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1.
BMC Anesthesiol ; 24(1): 3, 2024 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166658

RESUMEN

BACKGROUND: Rett Syndrome (RTT) is a rare, severe, and progressive developmental disorder with intellectual disability. Anesthesia in RTT patients presents a range of challenges. We report a child with RTT who received dental treatment under muscle relaxant-free general anesthesia in our ambulatory center. CASE PRESENTATION: A 15-year-old girl with RTT was admitted to our dental clinic with multiple dental caries and residual roots. Dental treatment was scheduled under ambulatory general anesthesia. After anesthesia induction, a nasal tube was initiated under the guidance of a fiberoptic bronchoscope. Multimodal analgesia, body temperature monitoring, and postoperative nausea and vomiting prevention were applied. No muscle relaxants were used throughout the process. The endotracheal tube was successfully removed after the operation and the patient was discharged home the same day. CONCLUSION: An individualized anesthesia strategy enabled a quick and safe recovery for this RTT patient after dental treatment under muscle relaxant-free general anesthesia.


Asunto(s)
Caries Dental , Síndrome de Rett , Niño , Femenino , Humanos , Adolescente , Anestesia General , Atención Odontológica , Músculos , Boca
2.
Macromol Rapid Commun ; 43(7): e2100874, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35139235

RESUMEN

The broad applications of 3D-printed poly-ether-ether-ketone (3D-PEEK) structures are largely hampered by their inadequate mechanical properties that can be improved by post treatments. At present, thermal annealing is generally used to improve the mechanical properties of 3D-PEEK. However, it cannot simultaneously improve strength and ductility. Here, a cost-effective postprocessing method is developed to improve the mechanical properties of 3D-PEEK, based on annealing in nonsolvent vapor at room temperature. The annealing in nonsolvent vapor at room temperature simultaneously improves the strength, ductility, and fracture energy of as-printed 3D-PEEK by 22.6%, 151.3%, and 109.1%, respectively. The improved mechanical properties are attributed to enhanced interfacial bonding, increased crystallinity, decreased pinhole defects, and stress relaxation in the 3D-PEEK. Moreover, the annealing in both polar solvents (such as acetone and chloroform) and nonpolar solvents (such as n-hexane) are demonstrated to be effective for improving the mechanical properties of 3D-PEEK. The nonsolvent vapor-annealed 3D-PEEK can thus have potential applications in the fields of medical implants, automotive, aerospace, and more.


Asunto(s)
Polietilenglicoles , Impresión Tridimensional , Benzofenonas , Cetonas/química , Polietilenglicoles/química , Polímeros
3.
J Org Chem ; 83(18): 11350-11358, 2018 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-30080046

RESUMEN

An organocatalytic asymmetric aldol reaction of 5-alkyl-4-nitroisoxazoles to paraformaldehyde has been developed. By using a chiral dipeptide-based urea-amide-guanidinium as the phase-transfer catalyst, the transformations were promoted by sodium acetate, leading to a range of enantio-enriched isoxazole derivatives in high yields with moderate to excellent enantioselectivities. This work represents the first example of constructing chiral C-C bonds at the α-position of 5-alkyl-4-nitroisoxazoles. The viability of readily accessing chiral fungicides from the obtained aldol products demonstrates the important utility of this method.


Asunto(s)
Formaldehído/química , Isoxazoles/química , Polímeros/química , Alquilación , Catálisis , Modelos Moleculares , Conformación Molecular , Estereoisomerismo
4.
Small ; 10(15): 3012-7, 2014 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-24700425

RESUMEN

The three-dimensional (3D) poly(3,4-ethylenedioxythiophene) (PEDOT)-based bioelectronic interfaces (BEIs) with diverse dimensional micro/nanorod array structures, varied surface chemical pro-perties, high electrical conductivity, reversible chemical redox switching, and high optical transparency are used for capturing circulating tumor cells (CTCs). Such 3D PEDOT-based BEIs can function as an efficient clinical diagonstic and therapeutic platform.


Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/química , Separación Celular/instrumentación , Conductometría/instrumentación , Nanotubos/química , Células Neoplásicas Circulantes/patología , Polímeros/química , Línea Celular Tumoral , Conductividad Eléctrica , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Miniaturización , Nanotubos/ultraestructura , Propiedades de Superficie , Análisis de Matrices Tisulares
5.
J Reprod Dev ; 59(3): 288-95, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23485957

RESUMEN

To completely avoid ice crystal formation and thus get a higher survival rate, vitrification methods have been commonly used for cryopreservation of oocytes and embryos. However, currently used vitrification methods for oocytes and embryos are not suitable for the cryopreservation of preantral follicles (PFs). In the present study, stainless steel mesh was fabricated into mini mesh cups to vitrify isolated PFs. Moreover, isolated follicles were encapsulated and then subjected to vitreous cryopreservation to facilitate in vitro culture/maturation of follicles after warming. The results showed that the percentages of viable follicles did not differ significantly between the vitrification group and fresh group soon after warming (81.25% vs. 85.29%, P>0.05) and after a 7-day culture period (77.78% vs. 83.33%, P>0.05). No difference in mean follicular diameter was observed between cryopreserved and fresh follicles when cultured in vitro. Transmission electron microscopic analysis revealed that vitreous cryopreservation could maintain the ultrastructure of follicles in alginate beads. In conclusion, the present vitrification method could efficiently cryopreserve isolated human ovarian follicles encapsulated by calcium alginate, which could be put into immediate use (in vitro culture/ maturation) after warming. However, more follicles and some detailed biochemical analyses are required to further investigate the effects of vitrification on the long-term growth of human encapsulated PFs.


Asunto(s)
Alginatos/química , Criopreservación/instrumentación , Criopreservación/métodos , Folículo Ovárico/citología , Vitrificación , Adulto , Técnicas de Cultivo de Célula , Femenino , Fluoresceínas/química , Ácido Glucurónico/química , Células de la Granulosa/citología , Ácidos Hexurónicos/química , Humanos , Oocitos/citología , Folículo Ovárico/ultraestructura , Acero Inoxidable , Timidina/química , Adulto Joven
6.
World J Microbiol Biotechnol ; 29(10): 1859-67, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23576015

RESUMEN

Efficiency on biodegradation of high concentration of nitrobenzene (NB) by peat-phosphate esterified polyvinyl alcohol-embedded NB-degrading bacteria Pseudomonas corrugata was conducted compared to free bacteria cells. Its biodegradation kinetics, reuse ability, degradation effect in the absence of the essential element needed for the growth of bacteria and degradation efficiency of the raw water from the contaminated site were also invested. Results show that the degradation rate when the concentration of NB was at 600, 750, and 900 mg/L reached 91.02, 83.23, and 55.9 %, which was higher than that observed in free bacteria at the same concentration levels. Biodegradation kinetics of the material could be well described by first- and zero-order kinetics when the concentration of NB was at 300, 450 mg/L and 600, 750, 900 mg/L, respectively. Stable degradation activity (stayed at a level of approximately 70 %) was displayed during the 11th repeat-batch experiment. The affect of absence of phosphorus in the medium can be abated ascribed to the addition of peat, which contributes with organic matter and other elements such as nitrogen and phosphorus necessary to maintain metabolically active the microorganisms. Effective biodegradation of the raw water from the experimental site revealed that the material can be a potential candidate for treating NB-contaminated wastewater in the practical setting.


Asunto(s)
Células Inmovilizadas/metabolismo , Nitrobencenos/metabolismo , Pseudomonas/metabolismo , Biotransformación , Cápsulas , Ésteres , Fosfatos , Alcohol Polivinílico
7.
ACS Appl Mater Interfaces ; 14(1): 123-137, 2022 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-34935351

