos , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Adesão Celular/efeitos dos fármacos , Propriedades de Superfície , Camundongos , Ratos , Força Compressiva
5.
J Appl Biomater Funct Mater ; 20: 22808000221136369, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36416210

RESUMO

The insufficient osteogenesis of magnesium phosphate cements (MPCs) limits its further application. It is significant to develop a bioactive MPC with osteogenic properties. In this work, MPCs were reinforced by zinc oxide nanoparticles (ZnO-NPs). The composition, microstructure, setting time, compressive strength and degradation of ZnO-NPs/MPCs (ZNMPCs) were evaluated. The results showed that the setting times of MPCs were prolonged from 8.2 to 25.3 min (5.0ZNMPC). The exothermic temperatures were reduced from 45.8 ± 0.4℃ (MPCs) to 39.3 ± 0.5℃ (1.0ZNMPC). The compressive strength of ZNMPC composite cement with 1 wt. % ZnO-NPs (1.0ZNMPC) was the highest (42.9 MPa) among all the composite cements. Furthermore, the ZNMPCs were cultured with mouse bone marrow mesenchymal stem cells (mBMSCs). The results yielded that the ZNMPCs exhibited good cytocompatibility with enhanced differentiation, proliferation, and mineralization on mBMSCs, and it also pronouncedly elevated the expressions of genes and proteins involving osteogenesis. These findings suggested that ZNMPCs could drive the differentiation toward osteogenesis and mineralization of mBMSCs, providing a simple way to the MPC with enhanced osteogenesis for further orthopedic applications.


Assuntos
Células-Tronco Mesenquimais , Óxido de Zinco , Camundongos , Animais , Osteogênese , Óxido de Zinco/farmacologia , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia
6.
Molecules ; 26(19)2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34641589

RESUMO

Pristine high-density bulk disks of MgB2 with added hexagonal BN (10 wt.%) were prepared using spark plasma sintering. The BN-added samples are machinable by chipping them into desired geometries. Complex shapes of different sizes can also be obtained by the 3D printing of polylactic acid filaments embedded with MgB2 powder particles (10 wt.%). Our present work aims to assess antimicrobial activity quantified as viable cells (CFU/mL) vs. time of sintered and 3D-printed materials. In vitro antimicrobial tests were performed against the bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecium DSM 13590, and Enterococcus faecalis ATCC 29212; and the yeast strain Candida parapsilosis ATCC 22019. The antimicrobial effects were found to depend on the tested samples and microbes, with E. faecium being the most resistant and E. coli the most susceptible.


Assuntos
Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Compostos de Boro/farmacologia , Fungos/efeitos dos fármacos , Compostos de Magnésio/farmacologia , Candida parapsilosis/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecium/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Poliésteres/farmacologia , Impressão Tridimensional , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
7.
Bull Exp Biol Med ; 171(3): 338-341, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34297285

RESUMO

The neurotrophic properties of magnesium comenate were studied under standard conditions and under conditions of oxidative stress. It was found that magnesium comenate has a stimulating effect on the neurotrophic processes of the spinal ganglia under normal conditions and under conditions of oxidative stress. Under standard conditions, magnesium comenate exhibits neurotrophic activity at a concentration of 0.0001 mM, under conditions of oxidative stress, magnesium comenate exhibits neurotrophic activity at concentration 0.1 mM.


Assuntos
Ácidos Carboxílicos/farmacologia , Gânglios Espinais/efeitos dos fármacos , Compostos de Magnésio/farmacologia , Crescimento Neuronal/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Pironas/farmacologia , Animais , Embrião de Galinha , Gânglios Espinais/metabolismo , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo , Técnicas de Cultura de Tecidos
8.
J Mater Chem B ; 9(28): 5698-5710, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34223587

