RESUMO
This work aimed to fabricate a Cloisite 30B-incorporated carboxymethyl cellulose graft copolymer of acrylic acid and itaconic acid hydrogel (Hyd) via a free radical polymerization method for controlled release of Sunitinib malate anticancer drug. The synthesized samples were characterized by FTIR, XRD, TEM, and SEM-dot mapping analyses. The encapsulation efficiency of Hyd and Hyd/Cloisite 30B (6 wt%) was 81 and 93%, respectively, showing the effectiveness of Cloisite 30B in drug loading. An in vitro drug release study showed that drug release from all samples in a buffer solution with pH 7.4 was higher than in a buffer solution with pH 5.5. During 240 min, the cumulative drug release from Hyd/Cloisite 30B (94.97% at pH 7.4) is lower than Hyd (53.71% at pH 7.4). Also, drug-loaded Hyd/Cloisite 30B (6 wt%) demonstrated better antibacterial activity towards S. Aureus bacteria and E. Coli. High anticancer activity of Hyd/Cloisite 30B against MCF-7 human breast cancer cells was shown by the MTT assay, with a MCF-7 cell viability of 23.82 ± 1.23% after 72-hour incubation. Our results suggest that Hyd/Cloisite 30B could be used as a pH-controlled carrier to deliver anticancer Sunitinib malate.
Assuntos
Carboximetilcelulose Sódica , Portadores de Fármacos , Hidrogéis , Indóis , Nanocompostos , Pirróis , Succinatos , Sunitinibe , Sunitinibe/química , Sunitinibe/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Succinatos/química , Succinatos/farmacologia , Carboximetilcelulose Sódica/química , Hidrogéis/química , Indóis/química , Indóis/farmacologia , Nanocompostos/química , Pirróis/química , Pirróis/farmacologia , Portadores de Fármacos/química , Células MCF-7 , Antineoplásicos/farmacologia , Antineoplásicos/química , Resinas Acrílicas/química , Administração Oral , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/administração & dosagem , Liberação Controlada de Fármacos , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacosRESUMO
Extracellular matrix (ECM) stiffness is fundamental in cell division, movement and differentiation. The stiffness that cells sense is determined not only by the elastic modulus of the ECM material but also by ECM geometry and cell density. We hypothesized that these factors would influence cell traction-induced matrix deformations and cellular differentiation in bone marrow stromal cells (BMSCs). To achieve this, we cultivated BMSCs on polyacrylamide hydrogels that varied in elastic modulus and geometry and measured cell spreading, cell-imparted matrix deformations and differentiation. At low cell density BMSCs spread to a greater extent on stiff compared with soft hydrogels, or on thin compared with thick hydrogels. Cell-imparted matrix deformations were greater on soft compared with stiff hydrogels or thick compared with thin hydrogels. There were no significant differences in osteogenic differentiation relative to hydrogel elastic modulus and thickness. However, increased cell density and/or prolonged culture significantly reduced matrix deformations on soft hydrogels to levels similar to those on stiff substrates. This suggests that at high cell densities cell traction-induced matrix displacements are reduced by both neighbouring cells and the constraint imposed by an underlying stiff support. This may explain observations of the lack of difference in osteogenic differentiation as a function of stiffness.
Assuntos
Diferenciação Celular , Hidrogéis , Células-Tronco Mesenquimais , Hidrogéis/química , Animais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Matriz Extracelular/metabolismo , Resinas Acrílicas/química , Módulo de Elasticidade , Mecanotransdução Celular/fisiologia , Osteogênese/fisiologia , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Células CultivadasRESUMO
Hydrogels are highly sought-after absorbent materials for absorbent pads; however, it is still challenging to achieve a satisfactory balance between mechanical performance, water absorption capacity, and active functionalities. In this work, we presented double-network hydrogels synthesized through acrylic acid (AA) polymerization in the presence of quaternized cellulose nanofibrils (QCNF) and Fe3+. Spectroscopic and microscopic analyses revealed that the combined QCNF and Fe3+ facilitated the formation of double-network hydrogels with combined chemical and physical crosslinking. The synergistic effect of QCNF and Fe3+ resulted in impressive mechanical properties, including tensile strength of 1.98 MPa, fracture elongation of 838.8 %, toughness of 7.47 MJ m-3, and elastic modulus of 0.35 MPa. In comparison to the single-network PAA hydrogel, the PAA/QCNF/Fe3+ (PQFe) hydrogels showed higher and relatively stable swelling ratios under varying pH levels and saline conditions. The PQFe hydrogels exhibited notable antioxidant activity, as evidenced by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and demonstrated effective antibacterial activity against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). These hydrogels show promising potential as an absorbent interlayer in absorbent pads for active food packaging.
