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1.
Clin Oral Investig ; 28(6): 305, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38722356

RESUMEN

OBJECTIVE: To evaluate the ability of the water glass treatment to penetrate zirconia and improve the bond strength of resin cement. MATERIAL AND METHODS: Water glass was applied to zirconia specimens, which were then sintered. The specimens were divided into water-glass-treated and untreated zirconia (control) groups. The surface properties of the water-glass-treated specimens were evaluated using surface roughness and electron probe micro-analyser (EPMA) analysis. A resin cement was used to evaluate the tensile bond strength, with2 and without a silane-containing primer. After 24 h in water storage at 37 °C and thermal cycling, the bond strengths were statistically evaluated with t-test, and the fracture surfaces were observed using SEM. RESULTS: The water glass treatment slightly increased the surface roughness of the zirconia specimens, and the EPMA analysis detected the water glass penetration to be 50 µm below the zirconia surface. The application of primer improved the tensile bond strength in all groups. After 24 h, the water-glass-treated zirconia exhibited a tensile strength of 24.8 ± 5.5 MPa, which was significantly higher than that of the control zirconia (17.6 ± 3.5 MPa) (p < 0.05). After thermal cycling, the water-glass-treated zirconia showed significantly higher tensile strength than the control zirconia. The fracture surface morphology was mainly an adhesive pattern, whereas resin cement residue was occasionally detected on the water-glass-treated zirconia surfaces. CONCLUSION: The water glass treatment resulted in the formation of a stable silica phase on the zirconia surface. This process enabled silane coupling to the zirconia and improved the adhesion of the resin cement.


Asunto(s)
Recubrimiento Dental Adhesivo , Vidrio , Ensayo de Materiales , Cementos de Resina , Silanos , Propiedades de Superficie , Resistencia a la Tracción , Agua , Circonio , Circonio/química , Cementos de Resina/química , Silanos/química , Agua/química , Recubrimiento Dental Adhesivo/métodos , Vidrio/química , Microscopía Electrónica de Rastreo , Análisis del Estrés Dental
2.
Chemosphere ; 358: 142164, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38685326

RESUMEN

As the adverse effects of using plastics and perfluorinated alkyl substances become more apparent, there is a growing need for sustainable hydrophobic products. Cellulose and its derivatives are the most abundant and widely used polymers, and cellulose-based products have great potential in industries where plastics and other hydrophobic polymers are used, such as stain-resistant fabrics, food packaging, and oil-water separation applications. In this study, we extracted cellulose from water hyacinth (WH) biomass, known for its negative environmental impact, and converted it into hydrophobic cellulose. This addresses the issue of managing WH waste and creating an environmentally friendly hydrophobic material. Initially, aldehyde groups were introduced through oxidation with periodate, followed by direct octadecyl amine (ODA) grafting onto dialdehyde cellulose (DAC) via a Schiff base condensation. The resulting ODA modified cellulose (ODA-C) was dispersed in ethanol and used to coat various materials, including cotton fabric, cellulose filter paper, and packaging paper. The modified materials showed excellent hydrophobicity as measured by their water contact angles (WCAs), and the application of the coating was demonstrated for oil-water separation, stain-resistant hydrophobic fabric, and paper-based packaging materials. FTIR, XRD, and WCA analysis confirmed the successful modification of cellulose. A high separation efficiency of 99% was achieved for diesel/water separation using modified filter paper (MoFP), under gravity. On application of the coating, cotton fabric became hydrophobic and resisted staining from dye, and paper-based packaging materials became more robust by becoming water-resistant. Overall, the facile synthesis, low cost, high efficiency, and use of environmentally friendly sustainable materials make this a promising strategy for hydrophobically modifying surfaces for a wide range of applications while reducing the menace of water hyacinth.