RESUMEN

Silk fibroin (SF)-based electroactive biomaterials with favorable electroconductive property and transparency have great potential applications for cell culture and tissue engineering. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is an excellent candidate as a conductive component, which has been widely used in the field of bioelectronics; however, it is hard to be directly coated onto the surface of regenerated SF (RSF) materials with good stability under a cell culture environment. In this study, a one-step facile PEDOT:PSS modification approach for RSF films based on a suitable post-treatment process of RSF was developed. PEDOT:PSS was successfully embedded and fixed into the shallow surface of an RSF film, forming a tightly conjunct conductive layer on the film surface based on the conformation transition of RSF during the post-treatment process. The conductive layer demonstrated a PSS-rich surface and a PEDOT-rich bulk structure and showed excellent stability under a cell culture environment. More specifically, the robust RSF/PEDOT:PSS film achieved in the post-treatment formula with 70% ethanol proportion possessed best comprehensive properties such as a sheet resistance of 3.833 × 103 Ω/square, a conductivity of 1.003 S/cm, and transmittance over 80% at maximum in the visible range. This kind of electroactive biomaterial also showed good electrochemical stability and degradable properties. Moreover, pheochromocytoma-derived cell line (PC12) cells were cultured on the RSF/PEDOT:PSS film, and an effective electrical stimulation cell response was demonstrated. The facile preparation strategy and the good electroconductive property and transparency make this RSF/PEDOT:PSS film an ideal candidate for neuronal tissue engineering and further for biomedical applications.


Asunto(s)
Medios de Cultivo/química , Fibroínas/química , Membranas Artificiales , Poliestirenos/química , Tiofenos/química , Animales , Bombyx/química , Técnicas de Cultivo de Célula/métodos , Supervivencia Celular/efectos de los fármacos , Conductividad Eléctrica , Técnicas Electroquímicas , Fenómenos Ópticos , Células PC12 , Ratas
8.
J Colloid Interface Sci ; 611: 706-717, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34999363

RESUMEN

Metal-organic frameworks (MOFs) are prospective photocatalysts for removing pollutants. However, the large size of MOFs results in unsatisfactory photocatalytic performance, thus restricting their further usage. Herein, ultrasmall Ti MOF (NH2-MIL-125(Ti)) nanodots (diameter: < 10 nm) were prepared on carbon fiber (CF) (diameter: ∼7 µm) based MoS2 (thickness: ∼20 nm, length: ∼200 nm) via a facile method and used as an efficient and reusable photocatalyst. The weaved CF/MoS2/NH2-MIL-125(Ti) cloth (0.15 g, 4 × 4 cm2) shows good reusability with an easy reusing process. Compared with large size NH2-MIL-125(Ti) based sample, our well-prepared NH2-MIL-125(Ti) nanodots based sample shows the improved surface area (290.1 m2 g-1) and it can generate more reactive oxygen species (ROS), which enhance removal performance (81.1% levofloxacin (LVFX), 67.9% acid orange 7 (AO7), 94.3% methylene blue (MB) and 100% Cr(Ⅵ)) in 120 min. Additionally, the recycling test for 4 cycles indicates high stability. This work highlights the function of easy-recyclable NH2-MIL-125(Ti) nanodots-based heterojunctions in wastewater purification.


Asunto(s)
Molibdeno , Titanio , Adsorción , Fibra de Carbono , Catálisis , Estudios Prospectivos
9.
Genet Test Mol Biomarkers ; 25(11): 707-719, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34788142

RESUMEN

Background: Periodontitis is a multifactorial disease mainly caused by the formation of plaque biofilm, which can lead to the gradual destruction of tooth-supporting tissues. Current research on the genetics and epigenetics of periodontitis remains relatively limited, and the molecular mechanisms remain largely unknown. Objective: Our aims were to construct competitive endogenous RNA (ceRNA) network and determine DNA methylation patterns of target genes to help elucidate the pathogenesis of periodontitis. Methods: We analyzed the expression profiles of the GSE16134, GSE54710, GSE10334, and GSE59932 datasets from the Gene Expression Omnibus database through the weighted gene coexpression network analysis system and screened mRNAs that are regulated by the level of methylation and are associated with the occurrence of periodontitis. Next, a lncRNA-miRNA-mRNA ceRNA network was constructed using databases including miRanda and TargetScan. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were conducted for genes in the clinically significant modules. Finally, a protein-protein interaction network was built. Results: We finally identified four mRNAs, four miRNAs, and six lncRNAs as shared differentially expressed genes related to the periodontitis inflammation pathway. IL-6, IFNA17, CXCL12, and TNFRSF13C were identified as key genes whose expression was significantly enriched in the nuclear factor κB and TLR4 pathways. Moreover, the expression of 28 genes were downregulated by hypermethylation and 70 genes were upregulated by hypomethylation. Conclusions: The constructed ceRNA network can improve our understanding of the pathogenesis of periodontitis. Candidate mRNAs from the ceRNA network could serve as new therapeutic targets and prognostic biomarkers in periodontitis.