RESUMO

Ischemia and hypoxia in the bone defect area remain an intractable problem when treating large bone defects. Thus, oxygen-releasing biomaterials have been widely researched in recent years. Magnesium peroxide (MgO2) can release oxygen (O2), and magnesium ions (Mg2+), simultaneously, which is seen to have significant potential in bone substitutes. In this study, we used 3D printing technology to fabricate a MgO2-contained composite scaffold, which was composed of polycaprolactone (PCL), beta-tricalcium phosphate (ß-TCP) and magnesium peroxide (MgO2). Physical properties and O2/Mg2+ releasing behavior of the scaffold were studied. Then, we evaluated the effects of the scaffold on cell survival, proliferation, migration, adhesion and osteogenic differentiation by the co-culture of bone marrow mesenchymal stem cells (BMSCs) and scaffold under normoxia and hypoxia in vitro. Finally, the osteogenic properties of the scaffold in vivo were evaluated via the rat femoral condylar bone defect model. The PCL/ß-TCP/MgO2 scaffold showed good mechanical properties and sustained O2 and Mg2+ release for about three weeks. Meanwhile, the scaffold showed appreciable promotion on the survival, proliferation, migration and osteogenic differentiation of BMSCs under hypoxia compared with control groups. The results of imaging studies and histological analysis showed that implantation of PCL/ß-TCP/MgO2 scaffold could promote seed cell survival and significantly increased new bone formation. In sum, the PCL/ß-TCP/MgO2 scaffold is promising with great potential for treating large bone defects.


Assuntos
Substitutos Ósseos/farmacologia , Fosfatos de Cálcio/farmacologia , Compostos de Magnésio/farmacologia , Transplante de Células-Tronco Mesenquimais , Peróxidos/farmacologia , Poliésteres/farmacologia , Impressão Tridimensional , Animais , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/química , Fosfatos de Cálcio/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Compostos de Magnésio/química , Masculino , Células-Tronco Mesenquimais/citologia , Osteogênese/efeitos dos fármacos , Oxigênio/metabolismo , Peróxidos/química , Poliésteres/química , Ratos , Ratos Sprague-Dawley
9.
Chem Biol Interact ; 336: 109393, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33508307

RESUMO

Skin decontamination following exposure to chemical agents is a most important component of the individual defense doctrine, removing the agent, ceasing its penetration and preventing secondary contamination of the first responders. The goal of the current study was to compare the efficacy of Reactive Skin Decontaminant Lotion (RSDL) and Fuller's Earth (FE) following exposure to sulfur mustard (SM) and VX, aiming to find the optimal procedure for mass casualty decontamination protocol. Decontamination efficacy was evaluated in pigs by measurement of lesion area and erythema (SM) and cholinesterase inhibition and clinical symptoms (VX). FE and RSDL were highly effective against both agents. Following SM exposure, the two decontaminants demonstrated a significant decrease in lesions' size together with the decrease in exposure duration. Likewise, skin decontamination following exposure to VX with either FE or RSDL resulted in reduction in clinical symptoms and prevention of death. Decontamination was worthwhile even if postponed, up to 30 min (SM) and 2 h (VX). In conclusion, both decontamination products were efficient in ameliorating the toxic effects even though in a different mechanism. Finally, for mass casualty scenario, FE is preferred as a universal decontaminant, considering its safety, ease of use and longer shelf life.


Assuntos
Compostos de Alumínio/farmacologia , Descontaminação , Compostos de Magnésio/farmacologia , Modelos Animais , Gás de Mostarda/farmacologia , Compostos Organotiofosforados/farmacologia , Silicatos/farmacologia , Creme para a Pele/farmacologia , Pele/efeitos dos fármacos , Suínos , Animais , Feminino , Pele/patologia
10.
Int J Mol Sci ; 22(2)2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33478090