Asunto(s)
Biomasa , Celulosa , Interacciones Hidrofóbicas e Hidrofílicas , Silanos , Celulosa/química , Celulosa/análogos & derivados , Silanos/química , Eichhornia/química , Agua/química , Flúor/química , Aceites/química
3.
Int J Biol Macromol ; 267(Pt 2): 131486, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38604420

RESUMEN

The molecular brush structures have been developed on cotton textiles for long-term and efficient broad-spectrum antimicrobial performances through the cooperation of alkyl-chain and quaternary ammonium sites. Results show that efficient antibacterial performances can be achieved by the regulation of the alkyl chain length and quaternary ammonium sites. The antibacterial efficiency of the optimized molecular brush structure of [3-(N,N-Dimethylamino)propyl]trimethoxysilane with cetyl modification on cotton textiles (CT-DM-16) can reach more than 99 % against both E. coli and S. aureus. Alkyl-chain grafting displayed significantly improvement in the antibacterial activity against S. aureus with (N,N-Diethyl-3-aminopropyl)trimethoxysilane modification on cotton textiles (CT-DE) based materials. The positive N sites and alkyl chains played important roles in the antibacterial process. Proteomic analysis reveals that the contributions of cytoskeleton and membrane-enclosed lumen in differentially expressed proteins have been increased for the S. aureus antibacterial process, confirming the promoted puncture capacity with alkyl-chain grafting. Theoretical calculations indicate that the positive charge of N sites can be enhanced through alkyl-chain grafting, and the possible distortion of the brush structure in application can further increase the positive charge of N sites. Uncovering the regulation mechanism is considered to be important guidance to develop novel and practical antibacterial materials.


Asunto(s)
Antibacterianos , Fibra de Algodón , Escherichia coli , Staphylococcus aureus , Textiles , Antibacterianos/farmacología , Antibacterianos/química , Staphylococcus aureus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/farmacología , Silanos/química
4.
J Med Chem ; 67(8): 6410-6424, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38592014

RESUMEN

We report two novel prodrug Pt(IV) complexes with bis-organosilane ligands in axial positions: cis-dichloro(diamine)-trans-[3-(triethoxysilyl)propylcarbamate]platinum(IV) (Pt(IV)-biSi-1) and cis-dichloro(diisopropylamine)-trans-[3-(triethoxysilyl) propyl carbamate]platinum(IV) (Pt(IV)-biSi-2). Pt(IV)-biSi-2 demonstrated enhanced in vitro cytotoxicity against colon cancer cells (HCT 116 and HT-29) compared with cisplatin and Pt(IV)-biSi-1. Notably, Pt(IV)-biSi-2 exhibited higher cytotoxicity toward cancer cells and lower toxicity on nontumorigenic intestinal cells (HIEC6). In preclinical mouse models of colorectal cancer, Pt(IV)-biSi-2 outperformed cisplatin in reducing tumor growth at lower concentrations, with reduced side effects. Mechanistically, Pt(IV)-biSi-2 induced permanent DNA damage independent of p53 levels. DNA damage such as double-strand breaks marked by histone gH2Ax was permanent after treatment with Pt(IV)-biSi-2, in contrast to cisplatin's transient effects. Pt(IV)-biSi-2's faster reduction to Pt(II) species upon exposure to biological reductants supports its superior biological response. These findings unveil a novel strategy for designing Pt(IV) anticancer prodrugs with enhanced activity and specificity, offering therapeutic opportunities beyond conventional Pt drugs.


Asunto(s)
Antineoplásicos , Compuestos Organoplatinos , Profármacos , Profármacos/farmacología , Profármacos/química , Profármacos/síntesis química , Humanos , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Animales , Compuestos Organoplatinos/farmacología , Compuestos Organoplatinos/química , Compuestos Organoplatinos/síntesis química , Ligandos , Ratones , Línea Celular Tumoral , Silanos/química , Silanos/farmacología , Relación Estructura-Actividad , Ensayos de Selección de Medicamentos Antitumorales , Células HT29
5.
J Chromatogr A ; 1722: 464871, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38593520

