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3.
Appl Sci (Basel) ; 14(3)2024.
Artículo en Inglés | MEDLINE | ID: mdl-38566838

RESUMEN

In robotic bin-picking applications, autonomous robot action is guided by a perception system integrated with the robot. Unfortunately, many perception systems output data contaminated by spurious points that have no correspondence to the real physical objects. Such spurious points in 3D data are the outliers that may spoil obstacle avoidance planning executed by the robot controller and impede the segmentation of individual parts in the bin. Thus, they need to be removed. Many outlier removal procedures have been proposed that work very well on unorganized 3D point clouds acquired for different, mostly outdoor, scenarios, but these usually do not transfer well to the manufacturing domain. This paper presents a new filtering technique specifically designed to deal with the organized 3D point cloud acquired from a cluttered scene, which is typical for a bin-picking task. The new procedure was tested on six different datasets (bins filled with different parts) and its performance was compared with the generic statistical outlier removal procedure. The new method outperforms the general procedure in terms of filtering efficacy, especially on datasets heavily contaminated by numerous outliers.

4.
Sci Rep ; 14(1): 1573, 2024 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-38238413

RESUMEN

Calcium phosphate (CaPO4) coating is one of various methods that is used to modify the topography and the chemistry of Ti dental implant surface to solve sever oral problems that result from diseases, accidents, or even caries due to its biocompatibility. In this work, anodized (Ti-bare) was coated by CaPO4 prepared from amorphous calcium phosphate nanoparticles (ACP-NPs) and confirmed the structure by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) techniques. Ti-bare was coated by prepared CaPO4 through the casting process, and the morphology of Ti/CaPO4 was characterized by scanning electron microscope (SEM) where the nano-flakes shape of CaPO4 and measured to be 60 ~ 80 nm was confirmed. The stability of Ti-bare and coated Ti/CaPO4 was studied in a simulated saliva solution using electrochemical impedance spectroscopy (EIS) and linear polarization techniques to deduce their corrosion resistance. Furthermore, three essential oils (EO), Cumin, Thyme, and Coriander, were used to stimulate their synergistic effect with the CaPO4 coat to enhance the corrosion resistance of Ti implant in an oral environment. The fitting EIS parameters based on Rs [RctC]W circuit proved that the charge transfer resistance (Rct) of Ti/CaPO4 increased by 264.4, 88.2, and 437.5% for Cumin, Thyme, and Coriander, respectively, at 2% concentration.


Asunto(s)
Implantes Dentales , Titanio , Corrosión , Ensayo de Materiales , Titanio/química , Espectroscopía Infrarroja por Transformada de Fourier , Microscopía Electrónica de Rastreo , Fosfatos de Calcio/química , Propiedades de Superficie , Aleaciones/química , Materiales Biocompatibles Revestidos/química
5.
Int J Biol Macromol ; 253(Pt 1): 126618, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37659491

RESUMEN

Currently, bio-natural injectable hydrogels are receiving a lot of attention due to their ability to control, adjust, and adapt to random bone defects, in addition, to their ability to mimic the composition of natural bones. From such a viewpoint, this study goal is to prepare and characterize the injectable hydrogels paste based on the natural alginate (Alg) derived from brown sea algae as a polysaccharide polymer, which coupled with nano biogenic-hydroxyapatite (n-HA) prepared from eggshells and enriched with valuable trace elements. The viscosity and mechanical properties of the paste were investigated. As well as the in-vitro study in terms of water absorption and biodegradability in the PBS, biocompatibility and the capability of the injectable Alginate/n-Hydroxyapatite (Alg/n-HA) to regenerate bone for the most suitable injectable form. The injectable hydrogel (BP -B sample) was chosen for the study as it had an appropriate setting time for injecting (13 mins), and suitable compressive strength reached 6.3 MPa. The in vivo study was also carried out including a post-surgery follow-up test of the newly formed bone (NB) in the defect area after 10 and 20 weeks using different techniques such as (SEM/EDX) and histological analysis, the density of the newly formed bone by Dual x-ray absorptiometry (DEXA), blood biochemistry and the radiology test. The results proved that the injectable hydrogels Alginate/n-Hydroxyapatite (Alg/n-HA) had an appreciated biodegradability and bioactivity, which allow the progress of angiogenesis, endochondral ossification, and osteogenesis throughout the defect area, which positively impacts the healing time and ensures the full restoration for the well-mature bone tissue that similar to the natural bone.


