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1.
J Chromatogr A ; 1625: 461274, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709326

RESUMO

An ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) method was employed for chemical identification in a commercial polyvinyl chloride/polyethylene (PVC/PE) multilayer film. Over 30 chemicals from different layers (PE layer, PVC layer, and adhesive layer) of the film were identified and were classified into 6 groups, including antioxidants, plasticizers, slip agents, antistatic agents, adhesive components, etc. Special attention was placed on the analysis of some non-intentionally added substances and oligomers in adhesive. Based on the identification results, six additives (all from PE layer) were selected and their migration behaviors were investigated via one-sided contact migration test. The migration test was performed by exposing the PE side of the film to different simulating solutions (water, 40% ethanol, and 95% ethanol) at 40°C, as well as recording the migration level as a function of time. No obvious migration was found into water for all additives, while the migration into 40% and 95% ethanol followed Fickian diffusion behavior, and could be described by Fick's diffusion equation. Diffusion coefficients derived from the equation were in a range of 10-13 to 10-10 cm2/s and were dependent on the type of additive and solution.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas , Polietilenos/química , Cloreto de Polivinila/química , Ácidos Erúcicos/análise , Soluções , Água/química
2.
J Chromatogr A ; 1625: 461282, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709333

RESUMO

In recent years, core-shell silica particles (CSSPs) have been increasingly used for highly efficient separation at fast flow rates and relatively low back pressures in high-performance liquid chromatography (HPLC). However, material synthesis techniques for producing CSSPs economically in batch processes remain elusive. In this report, a practical and straightforward method for the preparation of CSSPs is presented. By refluxing freshly prepared nonporous silica particles in ammonia-water solution in the presence of poly(diallyldimethylammonium chloride) at 70-100 °C, CSSPs with shell thicknesses of up to 300 nm and pore sizes from 8 to 25 nm were easily prepared. The effects of the synthetic conditions on the shell thickness, surface area, and pore size were investigated in detail, and the method reproducibility was evaluated in scale-up experiments. A mechanism of CSSP formation is also proposed. The CSSPs were characterized via scanning electron microscopy, transmission electron microscopy, laser particle size (dynamic light scattering) analysis, and nitrogen adsorption and desorption experiments. The synthesized 3.4-µm CSSPs were functionalized with dimethyloctadecylchlorosilane and used as an HPLC packing material, exhibiting excellent separation performance for both small molecules and large biomolecules. In summary, we report the simplest method developed thus far for the preparation of monodisperse core-shell silica particles suitable for HPLC column packing.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Sílica Gel/química , Adsorção , Amônia/análise , Difusão Dinâmica da Luz , Microesferas , Peso Molecular , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Polietilenos/química , Porosidade , Compostos de Amônio Quaternário/química , Reprodutibilidade dos Testes , Temperatura , Fatores de Tempo
3.
Int J Nanomedicine ; 15: 483-495, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32158206

RESUMO

Background: The complex preparation procedures and severe toxicities are two major obstacles facing the wide use of chimeric antigen receptor-modified T (CAR-T) cells in clinical cancer immunotherapy. The nanotechnology-based T cell temporary CAR modification may be a potential approach to solve these problems and make the CAR-T cell-based tumor therapy feasible and broadly applicable. Methods: A series of plasmid DNA-loaded self-assembled nanoparticles (pDNA@SNPsx/y) prepared from adamantane-grafted polyamidoamine (Ad-PAMAM) dendrimers of different generations (G1 or G5) and cyclodextrin-grafted branched polyethylenimine (CD-PEI) of different molecular weights (800, 2000, or 25,000 Da) were characterized and evaluated. The detailed physicochemical properties, cellular interaction, and cytotoxicity of selected pDNA@SNPG1/800 were systematically investigated. Thereafter, the epidermal growth factor receptor variant III (EGFRvIII) CAR-expression plasmid vector (pEGFRvIII-CAR) was constructed and encapsulated into SNPG1/800. The resulting pEGFRvIII-CAR@SNPG1/800 was used for Jurkat cell transient transfection, and the EGFRvIII-CAR expressed in transfected cells was measured by flow cytometry and Western blot. Finally, the response of EGFRvIII CAR-positive Jurkat T cell to target tumor cell was evaluated. Results: The pDNA@SNPG1/800 showed the highest efficacy in Jurkat cell gene transfection and exhibited low cytotoxicity. pEGFRvIII-CAR@SNPG1/800 can efficiently deliver pEGFRvIII-CAR into Jurkat T cells, thereby resulting in transient EGFRvIII-CAR expression in transfected cells. EGFRvIII-CAR that is present on the cell membrane enabled Jurkat T cells to recognize and bind specifically with EGFRvIII-positive tumor cells. Conclusion: These results indicated that pEGFRvIII-CAR@SNPG1/800 can effectively achieve T-cell transient CAR modification, thereby demonstrating considerable potential in CAR-T cancer therapy.