RESUMEN

Mixed-mode reversed-phase/anion-exchange chromatography (RP/AEX) is an effective method for the chromatographic analysis of acidic drugs because it combines reversed-phase chromatography (RP) with anion-exchange chromatography (AEX). However, the result repeatability for the RP/AEX analysis of acidic drugs is frequently compromised by the detrimental effects of residual silanol groups in an RP/AEX stationary phase on peak separation and analyte retention. In this study, an RP/weak-AEX stationary phase with amino anion-exchange groups, Sil-AA, was prepared. Subsequently, an RP/strong-AEX stationary phase, Sil-PBQA, was prepared by replacing the amino groups in Sil-AA with a benzene ring and a benzyl-containing quaternary ammonium salt. The chromatographic behaviors of Sil-PBQA and Sil-AA were compared, and the effect of residual silanol groups on the chromatographic behavior of an RP/AEX stationary phase was evaluated. Residual silanol groups not only caused additional electrostatic interactions for acidic analytes, but also competed with the analytes for the anion-exchange sites in an RP/AEX stationary phase. The effects of different salt-containing mobile-phase systems on the analyte-retention behavior of Sil-PBQA were investigated to develop a method that enhanced the repeatability of the RP/AEX acidic-analyte-analysis results obtained using Sil-PBQA and facilitated the separation of nonsteroidal anti-inflammatory drugs on Sil-PBQA. The ideas presented in this paper can improve the separation of peaks and repeatability of results in the RP/AEX analysis of acidic drugs.


Asunto(s)
Antiinflamatorios no Esteroideos , Cromatografía de Fase Inversa , Cromatografía de Fase Inversa/métodos , Cromatografía por Intercambio Iónico/métodos , Antiinflamatorios no Esteroideos/análisis , Antiinflamatorios no Esteroideos/química , Aniones/química , Aniones/análisis , Reproducibilidad de los Resultados , Silanos/química , Concentración de Iones de Hidrógeno , Cromatografía Líquida de Alta Presión/métodos
6.
J Chromatogr A ; 1722: 464889, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38598894

RESUMEN

In this paper, three imidazole- and C18- bifunctional silica stationary phases (Sil-Im-C18) were prepared by adjusting introduction interval of octadecyltrichlorosilane (ODS) and 3-imidazol-1-ylpropyl(trimethoxy)silane (TMPImS), which can be used for reversed-phase liquid chromatography (RPLC) and ion exchange chromatography (IEC) with adjustable performance. The successful preparation of Sil-Im-C18 were confirmed by the characterizations of elemental analysis, infrared spectroscopy (FTIR) and contact angle (CA). Chromatographic performance of Sil-Im-C18 were evaluated by the separation of Tanaka test mixture, alkylbenzenes, linear PAHs and a set of analytes with different properties (uracil, phenol, 1,2-dinitrobenzene and naphthalene), and compared with commonly used C18 column. It was found that the chromatographic performance of Sil-Im-C18 changed significantly with the difference in bonding amount of imidazole and C18. Sil-Im-C18 demonstrated the excellent separation performance towards polycyclic aromatic hydrocarbons (PAHs), phenylesters, phenylamines, phenols and inorganic anions, and notably, nucleobases and nucleosides can be separated using pure water as mobile phases. The van Deemter plot showed that the column efficiency of Sil-Im-C18-3 was 64,933 plate·m-1 for naphthalene, indicated that Sil-Im-C18 was reasonably chromatographic columns. The RSD values of retention time were 0.22 %-0.61 % for 10 needles alkylbenzenes injected continuously at 50 °C to investigate thermal stability and repeatability, all the fluctuations of k of naphthalene were less than 2.3 % for Sil-Im-C18-1 during flushing 24 h with the mobile phase at different pH values (pH = 3 and 8), the retention time of alkylbenzenes were almost same for Sil-Im-C18-1 at different time, the RSD values of retention time of alkylbenzenes were 0.45 %-2.28 % for two batches Sil-Im-C18-1, revealing the excellent repeatability, thermal stability, durability and reproducibility of Sil-Im-C18, and implying a commercial prospect.