Asunto(s)
Alginatos , Durapatita , Durapatita/química , Alginatos/química , Hidrogeles/farmacología , Hidrogeles/química , Huesos , Osteogénesis , Ingeniería de Tejidos/métodos
6.
Artículo en Inglés | MEDLINE | ID: mdl-37379081

RESUMEN

International guidelines designed to minimize the risk of complications that can occur when correcting severe hyponatremia have been widely accepted for a decade. On the basis of the results of a recent large retrospective study of patients hospitalized with hyponatremia, it has been suggested that hyponatremia guidelines have gone too far in limiting the rate of rise of the serum sodium concentration; the need for therapeutic caution and frequent monitoring of the serum sodium concentration has been questioned. These assertions are reminiscent of a controversy that began many years ago. After reviewing the history of that controversy, the evidence supporting the guidelines, and the validity of data challenging them, we conclude that current safeguards should not be abandoned. To do so would be akin to discarding your umbrella because you remained dry in a rainstorm. The authors of this review, who represent 20 medical centers in nine countries, have all contributed significantly to the literature on the subject. We urge clinicians to continue to treat severe hyponatremia cautiously and to wait for better evidence before adopting less stringent therapeutic limits.

7.
J Digit Imaging ; 36(1): 365-372, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36171520

RESUMEN

We describe the curation, annotation methodology, and characteristics of the dataset used in an artificial intelligence challenge for detection and localization of COVID-19 on chest radiographs. The chest radiographs were annotated by an international group of radiologists into four mutually exclusive categories, including "typical," "indeterminate," and "atypical appearance" for COVID-19, or "negative for pneumonia," adapted from previously published guidelines, and bounding boxes were placed on airspace opacities. This dataset and respective annotations are available to researchers for academic and noncommercial use.


Asunto(s)
COVID-19 , Humanos , Inteligencia Artificial , Radiografía , Aprendizaje Automático , Radiólogos , Radiografía Torácica/métodos
8.
IEEE Trans Biomed Circuits Syst ; 16(2): 296-311, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35380968

RESUMEN

With the increasing uptake of sport activities, onsite detection of associated knee injuries at early stages is in high demand to avoid severe ligament tear and long treatment period. Portable electromagnetic imaging (EMI) systems have the potential to meet that demand, but there are challenges. For example, EMI is based on the contrast in the dielectric properties due to the accumulated fluid after knee injury. However, that fluid can be in any shape and orientation. Therefore, to capture enough data for processing, EMI should operate as a dual-polarized wearable system with compact antennas. Thus, the proposed system is a textile brace worn on the knee and consists of an 8-element dual-polarized aperture antenna array, which is matched with the knee. Each of the utilized antennas is fed by two orthogonal coaxial feed, occupies a small size of 36 ×36 ×3.1 mm3, and is backed by a full ground plane for unidirectional radiation. The antenna covers the band 0.7-3.3 GHz (130%), with front to back ratio of more than 10 dB. The textile wool-felt is used as the substrate to enable building flexible brace system. The system's capability to reconstruct knee images with different injuries is verified on realistic knee models and phantoms. The double stage delay, multiply and sum algorithm (DS-DMAS) is used to reconstruct those images, which demonstrate the efficiency of the dual-polarized system and its superiority over single-polarized systems.


Asunto(s)
Fenómenos Electromagnéticos , Dispositivos Electrónicos Vestibles , Algoritmos , Animales , Fantasmas de Imagen , Textiles
10.
Acta Biomater ; 140: 686-699, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34875359

RESUMEN

Multidrug resistance (MDR) is the main challenge faced by cancer chemotherapy. Drug-conjugate offers a promising strategy for breast cancer therapy. In this regard, we developed a DNVM multifunctional drug delivery system by crosslinking doxorubicin (DOX) and vitamin E succinate (VES) with a pH-sensitive hydrazone bond and then encapsulated the DOX-NN-VES prodrug into pH-sensitive hyaluronic acid-2-(octadecyloxy)-1,3-dioxan-5-amine (HOD) micelles. DOX resistant MCF-7/ADR cell were adopted as a model to study the capability and mechanism of MDR reversal. DNVM exhibited much higher cytotoxicity and cell uptake efficiency compared with that of acid-insensitive DOX-VES loaded HOD micelles (DVSM) and DOX loaded HOD micelles (DOXM), indicating the better capacity of DNVM for the reversal of MDR. Moreover, DNVM prevented drug efflux more effectively, inhibited the expression of P-gp, induced excessive production of reactive oxygen species and affected the expression of apoptosis-related proteins. In vivo experiments showed that DNVM significantly inhibited the tumor growth with no obvious changes in the body weight of MCF-7/ADR cells-bearing nude mice. The results suggested that the "double gain" DNVM can synergistically enhance the efficacy of chemotherapeutics for DOX resistant tumor cells and has the potential to overcome tumor MDR. STATEMENT OF SIGNIFICANCE: A dual-functional pH-sensitive doxorubicin - vitamin E succinate prodrug was developed and loaded into tumor microenvironment-sensitive hyaluronic acid-2-(octadecyloxy)-1,3-dioxan-5-amine micelle system (DNVM) for sequencing stimuli-release and overcoming doxorubicin resistance. The "double gain" DNVM can synergistically enhance the efficacy of chemotherapeutics for doxorubicin resistant tumor cells and has the potential to overcome tumor multiple drug resistance.