Assuntos
Resinas Acrílicas , Antibacterianos , Celulose , Escherichia coli , Hidrogéis , Ferro , Nanofibras , Staphylococcus aureus , Resistência à Tração , Hidrogéis/química , Hidrogéis/farmacologia , Celulose/química , Staphylococcus aureus/efeitos dos fármacos , Resinas Acrílicas/química , Escherichia coli/efeitos dos fármacos , Nanofibras/química , Ferro/química , Antibacterianos/farmacologia , Antibacterianos/química , Antioxidantes/química , Antioxidantes/farmacologia , Módulo de ElasticidadeRESUMO
The ability to transform matter between numerous physical states or shapes without wires or external devices is a major challenge for robotics and materials design. Organisms can transform their shapes using biomolecules carrying specific information and localize at sites where transitions occur. Here, we introduce gel automata, which likewise can transform between a large number of prescribed shapes in response to a combinatorial library of biomolecular instructions. Gel automata are centimeter-scale materials consisting of multiple micro-segments. A library of DNA activator sequences can each reversibly grow or shrink different micro-segments by polymerizing or depolymerizing within them. We develop DNA activator designs that maximize the extent of growth and shrinking, and a photolithography process for precisely fabricating gel automata with elaborate segmentation patterns. Guided by simulations of shape change and neural networks that evaluate gel automata designs, we create gel automata that reversibly transform between multiple, wholly distinct shapes: four different letters and every even or every odd numeral. The sequential and repeated metamorphosis of gel automata demonstrates how soft materials and robots can be digitally programmed and reprogrammed with information-bearing chemical signals.
Assuntos
Resinas Acrílicas , DNA , Géis , Géis/química , DNA/química , Resinas Acrílicas/química , Redes Neurais de Computação , Algoritmos , Fenômenos Químicos , Sequência de BasesRESUMO
Recently, interest in tooth-colored fluoride-releasing dental materials has increased. Although physical and mechanical properties such as surface hardness, elastic modulus and surface roughness of the restorative materials have been investigated, the effect of different immersion media on these properties is still controversial. The aim of this study was to evaluate the nanohardness, elastic modulus and surface roughness of the fluoride release of tooth-colored restorative materials after immersion in acidic beverages. Prepared samples of three restorative materials (a highly viscous glass ionomer (EQUIA Forte; GC, Tokyo, Japan), a compomer (Dyract XP; Dentsply, Weybridge, UK), and a bioactive restorative material (Activa BioACTIVE; Pulpdent, MA, USA)) were randomly divided and immersed in distilled water, a cola and an orange juice for one week. The HYSITRON T1 950 TriboIndenter device (Hysitron, USA) with the Berkovich diamond indenter tip was used for all measurements. The nanohardness and elastic modulus of the samples were measured by applying a force of 6000 µN to five different points on the sample surface. Surface roughness measurements were evaluated on random samples by scanning five random 40 × 40 µm areas. The properties were measured at the initial and one week after immersion. The values of nanohardness, elastic modulus and surface roughness were tested for significant differences using a two-way analysis of variance (ANOVA) with repeated measures (p < 0.05). Tukey's honest significant difference (HSD) test was used for multiple comparisons. AB (Activa BioACTIVE) had the highest initial mean values for nanohardness. After post-immersion, the highest mean value for elastic modulus was the initial AB value. The lowest mean value for roughness of 100.36 nm was obtained for the initial DX (Dyract XP) measurement. Acidic beverages had a negative effect on the nanohardness, elastic modulus and surface roughness of the restorative materials.