Asunto(s)
Metilación de ADN , Periodontitis/genética , ARN Mensajero/metabolismo , Biología Computacional , Bases de Datos Genéticas , Redes Reguladoras de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , MicroARNs/metabolismo , Periodontitis/metabolismo , ARN no Traducido/metabolismo , Transcriptoma
10.
Front Neurorobot ; 15: 692562, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34335220

RESUMEN

Patients who have lost limb control ability, such as upper limb amputation and high paraplegia, are usually unable to take care of themselves. Establishing a natural, stable, and comfortable human-computer interface (HCI) for controlling rehabilitation assistance robots and other controllable equipments will solve a lot of their troubles. In this study, a complete limbs-free face-computer interface (FCI) framework based on facial electromyography (fEMG) including offline analysis and online control of mechanical equipments was proposed. Six facial movements related to eyebrows, eyes, and mouth were used in this FCI. In the offline stage, 12 models, eight types of features, and three different feature combination methods for model inputing were studied and compared in detail. In the online stage, four well-designed sessions were introduced to control a robotic arm to complete drinking water task in three ways (by touch screen, by fEMG with and without audio feedback) for verification and performance comparison of proposed FCI framework. Three features and one model with an average offline recognition accuracy of 95.3%, a maximum of 98.8%, and a minimum of 91.4% were selected for use in online scenarios. In contrast, the way with audio feedback performed better than that without audio feedback. All subjects completed the drinking task in a few minutes with FCI. The average and smallest time difference between touch screen and fEMG under audio feedback were only 1.24 and 0.37 min, respectively.

11.
Chemosphere ; 281: 130868, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34010720

RESUMEN

In this paper, a simple and efficient regeneration technology of low-temperature pickling regeneration process is proposed for Cu(II)-adsorbed activated carbon fiber felts (ACFFs). The regeneration process mainly uses the strong oxidation of acidic regenerant above boiling point to regenerate ACFFs in a confined space. With no demand for high temperature and high pressure, the regeneration process achieves a high efficiency regeneration and a remarkable enhancement of Cu(II) adsorptivity simultaneously for Cu(II)-adsorbed ACFFs. After parameter optimization, the pickling temperature of 383 K, pickling time of 3 h and HNO3 concentration of 150 g/L are adopted as optimum process parameters for the reutilization of ACFFs. The regeneration rates of ACFFs in five cycles are maintained at 424.08%-829.59%. Analytical results show that the enhancement of Cu(II) adsorptivity is mainly caused by the remarkable enhancement of specific surface area (increased by 106.08%), micropore volume (increased by 102.17%) and more abundant surface chemical structure (particularly carboxyl and nitro group) after treated by the regeneration process.


Asunto(s)
Carbón Orgánico , Adsorción , Fibra de Carbono , Oxidación-Reducción , Temperatura
12.
ACS Biomater Sci Eng ; 7(3): 1202-1215, 2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-33599501

RESUMEN

Bioelectronics based on biomaterial substrates are advancing toward biomedical applications. As excellent conductors, poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives have been widely developed in this field. However, it is still a big challenge to obtain a functional layer with a good electroconductive property, transparency, and strong adhesion on the biosubstrate. In this work, poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-OH) was chemically polymerized and deposited on the surface of a regenerated silk fibroin (RSF) film in an aqueous system. Sodium dodecyl sulfate (SDS) was used as the surfactant to form micelles which are beneficial to the polymer structure. To overcome the trade-off between transparency and the electroconductive property of the PEDOT-OH coating, a composite oxidant recipe of FeCl3 and ammonium persulfate (APS) was developed. Through electrostatic interaction of oppositely charged doping ions, a well-organized conductive nanoscale coating formed and a transparent conductive RSF/PEDOT-OH film was produced, which can hardly be achieved in a traditional single oxidant system. The produced film had a sheet resistance (Rs) of 5.12 × 104 Ω/square corresponding to a conductivity of 8.9 × 10-2 S/cm and a maximum transmittance above 73% in the visible range. In addition, strong adhesion between PEDOT-OH and RSF and favorable electrochemical stability of the film were demonstrated. Desirable transparency of the film allowed real-time observation of live cells. Furthermore, the PEDOT-OH layer provided an improved environment for adhesion and differentiation of PC12 cells compared to the RSF surface alone. Finally, the feasibility of using the RSF/PEDOT-OH film to electrically stimulate PC12 cells was demonstrated.


