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1.
Biomacromolecules ; 24(3): 1184-1193, 2023 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-36808988

RESUMEN

Polyurethane materials will come into contact with different solvents in daily life, and at the same time, they will be subject to different degrees of collision, wear and tear. Failure to take corresponding preventative or reparative measures will result in a waste of resources and an increase in costs. To this end, we prepared a novel polysiloxane with isobornyl acrylate and thiol groups as side groups, which was further used in the preparation of poly(thiourethane-urethane) materials. Thiourethane bonds generated by the click reaction of thiol groups with isocyanates endow poly(thiourethane-urethane) materials with the ability to heal and reprocess. Isobornyl acrylate with a large sterically hindered rigid ring promotes segment migration, accelerating the exchange of thiourethane bonds, which is beneficial to the recycling of materials. These results not only promote the development of terpene derivative-based polysiloxanes but also show the great potential of thiourethane as a dynamic covalent bond in the field of polymer reprocessing and healing.


Asunto(s)
Acrilatos , Siloxanos , Poliuretanos/química , Compuestos de Sulfhidrilo
2.
Biomacromolecules ; 24(2): 967-976, 2023 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-36607255

RESUMEN

The development of nanoprobes that have amplified enhanced permeability and retention (EPR) effect is crucial for their precise cancer diagnosis performance. Here, we present the development of functional dendrimer-based nanogels (DNGs) with the generation three primary amine-terminated poly(amidoamine) (PAMAM) dendrimers (G3·NH2) cross-linked by N,N'-bis(acryloyl) cystamine (BAC). The DNGs were prepared through a Michael addition reaction between G3·NH2 dendrimers and BAC via an inverse microemulsion method and entrapped with gold nanoparticles (Au NPs) to form Au-DNGs. The Au-DNGs were sequentially modified with diethylenetriamine penta-acetic acid (DTPA)-gadolinium (Gd) complex, poly(ethylene glycol) (PEG)-linked arginine-glycine-aspartic (RGD) peptide, and 1,3-propanesultone (1,3-PS). The formed multifunctional RGD-Gd@Au-DNGs-PS (R-G@ADP) possessing an average diameter of 122 nm are colloidally stable and display a high X-ray attenuation coefficient, excellent r1 relaxivity (9.13 mM-1 s-1), desired protein resistance rendered by the zwitterionic modification, and cytocompatibility. With the targeting specificity mediated by RGD and the much better tumor penetration capability than the counterpart material of single dendrimer-entrapped Au NPs, the developed multifunctional R-G@ADP enable targeted and enhanced computed tomography (CT)/magnetic resonance (MR) dual-modal imaging of a pancreatic tumor model in vivo. The current work demonstrates a unique design of targeted and zwitterionic DNGs with prolonged blood circulation time as an emerging nanoprobe for specific tumor CT/MR imaging through amplified passive EPR effect.


Asunto(s)
Dendrímeros , Nanopartículas del Metal , Neoplasias Pancreáticas , Humanos , Nanogeles , Oro , Tomografía Computarizada por Rayos X/métodos , Imagen por Resonancia Magnética/métodos , Oligopéptidos , Espectroscopía de Resonancia Magnética , Línea Celular Tumoral
3.
Rapid Commun Mass Spectrom ; 36(21): e9381, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-35986921

RESUMEN

RATIONALE: Various solvent supports have been developed to overcome solvent instability during liquid-phase microextraction. The hydrophobic polyurethane sponge (PS) possesses numerous cross-linked internal microchannels and terminal micropores that can facilitate steady solvent storage capacity, high extraction efficiency, extractant loading, and recycling convenience. METHODS: In this study, an easy, convenient, and efficient PS-supported liquid-phase microextraction (PS-LPME) coupled with gas chromatography-mass spectrometry (GC-MS) method was developed for the trace analysis of different organic compounds in aqueous solutions. Different extraction solvents, PS dosages, stirring speeds, and extraction times were first investigated by extracting eight polycyclic aromatic hydrocarbons (PAHs: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene), and then applied for the analysis of triazines, amides, chloroacetamides, and organophosphorus compounds. RESULTS: High enrichment factors (approximately 208-439) were observed for the monitored PAHs. Good linearities, with determination coefficients (r2 ) greater than 0.9992, were achieved in the concentration range of 0.01-50 µg L-1 . Low limits of detection and quantification were found in the ranges of 0.3-3 ng L-1 and 1-10 ng L-1 , respectively. At three spiked concentrations (0.1, 1, and 10 µg L-1 ), good recoveries were obtained in the range of 91.6-118.5% with intra- and inter-day relative standard deviations of less than 6.4% and 11.7%, respectively. CONCLUSIONS: The developed PS-LPME method coupled with GC-MS was successfully applied in the analysis of different organic compounds in aqueous solutions and has shown great convenience and satisfactory enrichment performance in microextraction analysis.