Asunto(s)
Micelas , Profármacos , Animales , Doxorrubicina/uso terapéutico , Resistencia a Antineoplásicos , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Células MCF-7 , Ratones , Ratones Desnudos , Profármacos/farmacología
11.
IEEE Trans Biomed Eng ; 69(5): 1651-1662, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34752378

RESUMEN

OBJECTIVE: The potential of electromagnetic knee imaging system verified on ex-vivo pig knee joint as an essential step before clinical trials is demonstrated. The system, which includes an antenna array of eight printed biconical elements operating at the band 0.7-2.2 GHz, is portable and cost-effective. Importantly, it can provide daily monitoring and onsite real-time examinations imaging tool for knee injuries. METHODS: Six healthy hind legs from three dead adult pigs were removed at the hip and suspended in the developed system. For each pig, the right- and left-knee were scanning sequentially. Then ligament tear was emulated by injecting distilled water into the left knee joint of each pig for early (5 mL water) and mid-stage (10 mL water) injuries. The injured left knees were re-scanned. A modified multi-static fast delay, multiply and sum algorithm (MS-FDMAS) is used to reconstruct imaging of the knee. All knee's connective tissues, such as anterior and posterior cruciate ligaments (ACL, PCL), lateral and medial collateral ligaments (LCL, MCL), tendons, and meniscus, are extracted from a healthy hind leg along with collected synovial fluid. The extracted tissues and fluid were characterized and modelled as their data are not available in the literature, then imported to build an equivalent model for pig knee of 1 mm3 resolution in a realistic simulation environment. RESULTS: The obtained results proved potential of the proposed system to detect ligament/tendon tears. CONCLUSION: The proposed system has the potential to detect early knee injuries in a realistic environment. SIGNIFICANCE: Contactless EM knee imaging system verified on ex-vivo pig joints confirms its potential to reconstruct knee images. This work lays the groundwork for clinical EM system for detecting and monitoring knee injuries. (EM).


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Traumatismos de la Rodilla , Animales , Lesiones del Ligamento Cruzado Anterior/diagnóstico por imagen , Estudios de Factibilidad , Articulación de la Rodilla , Porcinos , Agua
12.
Nat Commun ; 12(1): 7151, 2021 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-34887420

RESUMEN

The heterozygous Phospholamban p.Arg14del mutation is found in patients with dilated or arrhythmogenic cardiomyopathy. This mutation triggers cardiac contractile dysfunction and arrhythmogenesis by affecting intracellular Ca2+ dynamics. Little is known about the physiological processes preceding induced cardiomyopathy, which is characterized by sub-epicardial accumulation of fibrofatty tissue, and a specific drug treatment is currently lacking. Here, we address these issues using a knock-in Phospholamban p.Arg14del zebrafish model. Hearts from adult zebrafish with this mutation display age-related remodeling with sub-epicardial inflammation and fibrosis. Echocardiography reveals contractile variations before overt structural changes occur, which correlates at the cellular level with action potential duration alternans. These functional alterations are preceded by diminished Ca2+ transient amplitudes in embryonic hearts as well as an increase in diastolic Ca2+ level, slower Ca2+ transient decay and longer Ca2+ transients in cells of adult hearts. We find that istaroxime treatment ameliorates the in vivo Ca2+ dysregulation, rescues the cellular action potential duration alternans, while it improves cardiac relaxation. Thus, we present insight into the pathophysiology of Phospholamban p.Arg14del cardiomyopathy.