Assuntos
Receptores ErbB/genética , Técnicas de Transferência de Genes , Imunoterapia Adotiva/métodos , Nanopartículas/química , Linfócitos T/fisiologia , Linhagem Celular Tumoral , Dendrímeros/química , Vetores Genéticos , Humanos , Iminas/química , Imunoterapia , Células Jurkat , Peso Molecular , Polietilenos/química , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/genética , Transfecção/métodos
4.
Int J Nanomedicine ; 15: 497-511, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32158207

RESUMO

Introduction: RNA-based therapy for bone repair and regeneration is a highly safe and effective approach, which has been extensively investigated in recent years. However, the molecular stability of RNA agents still remains insufficient for clinical application. High porosity, tunable size, and ideal biodegradability and biosafety are a few of the characters of mesoporous silicon nanoparticles (MSNs) that render them a promising biomaterial carrier for RNA treatment. Materials and Methods: In this study, a novel miR-26a delivery system was constructed based on MSNs. Next, we assessed the miRNA protection of the delivery vehicles. Then, rat bone marrow mesenchymal stem cells (rBMSCs) were incubated with the vectors, and the transfection efficiency, cellular uptake, and effects on cell viability and osteogenic differentiation were evaluated. Results: The results demonstrated that the vectors protected miR-26a from degradation in vitro and delivered it into the cytoplasm. A relatively low concentration of the delivery systems significantly increased osteogenic differentiation of rBMSCs. Conclusion: The vectors constructed in our study provide new methods and strategies for the delivery of microRNAs in bone tissue engineering.


Assuntos
Diferenciação Celular , Técnicas de Transferência de Genes , Células-Tronco Mesenquimais/citologia , MicroRNAs/genética , Nanopartículas/química , Osteogênese/genética , Animais , Materiais Biocompatíveis/química , Células da Medula Óssea/citologia , Diferenciação Celular/genética , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Iminas/química , Células-Tronco Mesenquimais/fisiologia , Peptídeos/química , Polietilenos/química , Porosidade , Ratos Sprague-Dawley , Dióxido de Silício/química , Transfecção
5.
Curr Pharm Biotechnol ; 21(9): 852-861, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32065098

RESUMO

AIMS: Biodegradable polymeric microneedles containing atorvastatin calcium were developed in order to improve the percutaneous absorption of the drug, useful for the treatment of hypercholesterolemia. BACKGROUND: The use of physical enhancers like microneedles have shown good results to increase the delivery of drugs through the skin, the use of microneedles has very important advantages for transdermal drug delivery, for example, they are painless, easy to use and safe, they increase time interval of drug activity, dose, and reductions in adverse reactions, they also offer, the facility to remove the system instantly of the skin. OBJECTIVE: Develop polymer microneedles loaded with a calcium atorvastatin and evaluate them by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), bioadhesion, postwetting- bioadhesion, breaking strength, drug release test and in vitro percutaneous absorption studies to demonstrate the use of microneedles atorvastatin is able to cross the skin. METHODS: The microneedles were made with poly (methyl vinyl ether-alt-maleic acid) as biodegradable polymer using the technique of casting in solution in a mold. After solidification these microneedles were characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), bioadhesion, post-wetting-bioadhesion, breaking strength, drug release test and in vitro percutaneous absorption studies. RESULTS: In general, the performances were satisfactory for optimal formulation in terms of DSC with no interactions between drug and excipients, SEM shows microneedles with a conical shape, bioadhesion of 1570 g.f, post wetting-bioadhesion of 1503.4 g.f, breaking strength of 1566.7g.f that is sufficient to disrupt Stratum corneum, good drug release and a flux of 33.4 µg/cm2*h with a tLag of 15.14 h for the in vitro percutaneous absorption. CONCLUSION: The results indicate that it is possible to generate microneedles to increase the percutaneous absorption of calcium atorvastatin transdermally, with the potential to be used as an alternative to the oral route for the treatment of dyslipidemias.