Asunto(s)
Cromatografía de Fase Inversa , Imidazoles , Hidrocarburos Policíclicos Aromáticos , Dióxido de Silicio , Imidazoles/química , Dióxido de Silicio/química , Cromatografía de Fase Inversa/métodos , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/aislamiento & purificación , Hidrocarburos Policíclicos Aromáticos/química , Silanos/química , Cromatografía por Intercambio Iónico/métodos
7.
Biomolecules ; 14(4)2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38672508

RESUMEN

Reported herein is the development of assays for the spectrophotometric quantification of biocatalytic silicon-oxygen bond hydrolysis. Central to these assays are a series of chromogenic substrates that release highly absorbing phenoxy anions upon cleavage of the sessile bond. These substrates were tested with silicatein, an enzyme from a marine sponge that is known to catalyse the hydrolysis and condensation of silyl ethers. It was found that, of the substrates tested, tert-butyldimethyl(2-methyl-4-nitrophenoxy)silane provided the best assay performance, as evidenced by the highest ratio of enzyme catalysed reaction rate compared with the background (uncatalysed) reaction. These substrates were also found to be suitable for detailed enzyme kinetics measurements, as demonstrated by their use to determine the Michaelis-Menten kinetic parameters for silicatein.


Asunto(s)
Biocatálisis , Éteres , Silanos , Espectrofotometría , Hidrólisis , Espectrofotometría/métodos , Silanos/química , Cinética , Éteres/química , Éteres/metabolismo , Animales , Catepsinas/metabolismo , Catepsinas/química
8.
Int J Biol Macromol ; 268(Pt 2): 131790, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38677693

RESUMEN

The demand for paper-based packaging materials as an alternative to incumbent disposable petroleum-derived polymers for food packaging applications is ever-growing. However, typical paper-based formats are not suitable for use in unconventional applications due to inherent limitations (e.g., excessive hydrophilicity, lack antimicrobial ability), and accordingly, enabling new capabilities is necessity. Herein, a simple and environmentally friendly strategy was proposed to introduce antimicrobial and hydrophobic functions to cellulose paper through successive chemical grafting of 3-aminopropyltriethoxysilane (APS) and cinnamaldehyde (CA). The results revealed that cellulose paper not only showed long-term antibacterial effect on different bacteria, but also inhibited a wide range of fungi. Encouragingly, the modified paper, which is fluorine-free, displays a high contact angle of 119.7°. Thus, even in the wet state, the modified paper can still maintain good mechanical strength. Meanwhile, the multifunctional composite papers have excellent biocompatibility and biodegradability. Compared with ordinary cellulose paper, multifunctional composite paper can effectively prolong the shelf life of strawberries. Therefore, the multifunctional composite paper represents good application potential as a fruit packaging material.


Asunto(s)
Acroleína , Celulosa , Embalaje de Alimentos , Fragaria , Interacciones Hidrofóbicas e Hidrofílicas , Papel , Celulosa/química , Celulosa/análogos & derivados , Acroleína/análogos & derivados , Acroleína/química , Acroleína/farmacología , Fragaria/microbiología , Embalaje de Alimentos/métodos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Silanos/química , Conservación de Alimentos/métodos , Propilaminas/química , Pruebas de Sensibilidad Microbiana
9.
ACS Biomater Sci Eng ; 10(5): 3057-3068, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38641433

RESUMEN

Blood-contacting catheters play a pivotal role in contemporary medical treatments, particularly in the management of cardiovascular diseases. However, these catheters exhibit inappropriate wettability and lack antimicrobial characteristics, which often lead to catheter-related infections and thrombosis. Therefore, there is an urgent need for blood contact catheters with antimicrobial and anticoagulant properties. In this study, we employed tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) to create a stable hydrophilic coating under mild conditions. Heparin (Hep) and poly(lysine) (PL) were then modified on the TA-APTES coating surface using the layer-by-layer (LBL) technique to create a superhydrophilic TA/APTES/(LBL)4 coating on silicone rubber (SR) catheters. Leveraging the superhydrophilic nature of this coating, it can be effectively applied to blood-contacting catheters to impart antibacterial, antiprotein adsorption, and anticoagulant properties. Due to Hep's anticoagulant attributes, the activated partial thromboplastin time and thrombin time tests conducted on SR/TA-APTES/(LBL)4 catheters revealed remarkable extensions of 276 and 103%, respectively, when compared to uncoated commercial SR catheters. Furthermore, the synergistic interaction between PL and TA serves to enhance the resistance of SR/TA-APTES/(LBL)4 catheters against bacterial adherence, reducing it by up to 99.9% compared to uncoated commercial SR catheters. Remarkably, the SR/TA-APTES/(LBL)4 catheter exhibits good biocompatibility with human umbilical vein endothelial cells in culture, positioning it as a promising solution to address the current challenges associated with blood-contact catheters.