Asunto(s)
Fenantrenos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Acenaftenos/análisis , Amidas , Antracenos/análisis , Fluorenos/análisis , Límite de Detección , Compuestos Organofosforados , Fenantrenos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Poliuretanos , Pirenos , Solventes/química , Triazinas/análisis , Agua/química , Contaminantes Químicos del Agua/análisis
4.
BMC Endocr Disord ; 22(1): 201, 2022 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-35945517

RESUMEN

BACKGROUND: To evaluate the effectiveness of individualized-dose polyethylene glycol recombinant human growth hormone (PEG-rhGH) for short stature. METHODS: This real-world study enrolled children with short stature in 19 hospitals throughout China. They were treated with PEG-rhGH for 6 months. The starting dosage ranged from 0.10 to 0.20 mg/kg/week. The primary outcome was the change in height standard deviation score (ΔHt SDS). RESULTS: Five hundred and ten patients were included and grouped based on dosage as A (0.10-0.14 mg/kg/week), B (0.15-0.16 mg/kg/week), C (0.17-0.19 mg/kg/week), and D (0.20 mg/kg/week). The mean 6-month ΔHt SDS for the total cohort was 0.49 ± 0.27, and the means differed among the four dose groups (P = 0.002). The ΔHt SDS was lower in group A than in groups B (LSM difference [95%CI], -0.09 [-0.17, -0.01]), C (LSM difference [95%CI], -0.10 [-0.18, -0.02]), and D (LSM difference [95%CI], -0.13 [-0.21, -0.05]) after adjusting baseline covariates. There were no significant differences among groups B, C, and D. When the baseline IGF-1 was < -2 SDS or > 0 SDS, the △Ht SDS was not different among the four groups (P = 0.931 and P = 0.400). In children with baseline IGF-1 SDS of -2 ~ 0 SDS, a higher dosage was associated with a better treatment effect (P = 0.003), and the △Ht SDS was lower in older children than in younger ones (P < 0.001). CONCLUSIONS: PEG-rhGH could effectively increase height in prepubertal short children. When the baseline IGF-1 was < -2 SDS, 0.10 mg/kg/week could be a starting dose. In other IGF-1 statuses, 0.15-0.20 mg/kg/week might be preferred. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03249480 , retrospectively registered.


Asunto(s)
Enanismo , Hormona de Crecimiento Humana , Estatura , Niño , Trastornos del Crecimiento/tratamiento farmacológico , Hormona de Crecimiento Humana/análogos & derivados , Hormona de Crecimiento Humana/uso terapéutico , Humanos , Factor I del Crecimiento Similar a la Insulina , Polietilenglicoles
5.
Mar Drugs ; 20(9)2022 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-36135753

RESUMEN

Alginate is an acidic polysaccharide mainly extracted from kelp or sargassum, which comprises 40% of the dry weight of algae. It is a linear polymer consisting of ß-D-mannuronic acid (M) and α-L-guluronic acid (G) with 1,4-glycosidic linkages, possessing various applications in the food and nutraceutical industries due to its unique physicochemical properties and health benefits. Additionally, alginate is able to form a gel matrix in the presence of Ca2+ ions. Alginate properties also affect its gelation, including its structure and experimental conditions such as pH, temperature, crosslinker concentration, residence time and ionic strength. These features of this polysaccharide have been widely used in the food industry, including in food gels, controlled-release systems and film packaging. This review comprehensively covers the analysis of alginate and discussed the potential applications of alginate in the food industry and nutraceuticals.