Asunto(s)
Polímeros , Seda , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes , Conductividad Eléctrica , Ratas
13.
Shanghai Kou Qiang Yi Xue ; 30(3): 316-322, 2021 Jun.
Artículo en Zh | MEDLINE | ID: mdl-34476453

RESUMEN

PURPOSE: To analyze the opening of mid-palatal suture, transverse changes in dental and dentoalveolar measurements and shift of midfacial bony structures induced by maxillary skeletal expansion (MSE) with cone-beam CT (CBCT), and to evaluate the effect of maxillary skeletal expansion and its influence on adjacent bony structures in adults. METHODS: The study sample consisted of 12 adult patients with maxillary transverse deficiency (4 males, 8 females) at a mean age of (21.17±4.13) years old. All patients were treated with MSE. After treatment, the posterior crossbite was corrected, and the width of the maxillary arch was achieved the optimal width. Pre- and post-treatment CBCT exams were taken before and after MSE treatment. Multiplanar coronal and axial slices obtained from CBCT images were used to measure the changes in transverse widths, angular changes and tooth inclination with Dolphin Imaging 11.9. SPSS 26.0 software package was used for statistical analysis. RESULTS: After MSE treatment, the anterior nasal spine width increased by (2.38±1.01) mm, posterior nasal spine width increased by (2.25±1.08) mm (P<0.01). The inter-crown and inter-apex distance at the first molar increased by (5.56±1.38) mm and (4.14±1.29) mm, respectively (P<0.01). No significant difference was seen in terms of tooth inclination of the first molar(P>0.05). Pterygoid process angle, pterygoid process width, anterior inter-maxillary distance, upper and lower inter-zygomatic distance were significantly larger after treatment (P<0.01), while the inter-temporal distance and bilateral zygomaticomaxillary angle remained unchanged(P>0.05). CONCLUSIONS: MSE has a favorable effect in adult patients with parallel skeletal expansion of the mid-palatal suture achieved after expansion. The teeth present with certain buccal inclination but show no significant movement relative to the alveolar bone. The midfacial bony structures also shift in three-dimensional under the effect of the expansion force.


Asunto(s)
Técnica de Expansión Palatina , Hueso Paladar , Adulto , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Maxilar/diagnóstico por imagen , Suturas
14.
J Mater Chem B ; 9(11): 2717-2726, 2021 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-33683271

RESUMEN

Strong nonspecific protein/cell adhesion on conducting polymer (CP)-based bioelectronic devices can cause an increase in the impedance or the malfunction of the devices. Incorporating oligo(ethylene glycol) or zwitterionic functionalities with CPs has demonstrated superior performance in the reduction of nonspecific adhesion. However, there is no report on the evaluation of the antifouling stability of oligo(ethylene glycol) and zwitterion-functionalized CPs under electrical stimulation as a simulation of the real situation of device operation. Moreover, there is a lack of understanding of the correlation between the molecular structure of antifouling CPs and the antifouling and electrochemical stabilities of the CP-based electrodes. To address the aforementioned issue, we fabricated a platform with antifouling poly(3,4-ethylenedioxythiophene) (PEDOT) featuring tri(ethylene glycol), tetra(ethylene glycol), sulfobetaine, or phosphorylcholine (PEDOT-PC) to evaluate the stability of the antifouling/electrochemical properties of antifouling PEDOTs before and after electrical stimulation. The results reveal that the PEDOT-PC electrode not only exhibits good electrochemical stability, low impedance, and small voltage excursion, but also shows excellent resistance toward proteins and HAPI microglial cells, as a cell model of inflammation, after the electrical stimulation. The stable antifouling/electrochemical properties of zwitterionic PEDOT-PC may aid its diverse applications in bioelectronic devices in the future.