Assuntos
Bebidas Gaseificadas , Módulo de Elasticidade , Fluoretos , Dureza , Teste de Materiais , Propriedades de Superfície , Fluoretos/química , Compômeros/química , Humanos , Materiais Dentários/química , Sucos de Frutas e Vegetais , Resinas Acrílicas/química , Restauração Dentária Permanente/métodos , Água/química , Cariostáticos/química , Cimentos de Ionômeros de Vidro/química , Citrus sinensis/química , Imersão , Resinas Compostas/química , Dióxido de SilícioRESUMO
Organic modification can generally endow inorganic materials with novel and promotional characteristics to fit into new functionalities. In this paper, new cement-based composite materials, with Portland cement as the substrate and polyacrylamide (PAM, alone) and PAM/chitosan as the functional components mixed with cement (bulk modified) or served as the surface coating (surface modified), were prepared and engineered as sampling substrates for biofilm and coral co-culture. In comparison to the bulk modified substrate and pure cement material, the surface modified substrate showed a balanced mechanical property, considering both bending and compressive strengths and distinctive surface features toward facilitating biofilm and coral growth, as characterized by spectroscopic, morphological, mechanical, and biofilm and coral co-culture experiments. We, thus, believe that the as-prepared surface modified substrate has the very potential to be applied as a substitute/alternative for the conventional cement material in the construction and engineering of artificial facilities with ecological protection functions.
Assuntos
Antozoários , Materiais Biocompatíveis , Biofilmes , Animais , Antozoários/química , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Materiais Biocompatíveis/química , Resinas Acrílicas/química , Propriedades de Superfície , Organismos Aquáticos/química , Quitosana/química , Técnicas de Cocultura , Materiais de Construção/microbiologiaRESUMO
Despite the remoteness of the Antarctic continent and Southern Ocean, microplastic (MPs) contamination has been evidenced in recent years. However, the deep-sea compartments of the Southern Ocean are yet to be investigated. In the present study, we conducted a baseline MP assessment of the deep-sea waters and bottom sediments of the Bransfield Strait, Antarctica. A low abundance of suspected MPs was found. The average MP abundances in bottom sediments and water samples were 0.09 MP/g (range of 0-0.2 MP/g) and 7.00 MP/L (range of 0-16 MP/L), respectively. The majority of the particles were fibers identified as cellulose, although polyethylene terephthalate (PET) and polyacrylonitrile (PAN) was also detected. These results suggest low MP contamination levels in the Southern Ocean's deepest environmental compartments. However, future studies must aim to investigate the smallest MP fractions and, if possible, nanoplastic (<1 µm) contamination in these remote compartments.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Microplásticos , Água do Mar , Poluentes Químicos da Água , Sedimentos Geológicos/química , Regiões Antárticas , Microplásticos/análise , Poluentes Químicos da Água/análise , Água do Mar/química , Polietilenotereftalatos/química , Resinas Acrílicas/químicaRESUMO
Riboflavin-5-phosphate (riboflavin) is the most commonly used photosensitizer in corneal crosslinking (CXL); while its efficient delivery into the stroma through the corneal epithelial barrier is challenging. In this paper, we presented novel responsive porous microneedles with ocular microinjection capability to deliver riboflavin controllably inside the cornea to facilitate CXL. The microneedle patch was composed of Poly (N-isopropyl acrylamide) (PNIPAM), graphene oxide (GO), and riboflavin-loaded gelatin. After penetrating the cornea by the stiff and porous gelatin needle tip, the photothermal-responsive characteristic of the PNIPAM/GO hydrogel middle layer could realize the contraction of the gel under the stimulation of near-infrared light, which subsequently could control the release of riboflavin from the backing layer into the cornea stromal site both in vitro and in vivo. Based on the microneedles system, we have demonstrated that this microinjection technique exhibited superior riboflavin delivery capacity and treatment efficacy to the conventional epithelial-on protocol in a rabbit keratoconus model, with benefits including minimal invasiveness and precise administering. Thus, we believe the responsive porous microneedles with riboflavin ocular microinjection capability are promising for clinical corneal crosslinking without epithelial debridement.