Asunto(s)
Alginatos , Suplementos Dietéticos , Alginatos/química , Preparaciones de Acción Retardada , Geles , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Iones , Polímeros
6.
Biomed Eng Online ; 20(1): 15, 2021 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-33546713

RESUMEN

BACKGROUND: The objective of the study was to validate biomechanical characteristics of a 3D-printed, novel-designated fixation plate for treating mandibular angle fracture, and compare it with two commonly used fixation plates by finite element (FE) simulations and experimental testing. METHODS: A 3D virtual mandible was created from a patient's CT images as the master model. A custom-designed plate and two commonly used fixation plates were reconstructed onto the master model for FE simulations. Modeling of angle fracture, simulation of muscles of mastication, and defining of boundary conditions were integrated into the theoretical model. Strain levels during different loading conditions were analyzed using a finite element method (FEM). For mechanical test design, samples of the virtual mandible with angle fracture and the custom-designed fixation plates were printed using selective laser sintering (SLS) and selective laser melting (SLM) printing methods. Experimental data were collected from a testing platform with attached strain gauges to the mandible and the plates at different 10 locations during mechanical tests. Simulation of muscle forces and temporomandibular joint conditions were built into the physical models to improve the accuracy of clinical conditions. The experimental vs the theoretical data collected at the 10 locations were compared, and the correlation coefficient was calculated. RESULTS: The results show that use of the novel-designated fixation plate has significant mechanical advantages compared to the two commonly used fixation plates. The results of measured strains at each location show a very high correlation between the physical model and the virtual mandible of their biomechanical behaviors under simulated occlusal loading conditions when treating angle fracture of the mandible. CONCLUSIONS: Based on the results from our study, we validate the accuracy of our computational model which allows us to use it for future clinical applications under more sophisticated biomechanical simulations and testing.


Asunto(s)
Placas Óseas , Análisis de Elementos Finitos , Fijación Interna de Fracturas/instrumentación , Fracturas Mandibulares/cirugía , Fenómenos Biomecánicos , Humanos , Estrés Mecánico
7.
Plant J ; 88(1): 26-42, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27273756

RESUMEN

Glycosylation of monolignols has been found to be widespread in land plants since the 1970s. However, whether monolignol glycosylation is crucial for cell wall lignification and how it exerts effects are still unknown. Here, we report the identification of a mutant ugt72b1 showing aggravated and ectopic lignification in floral stems along with arrested growth and anthocyanin accumulation. Histochemical assays and thioacidolysis analysis confirmed the enhanced lignification and increased lignin biosynthesis in the ugt72b1 mutant. The loss of UDP-glycosyltransferase UGT72B1 function was responsible for the lignification phenotype, as demonstrated by complementation experiments. Enzyme activity analysis indicated that UGT72B1 could catalyze the glucose conjugation of monolignols, especially coniferyl alcohol and coniferyl aldehyde, which was confirmed by analyzing monolignol glucosides of UGT72B1 transgenic plants. Furthermore, the UGT72B1 gene was strongly expressed in young stem tissues, especially xylem tissues. However, UGT72B1 paralogs, such as UGT72B2 and UGT72B3, had weak enzyme activity toward monolignols and weak expression in stem tissues. Transcriptomic profiling showed that UGT72B1 knockout resulted in extensively increased transcript levels of genes involved in monolignol biosynthesis, lignin polymerization and cell wall-related transcription factors, which was confirmed by quantitative real-time PCR assays. These results provided evidence that monolignol glucosylation catalyzed by UGT72B1 was essential for normal cell wall lignification, thus offering insight into the molecular mechanism of cell wall development and cell wall lignification.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Arabidopsis/metabolismo , Pared Celular/metabolismo , Glucosa/metabolismo , Glicosiltransferasas/metabolismo , Lignina/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Glicosiltransferasas/genética
8.
Water Environ Res ; 88(12): 2257-2259, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-28061938

RESUMEN

Curly-leaf pondweed (Potamogeton crispus) was utilized as the representative to investigate the biodecomposition process of aquatic plants under different reducible conditions. Results showed that the methane production was inhibited when different electron acceptors (Fe(III), and ) were available. The methane production was decreased by 57% when Fe(III) and or were both available compared to the control. The degradation efficiency of hemicellulose and lignin with Fe(III) and were increased significantly. This provided a theoretical basis for slowing down the emissions of methane.