Asunto(s)
Catéteres , Materiales Biocompatibles Revestidos , Heparina , Polifenoles , Taninos , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Humanos , Catéteres/microbiología , Polifenoles/química , Polifenoles/farmacología , Heparina/química , Heparina/farmacología , Taninos/química , Taninos/farmacología , Silanos/química , Silanos/farmacología , Anticoagulantes/química , Anticoagulantes/farmacología , Propilaminas/química , Aminas/química , Aminas/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Polilisina/química , Polilisina/farmacología , Propiedades de Superficie , Interacciones Hidrofóbicas e Hidrofílicas , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Elastómeros de Silicona/química , Adsorción , Escherichia coli/efectos de los fármacos
11.
Int J Biol Macromol ; 265(Pt 2): 131053, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38521299

RESUMEN

How to efficiently produce high performance plywood is of particular interest, while its sensitivity to moisture is overcome. This paper presents a simple and scalable strategy for the preparation of high-performance plywood based on the chemical bonding theory; a wood interfacial functionalized platform (WIFP) based on (3-aminopropyl) triethoxysilane (APTES) was established. Interestingly, the APTES-enhanced dialdehyde cellulose-based adhesive (DAC-APTES) was able to effectively establish chemically active adhesive interfaces; the dry/wet shear strength of WIFP/DAC-APTES adhesive was 3.15/1.31 MPa, which was much higher than 0.7 MPa (GB/T 9846-2015). The prepared plywood showed excellent wood-polymer interface adhesion, which exceeded the force that the wood itself could withstand. In addition, the DAC-APTES adhesive exhibits moisture evaporation-induced curing behavior at room temperature and can easily support the weight of an adult weighing 65.7 Kg. This research provides a novel approach for functionalized interface design of wood products, an effective means to prepare high-performance plywood.


Asunto(s)
Celulosa , Silanos , Madera , Adulto , Humanos , Polímeros , Propilaminas
12.
J Mater Chem B ; 12(15): 3710-3718, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38529668

RESUMEN

Meeting the demand for efficient photosensitizers in photodynamic therapy (PDT), a series of iridium(III) complexes decorated with silicane-modified rhodamine (Si-rhodamine) was meticulously designed and synthesized. These complexes demonstrate exceptional PDT potential owing to their strong absorption in the near-infrared (NIR) spectrum, particularly responsive to 808 nm laser stimulation. This feature is pivotal, enabling deep-penetration laser excitation and overcoming depth-related challenges in clinical PDT applications. The molecular structures of these complexes allow for reliable tuning of singlet oxygen generation with NIR excitation, through modification of the cyclometalating ligand. Notably, one of the complexes (4) exhibits a remarkable ROS quantum yield of 0.69. In vivo results underscore the efficacy of 4, showcasing significant tumor regression at depths of up to 8.4 mm. This study introduces a promising paradigm for designing photosensitizers capable of harnessing NIR light effectively for deep PDT applications.


Asunto(s)
Fotoquimioterapia , Fármacos Fotosensibilizantes , Silanos , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Fotoquimioterapia/métodos , Iridio/farmacología , Iridio/química , Rodaminas , Línea Celular Tumoral , Rayos Infrarrojos
13.
Braz Dent J ; 35: e245674, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38537020