RESUMO

Magnesium (Mg)-based biomaterials hold considerable promise for applications in regenerative medicine. However, the degradation of Mg needs to be reduced to control toxicity caused by its rapid natural corrosion. In the process of developing new Mg alloys with various surface modifications, an efficient assessment of the relevant properties is essential. In the present study, a WE43 Mg alloy with a plasma electrolytic oxidation (PEO)-generated surface was investigated. Surface microstructure, hydrogen gas evolution in immersion tests and cytocompatibility were assessed. In addition, a novel in vitro immunological test using primary human lymphocytes was introduced. On PEO-treated WE43, a larger number of pores and microcracks, as well as increased roughness, were observed compared to untreated WE43. Hydrogen gas evolution after two weeks was reduced by 40.7% through PEO treatment, indicating a significantly reduced corrosion rate. In contrast to untreated WE43, PEO-treated WE43 exhibited excellent cytocompatibility. After incubation for three days, untreated WE43 killed over 90% of lymphocytes while more than 80% of the cells were still vital after incubation with the PEO-treated WE43. PEO-treated WE43 slightly stimulated the activation, proliferation and toxin (perforin and granzyme B) expression of CD8+ T cells. This study demonstrates that the combined assessment of corrosion, cytocompatibility and immunological effects on primary human lymphocytes provide a comprehensive and effective procedure for characterizing Mg variants with tailorable degradation and other features. PEO-treated WE43 is a promising candidate for further development as a degradable biomaterial.


Assuntos
Materiais Revestidos Biocompatíveis , Magnésio/química , Teste de Materiais , Animais , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacocinética , Materiais Revestidos Biocompatíveis/farmacologia , Corrosão , Equipamentos e Provisões , Humanos , Sistema Imunitário/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Linfócitos/fisiologia , Magnésio/farmacocinética , Magnésio/farmacologia , Compostos de Magnésio/química , Compostos de Magnésio/farmacocinética , Compostos de Magnésio/farmacologia , Teste de Materiais/métodos , Camundongos , Oxirredução
11.
Macromol Biosci ; 21(1): e2000299, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33043625

RESUMO

Injectable hydrogels for nonsteroidal anti-inflammatory drugs' (NSAIDs) delivery to minimize the side effects of NSAIDs and achieve long-term sustained release at the targeted site of synovial joint are attractive for osteoarthritis therapy, but how to improve its mechanical strength remains a challenge. In this work, a kind of 1D natural clay mineral material, attapulgite (ATP), is introduced to a classical cyclodextrin pseudopolyrotaxane (PPR) system to form a reinforced supramolecular hydrogel for sustained release of diclofenac sodium (DS) due to its rigid, rod-like morphology, and unique structure, which has great potential in tissue regeneration, repair, and engineering. Investigation on the interior morphology and rheological property of the obtained hydrogel points out that the ATP distributed in PPR hydrogel plays a role similar to the "reinforcement in concrete" and exhibits a positive effect on improving the mechanical properties of PPR hydrogel by regulating their interior morphology from a randomly distributed style to the well-ordered porous frame structure. The hybrid hydrogels demonstrate good shear-thinning and thixotropic properties, excellent biocompability, and sustained release behavior both in vitro and in vivo. Furthermore, preliminary in vivo treatment in an acute inflammatory rat model reveals that the ATP hybrid hydrogels present sustained anti-inflammatory effect.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Regeneração Óssea/efeitos dos fármacos , Hidrogéis/farmacologia , Compostos de Magnésio/farmacologia , Osteoartrite/tratamento farmacológico , Compostos de Silício/farmacologia , Animais , Anti-Inflamatórios não Esteroides/efeitos adversos , Ciclodextrinas/farmacologia , Diclofenaco/farmacologia , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos/efeitos dos fármacos , Humanos , Hidrogéis/química , Injeções Intra-Articulares , Osteoartrite/patologia , Poloxâmero/farmacologia , Polietilenoglicóis/farmacologia , Ratos , Rotaxanos/farmacologia
12.
IUBMB Life ; 73(2): 418-431, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33372380

RESUMO

Vibrio cholerae is the causative agent of the diarrheal disease cholera, for which biofilm communities are considered to be environmental reservoirs. In endemic regions, and after algal blooms, which may result from phosphate enrichment following agricultural runoff, the bacterium is released from biofilms resulting in seasonal disease outbreaks. However, the molecular mechanism by which V. cholerae senses its environment and switches lifestyles from the biofilm-bound state to the planktonic state is largely unknown. Here, we report that the major biofilm scaffolding protein RbmA undergoes autocatalytic proteolysis via a phosphate-dependent induced proximity activation mechanism. Furthermore, we show that RbmA mutants that are defective in autoproteolysis cause V. cholerae biofilms to grow larger and mechanically stronger, correlating well with the observation that RbmA stability directly affects microbial community homeostasis and rheological properties. In conclusion, our biophysical study characterizes a novel phosphate-dependent breakdown pathway of RbmA, while microbiological data suggest a new, sensory role of this biofilm scaffolding element.