Asunto(s)
Proteínas de Unión al Calcio/genética , Calcio/metabolismo , Cardiomiopatía Dilatada/genética , Etiocolanolona/análogos & derivados , Pez Cebra/metabolismo , Animales , Proteínas de Unión al Calcio/metabolismo , Cardiomiopatía Dilatada/metabolismo , Cardiomiopatía Dilatada/fisiopatología , Modelos Animales de Enfermedad , Ecocardiografía , Etiocolanolona/administración & dosificación , Femenino , Técnicas de Sustitución del Gen , Humanos , Masculino , Contracción Miocárdica , Miocardio/metabolismo , Eliminación de Secuencia , Pez Cebra/genética
13.
Drug Des Devel Ther ; 15: 3223-3239, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34349500

RESUMEN

BACKGROUND: The active-targeted drug delivery systems had attracted more and more attention to efficiently overcome multidrug resistance (MDR) in cancer treatments. The aim of the work was to develop a multifunctional nano-structured liposomal system for co-delivery of doxorubicin hydrochloride (DOX) and celecoxib (CEL) to overcome doxorubicin resistance in breast cancer. METHODS: A functional hybrid peptide (MTS-R8H3) with unique cellular penetrability, endo-lysosomal escape and mitochondrial targeting ability was successfully synthesized using solid phase synthesis technology. The peptide modified targeted liposomes (DOX/CEL-MTS-R8H3 lipo) for co-delivery of DOX and CEL were formulated to overcome the chemoresistance in MCF/ADR cells. RESULTS: DOX/CEL-MTS-R8H3 lipo showed nanosized shape and displayed high stability for one month. The cytotoxicity effect of the co-delivery of DOX and CEL through peptide modified liposomes had remarkable treatment efficacy on killing MCF/ADR cells. Targeted liposome exhibited greater cellular entry ability about 5.72-fold stronger than DOX solution. Moreover, as compared with unmodified liposomes, the presence of MTS-R8H3 peptide entity on liposome surface enhanced the mitochondrial-targeting ability and achieved effective reactive oxygen species (ROS) production with significant inhibition of P-gp efflux activity. CONCLUSION: The study suggested that the DOX/CEL-MTS-R8H3 lipo is a promising strategy for overcoming drug resistance in breast cancer treatments with high targeting inhibition efficiency.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/administración & dosificación , Sistemas de Liberación de Medicamentos , Péptidos/administración & dosificación , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Neoplasias de la Mama/metabolismo , Celecoxib/administración & dosificación , Doxorrubicina/química , Liberación de Fármacos , Resistencia a Antineoplásicos , Estabilidad de Medicamentos , Femenino , Humanos , Liposomas/administración & dosificación , Células MCF-7 , Especies Reactivas de Oxígeno/metabolismo
14.
Kidney Int Rep ; 6(5): 1211-1224, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34013099

RESUMEN

We discuss the use of urine electrolytes and urine osmolality in the clinical diagnosis of patients with fluid, electrolytes, and acid-base disorders, emphasizing their physiological basis, their utility, and the caveats and limitations in their use. While our focus is on information obtained from measurements in the urine, clinical diagnosis in these patients must integrate information obtained from the history, the physical examination, and other laboratory data.

15.
Ann R Coll Surg Engl ; 103(3): e85-e87, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33645266

RESUMEN

Epidermolysis bullosa simplex (EBS) is a debilitating condition affecting the skin and mucous membranes that is characterised by frequent ulceration and blistering on trivial trauma. In EBS, oral cavity mucosal injuries lead to a high propensity for developing squamous cell carcinomas. Locally advanced tongue carcinoma arising in this background presents a challenging therapeutic conundrum. To our knowledge, this is the first case of aggressive locally advanced tongue carcinoma that has developed sporadically in a patient with EBS and no family history. Routine screening of oral mucosal lesions will lead to early detection and timely management of this debilitating condition.


Asunto(s)
Epidermólisis Ampollosa Simple/diagnóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de la Lengua/diagnóstico por imagen , Adulto , Progresión de la Enfermedad , Epidermólisis Ampollosa Simple/complicaciones , Epidermólisis Ampollosa Simple/patología , Resultado Fatal , Humanos , Masculino , Estadificación de Neoplasias , Radiodermatitis/etiología , Radioterapia de Intensidad Modulada/efectos adversos , Carcinoma de Células Escamosas de Cabeza y Cuello/complicaciones , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/radioterapia , Estomatitis/etiología , Neoplasias de la Lengua/complicaciones , Neoplasias de la Lengua/patología , Neoplasias de la Lengua/radioterapia
16.
Asian J Pharm Sci ; 15(1): 83-94, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32175020