Assuntos
Córnea , Reagentes de Ligações Cruzadas , Microinjeções , Agulhas , Fármacos Fotossensibilizantes , Riboflavina , Riboflavina/farmacologia , Animais , Microinjeções/métodos , Microinjeções/instrumentação , Coelhos , Córnea/efeitos dos fármacos , Porosidade , Reagentes de Ligações Cruzadas/química , Fármacos Fotossensibilizantes/farmacologia , Ceratocone/tratamento farmacológico , Grafite/química , Resinas Acrílicas/química , Sistemas de Liberação de Medicamentos/métodos , Hidrogéis/química , Gelatina/química , Modelos Animais de DoençasRESUMO
This study aimed to investigate the effect of acidulated phosphate fluoride (APF) application on filler-free polymethyl methacrylate (PMMA)-based resin blocks for computer-aided design/computer-aided manufacturing (CAD-CAM), focusing on their use in pediatric crowns. Three types of PMMA-based blocks for CAD-CAM were evaluated, and a composite resin block for CAD-CAM was used as a control. Statistical analysis (p<0.05) of the data revealed that all PMMA-based blocks showed significantly higher gloss levels than the composite resin blocks. Two PMMA-based blocks also demonstrated significantly lower Ra and Sa values. SEM images showed no irregular changes in the surface properties of the PMMA-based blocks compared to those of the composite resin block. These results are significant in meeting the increasing demand for esthetic restorative treatments in pediatrics, where APF is commonly used for caries prevention. PMMA-based resin blocks for CAD-CAM are an effective alternative to prevent esthetic degradation from gloss reduction and plaque accumulation.
Assuntos
Fluoreto de Fosfato Acidulado , Resinas Acrílicas , Resinas Compostas , Desenho Assistido por Computador , Coroas , Teste de Materiais , Polimetil Metacrilato , Propriedades de Superfície , Humanos , Polimetil Metacrilato/química , Resinas Acrílicas/química , Fluoreto de Fosfato Acidulado/química , Resinas Compostas/química , Microscopia Eletrônica de Varredura , Polimerização , Criança , Materiais Dentários/químicaRESUMO
The application of biomaterials in bone regeneration is a prevalent clinical practice. However, its efficacy in elderly patients remains suboptimal, necessitating further advancements. While biomaterial properties are known to orchestrate macrophage (MΦ) polarization and local immune responses, the role of biomaterial cues, specifically stiffness, in directing the senescent macrophage (S-MΦ) is still poorly understood. This study aimed to elucidate the role of substrate stiffness in modulating the immunomodulatory properties of S-MΦ and their role in osteo-immunomodulation. Our results demonstrated that employing collagen-coated polyacrylamide hydrogels with varying stiffness values (18, 76, and 295 kPa) as model materials, the high-stiffness hydrogel (295 kPa) steered S-MΦs towards a pro-inflammatory M1 phenotype, while hydrogels with lower stiffness (18 and 76 kPa) promoted an anti-inflammatory M2 phenotype. The immune microenvironment created by S-MΦs promoted the bioactivities of senescent endothelial cells (S-ECs) and senescent bone marrow mesenchymal stem cells BMSCs (S-BMSCs). Furthermore, the M2 S-MΦs, particularly incubated on the 76 kPa hydrogel matrices, significantly enhanced the ability of angiogenesis of S-ECs and osteogenic differentiation of S-BMSCs, which are crucial and interrelated processes in bone healing. This modulation aided in reducing the accumulation of reactive oxygen species in S-ECs and S-BMSCs, thereby significantly contributing to the repair and regeneration of aged bone tissue.
Assuntos
Regeneração Óssea , Hidrogéis , Imunomodulação , Macrófagos , Células-Tronco Mesenquimais , Osteogênese , Regeneração Óssea/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Hidrogéis/química , Osteogênese/efeitos dos fármacos , Células-Tronco Mesenquimais/imunologia , Animais , Senescência Celular/efeitos dos fármacos , Humanos , Diferenciação Celular , Neovascularização Fisiológica/efeitos dos fármacos , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Materiais Biocompatíveis/farmacologia , Propriedades de Superfície , Colágeno/metabolismoRESUMO
Despite decades of research and development, the optimal efficiency of slurry-packed HPLC columns is still hindered by inherent long-range flow heterogeneity from the wall to the central bulk region of these columns. Here, we show an example of how this issue can be addressed through the straightforward addition of a semidilute amount (500 ppm) of a large, flexible, synthetic polymer (18 MDa partially hydrolyzed polyacrylamide, HPAM) to the mobile phase (1% NaCl aqueous solution, hereafter referred to as "brine") during operation of a 4.6 mm × 300 mm column packed with 10µm BEHTM 125 Å particles. Addition of the polymer imparts elasticity to the mobile phase, causing the flow in the interparticle pore space to become unstable above a threshold flow rate. We verify the development of this elastic flow instability using pressure drop measurements of the friction factor versus Reynolds number. In prior work, we showed that this flow instability is characterized by large spatiotemporal fluctuations in the pore-scale flow velocities that may promote analyte dispersion across the column. Axial dispersion measurements of the quasi non-retained tracer thiourea confirm this possibility: they reveal that operating above the onset of the instability improves column efficiency by greater than 100%. These experiments thereby suggest that elastic flow instabilities can be harnessed to mitigate the negative impact of trans-column flow heterogeneities on the efficiency of slurry-packed HPLC columns. While this approach has its own inherent limitations and constraints, our results lay the groundwork for future targeted development of polymers that can impart elasticity when dissolved in commonly used liquid chromatography mobile phases, and can thereby generate elastic flow instabilities to help improve the resolution of HPLC columns.