Asunto(s)
Incrustaciones Biológicas/prevención & control , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Técnicas Electroquímicas , Polímeros/farmacología , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Células Cultivadas , Ratones , Microelectrodos , Estructura Molecular , Células 3T3 NIH , Imagen Óptica , Polimerizacion , Polímeros/síntesis química , Polímeros/química , Ratas
15.
Zhongguo Zhen Jiu ; 40(8): 865-7, 2020 Aug 12.
Artículo en Zh | MEDLINE | ID: mdl-32869596

RESUMEN

To introduce professor ZHANG Ren's experience that different stages of refractory facial paralysis should be treated with different acupuncture methods.In early stage of facial paralysis,identifcation is important. Electroacupuncture is applied to connect Qianzheng (Extra) with Cuanzhu (BL 2), Sibai (ST 2) and Jiachengjiang (Extra), by observing the twitches of facial muscles, it is determined whether it is easy to develop into refractory facial paralysis, in order to actively take preventive treatment. In the recovery stage of refractory facial paralysis, comprehensive therapy including acupuncture, acupoint injection, quick cupping and auricular point pressure are adopted, and penetration needling is applied at three points of mouth, three points of cheek and three points of forehead.In the sequelae stage of refractory facial paralysis,on the basis of comprehensive therapy, targeted treatment is adopted according to different sequelae.


Asunto(s)
Terapia por Acupuntura , Electroacupuntura , Parálisis Facial , Puntos de Acupuntura , Músculos Faciales , Parálisis Facial/terapia , Humanos
16.
Int J Biol Macromol ; 153: 1272-1280, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-31758994

RESUMEN

Poly(ε-caprolactone)/poly(lactic acid) (PCL/PLA) blends are promising biomaterials with biodegradable characteristics. However, poor compatibility of the two components may lead to undesirable mechanical properties. In this work, the effect of combining carboxyl multi-walled carbon nanotubes (CNTs) and organically modified montmorillonite (MMT) on the morphology and properties of PCL/PLA blend was investigated. The morphological observations and rheological analysis showed that exfoliated MMT platelets enhanced interfacial adhesion of the two phases, whereas CNTs formed a percolating network in PCL matrix. The addition of CNTs/MMT (0.5 wt%: 0.5 wt%) led to an increase by 137.4% in elongation at break, 79.6% in tensile strength, and 14 °C in decomposition temperature without sacrificing its rigidity apparently for the PCL/PLA matrix. Obvious synergistic effect was demonstrated in comparison to the blends containing single nanofiller. This study demonstrated that combining CNTs and MMT is a facile way to preparing immiscible PCL/PLA blends based nanocomposites with interesting structure and properties.


Asunto(s)
Arcilla/química , Fenómenos Mecánicos , Nanotubos de Carbono/química , Poliésteres/química , Temperatura , Estabilidad de Medicamentos , Reología
17.
Int J Biol Macromol ; 151: 628-634, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32092421

RESUMEN

Polylactic acid (PLA) is a biodegradable and biocompatible polyester derived from renewable resources like corn starch, presenting great potential in clinical applications like tissue engineering, implants and drug delivery systems. However, the intrinsic brittleness restricts its real applications. In this work, PLA nanocomposites were prepared by incorporating a small amount of carboxyl functionalized multi-walled carbon nanotubes (CNTs) and surface compatabilized montmorillonite (MMT) via technologies of freeze-drying and masterbatch-based melt blending. In the resulting nanocomposites, a well-distributed nano-filler network with microstructures of 1-D CNTs/2-D MMT platelets is formed favored by the enhanced interfacial interaction between the organic modified fillers with PLA matrix. Thanks to the well dispersed organic modified nanofillers, a large number of microcracks and extremely stretched PLA matrix are induced during tensile process, dissipating amounts of energy. As a result, the filler networks reinforce PLA with increment of 19% in modulus, remarkably increase by 13.8 times in toughness relative to PLA control without sacrificing strength. Thus, the PLA nanocomposites with excellent properties prepared through the facile and effective route possess broad prospect in biomedical applications.