Asunto(s)
Potamogetonaceae/metabolismo , Anaerobiosis , Biodegradación Ambiental , Hierro/química , Lignina , Metano/metabolismo , Nitratos/química , Óxidos de Azufre/química
9.
Nano Lett ; 13(2): 740-5, 2013 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-23311754

RESUMEN

Inspired by the cucumber-like structure, by combining the in situ chemical oxidative polymerization with facile soaking process, we designed the heterostructured nanomaterial with PEDOT as the shell and MnO(2) nanoparticles as the protuberance and synthesized the novel cucumber-like MnO(2) nanoparticles enriched vanadium pentoxide/poly(3,4-ethylenedioxythiophene) (PEDOT) coaxial nanowires. This heterostructured nanomaterial exhibits enhanced electrochemical cycling performance with the decreases of capacity fading during 200 cycles from 0.557 to 0.173% over V(2)O(5) nanowires at the current density of 100 mA/g. This method is proven to be an effective technique for improving the electrochemical cycling performance and stability of nanowire electrodes especially at low rate for application in rechargeable lithium batteries.


Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/química , Técnicas Electroquímicas , Compuestos de Manganeso/química , Nanocables/química , Óxidos/química , Polímeros/química , Compuestos de Vanadio/química , Tamaño de la Partícula , Propiedades de Superficie
10.
Medicine (Baltimore) ; 103(11): e37471, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38489729

RESUMEN

BACKGROUND: Bone ring (BR) grafts have been introduced to reconstruct alveolar ridge defects with simultaneous implant placement, but its clinical effectiveness remains undetermined. This systematic review aimed to comprehensively investigate BR grafts in diverse scenarios of ridge defect with simultaneous or staged implant placement. METHODS: Electronic retrieval of MEDLINE, Embase, Cochrane Library(CENTRAL), Web of Science, Scopus, and citation search until August 3, 2023, was used to identify relevant clinical articles that utilized BR grafts for ridge defect reconstruction. The quality of evidence in the studies reviewed was assessed with the Joanna Briggs Institute Critical Appraisal tool. The protocol was registered in Prospective Register of Systematic Reviews (CRD42023453943). RESULTS: Fourteen studies with 251 BRs were identified, of which 8 studies were for alveolar ridge augmentation, 4 studies were for extraction socket augmentation, and 2 studies were for sinus floor elevation. Reported sources of BRs included autografts, allografts, and xenografts. The follow-up period ranged from 4 months to 4.7 years. Regarding the primary outcomes, the utilization of BR grafts demonstrated favorable bone gain along with acceptable graft absorption and marginal bone loss. Regarding the secondary outcomes, satisfactory bone mineral density and implant stability were confirmed, accompanied by a recorded incidence of postoperative complications (20 cases) and an implant failure rate of 5.58%. CONCLUSIONS: BR grafting with simultaneous or staged implant insertion is an effective approach for reconstructing alveolar ridge deficiencies. The BR grafts demonstrate favorable bone remodeling and osteointegration with the alveolar bone and implant; however, its success may be compromised by complications. Future studies should further investigate the clinical efficacy of BR grafting comparing to other bone augmentation techniques in diverse scenarios.


Asunto(s)
Aumento de la Cresta Alveolar , Elevación del Piso del Seno Maxilar , Humanos , Elevación del Piso del Seno Maxilar/métodos , Revisiones Sistemáticas como Asunto , Proceso Alveolar/cirugía , Aumento de la Cresta Alveolar/métodos , Trasplante Óseo/métodos , Implantación Dental Endoósea
11.
Int J Biol Macromol ; 265(Pt 2): 131143, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38537861

RESUMEN

Hydrogel electrolyte is an ideal candidate material for flexible energy storage devices due to its excellent softness and conductivity properties. However, challenges such as the inherent mechanical weakness, the susceptibility to be frozen in low-temperature environments, and the insufficiency of hydrogel-electrode contact persist. Herein, a "Multi in One" strategy is employed to effectively conquer these difficulties by endowing hydrogels with high strength, freeze-resistance, and self-adhesive ability. Multiple hydrogen bond networks and ion crosslinking networks are constructed within the hydrogel electrolyte (PVA/PAAc/XG) containing polyvinyl alcohol (PVA), acrylic acid (AAc), and xanthan gum (XG), promoting the enhanced mechanical property, and the adhesion to electrode materials is also improved through abundant active groups. The introduction of zinc ions provides the material with superior frost resistance while also promoting electrical conductivity. Leveraging its multifunction of superior mechanical strength, anti-freeze property, and self-adhesive characteristic, the PVA/PAAc/XG hydrogel electrolyte is employed to fabricate zinc ion hybrid supercapacitors (ZHS). Remarkably, ZHS exhibits outstanding electrochemical performance and cycle stability. A remarkable capacity retention rate of 83.86 % after 10,000 charge-discharge cycles can be achieved at high current densities, even when the operational temperature decreases to -60 °C, showing great potential in the field of flexible energy storage devices.