Assuntos
Resinas Acrílicas , Cromatografia Líquida de Alta Pressão/métodos , Cinética , Resinas Acrílicas/química , ElasticidadeRESUMO
The field of 3-dimensional (3D) bioprinting has significantly expanded capabilities in producing precision-engineered hydrogel constructs, and recent years have seen the development of various stimuli-responsive bio- and photoinks. There is, however, a distinct lack of digital light processing (DLP)-compatible photoinks with thermoresponsivity. To remedy this, this work focuses on formulating and optimizing a versatile ink for DLP printing of thermoresponsive hydrogels, with numerous potential applications in tissue engineering, drug delivery, and adjacent biomedical fields. Photoink optimization was carried out using a multifactorial study design. The optimized photoink yielded crosslinked hydrogels with strong variations in hydrophobicity (contact angles of 44.4°
Assuntos
Resinas Acrílicas , Bioimpressão , Hidrogéis , Bioimpressão/métodos , Hidrogéis/química , Hidrogéis/síntese química , Humanos , Resinas Acrílicas/química , Temperatura , Tinta , Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Luz , Impressão Tridimensional , Engenharia Tecidual , AnimaisRESUMO
BACKGROUND: There is a lack of studies comparing the dimensional accuracy and color stability of denture base resins made using computer-aided design and computer-aided manufacturing (CAD-CAM) milling, 3-dimensional (3D) printing, and conventional denture processing techniques. This makes it challenging to determine the best method to fabricate complete dentures. The objective of this in vitro investigation was to assess and contrast the color stability and dimensional accuracy of denture base resins that were 3D printed and CAD-CAM milled, both before and after aging by thermocycling using digital surface matching technology and a benchtop laser scanner without using a spray, to optimize adaptation of the denture base and cast to minimize any imperfections and to evaluate the impact of the denture cleansing solution on the stability of color. METHODS: Evaluation of the dimensional accuracy (n = 27) was completed on a sectional maxillary stone cast using a digital 3D-surface matching software before and after 5000 thermocycles. A spectrophotometer was used to measure the color change (â³E00) of all disc specimens (N = 54) before and after 500 thermocycles and immersion in denture cleansing solution for 30 cycles (3 min each) daily for 6 days. The Kruskal Wallis test, Dunn's post hoc test, Tukey's test with Bonferroni adjustment, one sample t test and independent t test were used to statistically analyze the data (α < 0.05). RESULTS: Thermocycling decreased the dimensional accuracy of the heat polymerized group at all 5 locations and the 3D-printed group at locations 1, 3 and 5 (P > .05), while it had no significant difference on the CAD-CAM milled group at all locations (P < .05). The color change (â³E00) was lowest in the CAD-CAM milled group, moderate in the heat-polymerized group and highest in the 3D-printed group. After immersion in denture cleanser, the color change (â³E00) was significantly higher in the 3 groups compared with after thermocycling (P > .001). CONCLUSIONS: CAD-CAM milled resins had the highest dimensional accuracy and the best color stability, conventional heat polymerized acrylic resins showed moderate change in dimensional accuracy and color stability, while the 3D- printed resin had the lowest dimensional accuracy and color stability after aging by thermocycling.