Assuntos
Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Compostos de Magnésio/farmacologia , Fosfatos/farmacologia , Proteólise , Vibrio cholerae/metabolismo , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Vibrio cholerae/efeitos dos fármacos , Vibrio cholerae/crescimento & desenvolvimento
13.
Int J Biol Macromol ; 165(Pt A): 1276-1285, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33035527

RESUMO

Active silica nanorod (OPal) was prepared from natural palygorskite (RPal) using an updated acid leaching route, and then the effect of RPal and OPal as nano-filler on the network structure, mechanical, thermal and anti-aging properties of chitosan/polyvinylpyrrolidone (CS/PVP) films was studied comparatively. It was revealed that OPal had a better dispersibility than RPal in CS/PVP substrate, and its incorporation improved the mechanical properties and thermal stability of the films significantly. The optimal composite film containing OPal shows the maximum tensile strength of 27.53 MPa (only 14.87 MPa and 22.47 MPa for CS/PVP and CS/PVP/RPal films, respectively), resulting from the more uniform dispersion of OPal in polymer substrate and its stronger interaction with 3D polymer network. By a controllable acid-leaching process, the metal ions in octahedral sheets of RPal were dissolved out continuously, which is favorable to alleviate the adverse effects of variable metal ions on the film under UV light irradiation, and thus improve the aging-resistant ability of films. This study provides new ideas for improving the reinforcing ability of natural clay minerals towards biopolymer-based material, finds a new way to resolve the aging problem of polymer composites caused by incorporation of natural clay minerals.


Assuntos
Quitosana/química , Compostos de Magnésio/química , Nanotubos/química , Povidona/química , Compostos de Silício/química , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Quitosana/farmacologia , Argila/química , Humanos , Compostos de Magnésio/farmacologia , Nanocompostos/química , Povidona/farmacologia , Compostos de Silício/farmacologia , Dióxido de Silício/química , Staphylococcus aureus/efeitos dos fármacos , Resistência à Tração , Difração de Raios X
14.
Int J Nanomedicine ; 15: 6593-6603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982220

RESUMO

PURPOSE: Micro-arc oxidation (MAO) is a fast and effective method to prepare nanoporous coatings with high biological activity and bonding strength. Simple micro/nano-coatings cannot fully meet the requirements of osteogenesis. To further improve the biological activity of a titanium surface, we successfully added biological magnesium (Mg2+) to a coating by micro-arc oxidation and evaluated the optimal magnesium concentration in the electrolyte, biocompatibility, cell adhesion, proliferation, and osteogenesis in vitro. METHODS: Nanoporous titanium coatings with different concentrations of magnesium were prepared by micro-arc oxidation and characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The Mg2+ release ability of the magnesium-incorporated nanoporous titanium coatings was determined by inductively coupled plasma emission spectrometry (ICP-OES). The cytotoxicity of the magnesium-incorporated nanoporous titanium coatings was detected with live/dead double-staining tests. A CCK-8 assay was employed to evaluate cell proliferation, and FITC-phalloidin was used to determine the structure of the cytoskeleton by staining ß-actin. Alkaline phosphatase (ALP) activity was evaluated by alizarin red S (ARS) staining to determine the effect of the coatings on osteogenic differentiation in vitro. The mRNA expression of osteogenic differentiation-related markers was measured using qRT-PCR. RESULTS: EDS analyses revealed the successful addition of magnesium to the microporous coatings. The best magnesium concentration of the electrolyte for preparing the new coating was determined. The results showed that the nano-coatings prepared using the electrolyte with 2 g/L magnesium acetate best promoted the adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). CONCLUSION: These results suggest that the new titanium metal coating with a dual effect of promoting bone morphology and supplying the biological ion Mg2+ can be beneficial for rapid osseointegration.