Asunto(s)
Polisacáridos Bacterianos , Cementos de Resina , Zinc , Hidrogeles , Electrólitos , Iones
12.
Int J Biol Macromol ; 263(Pt 2): 130511, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38423443

RESUMEN

The mechanical properties of ionic conductive hydrogels (ICHs) are generally inadequate, leading to their susceptibility to breakage under external forces and consequently resulting in the failure of flexible electronic devices. In this work, a simple and convenient strategy was proposed based on the synergistic effect of ion cross-linking and salting out, in which the hydrogels consisting of polyvinyl alcohol (PVA) and xanthan gum (XG) were immersed in zinc sulfate (ZnSO4) solution to obtain ICHs with exceptional mechanical properties. The salt-out effects between PVA chains and SO42- ions along with the cross-linked network of XG chains and Zn2+ ions contribute to the desirable mechanical properties of ICHs. Notably, the mechanical properties of ICHs can be adjusted by changing the concentration of ZnSO4 solution. Consequently, the optimum fracture stress and the fracture energy can reach 3.38 MPa and 12.13 KJ m-2, respectively. Moreover, the ICHs demonstrated a favorable sensitivity (up to 2.05) when utilized as a strain sensor, exhibiting an accurate detection of human body movements across various amplitudes.


Asunto(s)
Hidrogeles , Polisacáridos Bacterianos , Alcohol Polivinílico , Humanos , Etanol , Cloruro de Sodio , Conductividad Eléctrica , Iones , Poli A , Cloruro de Polivinilo
13.
Biomater Adv ; 161: 213899, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38772133

RESUMEN

Large bone defects, particularly those exceeding the critical size, present a clinical challenge due to the limited regenerative capacity of bone tissue. Traditional treatments like autografts and allografts are constrained by donor availability, immune rejection, and mechanical performance. This study aimed to develop an effective solution by designing gradient gyroid scaffolds with titania (TiO2) surface modification for the repair of large segmental bone defects. The scaffolds were engineered to balance mechanical strength with the necessary internal space to promote new bone formation and nutrient exchange. A gradient design of the scaffold was optimized through Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) simulations to enhance fluid flow and cell adhesion. In vivo studies in rabbits demonstrated that the G@TiO2 scaffold, featuring a gradient structure and TiO2 surface modification, exhibited superior healing capabilities compared to the homogeneous structure and TiO2 surface modification (H@TiO2) and gradient structure (G) scaffolds. At 12 weeks post-operation, in a bone defect representing nearly 30 % of the total length of the radius, the implantation of the G@TiO2 scaffold achieved a 27 % bone volume to tissue volume (BV/TV) ratio, demonstrating excellent osseointegration. The TiO2 surface modification provided photothermal antibacterial effects, enhancing the scaffold's biocompatibility and potential for infection prevention. These findings suggest that the gradient gyroid scaffold with TiO2 surface modification is a promising candidate for treating large segmental bone defects, offering a combination of mechanical strength, bioactivity, and infection resistance.