Assuntos
Cor , Desenho Assistido por Computador , Bases de Dentadura , Impressão Tridimensional , Técnicas In Vitro , Planejamento de Dentadura , Fatores de Tempo , Espectrofotometria , Humanos , Propriedades de Superfície , Resinas Acrílicas/química , Teste de Materiais , Higienizadores de Dentadura/químicaRESUMO
Poly(N-isopropylacrylamide) (PNIPAM) offers a promising platform for non-invasive and gentle cell detachment. However, conventional PNIPAM-based substrates often suffer from limitations including limited stability and reduced reusability, which hinder their widespread adoption in biomedical applications. In this study, PNIPAM copolymer films were formed on the surfaces of glass slides or silicon wafers using a two-step film-forming method involving coating and grafting. Subsequently, a comprehensive analysis of the films' surface wettability, topography, and thickness was conducted using a variety of techniques, including contact angle analysis, atomic force microscopy (AFM), and ellipsometric measurements. Bone marrow mesenchymal stem cells (BMMSCs) were then seeded onto PNIPAM copolymer films prepared from different copolymer solution concentrations, ranging from 0.2 to 10 mg·mL-1, to select the optimal culture substrate that allowed for good cell growth at 37 °C and effective cell detachment through temperature reduction. Furthermore, the stability and reusability of the optimal copolymer films were assessed. Finally, AFM and X-ray photoelectron spectroscopy (XPS) were employed to examine the surface morphology and elemental composition of the copolymer films after two rounds of BMMSC adhesion and detachment. The findings revealed that the surface properties and overall characteristics of PNIPAM copolymer films varied significantly with the solution concentration. Based on the selection criteria, the copolymer films derived from 1 mg·mL-1 solution were identified as the optimal culture substrates for BMMSCs. After two rounds of cellular adhesion and detachment, some proteins remained on the film surfaces, acting as a foundation for subsequent cellular re-adhesion and growth, thereby implicitly corroborating the practicability and reusability of the copolymer films. This study not only introduces a stable and efficient platform for stem cell culture and harvesting but also represents a significant advance in the fabrication of smart materials tailored for biomedical applications.
Assuntos
Resinas Acrílicas , Adesão Celular , Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Resinas Acrílicas/química , Adesão Celular/efeitos dos fármacos , Técnicas de Cultura de Células/métodos , Propriedades de Superfície , Proliferação de Células/efeitos dos fármacos , Temperatura , Animais , Microscopia de Força Atômica , Células Cultivadas , Células da Medula Óssea/citologiaRESUMO
Conductive hydrogels have been increasingly employed to construct wearable mechanosensors due to their excellent mechanical flexibility close to that of soft tissues. In this work, piezoelectric hydrogels are prepared through free radical copolymerization of acrylamide (AM) and acrylonitrile (AN) and further utilized in assembling flexible wearable mechanosensors. Introduction of the polyacrylonitrile (PAN) component in the copolymers endows the hydrogels with excellent piezoelectric properties. Meanwhile, significant enhancement of mechanical properties has been accessed by forming dipole-dipole interactions, which results in a tensile strength of 0.51 MPa. Flexible wearable mechanosensors are fabricated by utilizing piezoelectric hydrogels as key signal converting materials. Self-powered piezoelectric pressure sensors are assembled with a sensitivity (S) of 0.2 V kPa-1. Additionally, resistive strain sensors (gauge factor (GF): 0.84, strain range: 0-250%) and capacitive pressure sensors (S: 0.23 kPa-1, pressure range: 0-8 kPa) are fabricated by utilizing such hydrogels. These flexible wearable mechanosensors can monitor diverse body movements such as joint bending, walking, running, and stair climbing. This work is anticipated to offer promising soft materials for efficient mechanical-to-electrical signal conversion and provides new insights into the development of various wearable mechanosensors.