Assuntos
Acetatos/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Compostos de Magnésio/farmacologia , Osseointegração/efeitos dos fármacos , Acetatos/química , Animais , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Magnésio/química , Magnésio/farmacocinética , Compostos de Magnésio/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Nanoporos , Osseointegração/fisiologia , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Oxirredução , Próteses e Implantes , Ratos Sprague-Dawley , Espectrometria por Raios X , Propriedades de Superfície
15.
Int J Nanomedicine ; 15: 6761-6777, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982232

RESUMO

PURPOSE: Guided bone regeneration (GBR) therapy, which is a widely used technique in clinical practice and is effective in improving the repair of alveolar bone defects or bone mass deficiency regeneration, requires the use of membrane materials with good biocompatibility, barrier function, rigidity matching the space maintenance ability, economic benefits and excellent clinical applicability. The aim of this study was to develop an electrospun attapulgite (ATT)-doped poly (lactic-co-glycolic acid) (PLGA) scaffold (PLGA/ATT scaffold) as a novel material for GBR applications. METHODS AND RESULTS: Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to determine the morphology and the crystalline structure of the PLGA/ATT scaffolds, respectively. Porosity and contact-angle measurements were also carried out to further characterize the physical properties of the PLGA/ATT scaffolds. The results of in vitro studies showed that bone marrow mesenchymal stem cells (BMSCs) attached more readily to and spread better over the PLGA/ATT scaffolds than the Bio-Gide membrane. Furthermore, in the in vitro osteoinductive experiments with BMSCs, the PLGA/ATT scaffolds were found to enhance the activity of alkaline phosphatase (ALP), promote the formation of mineralized bone nodules, and up-regulate the expression of several osteogenic markers-namely, runt-related transcription factor 2, alkaline phosphatase, osteopontin, and osteocalcin-which are similar to the effects of the Bio-Gide membrane. Further, in in vivo studies, the results of sequential fluorescent labeling, micro-computed tomography, and histological analysis suggest that using the PLGA/ATT scaffolds for repairing V-shaped buccal dehiscence on a dog's tooth root improved bone regeneration, which is not only similar to the result obtained using the Bio-Gide membrane but also much better than that obtained using PLGA scaffolds and the negative control. CONCLUSION: To achieve satisfactory therapeutic results and to lower the cost of GBR treatment, this study provided a promising alternative material of bio-degradable membrane in clinical treatment.


Assuntos
Perda do Osso Alveolar/terapia , Regeneração Óssea/fisiologia , Compostos de Magnésio/farmacologia , Compostos de Silício/farmacologia , Alicerces Teciduais/química , Animais , Regeneração Óssea/efeitos dos fármacos , Calcificação Fisiológica , Colágeno , Cães , Expressão Gênica , Gengiva/citologia , Humanos , Compostos de Magnésio/química , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteogênese/fisiologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Porosidade , Ratos Sprague-Dawley , Compostos de Silício/química , Raiz Dentária/diagnóstico por imagem , Microtomografia por Raio-X
16.
Life Sci ; 257: 117999, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32585244