Assuntos
Anticolesterolemiantes/administração & dosagem , Atorvastatina/administração & dosagem , Plásticos Biodegradáveis/química , Portadores de Fármacos/química , Maleatos/química , Polietilenos/química , Administração Cutânea , Animais , Anticolesterolemiantes/farmacocinética , Atorvastatina/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Humanos , Técnicas In Vitro , Agulhas , Pele/metabolismo , Absorção Cutânea
6.
Food Chem ; 313: 126164, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31935662

RESUMO

A thermoseparating aqueous two-phase system (ATPS) based on ethylene oxide-propylene oxide (EOPO) copolymer and deep eutectic solvents (DES) was developed for the extraction and preliminary purification of polysaccharides in Camellia oleifera Abel. seed cake. DESs were used as the extraction media for obtaining the crude extract. The maximum extraction yield (Y) of polysaccharides was 152.37 mg/g in the crude extract. Then the crude polysaccharides were extracted and preliminary purified by EOPO/DES ATPS. The maximum extraction efficiency (E.E.) of polysaccharides was 86.91% in EOPO-rich phase by the first ATPS extraction. The EOPO-rich phase was separated and the polysaccharides were recovered by temperature-induced phase separation. The maximum recovery efficiency (R.E.) was 84.92% in aqueous phase by the second ATPS extraction. This thermoseparating ATPS possesses the merits of good environment-friendlies, simple operation, and easy recovery of components, which can be used as an efficient method for the extraction and separation of polysaccharides.


Assuntos
Camellia/química , Fracionamento Químico/métodos , Polissacarídeos/isolamento & purificação , Solventes/química , Manipulação de Alimentos/métodos , Polietilenos/química , Polipropilenos/química , Polissacarídeos/química , Sementes/química , Temperatura , Água
7.
Food Chem Toxicol ; 137: 111126, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954714

RESUMO

Syringic acid (SA), a natural polyphenol found in fruits and vegetables, is claimed to show notable hepatoprotection. Nevertheless, low solubility and bioavailability hamper the application of SA. This study aimed to investigate the potential of TPGS/F127/F68 mixed polymeric micelles as a sustained and liver-targeting nanocarrier for SA. Herein, the prepared SA-loaded TPGS/F127/F68 mixed polymeric micelles (SA-TPGS-Ms) were spherically-shaped and homogeneously-distributed nanoparticles with high entrapment efficiency (94.67 ± 2.05%) and sustained release. Besides, in-vitro cell culture studies revealed that SA-TPGS-Ms substantially promoted cellular uptake with excellent biocompatibility. After oral administration, SA-TPGS-Ms demonstrated an increased bioavailability (2.3-fold) and delayed in-vivo elimination compared with the free SA. Furthermore, the alleviation of oxidative stress and amelioration of hepatic injury in CCl4-induced hepatotoxicity mice further demonstrated the excellent hepatoprotection of SA-TPGS-Ms. Collectively, SA-TPGS-Ms could be a promising nanocarrier for the utilization of SA in functional foods, with enhanced bioavailability and hepatoprotection.


Assuntos
Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Ácido Gálico/análogos & derivados , Administração Oral , Animais , Disponibilidade Biológica , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/instrumentação , Ácido Gálico/administração & dosagem , Ácido Gálico/química , Ácido Gálico/farmacocinética , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Micelas , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Polietilenoglicóis/química , Polietilenos/química , Polipropilenos/química , Propilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Vitamina E/química
8.
Carbohydr Polym ; 231: 115725, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888813

RESUMO

In order to further enhance hydrophilicity of zein and achieve nano-scale pesticide system, phosphorylated zein (P-Zein) was incorporated with graft copolymer CMC-g-PDMDAAC by electrostatic interaction, in which carboxymethyl cellulose (CMC) and diallyldimethylammonium chloride (DMDAAC) as monomers. P-Zein/CMC-g-PDMDAAC was applied to encapsulate model pesticide avermectin (AVM) via electrostatic interaction to achieve AVM@P-Zein/CMC-g-PDMDAAC nano-pesticides. The stability, drug loading, anti-ultraviolet, adhesion, sustained-release and toxicity of nano-pesticides presented considerable behavior confirmed via various characteristics. The results indicated that AVM@P-Zein/CMC-g-PDMDAAC had an average particle size of 360 nm, and possessed favorable dispersion performance and excellent anti-ultraviolet property compared to P-Zein. And comparatively, encapsulation efficiency increased up to 82.11%. In addition, adhesion performance of AVM@P-Zein/CMC-g-PDMDAAC on foliage also improved by about 20% compared to P-Zein. Also, AVM@P-Zein/CMC-g-PDMDAAC can intelligently control pesticide release by adjusting monomer ratio and pH values. More importantly, such nano-pesticide system presented no significant difference on toxicity in comparison with bare AVM.