Asunto(s)
Aleaciones , Propiedades de Superficie , Andamios del Tejido , Titanio , Titanio/química , Animales , Conejos , Andamios del Tejido/química , Aleaciones/química , Regeneración Ósea/efectos de los fármacos , Oseointegración/efectos de los fármacos , Huesos , Ingeniería de Tejidos/métodos , Análisis de Elementos Finitos , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología
14.
Medicine (Baltimore) ; 102(48): e36391, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38050282

RESUMEN

BACKGROUND: Autogenous particulate dentin (APD) has been used as a bone graft material for bone augmentation, but the specifics of its effect on alveolar ridge preservation (ARP) are uncertain. The aim of this study was to investigate the clinical and histomorphometric performance of APD compared with blood clot healing or other grafted materials in ARP. METHODS: MEDLINE, Embase, Web of Science, Scopus and the Cochrane Library and citation databases were searched until August 2, 2023 to identify randomized controlled trials that employed APD for ARP. Two independent meta-analyses were performed based on the different control groups (Group I: blood clot healing; Group II: other grafted materials). Weighted or mean differences (MDs) and corresponding 95% confidence intervals (CIs) were calculated. The protocol was prospectively registered with PROSPERO (CRD42023409339). RESULTS: A total of 238 records were identified, of which ten studies with 182 participants were included. The meta-analysis indicated that APD resulted in fewer changes in horizontal ridge width (Group I: MD = 1.61, 95% CI 0.76-2.46; Group II: MD = 1.28, 95% CI 1.08-1.48) and labial bone height (Group I: MD = 1.75, 95% CI 0.56-2.94; Group II: P < .05) than the control treatments. Regarding histomorphometry, APD yielded a satisfactory proportion of vital bone area (MD = 10.51, 95% CI 4.70-16.32) and residual material area (MD = -8.76, 95% CI -12.81 to -4.71) in Group II, while there was no significant difference in Group I. Moreover, none of the secondary outcomes were significantly differed between groups. CONCLUSION: Within this study limitations, APD effectively maintained the horizontal and vertical dimensions of the extraction sockets and exhibited favorable osteogenic properties and degradation capacity. Further well-designed randomized controlled trials with larger samples and longer follow-up periods are needed to evaluate whether APD is superior to other substitutes for ARP.


Asunto(s)
Aumento de la Cresta Alveolar , Trombosis , Humanos , Alveolo Dental/cirugía , Aumento de la Cresta Alveolar/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Minerales , Extracción Dental/métodos , Dentina , Trombosis/cirugía
15.
J Colloid Interface Sci ; 631(Pt B): 239-248, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36401931

RESUMEN

Recently, conductive composites have been used in flexible electronic devices and have attracted attention. The integration of self-healing, high sensitivity, large tensile strength, environmental stability, and easy recyclability into conductive composites is very desirable yet challenging. Hence, a conductive composite as a flexible strain sensor with a self-healing and recyclability is facilely developed, with a polyurethane (PU) elastomer bearing dynamic boronic ester as the polymer matrix and carbon nanotubes (CNTs) as a conductive filler. Due to the dynamic boronic ester bond and hydrogen bond, the prepared polyurethane conductive composite has good self-healing and mechanical properties. It not only has a high healing efficiency of 78 % but also has a tensile strength of 15.4 MPa and an elongation at break of 420 %. In addition, the prepared conductive composite has high conductivity (0.57 mS/cm) and sensitivity. As a wearable sensor, it can identify human activities in all directions, such as elbow and finger bending, speaking, and facial changes. Consequently, the polyurethane conductive composite prepared in this study exhibited wonderful application potential in wearable electronic devices such as self-healing strain sensors.


Asunto(s)
Nanotubos de Carbono , Dispositivos Electrónicos Vestibles , Humanos , Poliuretanos , Conductividad Eléctrica , Ésteres
16.
Int J Biol Macromol ; 233: 123573, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36754269

RESUMEN

Ionic conductive hydrogels (ICHs) have received widespread attention as an ideal candidate for flexible electronic devices. However, conventional ICHs failed in widespread applications due to their inability to simultaneously possess high toughness, high ionic conductivity, and anti-freezing properties. Here, polyvinyl alcohol (PVA) and polyacrylamide (PAAm) were first dissolved in the zinc chloride solution, in which zinc ions (Zn2+) act as ionic cross-linkers and conducting ions, followed by the introduction of xanthan gum (XG) with a unique structure of trisaccharide side chains into the PVA/PAAm semi-interpenetrating network to prepare a dual-network ICHs (refers as PPXZ). Enabled by the synergistic effect of intermolecular chemical covalent cross-linking and physical cross-linking, PPXZ hydrogels exhibit significantly improved mechanical properties without sacrificing electrical conductivity. Furthermore, PPXZ hydrogels are successfully applied to flexible electronic devices, such as strain sensors and zinc ion hybrid supercapacitors, exhibiting satisfactory sensing sensitivity and cycling stability at a wide temperature range, respectively. Even at a high current density (10 A g-1), the capacity of the supercapacitor retains 88.24 % after 10,000 cycles. This strategy provides new insight for ICHs in wide temperature-applied flexible electronic devices.