RESUMEN

Heparosan is a natural precursor of heparin biosynthesis in mammals. It is stable in blood circulation but can be degraded in lysosomes, showing good biocompatibility and long circulation features. So heparosan can be designed as anticancer drug carriers to increase tumor selectivity and improve the therapeutic effect. A novel redox-sensitive heparosan-cystamine-vitamin E succinate (KSV) micelle system was constructed for intracellular delivery of doxorubicin (DOX). Simultaneously, the redox-insensitive heparosan-adipic acid dihydrazide-vitamin E succinate copolymer (KV) was synthesized as control. DOX-loaded micelles (DOX/KSV) with an average particle size of 90-120 nm had good serum stability and redox-triggered depolymerization. In vitro drug release test showed that DOX/KSV micelles presented obvious redox-triggered release behavior compared with DOX/KV. Cytotoxicity and cell uptake were investigated using MGC80-3 tumor cells and COS7 fibroblast-like cells. The cell survival rate of blank micelles was more than 90%, and the cytotoxicity of DOX/KSV in MGC80-3 cells was higher than in COS7 cells, indicating that the carrier has better biocompatibility and less toxicity side effect. The cytotoxicity of DOX/KSV against MGC80-3 cells was significantly greater than that of free DOX and DOX/KV. Furthermore, compared with DOX/KV in MGC80-3 cells, DOX/KSV micelles uptook more anticancer drugs and then released DOX faster into the cell nucleus. The micelles were endocytosed by multiple pathways, but clathrin-mediated endocytosis was the main pathway. Therefore, heparosan polysaccharide could be a potential option as anticancer carrier for enhancing efficacy and mitigating toxicity.

17.
Kidney Int ; 97(1): 75-88, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31784049

RESUMEN

L-lactic acidosis (L-LA) is the most common cause of metabolic acidosis in the critical care setting, which has been associated with a large increase in mortality. The purpose of this article is to provide clinicians with an overview of the biochemical and metabolic background required to understand the different pathophysiological mechanisms that may lead to the development of L-LA. We propose a classification based on whether the pathophysiology of L-LA is due predominantly to increased production or decreased removal of L-lactic acid. In this article, we provide an overview of the biochemical and metabolic aspects of glucose oxidation, the production and removal of L-lactic acid, and a discussion of the pathophysiology of the various causes of L-LA.


Asunto(s)
Acidosis Láctica/etiología , Bicarbonatos/metabolismo , Hipoxia/etiología , Ácido Láctico/metabolismo , Acidosis Láctica/sangre , Acidosis Láctica/diagnóstico , Acidosis Láctica/mortalidad , Aniones/sangre , Aniones/metabolismo , Bicarbonatos/sangre , Ciclo del Ácido Cítrico/fisiología , Enfermedad Crítica , Proteínas del Complejo de Cadena de Transporte de Electrón/metabolismo , Gluconeogénesis/fisiología , Glucosa/metabolismo , Glucólisis/fisiología , Mortalidad Hospitalaria , Humanos , Concentración de Iones de Hidrógeno , Hipoxia/sangre , Hipoxia/diagnóstico , Hipoxia/mortalidad , Unidades de Cuidados Intensivos/estadística & datos numéricos , Riñón/metabolismo , Riñón/fisiología , Ácido Láctico/sangre , Hígado/metabolismo , Hígado/fisiopatología , Músculo Esquelético/metabolismo , Oxidación-Reducción , Fosforilación Oxidativa , Oxígeno/metabolismo
18.
J Liposome Res ; 30(3): 285-296, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31223044

RESUMEN

Combination therapy with conventional chemotherapeutic drugs strongly demonstrates a good approach to reduce cytotoxicity, resistance, and the dose of the potent anticancer drugs. The purpose of this research was to design and characterize liposome incorporating celecoxib (CEL) and doxorubicin hydrochloride (DOX) and investigate the anti-tumor efficacy of this combination on different tumor cells. A simple comparison study had been performed for liposomes formulation using thin-film hydration method and pH-gradient method. HSPC-incorporated liposomes were chosen for encapsulation of both CEL and DOX. The formulations showed small particle size and polydispersity index with high encapsulation efficiency. DOX/CEL liposomes displayed the strongest cytotoxicity against B16 and MGC80-3 cells in comparison to the corresponding drug solutions. By incorporation of both agents, a significant reduction in IC50 from 0.927 to 0.198 µg/ml and from 0.81 to 0.535 µg/ml against B16 cells and MGC80-3 cells, respectively, was observed. CEL also significantly improved the intracellular retention and accumulation of DOX in vitro. Our data suggest that the developed liposomal formulation proved to be the most effective formulative strategy as a dual drug delivery system for incorporation of both doxorubicin HCL and CEL and could be considered a useful tool for enhancing the therapeutic efficacy of the anticancer drug.