Assuntos
Carboximetilcelulose Sódica/química , Composição de Medicamentos , Praguicidas/química , Zeína/química , Cápsulas/química , Cápsulas/farmacologia , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ivermectina/análogos & derivados , Ivermectina/química , Ivermectina/farmacologia , Nanopartículas/química , Tamanho da Partícula , Praguicidas/farmacologia , Polietilenos/química , Polietilenos/farmacologia , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia
9.
Anal Bioanal Chem ; 412(3): 669-680, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31834450

RESUMO

A layer-by-layer self-assembled nitrogen-doped graphene/PDDA/gold nanoparticle (NDG/PDDA/GNP) composite was described. Citrate-stabilizing gold nanoparticle colloids (GNPs) were electrostatically adsorbed onto NDG nanosheets using a cationic polyelectrolyte, polydiallyldimethylammonium (PDDA), as the linker, thereby creating a high-performance electrochemical interface. The morphology and chemical composition were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, infrared spectroscopy, and Raman spectroscopy. Analytical application was manifested by electrochemical sensing of uric acid (UA), a biomarker involved with a variety of clinical diseases. The prepared nanocomposite exhibited noticeable electroactivity to uric acid oxidation and can give effective peak separation with ascorbic acid and dopamine. Additionally, the nanocomposite practically averted from other potentially interferents including glucose, urea, and serotonin, thus allowing selective voltammetric detection of UA in the biological matrix. Under the optimal condition, peak currents measured by differential pulse voltammetry were proportional to UA concentrations in the range of 0.5~100 µM (R2 = 0.998), with the detection limit of 53 nM. The NDG/PDDA/GNP nanocomposite as presented herein holds potential for aiding the diagnosis of UA-associated diseases and should be a new opportunity for biochemical analysis and biosensing applications. Graphical abstract.


Assuntos
Técnicas Eletroquímicas/métodos , Ouro/química , Grafite/química , Nanopartículas Metálicas/química , Nitrogênio/química , Polietilenos/química , Compostos de Amônio Quaternário/química , Eletricidade Estática , Ácido Úrico/análise , Limite de Detecção
10.
Colloids Surf B Biointerfaces ; 185: 110578, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678812

RESUMO

Pseudo-binary mixtures of different glycolipids, four different rhamnolipids (RL) and an alkyl polyglucoside (APG), with poly(diallyl-dimethylammonium chloride) (PDADMAC) have been studied in relation to their adsorption onto negatively charged surfaces to shed light on the impact of the molecular structure of surfactants from natural sources (instead of synthetic surfactant, such as sodium laureth sulfate) on the adsorption of hair-conditioning polymers. For this purpose, the self-assembly of such mixtures in aqueous solution and their adsorption onto negatively charged surfaces mimicking the negative charge of damaged hair fibres have been studied combining experiments and self-consistent field (SCF) calculations. The results show that the specific physico-chemical properties of the surfactants (charge, number of sugar rings present in surfactant structure and length of the hydrocarbon length) play a main role in the control of the adsorption process, with the adsorption efficiency and hydration being improved in relation to conventional sulfate-based systems for mixtures of PDADMAC and glycolipids with the shortest alkyl chains. SCF calculations and Energy Dispersive X-Ray Spectroscopy (EDS) analysis on real hair confirmed such observations. The results allow one to assume that the characteristic of the surfactants, especially rhamnolipids, conditions positively the adsorption potential of polyelectrolytes in these model systems. This study provides important insights on the mechanisms underlying the performance of more complex but eco-friendly washing formulations.