Asunto(s)
Arcilla/química , Nanocompuestos/química , Nanotubos de Carbono/química , Poliésteres/química , Algoritmos , Materiales Biocompatibles/química , Fenómenos Mecánicos , Modelos Teóricos , Estructura Molecular , Nanocompuestos/ultraestructura , Nanotubos de Carbono/ultraestructura , Difracción de Rayos X
18.
ACS Appl Mater Interfaces ; 12(10): 12362-12372, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32057222

RESUMEN

Zwitterionic poly(3,4-ethylenedioxythiophene) (PEDOT) is an effective electronic material for bioelectronics because it exhibits efficient electrical trade-off and diminishes immune response. To promote the use of zwitterionic PEDOTs in bioelectronic devices, especially for cell alignment control and close electrocoupling, features such as tunable interaction of PEDOTs with proteins/cells and spatially modulating cell behavior are required. However, there is a lack of reliable methods to assemble zwitterionic EDOTs with other functionalized EDOT materials, having different polarities and oxidation potentials, to prepare PEDOTs with the aforementioned surface properties. In this study, we have developed a surfactant-assisted electropolymerization to assemble phosphorylcholine (PC)-functionalized EDOT with other functionalized EDOTs. By adjusting compositions, the interaction of PEDOT copolymers with proteins/cells can be finely tuned; the composition adjustment has an ignorable influence on the impedance of the copolymers. We also demonstrate that the cell-repulsive force generated from PC can spatially guide the neurite outgrowth to form a neuron network at single-cell resolution and greatly enhance the neurite outgrowth by 179%, which is significantly more distinctive than the reported topography effect. We expect that the derived tunable protein/cell interaction and the PC-induced repulsive guidance for the neurite outgrowth can make low-impedance zwitterionic PEDOTs more useful in bioelectronics.


Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/química , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Proyección Neuronal/efectos de los fármacos , Polímeros/química , Polímeros/farmacología , Línea Celular , Impedancia Eléctrica , Oxidación-Reducción/efectos de los fármacos , Unión Proteica/efectos de los fármacos
19.
Mater Sci Eng C Mater Biol Appl ; 105: 110041, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31546462

RESUMEN

The increasing employment of non-degradable polymers based single-use, disposable medical devices have led to huge environmental pressure. Replacement of non-degradable polymers with biodegradable alternatives could be one solution. Since terminal sterilization is a necessary procedure for medical devices to eliminate infections, in this paper, the modifications of sterilization on the transparency, yellow index, dimensional stability and mechanical properties of commercial biodegradable poly(lactic acid) (PLA), poly(butylenes adipate-co-terephthalate) (PBAT) and their blends were investigated. The samples were prepared by compression molding and exposed to four sterilization treatments including ethylene oxide gas (EtO), saturated steam (SS), electron beam (EB), and hydrogen peroxide gas plasma (HPGP). It is concluded that EB can be applied for the sterilization of all the materials investigated, while SS and EtO are not recommended for PLA, and HPGP is not for PBAT and PLA/PBAT blends. This study demonstrates that, when a suitable sterilization process is chosen, PLA has potential to be used for transparent medical devices such as the barrel of syringes or microfluidic chips, while PBAT and PLA/PBAT blends for other non-transparent medical packaging applications.


Asunto(s)
Materiales Biocompatibles/química , Equipos Desechables , Equipos y Suministros , Poliésteres/química , Esterilización/métodos , Rastreo Diferencial de Calorimetría , Peso Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Estrés Mecánico , Temperatura
20.
Environ Sci Pollut Res Int ; 26(28): 29497-29501, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31444725

RESUMEN

Microfibers are a major component of microplastics and have been found nearly everywhere, especially in marine and freshwater habitats around the world. Therefore, microfibers have gained considerable attention in environmental science research. However, there is still no clear consensus on a definition that can encompass all necessary properties to describe microfibers as emerging pollutants. Therefore, we propose a definition for debate by taking the related descriptions of microplastics and textile fibers as references. Moreover, the potential sources from the perspectives of textile engineering, including production, use, care, and end-of-life disposal of fibrous materials, are discussed. For further investigation of microfiber pollution, the gap between current knowledge and major microfiber pollution concerns must be bridged.


Asunto(s)
Agua Dulce/química , Plásticos/química , Textiles/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Ambientales , Contaminantes Químicos del Agua/química
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