Asunto(s)
Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Celecoxib/administración & dosificación , Celecoxib/farmacología , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Sistemas de Liberación de Medicamentos , Animales , Antineoplásicos/química , Celecoxib/química , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxorrubicina/química , Portadores de Fármacos/química , Liberación de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Liposomas , Ratones , Tamaño de la Partícula , Relación Estructura-Actividad , Propiedades de Superficie , Células Tumorales Cultivadas
19.
Int J Biol Macromol ; 140: 886-894, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31449867

RESUMEN

The chitosan/polyacrylic acid/polypyrrole/loaded with silver nanoparticles (CS/PAA/PPy/Ag-NPs) bionanocomposite as conductive, biodegradable, and biocompatible hydrogels were prepared by the casting method. Silver nanoparticles (Ag-NPs) were incorporated into the prepared bionanocomposite hydrogels to reinforce the electrical conductivity as well as the antimicrobial properties of the prepared hydrogels. The scanning electron microscopy revealed the compatibility of chitosan, polyacrylic acid, and polypyrrole, as well as Ag-NPs, were inserted in the polymer matrix and dispersed well on the superficies of the prepared bionanocomposites. X-ray diffraction displayed the presence of Ag-NPs into the polymer matrix. Also, the appearance of characteristic peaks in the Fourier transform infrared confirmed the compatibility of three polymers. Additionally, the swelling properties, antimicrobial activity as well as the electrical and dielectric characteristics of the fabricated bionanocomposites hydrogels were investigated. Moreover, the DC-conductivity was studied and our data designated that the DC-conductivity of the prepared bio-nanocomposites was improved by the existence of PPy more precisely than that of Ag-NPs. However, both were of high conductivity compared to that of the CS/PAA and found to follow the BNN universal relation. Also, The activation energy of about 55 kJ/mol of CS:2PAA hydrogel and reduce to about 15 kJ/mol in all the considered bionanocomposites after addition of Ag-NPs. Furthermore, the antibacterial activities of the knowledgeable microbes were improved as a result of the presence of Ag-NPs in bionanocomposites hydrogels.


Asunto(s)
Materiales Biocompatibles/química , Quitosano/química , Conductividad Eléctrica , Hidrogeles/química , Nanocompuestos/química , Plata/química , Resinas Acrílicas/química , Antibacterianos/química , Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Nanocompuestos/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier
20.
Carbohydr Polym ; 216: 54-62, 2019 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-31047082

RESUMEN

Biodegradable, antimicrobial, and semiconducting cellulosic composite was synthesized by in-situ polymerization of polyaniline in the presence of cellulose. The cobalt ferrite nanoparticles (CFO-NPs) were added during the polymerization process to acquire this composite magnetic property. The CFO-NPs were prepared by sol-gel method with average particles size less than 50 nm. The nanocomposites were characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). In addition, their magnetic, dielectric constant, dielectric loss, and conductivity behaviors were studied. The magnetization (Ms) and conductivity increased up to 3.7 emu/g and 3.5 × 10-3 S/cm, respectively, with increasing CFO-NPs content. The prepared electromagnetic nanocomposite exhibits highly efficient biodegradability and antimicrobial activity against Escherichia coli, Bacillus subtilis, and Candida albicans. The antimicrobial activity increased with increasing CFO-NPs while the biodegradability decreased.


Asunto(s)
Compuestos de Anilina/farmacología , Celulosa/farmacología , Cobalto/farmacología , Compuestos Férricos/farmacología , Nanocompuestos/química , Nanopartículas/química , Compuestos de Anilina/síntesis química , Compuestos de Anilina/química , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Antifúngicos/síntesis química , Antifúngicos/química , Antifúngicos/farmacología , Bacillus subtilis/efectos de los fármacos , Plásticos Biodegradables/síntesis química , Plásticos Biodegradables/química , Plásticos Biodegradables/farmacología , Candida albicans/efectos de los fármacos , Celulosa/análogos & derivados , Celulosa/síntesis química , Cobalto/química , Conductividad Eléctrica , Escherichia coli/efectos de los fármacos , Compuestos Férricos/síntesis química , Compuestos Férricos/química , Fenómenos Magnéticos , Tamaño de la Partícula
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