Assuntos
Glicolipídeos/química , Cabelo/efeitos dos fármacos , Teste de Materiais , Polietilenos/química , Polímeros/química , Compostos de Amônio Quaternário/química , Tensoativos/química , Adsorção , Biomimética , Glicolipídeos/metabolismo , Cabelo/química , Humanos , Modelos Moleculares , Estrutura Molecular , Polímeros/administração & dosagem , Tensoativos/metabolismo
11.
Sensors (Basel) ; 20(1)2019 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-31877704

RESUMO

Catching cancer at an early stage is necessary to make it easier to treat and to save people's lives rather than just extending them. Reactive oxygen species (ROS) have sparked a huge interest owing to their vital role in various biological processes, especially in tumorigenesis, thus leading to the potential of ROS as prognostic biomarkers for cancer. Herein, a non-enzymatic biosensor for the dynamic monitoring of intracellular hydrogen peroxide (H2O2), the most important ROS, via an effective electrode composed of poly (diallyldimethylammonium chloride) (PDDA)-capped reduced graphene oxide (RGO) nanosheets with high loading trimetallic AuPtAg nanoalloy, is proposed. The designed biosensor was able to measure H2O2 released from different cancerous cells promptly and precisely owing to the impressive conductivity of RGO and PDDA and the excellent synergistic effect of the ternary alloy in boosting the electrocatalytic activity. Built upon the peroxidase-like activity of the nanoalloy, the developed sensor exhibited distinguished electrochemical performance, resulting in a low detection limit of 1.2 nM and a wide linear range from 0.05 µM to 5.5 mM. Our approach offers a significant contribution toward the further elucidation of the role of ROS in carcinogenesis and the effective screening of cancer at an early stage.


Assuntos
Ligas/química , Técnicas Eletroquímicas/métodos , Grafite/química , Peróxido de Hidrogênio/análise , Nanocompostos/química , Polietilenos/química , Compostos de Amônio Quaternário/química , Linhagem Celular Tumoral , Eletrodos , Ouro/química , Humanos , Limite de Detecção , Platina/química , Reprodutibilidade dos Testes , Prata/química
12.
Bull Exp Biol Med ; 168(1): 58-61, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31768778

RESUMO

We studied antibacterial activity of a hybrid polymeric construction consisting of continuous and porous layers of ultrahigh-molecular-weight polyethylene reinforced by titanium. Experimental samples were impregnated with amoxycillin in subcritical Freon R22. The contact of bacterial culture with hybrid polymeric constructions saturated with amoxycillin suppressed the growth of microorganisms and the formation of their colonies. These results attest to the presence of a bactericidal effect of hybrid scaffold samples impregnated with an antibacterial component.


Assuntos
Antibacterianos/química , Polietilenos/química , Polímeros/química , Tecidos Suporte/química , Amoxicilina/química , Porosidade
13.
ACS Appl Mater Interfaces ; 11(49): 46286-46295, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31725262

RESUMO

Nanocarbonaceous materials with specific geometries and physicochemical properties allow the development of high-performance polymer-based smart composite materials. Among them, chemical treatments of graphene allow tailoring its electrical conductivity and, therefore, tuning functional response of materials for sensing applications. Polymer-based nanocomposites have been developed from styrene-ethylene-butylene-styrene (SEBS), a high deformation thermoplastic elastomer, and different graphene-based fillers, including graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanoplatelets (G-NPLs). It is shown that the electrical conductivity shows a percolation threshold around 2 wt % for GO and rGO, remaining nearly independent of the filler content for G-NPL filler contents up to 6 wt %. Furthermore, GO/SEBS and rGO/SEBS composites show high piezoresistive sensibility with gauge factors ranging from 15 up to 120 for strains up to 10%. Thus, GO/SEBS and rGO/SEBS composites can represent a new generation of materials for strain sensor applications, as demonstrated in their implementation in a hand glove prototype with finger movement monitoring.


Assuntos
Técnicas Biossensoriais , Monitorização Fisiológica , Movimento/fisiologia , Nanocompostos/química , Elastômeros/química , Dedos/fisiologia , Grafite/química , Humanos , Polietilenos/química , Poliestirenos/química
14.
Chem Commun (Camb) ; 55(92): 13880-13883, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31675031

RESUMO

Based on the unique property of preferential sequestration of guest molecules, coacervate microdroplets are proposed as enzyme active membrane-free protocells, in which uricase is loaded for efficient detoxification of uric acid in serum.