RESUMO

AIM: This paper was mainly aimed at synthesis of Ce-containing nano-Mg-phosphate ceramic as a multifunctional material. MATERIALS AND METHODS: Two ceramics based on Mg3(PO4)2 and Ce0.2Mg2.8(PO4)2 formulas (MP and MP-C, respectively) were synthesized. The synthesized powders were characterized by XRD, TEM, Zeta potential, and FTIR. Also, their dissolution behavior was tested in Tris-HCl buffer solution. Moreover, the antimicrobial efficacy was evaluated against gram-positive bacteria (Bacillus sphaericus MTCC 511 &Staphylococcus aureus MTCC 87) and gram-negative bacteria (Enterobacter aerogenes MTCC 111 &Pseudomonas aeruginosa MTCC 1034) using dick diffusion assay and microdilution method. Furthermore, the cell viability test was performed for the ceramics on Vero cells (African green monkey kidney cells), and their antitumor activity was determined by PC3 cell line (prostatic cancer). Also, the cellular uptake was determined by the flow cytometry. KEY FINDINGS: The results showed that the substitution of Mg by Ce decreased the particle size from 40 to 90 nm for MP sample to 2-10 nm for MP-C sample and increased the degradation rate. Both samples showed excellent antimicrobial activities. Moreover, MP demonstrated more cell viability than MP-C on Vero cells at high concentrations, whereas, MP-C showed more antitumor activity on PC3 cells than MP sample. Moreover, MP-C showed a higher cell uptake than MP due to its smaller size and more negative charge. SIGNIFICANCE: Mg-phosphate ceramic can be used in this study successfully as a delivery system for cerium ions and showed a high antitumor activity, which makes it highly recommended as safe and effective cancer treatment materials.


Assuntos
Cerâmica/farmacologia , Cério/farmacologia , Compostos de Magnésio/farmacologia , Fosfatos/farmacologia , Animais , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Bacillaceae/efeitos dos fármacos , Osso e Ossos/microbiologia , Osso e Ossos/cirurgia , Sobrevivência Celular , Cério/metabolismo , Chlorocebus aethiops , Enterobacter aerogenes/efeitos dos fármacos , Humanos , Compostos de Magnésio/metabolismo , Testes de Sensibilidade Microbiana/métodos , Células PC-3 , Fosfatos/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células Vero
17.
Int J Biol Macromol ; 160: 101-111, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32450325

RESUMO

Magnesium phosphate cement (MPC) can be injected to form an in situ scaffold to repair bone defects. Here we synthesized novel injectable bioactive cements (CMPCs) by incorporating different ratios of carboxymethyl chitosan (CMC, 0-10%) into MPC. The physiochemical properties, compositions, and microstructures of CMPCs were evaluated. The in vitro cellular responses of pre-osteoblast MC3T3-E1 cells to CMPCs including adhesion, proliferation, and differentiation were quantified and the underlying cellular mechanisms investigated. CMPCs had longer setting times and lower setting temperatures. CMPC injectability was enhanced by the addition of CMC. The CMPC containing 5% CMC had the highest compressive strength and washout resistance. CMPCs had a more neutral pH compared to MPC at four weeks. Furthermore, CMPC samples showed similar degradability and Mg2+ release to MPC in Tris-HCl buffer. Osteoblasts (MC3T3-E1) showed significantly greater adherence, proliferation, and differentiation on CMPC specimens than on MPC. Finally, CMPCs effectively increased the adsorption of fibronectin and activated integrin signaling as indicated by enhanced FAK and ERK phosphorylation. Our novel CMPC composites have improved physicochemical properties and cellular responses and represent a promising material for bone regeneration.


Assuntos
Cimentos Ósseos/química , Cimentos Ósseos/farmacologia , Regeneração Óssea/efeitos dos fármacos , Quitosana/análogos & derivados , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Fosfatos/química , Fosfatos/farmacologia , Células 3T3 , Animais , Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Quitosana/farmacologia , Força Compressiva/efeitos dos fármacos , Fibronectinas/metabolismo , Quinase 1 de Adesão Focal/metabolismo , Concentração de Íons de Hidrogênio , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Teste de Materiais/métodos , Camundongos , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Temperatura
18.
Mater Sci Eng C Mater Biol Appl ; 109: 110497, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32228962

RESUMO

Lack of bioactivity and monomer toxicity are limiting factors of polymethyl methacrylate (PMMA) bone cement in orthopedic applications. Herein, we address these shortcomings by proposing two-dimensional magnesium phosphate (MgP) nanosheets and hydroxyapatite (HA) nanofibers as novel fillers in PMMA bone cement nanocomposites. Two-dimensional MgP nanosheets and one-dimensional HA nanofibers were synthesized by tuning the crystallization of the sodium-magnesium-phosphate ternary system and hydrothermal homogeneous precipitation, respectively. We show that MgP nanosheets exhibit antibacterial properties against Escherichia coli (E. coli). In addition, HA nanofibers with high level of bioactivity are the proper choice to induce cell viability in the nanocomposite. Results indicate that the combination of both fillers can act as deformation locks enhancing the compressive strength of the nanocomposites. The synthesized nanocomposite possesses excellent bioactivity, mechanical properties, and cytocompatibility potentially opening new paradigm in the design of next generation bone cement composites.