RESUMEN

This study verified the effect of surface treatments of the zirconia-reinforced lithium disilicate ceramic bonded to resin cement. Ceramic blocks were divided according to treatments (n=10): FA+SRX (Fluoric acid + silane RX), FA+MDP (Fluoric acid + MDP), FA+SCF+MDP (Fluoric acid + silane CF + MDP), FA+MEP (Fluoric acid + MEP), and MEP (Self-etch primer). Resin cement cylinders were made in the ceramic blocks, photoactivated with 1,200 mW/cm² for 40s, stored in water at 37°C for 24h, and evaluated by the microshear strength test, optical failure descriptive analysis (%), surface characterization (SEM) and contact angle (Goniometer). Other samples were submitted to 10,000 thermocycles between 5°C and 55°C. Bond strength data were submitted to two-way ANOVA and Tukey's test. Contact angle to one-way ANOVA and Games-Howell's test (5%). At 24h, MEP showed higher bond strength, and FA+SRX the lower. FA+MDP and FA+SCF+MDP showed similar values and FA+MEP was intermediate. After thermocycling, FA+SCF+MDP, FA+MEP, and MEP showed higher values, and FA+SRX the lower while FA+MDP was intermediate. When the periods were compared, FA+MDP, FA+SCF+MDP, FA+MEP, and MEP showed higher values for 24h while FA+SRX was similar. SEM showed retentive surface and crystal exposure when treated with FA+SCF+MDP. The less retentive surface was obtained with MEP, and the other treatments promoted intermediate irregularities. In conclusion, surface treatment and thermocycling promoted different values of adhesive strength and contact angle in a zirconia-reinforced lithium silicate ceramic. Failures were predominantly adhesive, and the ceramic surface was characterized by different levels of roughness and selective exposure of crystals.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Cementos de Resina/química , Silanos/química , Propiedades de Superficie , Porcelana Dental/química , Cerámica/química , Circonio/química , Ensayo de Materiales
14.
Braz Dent J ; 35: e245641, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38537017

RESUMEN

This study verified the effect of the combination of preheated hydrofluoric acid/silane/electric current in the adhesion of the resin cement to ceramic. IPS E.max Press ceramic discs embedded in PVC rigid tubes were divided into four groups associating preheated hydrofluoric acid and silane applied with electrical current (n=10): Ha+S (Heated acid + silane); Ha+S+Ec (Heated acid + silane + electrical current); A+S (Acid + silane) and A+S+Ec (Acid + silano + electrical current). Resin cement/ceramic samples were stored in water at 37°C for 24h. After storage, they were submitted to the microshear test, fracture analysis, and contact angle at 24h or after thermocycling (10,000 cycles/5-55ºC). Bond strength data were evaluated by two-way ANOVA. For comparison between evaluation times (24h or thermocycling) was applied unpaired t-test. A significance post-hoc test of p=0.05 was assumed for analyses and graphs (GraphPad Prism 9.0 software). At 24h, the microshear strength showed similar values between Ha+S, Ha+S+Ec, and A+S+Ec groups, while A+S showed the lowest value with a statistical difference. After thermocycling, Ha+S and Ha+S+Ec were similar, as well as A+S and A+S+Ec. There was a significant difference in all groups comparing 24h (highest value) with after thermocycling (lowest value). Adhesive fracture was predominant in all groups and evaluation times. Ha+S and A+S groups showed higher contact angle values compared to the Ha+S+Ec and A+S+Ec with lower values. In conclusion, the association of preheated hydrofluoric acid/silane applied or not with electric current promoted different microshear strength values, fracture types, and contact angles in the resin cement/ceramic bond.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Cementos de Resina/química , Silanos/química , Ácido Fluorhídrico/química , Propiedades de Superficie , Grabado Ácido Dental , Cerámica/química , Porcelana Dental/química , Ensayo de Materiales
15.
Dent Mater J ; 43(2): 312-319, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38432950

RESUMEN

We examined how different methods of surface treatment and different universal adhesives with or without extra silane affected the repair bonding strength of hybrid ceramic CAD/CAM restorations. Cerasmart specimens (n=320) were subjected to thermocycling and assigned to the following surface pretreatment protocols: control, diamond bur (DB), hydrofluoric acid (HF), and tribochemical silica coating (TSC). Half the specimens received a coating of silane, followed by application of the universal adhesives Futurabond M+ (FMU), Tokuyama Universal Bond (TUB), Single Bond Universal (SBU), or Clearfil Universal Bond Quick (CUQ) (n=10). A hybrid composite resin was used to simulate repair; then the specimens underwent further thermocycling. Shear bond strength (SBS) was determined and modes of failure were examined. The TSC-CUQ silane (-) group showed the highest SBS values. The best repairs were obtained when the surface was treated with TSC, with the exception of the DB-TUB silane (-) group. TUB increased SBS more than the other adhesives. Additional silane decreased SBS in the HF-TUB and TSC-CUQ groups, while increasing it in the TSC-TUB and DB-FMU groups (p<0.05).