Assuntos
Urato Oxidase/metabolismo , Ácido Úrico/metabolismo , Células Artificiais/química , Dextranos/química , Corantes Fluorescentes/química , Humanos , Polietilenos/química , Estabilidade Proteica , Compostos de Amônio Quaternário/química , Solubilidade , Ácido Úrico/sangue
15.
ACS Appl Mater Interfaces ; 11(46): 43500-43508, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31657539

RESUMO

The artificial joints, for example, knee and hip implants, are widely used for the treatment of degenerative joint diseases and trauma. The current most common material choice for clinically used implants is the combination of polymer-on-metal structures. Unfortunately, these joints often suffer from high friction and wear, leading to associated inflammation and infection and ultimate failure of the artificial joints. Here, we propose an alternative solution to this tribologically induced failure of the joint materials. We demonstrate that the friction and wear behavior of ultrahigh-molecular-weight polyethylene (UHMWPE) and titanium tribopair, used to mimic the artificial joint interface, can be improved by introducing nanodiamond (ND) particles in the sliding contact. Characterization of the wear track using energy-dispersive spectroscopy and Raman spectroscopy revealed that the tribofilm formed from embedded NDs during sliding significantly suppressed the wear of the UHMWPE surface. In addition to the improved lubrication characteristics, NDs exhibit high biocompatibility with the bone cells and promising antibacterial properties against Staphylococcus aureus, the most common strain associated with artificial joint infection. These results indicate that NDs can be used as a promising nontoxic human-body lubricant with antiwear and antibacterial features, thus demonstrating their great potential to treat artificial joint complications through intra-articular injection.


Assuntos
Antibacterianos , Materiais Biocompatíveis , Lubrificantes , Nanodiamantes , Polietilenos , Próteses e Implantes , Staphylococcus aureus/crescimento & desenvolvimento , Titânio , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Lubrificantes/química , Lubrificantes/farmacologia , Camundongos , Nanodiamantes/química , Nanodiamantes/uso terapêutico , Polietilenos/química , Polietilenos/farmacologia , Propriedades de Superfície , Titânio/química , Titânio/farmacologia
16.
Bone Joint J ; 101-B(10): 1192-1198, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31564144

RESUMO

AIMS: Radiostereometric analysis (RSA) studies of vitamin E-doped, highly crosslinked polyethylene (VEPE) liners show low head penetration rates in cementless acetabular components. There is, however, currently no data on cemented VEPE acetabular components in total hip arthroplasty (THA). The aim of this study was to evaluate the safety of a new cemented VEPE component, compared with a conventional polyethylene (PE) component regarding migration, head penetration, and clinical results. PATIENTS AND METHODS: We enrolled 42 patients (21 male, 21 female) with osteoarthritis and a mean age of 67 years (sd 5), in a double-blinded, noninferiority, randomized controlled trial. The subjects were randomized in a 1:1 ratio to receive a reverse hybrid THA with a cemented component of either argon-gas gamma-sterilized PE component (controls) or VEPE, with identical geometry. The primary endpoint was proximal implant migration of the component at two years postoperatively measured with RSA. Secondary endpoints included total migration of the component, penetration of the femoral head into the component, and patient-reported outcome measurements. RESULTS: In total, 19 control implants and 18 implants in the VEPE group were analyzed for the primary endpoint. We found a continuous proximal migration of the component in the VEPE group that was significantly higher with a difference at two years of a mean 0.21 mm (95% confidence interval (CI) 0.05 to 0.37; p = 0.013). The total migration was also significantly higher in the VEPE group, but femoral head penetration was lower. We found no difference in clinical outcomes between the groups. CONCLUSION: At two years, this cemented VEPE component, although having a low head penetration and excellent clinical results, failed to meet noninferiority compared with the conventional implant by a proximal migration above the proposed safety threshold of RSA. The early proximal migration pattern of the VEPE component is a reason for continued monitoring, although a specific threshold for proximal migration and risk for later failure cannot be defined and needs further study. Cite this article: Bone Joint J 2019;101-B:1192-1198.


Assuntos
Artroplastia de Quadril/efeitos adversos , Migração de Corpo Estranho/diagnóstico por imagem , Osteoartrite do Quadril/cirurgia , Polietilenos/química , Desenho de Prótese , Falha de Prótese/tendências , Fatores Etários , Idoso , Artroplastia de Quadril/métodos , Método Duplo-Cego , Feminino , Migração de Corpo Estranho/epidemiologia , Prótese de Quadril , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/diagnóstico por imagem , Prognóstico , Análise Radioestereométrica , Medição de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Estatísticas não Paramétricas , Suécia , Vitamina E/farmacologia
17.
Bone Joint J ; 101-B(10): 1238-1247, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31564153