Assuntos
Cimentos Ósseos/química , Nanocompostos/química , Nanofibras/química , Polimetil Metacrilato/química , Força Compressiva , Durapatita/química , Escherichia coli/efeitos dos fármacos , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Fosfatos/química , Fosfatos/farmacologia
19.
Micron ; 129: 102796, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31821933

RESUMO

Ultra-fine grained biodegradable Mg-based Mg1Zn1Mn0.3 Zr - HA and Mg4Y5.5Dy0.5 Zr - 45S5 Bioglass composites have shown great medical potential. Two types of these Mg-based biomaterials subjected to different treatments were tested and as shown earlier they are biocompatible. The aim of the study is to determine how much culture media incubated with these ultra-fine trained Mg-based composites can cause inflammatory reactions and /or periodontal cell death. The incubation of composites in the medium releases metal ions into the solution. It can be assumed that this process is permanent and also occurs in the human body. The results have shown that the effect of proinflammatory IL-6 and TNF- cytokines results in the strongest production of the acute phase proteins in the first day on the Mg1Zn1Mn0.3 Zr-5 wt.% HA-1 wt. % Ag HF-treated biocomposite after immersion for 2 h in 40 % HF and then the fastest decrease in these processes on the third day. In turn, the inflammatory process induced on the Mg1Zn1Mn0.3 Zr-5 wt.% HA-1 wt. % Ag biomaterial, in BAX / BCL ratio assessment, is the strongest on the third day and maintains a significantly high level on the following day, which, at the same time, confirms its persistence and development. In addition, these results confirm the successively generated necrotic processes. Ions can induce inflammatory reactions, which in the case of the implant may take a long time, which results in the loss of the implant. Even if the material is biocompatible in rapid in-vitro tests, it can induce inflammation in the body after some time due to the release of ions. Not every treatment improves the material's properties in terms of subsequent safety.


Assuntos
Materiais Biocompatíveis/farmacologia , Compostos de Magnésio/farmacologia , Magnésio/farmacologia , Teste de Materiais/métodos , Periodonto/efeitos dos fármacos , Células Cultivadas , Cerâmica/farmacologia , Vidro , Humanos , Inflamação/induzido quimicamente , Interleucina-6/biossíntese , Osteoblastos/efeitos dos fármacos , Periodonto/citologia , Próteses e Implantes , Propriedades de Superfície , Fator de Necrose Tumoral alfa/biossíntese
20.
Transcription ; 10(4-5): 187-194, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31668122

RESUMO

Inorganic phosphate (Pi), a ubiquitous metabolite, is involved in all major biochemical pathways. We demonstrate that, in vitro, MgHPO4 (the intracellular Pi form) at physiological concentrations can exist in a metastable supersaturated dissolved state or as a precipitate. We have shown that in solution, MgHPO4 strongly stimulates exonuclease nascent transcript cleavage by RNA polymerase. We report here that MgHPO4 precipitate selectively and efficiently inhibits transcription initiation in vitro. In view of the MgHPO4 solubility and in vitro sensitivity of RNA synthesis to MgHPO4 precipitate, at physiological concentrations, MgHPO4 should cause a 50-98% inhibition of cellular RNA synthesis, thus exerting a strong regulatory action. The effects of Pi on transcription in vivo will, therefore, reflect the physical state of intracellular Pi.


Assuntos
Exonucleases/metabolismo , Fosfatos/metabolismo , RNA Mensageiro/metabolismo , Precipitação Química , RNA Polimerases Dirigidas por DNA/metabolismo , Compostos de Magnésio/metabolismo , Compostos de Magnésio/farmacologia , Fosfatos/farmacologia , Solubilidade , Transcrição Gênica/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...