Asunto(s)
Recubrimiento Dental Adhesivo , Silanos , Silanos/química , Cementos Dentales , Propiedades de Superficie , Ensayo de Materiales , Cerámica/química , Resistencia al Corte , Cementos de Resina/química
16.
Sci Rep ; 14(1): 5946, 2024 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-38467715

RESUMEN

The use of dendrimers as drug and nucleic acid delivery systems requires knowledge of their interactions with objects on their way to the target. In the present work, we investigated the interaction of a new class of carbosilane dendrimers functionalized with polyphenolic and caffeic acid residues with human serum albumin, which is the most abundant blood protein. The addition of dendrimers to albumin solution decreased the zeta potential of albumin/dendrimer complexes as compared to free albumin, increased density of the fibrillary form of albumin, shifted fluorescence spectrum towards longer wavelengths, induced quenching of tryptophan fluorescence, and decreased ellipticity of circular dichroism resulting from a reduction in the albumin α-helix for random coil structural form. Isothermal titration calorimetry showed that, on average, one molecule of albumin was bound by 6-10 molecules of dendrimers. The zeta size confirmed the binding of the dendrimers to albumin. The interaction of dendrimers and albumin depended on the number of caffeic acid residues and polyethylene glycol modifications in the dendrimer structure. In conclusion, carbosilane polyphenolic dendrimers interact with human albumin changing its structure and electrical properties. However, the consequences of such interaction for the efficacy and side effects of these dendrimers as drug/nucleic acid delivery system requires further research.


Asunto(s)
Ácidos Cafeicos , Dendrímeros , Ácidos Nucleicos , Humanos , Albúmina Sérica Humana/metabolismo , Dendrímeros/química , Silanos/química
17.
J Colloid Interface Sci ; 665: 814-824, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38555749

RESUMEN

The outer bacterial membrane of drug-resistant bacteria is a significant barrier to many antimicrobials. Therefore, the development of new antibacterials primarily focuses on damaging the outer bacterial membrane of Gram-negative bacteria. Among many membrane-disrupting substances, the most promising are cationic dendritic systems. However, the mode of action may vary among different strains due to variations in the lipid compositions of the membrane. Here, we investigated the interaction of two types of cationic imidazolium carbosilane dendrimers: one with a single cationic group (methyl imidazolium) and the other with the same cationic group but attached to a functional group (a pendant pyridyl moiety), capable of establishing interactions with membranes through H-bonding or ion-dipole electrostatic interactions. We used different models of the outer membrane of Gram-negative bacteria - Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Additionally, we assessed the combined effect of the dendrimers and the antibacterial endolysin on P. aeruginosa. Our results show that the mechanism of action depends on the type of dendrimer and the lipid composition of the membrane. We also demonstrate that the alteration of membrane fluidity and permeability to endolysin by the methyl imidazolium and pyridyl imidazolium dendrimers may play a more significant role in antimicrobial activity compared to membrane damage caused by positively charged dendrimers.


Asunto(s)
Dendrímeros , Endopeptidasas , Silanos , Dendrímeros/farmacología , Antibacterianos/farmacología , Bacterias Gramnegativas , Permeabilidad , Lípidos , Pruebas de Sensibilidad Microbiana
18.
Bioprocess Biosyst Eng ; 47(4): 533-547, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38485804