RESUMO

AIMS: Options for the treatment of intra-articular ligament injuries are limited, and insufficient ligament reconstruction can cause painful joint instability, loss of function, and progressive development of degenerative arthritis. This study aimed to assess the capability of a biologically enhanced matrix material for ligament reconstruction to withstand tensile forces within the joint and enhance ligament regeneration needed to regain joint function. MATERIALS AND METHODS: A total of 18 New Zealand rabbits underwent bilateral anterior cruciate ligament reconstruction by autograft, FiberTape, or FiberTape-augmented autograft. Primary outcomes were biomechanical assessment (n = 17), microCT (µCT) assessment (n = 12), histological evaluation (n = 12), and quantitative polymerase chain reaction (qPCR) analysis (n = 6). RESULTS: At eight weeks, FiberTape alone or FiberTape-augmented autograft demonstrated increased biomechanical stability compared with autograft regarding ultimate load to failure (p = 0.035), elongation (p = 0.006), and energy absorption (p = 0.022). FiberTape-grafted samples also demonstrated increased bone mineral density in the bone tunnel (p = 0.039). Histological evaluation showed integration of all grafts in the bone tunnels by new bone formation, and limited signs of inflammation overall. A lack of prolonged inflammation in all samples was confirmed by quantification of inflammation biomarkers. However, no regeneration of ligament-like tissue was observed along the suture tape materials. Except for one autograft failure, no adverse events were detected. CONCLUSION: Our results indicate that FiberTape increases the biomechanical performance of intra-articular ligament reconstructions in a verified rabbit model at eight weeks. Within this period, FiberTape did not adversely affect bone tunnel healing or invoke a prolonged elevation in inflammation. Cite this article: Bone Joint J 2019;101-B:1238-1247.


Assuntos
Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Polietilenos/química , Tendões/transplante , Resistência à Tração/fisiologia , Análise de Variância , Animais , Fenômenos Biomecânicos , Modelos Animais de Doenças , Feminino , Humanos , Peso Molecular , Coelhos , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Técnicas de Sutura , Suturas , Transplante Autólogo
18.
J Colloid Interface Sci ; 556: 529-540, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473542

RESUMO

The fast and scalable spray-drying-assisted evaporation-induced self-assembly (EISA) synthesis of hierarchically porous SBA-15-type silica microparticles from a water-based system is demonstrated. The SBA-15-type silica microparticles has bowl-like shapes, uniform micro-sizes (∼90 µm), large ordered mesopores (∼9.5 nm), hierarchical meso-/macropores (20-100 nm) and open surfaces. In the synthesis, soft- and hard-templating approaches are combined in a single rapid drying process with a non-ionic tri-block copolymer (F127) and a water-insoluble polymer colloid (Eudragit RS, 120 nm) as the co-templates. The RS polymer colloid plays three important roles. First, the RS nanoparticles can be partially dissolved by in-situ generated ethanol to form RS polymer chains. The RS chains swell and modulate the hydrophilic-hydrophobic balance of F127 micelles to allow the formation of an ordered mesostructure with large mesopore sizes. Without RS, only worm-like mesostructure with much smaller mesopore sizes can be formed. Second, part of the RS nanoparticles plays a role in templating the hierarchical pores distributed throughout the microparticles. Third, part of the RS polymer forms surface "skins" and "bumps", which can be removed by calcination to enable a more open surface structure to overcome the low pore accessibility issue of spray-dried porous microparticles. The obtained materials have high surface areas (315-510 m2 g-1) and large pore volumes (0.64-1.0 cm3 g-1), which are dependent on RS concentration, HCl concentration, silica precursor hydrolysis time and drying temperature. The representative materials are promising for the adsorption of lysozyme. The adsorption occurs at a >three-fold faster rate, in a five-fold larger capacity (an increase from 20 to 100 mg g-1) and without pore blockage compared with the adsorption of lysozyme onto spray-dried microparticles of similar physicochemical properties obtained without the use of RS.