Assuntos
Resinas Acrílicas , Hidrogéis , Dispositivos Eletrônicos Vestíveis , Hidrogéis/química , Resinas Acrílicas/química , Humanos , Resistência à Tração , Acrilamida/químicaRESUMO
Triboelectric nanogenerators (TENGs) have attracted widespread attention as a promising candidate for energy harvesting due to their flexibility and high power density. To meet diverse application scenarios, a highly stretchable (349%), conductive (1.87 S m-1), and antibacterial electrode composed of carbon quantum dots/LiCl/agar-polyacrylamide (CQDs/LiCl/agar-PAAm) dual-network (DN) hydrogel is developed for wearable TENGs. Notably, the concentration of agar alters the pore spacing and pore size of the DN hydrogel, thereby impacting the network cross-linking density and the migration of conductive ions (Li+ and Cl-). This variation further affects the mechanical strength and conductivity of the hydrogel electrode, thus modulating the mechanical stability and electrical output performance of the TENGs. With the optimal agar content, the tensile strength and conductivity of the hydrogel electrode increase by 211 and 719%, respectively. This enhancement ensures the stable output of TENGs during continuous operation (6000 cycles), with open-circuit voltage, short-circuit current, and transferred charge increasing by 200, 530, and 155%, respectively. Additionally, doping with CQDs enables the hydrogel electrode to effectively inhibit the Gram-negative bacterium Escherichia coli. Finally, the TENGs are utilized as a self-power smart ring for efficient and concise information transmission via Morse code. Consequently, this study introduces a creative approach for designing and implementing multifunctional, flexible wearable devices.
Assuntos
Antibacterianos , Eletrodos , Escherichia coli , Hidrogéis , Dispositivos Eletrônicos Vestíveis , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Hidrogéis/química , Hidrogéis/farmacologia , Pontos Quânticos/química , Resinas Acrílicas/química , Condutividade Elétrica , Fontes de Energia Elétrica , Ágar/química , Carbono/química , HumanosRESUMO
The objective of the study was to develop a novel topical gel by mixing Potentilla tormentilla ethanolic extract, thermosensitive poloxamer 407, and carbomer 940 and evaluating its stability and rheological behavior. The irritation potential of the gel was evaluated in accordance with the Organization for Economic Cooperation and Development Guidelines 404. The potential anti-inflammatory effects of the developed gel were evaluated in vivo in rats using the carrageenan-induced paw edema test. Moreover, the in silico binding affinity for chlorogenic and ellagic acid, as dominant components in the extract, against cyclooxygenase (COX) 1 and 2 was also determined. Our findings suggest that the gel containing Potentilla tormentilla extract remained stable throughout the observation period, exhibited pseudoplastic behavior, and caused no irritation in rats, thus being considered safe for topical treatment. Additionally, the developed gel showed the capability to reduce rat paw edema, which highlights significant anti-inflammatory potential. In silico analysis revealed that chlorogenic and ellagic acid exhibited a reduced binding affinity against COX-1 but had a similar inhibitory effect on COX-2 as flurbiprofen, which was confirmed by molecular dynamics results. The study proposes the possible application of Potentilla tormentilla ethanolic extract gel for the alleviation of localized inflammatory diseases; however, future clinical evaluation is required.
Assuntos
Anti-Inflamatórios , Ciclo-Oxigenase 1 , Edema , Extratos Vegetais , Potentilla , Animais , Potentilla/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Edema/tratamento farmacológico , Edema/induzido quimicamente , Masculino , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 1/química , Géis/química , Ácido Elágico/farmacologia , Ácido Elágico/química , Ciclo-Oxigenase 2/metabolismo , Carragenina , Ratos Wistar , Poloxâmero/química , Resinas Acrílicas/química , Ácido Clorogênico/química , Ácido Clorogênico/farmacologiaRESUMO
This work presents the results of an investigation on the physiochemical and structural characteristics of polyacrylonitrile (PAN) nanofiltration (NF) membranes prepared using a novel concept of binary solvents for nickel (Ni) removal from wastewater streams. The thermodynamic and kinetic aspects are emphasized aiming to optimize dope formulation, membrane performance, and durability. The fabricated membranes were characterized by scanning electron microscopy (SEM), porosimetry, tensile stress/strain, and flux and rejection. Results revealed that the use of an equal (1:1) mixture of n-methyl-2-pyrrolidone (NMP) and dimethylformamide (DMF) as dope solvents led to the formation of membranes with enhanced performance, offering pure water flux of 2.33 L·m-2·h-1·bar-1 and Ni rejection of 90.84%. Moreover, the incorporation of 0.5 wt.% PEG as a pore-forming agent to the dope solution further boosted pure water flux to 4.97 L·m-2·h-1·bar-1 with negligible impact on Ni rejection. Besides attractive performance, the adopted strategy offered membranes of exceptionally high flexibility with no sign of defect or failure especially during module fabrication and testing enabling smooth and hassle-free scale-up and extension to other applications. PRACTITIONER POINTS: Optimized solvent mixture: A 1:1 blend of n-methyl-2-pyrrolidone (NMP) and dimethylformamide (DMF) as solvents resulted in enhanced membrane performance. High flux and Ni rejection: The fabricated membranes exhibited a pure water flux of 2.33 L·m-2·h-1·bar-1 and a remarkable Ni rejection of 90.84%. PEG enhancement: Incorporating 0.5 wt.% PEG as a pore-forming agent further improved the membrane's pure water flux to 4.97 L·m-2·h-1·bar-1, without compromising Ni rejection. Exceptional flexibility: The adopted strategy yielded membranes with exceptional flexibility, making them suitable for scale-ups and other applications.