RESUMEN

The calorific value of post-fermentation biogas is a way down below standard and quite low due to the presence of high amount level of carbon dioxide (CO2) biogas mixture. Therefore, it raises the need to process the biogas, separating it from CO2 in order to obtain high-purity biogas as well as to maximize its calorific value. One widely available material that can be used as a sustainable carbon capture adsorbent is silica extracted from bamboo leaves. However, so that silica can act as CO2 adsorber, it is necessary to modify the surface of silica with CTAB and APTES (3-aminopropyl triethoxysilane). In this study, 2-stage method was carried out, namely preparation of mesoporous silica and surface modification using APTES on the mesoporous silica. Experiments in synthesizing APTES-modified silica were obtained by varying its composition: CTAB (1.5-5%w), (HCl 1.5-5 N), and APTES (10-30%). A central composite design (CCD) was employed in exploring the interaction between all variables and also performed for the optimization. Through analysis of variance, it shows that optimum CO2 adsorption capacity reaches 47.02 mg g-1, by applying 4.98% of CTAB, 4.28 N of HCl and 10.08% of APTES. Pseudo-second-order kinetic and Redlich-Peterson isotherm models are more representative to show the adsorption behavior of CO2 into the modified silica. The results show that the modified silica with APTES shows a prospective application of silica for CO2 removal from biogas.


Asunto(s)
Biocombustibles , Propilaminas , Silanos , Dióxido de Silicio , Cetrimonio , Dióxido de Carbono
19.
Mikrochim Acta ; 191(4): 181, 2024 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-38446252

RESUMEN

Silica nanoparticles (SiNPs) with a chemically modified surface typically have a complicated chemical composition, which can significantly differ from their intended design. In this study, we systematically studied the effects of two surface modification methods on active-targeting of intracellular organelles of SiNPs: (1) the widely used step-by-step approach, which involves modifying SiNPs in two steps, i.e., the outer surface of SiNPs was firstly modified with amino groups and then these amino groups were linked with targeting groups, and (2) a newly developed one-step approach in which the ligand-silane complex is initially synthesized, followed by chemically immobilizing the complex on the surface of SiNPs. In the one-step approach, the molar ratio of reactants was precisely tuned so that there are no reactive groups left on the outer surface of SiNPs. Two essential organelles, mitochondria and the nucleus, were selected to compare the targeting performances of SiNPs synthesized via these two approaches. By characterizing physicochemical properties, including structural properties, the number of amino groups, surface charge, polydispersity, and cell colocalization, we demonstrated that SiNPs synthesized via the one-step approach with no residual linkage groups on their surface showed significantly improved mitochondria- and nucleus-targeting performances. This precise control of surface properties allows for optimized biological behavior and active-targeting efficiency of SiNPs. We anticipate that such simple and efficient synthetic strategies will enable the synthesis of effective SiNPs for active-targeting organelles in various biological applications.


Asunto(s)
Mitocondrias , Nanopartículas , Colorantes , Silanos , Dióxido de Silicio
20.
Biosensors (Basel) ; 14(3)2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38534248

RESUMEN

Bovine serum albumin (BSA) is commonly incorporated in vaccines to improve stability. However, owing to potential allergic reactions in humans, the World Health Organization (WHO) mandates strict adherence to a BSA limit (≤50 ng/vaccine). BSA detection with conventional techniques is time-consuming and requires specialized equipment. Efficient alternatives such as the ion-sensitive field-effect transistor (ISFET), despite rapid detection, affordability, and portability, do not detect BSA at low concentrations because of inherent sensitivity limitations. This study proposes a silicon-on-insulator (SOI) substrate-based dual-gate (DG) ISFET platform to overcome these limitations. The capacitive coupling DG structure significantly enhances sensitivity without requiring external circuits, owing to its inherent amplification effect. The extended-gate (EG) structure separates the transducer unit for electrical signal processing from the sensing unit for biological detection, preventing chemical damage to the transducer, accommodating a variety of biological analytes, and affording easy replaceability. Vapor-phase surface treatment with (3-Aminopropyl) triethoxysilane (APTES) and the incorporation of a SnO2 sensing membrane ensure high BSA detection efficiency and sensitivity (144.19 mV/log [BSA]). This DG-FET-based biosensor possesses a simple structure and detects BSA at low concentrations rapidly. Envisioned as an effective on-site diagnostic tool for various analytes including BSA, this platform addresses prior limitations in biosensing and shows promise for practical applications.


Asunto(s)
Técnicas Biosensibles , Propilaminas , Albúmina Sérica Bovina , Humanos , Iones , Silanos , Silicio , Técnicas Biosensibles/métodos , Transistores Electrónicos
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