Assuntos
Resinas Acrílicas/química , Micelas , Nanopartículas/química , Polietilenos/química , Polipropilenos/química , Dióxido de Silício/química , Adsorção , Animais , Proteínas Aviárias/química , Galinhas , Dessecação , Interações Hidrofóbicas e Hidrofílicas , Muramidase/química , Porosidade
19.
J Mater Sci Mater Med ; 30(9): 103, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31493091

RESUMO

Metal-on-metal (MoM) hip arthroplasties produce abundant implant-derived wear debris composed mainly of cobalt (Co) and chromium (Cr). Cobalt-chromium (Co-Cr) wear particles are difficult to identify histologically and need to be distinguished from other wear particle types and endogenous components (e.g., haemosiderin, fibrin) which may be present in MoM periprosthetic tissues. In this study we sought to determine whether histological stains that have an affinity for metals are useful in identifying Co-Cr wear debris in MoM periprosthetic tissues. Histological sections of periprosthetic tissue from 30 failed MoM hip arthroplasties were stained with haematoxylin-eosin (HE), Solochrome Cyanine (SC), Solochrome Azurine (SA) and Perls' Prussian Blue (PB). Sections of periprosthetic tissue from 10 cases of non-MoM arthroplasties using other implant biomaterials, including titanium, ceramic, polymethylmethacrylate (PMMA) and ultra-high molecular weight polyethylene (UHMWP) were similarly analysed. Sections of 10 cases of haemosiderin-containing knee tenosynovial giant cell tumour (TSGCT) were also stained with HE, SC, SA and PB. In MoM periprosthetic tissues, SC stained metal debris in phagocytic macrophages and in the superficial necrotic zone which exhibited little or no trichrome staining for fibrin. In non-MoM periprosthetic tissues, UHMWP, PMMA, ceramic and titanium particles were not stained by SC. Prussian Blue, but not SC or SA, stained haemosiderin deposits in MoM periprosthetic tissues and TSGT. Our findings show that SC staining (most likely Cr-associated) is useful in distinguishing Co-Cr wear particles from other metal/non-metal wear particles types in histological preparations of periprosthetic tissue and that SC reliably distinguishes haemosiderin from Co-Cr wear debris.


Assuntos
Benzenossulfonatos , Corantes/farmacologia , Análise de Falha de Equipamento/métodos , Articulação do Quadril/patologia , Nanopartículas Metálicas/análise , Próteses Articulares Metal-Metal , Coloração e Rotulagem/métodos , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Azurina/química , Azurina/farmacologia , Benzenossulfonatos/química , Benzenossulfonatos/farmacologia , Cromo/química , Corantes/síntese química , Corantes/química , Amarelo de Eosina-(YS)/química , Amarelo de Eosina-(YS)/farmacologia , Ferrocianetos/química , Ferrocianetos/farmacologia , Células Gigantes de Corpo Estranho/efeitos dos fármacos , Células Gigantes de Corpo Estranho/patologia , Hematoxilina/química , Hematoxilina/farmacologia , Articulação do Quadril/química , Articulação do Quadril/efeitos dos fármacos , Prótese de Quadril , Técnicas Histológicas/métodos , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Próteses Articulares Metal-Metal/efeitos adversos , Polietilenos/análise , Polietilenos/química
20.
Mater Sci Eng C Mater Biol Appl ; 105: 110117, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546366

RESUMO

Failure of fixation between bone and implant surface due to bacterial infection, is one of the key challenges in total hip arthroplasty. It might lead to poor implant stability and complex revision surgery. Surface modification of an acetabular cup liner for sustained drug delivery is an effective approach to reduce the biofilms associated infection. The aim of the study is to evaluate the influence of different surface modification technique on drug delivery, mechanical and tribological performances of the acetabular cup liner. Solvent-based etching and electrostatic spray deposition technique was individually used to engineer a thin microporous surface layer on ultra-high molecular weight polyethylene (UHMWPE), which is commercially used as acetabular cup liner in total hip implant. Porous surfaces were filled with drug (gentamicin) containing biodegradable polymer (chitosan) through impregnation process and their efficacy was compared in the intended application. The surfaces, modified by both techniques, have shown lower friction coefficient. The higher wear rates were noticed for electrostatic sprayed coating. Both the modified surfaces have shown slight decrease in hardness and elastic modulus, which may be attributed to improper impregnation of polymer inside porous surface. However, after the release of drug, the solvent-based etched surface regains its mechanical and tribological properties, in similar range to the unmodified UHMWPE surface. Both the modified surfaces have shown an impressive drug release profile and in vitro antibacterial efficacy. The drug release duration was more for electrostatic spray modified surface. Hence, these surfaces modified implant parts shown great promise for fighting against post-surgery bacterial infection.


Assuntos
Liberação Controlada de Fármacos , Ortopedia , Polietilenos/química , Próteses e Implantes , Eletricidade Estática , Anti-Infecciosos/farmacologia , Módulo de Elasticidade , Fricção , Gentamicinas/farmacologia , Dureza , Cinética , Porosidade , Propriedades de Superfície
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