Assuntos
Resinas Acrílicas , Membranas Artificiais , Níquel , Solventes , Águas Residuárias , Poluentes Químicos da Água , Níquel/química , Resinas Acrílicas/química , Poluentes Químicos da Água/química , Águas Residuárias/química , Solventes/química , Purificação da Água/métodos , Filtração/métodos , Eliminação de Resíduos Líquidos/métodosRESUMO
The present study elucidates the effectiveness of a molecularly imprinted polyacrylonitrile-imbued graphite-base electrode (MAN@G) for the selective detection of folic acid (FA) in food samples. The prime objective of the recognition and quantification of vitamin compounds like FA is the overall quality assessment of vegetables and fruits. The cost-effective, reproducible, and durable MAN@G electrode has been fabricated using acrylonitrile (AN) as the monomer and FA as the template over graphite-base. The characterization of the synthesized MAN@G electrode material has been accomplished by utilizing UV-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM). A tri-electrode system based on differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques was employed to explore the analytical performance of the synthesized electrode. Rigorous analyses divulged that a widespread linearity window could be exhibited by the electrode under an optimized experimental environment, ranging from 20 µM to 400 µM concentrations with an acceptable lower limit of detection (LOD) and limit of quantification (LOQ) of 18 nM, and 60 nM respectively. Additionally, this electrode exhibits high reproducibility, good stability, and high repeatability, with RSD values of 1.72 %, 1.32 %, and 1.19 %, respectively. The detection efficacy of the proposed electrode has been further examined in food extracts, namely orange, spinach, papaya, soybean, and cooked rice, which endorsed high accuracy compared to the high-performance liquid chromatography (HPLC) method. Moreover, the statistical results obtained from the t-test analysis were also satisfactory for the FA concentrations present in those five samples.
Assuntos
Resinas Acrílicas , Técnicas Eletroquímicas , Eletrodos , Ácido Fólico , Grafite , Grafite/química , Resinas Acrílicas/química , Ácido Fólico/análise , Impressão Molecular , Limite de Detecção , Análise de Alimentos/métodos , Polímeros Molecularmente Impressos/química , Frutas/químicaRESUMO
Drug treatment of glioblastoma, the most aggressive and widespread form of brain cancer, is complicated due to the difficulty of penetration of chemotherapeutic drugs through the blood-brain barrier (BBB). Moreover, with surgical removal of tumors, in 90 % of cases they reappear near the original focus. To solve this problem, we propose to use hydrogel based on cellulose nanocrystals grafted with poly(N-isopropylacrylamide) (CNC-g-PNIPAM) as a promising material for filling postoperative cavities in the brain with the release of antitumor drugs. The CNC-g-PNIPAM is formed by "grafting to" method for precise control of molecular weight and grafting density. This colloidal system is liquid under injection conditions (at r. t.) and turns into a gel at human body temperature (when filling the postoperative area). It was shown for the first time that due to the rod-shaped of CNC, the gel has a fibrillar structure and, thus, mechanical properties similar to those of brain tissue, including nonlinear mechanics (strain-stiffening and compression softening). The biocompatibility of the hydrogel with primary brain cells is demonstrated. In addition, the release of the antitumor drug paclitaxel from the hydrogel and its antitumor activity is shown. The resulting nanocolloid system provides an innovative alternative approach to filling postoperative cavities and can be used for postoperative treatment due to the programmable release of drugs, as well as for in vitro modeling of tumor interaction with the BBB affecting drug transport in the brain.