Asunto(s)
Electrónica , Alcohol Polivinílico , Conductividad Eléctrica , Hidrogeles , Iones
17.
Mil Med Res ; 10(1): 15, 2023 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-36949519

RESUMEN

BACKGROUND: Reconstruction of damaged tissues requires both surface hemostasis and tissue bridging. Tissues with damage resulting from physical trauma or surgical treatments may have arbitrary surface topographies, making tissue bridging challenging. METHODS: This study proposes a tissue adhesive in the form of adhesive cryogel particles (ACPs) made from chitosan, acrylic acid, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The adhesion performance was examined by the 180-degree peel test to a collection of tissues including porcine heart, intestine, liver, muscle, and stomach. Cytotoxicity of ACPs was evaluated by cell proliferation of human normal liver cells (LO2) and human intestinal epithelial cells (Caco-2). The degree of inflammation and biodegradability were examined in dorsal subcutaneous rat models. The ability of ACPs to bridge irregular tissue defects was assessed using porcine heart, liver, and kidney as the ex vivo models. Furthermore, a model of repairing liver rupture in rats and an intestinal anastomosis in rabbits were established to verify the effectiveness, biocompatibility, and applicability in clinical surgery. RESULTS: ACPs are applicable to confined and irregular tissue defects, such as deep herringbone grooves in the parenchyma organs and annular sections in the cavernous organs. ACPs formed tough adhesion between tissues [(670.9 ± 50.1) J/m2 for the heart, (607.6 ± 30.0) J/m2 for the intestine, (473.7 ± 37.0) J/m2 for the liver, (186.1 ± 13.3) J/m2 for muscle, and (579.3 ± 32.3) J/m2 for the stomach]. ACPs showed considerable cytocompatibility in vitro study, with a high level of cell viability for 3 d [(98.8 ± 1.2) % for LO2 and (98.3 ± 1.6) % for Caco-2]. It has comparable inflammation repair in a ruptured rat liver (P = 0.58 compared with suture closure), the same with intestinal anastomosis in rabbits (P = 0.40 compared with suture anastomosis). Additionally, ACPs-based intestinal anastomosis (less than 30 s) was remarkably faster than the conventional suturing process (more than 10 min). When ACPs degrade after surgery, the tissues heal across the adhesion interface. CONCLUSIONS: ACPs are promising as the adhesive for clinical operations and battlefield rescue, with the capability to bridge irregular tissue defects rapidly.


Asunto(s)
Adhesivos , Adhesivos Tisulares , Ratas , Humanos , Porcinos , Conejos , Animales , Criogeles , Células CACO-2 , Inflamación
18.
J Clin Endocrinol Metab ; 108(8): 2078-2086, 2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-36669772

RESUMEN

CONTEXT: The evidence of long-term polyethylene glycol recombinant human GH (PEG-rhGH) in pediatric GH deficiency (GHD) is limited. OBJECTIVE: This study aimed to examine the effectiveness and safety of long-term PEG-rhGH in children with GHD in the real world, as well as to examine the effects of dose on patient outcomes. DESIGN: A prospective, observational, posttrial study (NCT03290235). SETTING, PARTICIPANTS AND INTERVENTION: Children with GHD were enrolled from 81 centers in China in 4 individual clinical trials and received weekly 0.2 mg/kg/wk (high-dose) or 0.1 to <0.2 mg/kg/wk (low-dose) PEG-rhGH for 30 months. MAIN OUTCOMES MEASURES: Height SD score (Ht SDS) at 12, 24, and 36 months. RESULTS: A total of 1170 children were enrolled in this posttrial study, with 642 patients in the high-dose subgroup and 528 in the low-dose subgroup. The Ht SDS improved significantly after treatment in the total population (P < 0.0001), with a mean change of 0.53 ± 0.30, 0.89 ± 0.48, 1.35 ± 0.63, 1.63 ± 0.75 at 6 months, 12 months, 24 months, and 36 months, respectively. In addition, the changes in Ht SDS from baseline were significantly improved in the high-dose subgroup compared with the low-dose subgroup at 6, 12, 24, and 36 months after treatment (all P < 0.05). A total of 12 (1.03%) patients developed serious adverse events. There was no serious adverse event related to the treatment, and no AEs leading to treatment discontinuation or death occurred. CONCLUSIONS: PEG-rhGH showed long-term effectiveness and safety in treating children with GHD. Both dose subgroups showed promising outcomes, whereas PEG-rhGH 0.2 mg/kg/wk might show additional benefit.


Asunto(s)
Enanismo Hipofisario , Hormona de Crecimiento Humana , Humanos , Niño , Estudios Prospectivos , Hormona de Crecimiento Humana/uso terapéutico , Trastornos del Crecimiento/tratamiento farmacológico , Enanismo Hipofisario/tratamiento farmacológico , Factor I del Crecimiento Similar a la Insulina , Polietilenglicoles/efectos adversos , Proteínas Recombinantes/efectos adversos
19.
Chem Res Toxicol ; 25(6): 1265-70, 2012 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-22587431

RESUMEN

As graphene becomes one of the most exciting candidates for multifunctional biomedical applications, contact between eyes and graphene-based materials is inevitable. On the other hand, eyes, as a special organ in the human body, have unique advantages to be used for testing new biomedical research and development, such as drug delivery. Intraocular biocompatible studies on graphene-related materials are thus essential. Here, we report our recent studies on intraocular biocompatibility and cytotoxicity of graphene oxide (GO) both in vitro and in vivo. The successful preparation of GO nanosheets was confirmed using atomic force microscopy, contact angle analyzer, Fourier transform infrared spectroscopy, and Raman spectroscopy. The influence of GO on human retinal pigment epithelium (RPE) cells in terms of the cell morphology, viability, membrane integrity, and apoptosis was investigated using various techniques, including optical micrography, cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, and apoptosis assay. The addition of GO had little influence on cell morphology, but the change was visible after long-time culturing. RPE cells showed higher than 60% cell viability by CCK-8 assay in GO solutions and less than 8% LDH release, although a small amount of apoptosis (1.5%) was observed. In vitro results suggested good biocompatibility of GO to RPE cells with slight adverse influence, on the cell viability and morphology in long-time periods, along with aggregation of GO. Thus, some further studies are needed to clarify the cytotoxicity mechanism of GO. GO intravitreally injected eyes showed few changes in eyeball appearance, intraocular pressure (IOP), eyesight, and histological photos. Our results suggested that GO did not cause any significant toxicity to the cell growth and proliferation. Intravitreal injection of GO into rabbits' eyes did not lead to much change in the eyeball appearance, IOP, electroretinogram, and histological examination.


Asunto(s)
Ojo/efectos de los fármacos , Ojo/fisiopatología , Grafito/toxicidad , Óxidos/toxicidad , Animales , Apoptosis/efectos de los fármacos , Materiales Biocompatibles , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Electrorretinografía , Ojo/patología , Grafito/administración & dosificación , Grafito/química , Humanos , Óxidos/administración & dosificación , Óxidos/química , Conejos , Relación Estructura-Actividad
20.
Int J Biol Macromol ; 213: 478-485, 2022 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-35643158

RESUMEN

Polyguluronate (PG) consists entirely of α-L-guluronic acid derived from alginate, which is an acidic polysaccharide extracted from brown algae. PG has a short half-life and is easily degraded by microorganisms, resulting in decreased activity and thus its application in the medical field. In this study, polyguluronate liposomes (PGLs) were prepared to improve the macrophage-stimulating activity of PG. The morphology, encapsulation efficiency, particle size distribution, zeta potential and stability of the PGLs were characterized. Results showed that PGLs were uniformly round with an encapsulation efficiency of 77.76 ± 0.89%, a particle size of 63.96 ± 3.98 nm and a zeta potential of -53.4 ± 1.75 mV. The stability studies showed that PGLs should be stored in a neutral environment at 4 °C. The macrophage-stimulating activity of PGLs was better than that of PG. This study provides a promising carrier for the further application of PG in food or medicine.


Asunto(s)
Liposomas , Polisacáridos Bacterianos , Macrófagos , Tamaño de la Partícula
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