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1.
Nanotoxicology ; 14(3): 404-419, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32031476

RESUMO

The objective of this study was to evaluate the association between carbon nanotube and nanofiber (CNT/F) exposure and ex vivo responses of whole blood challenged with secondary stimulants, adjusting for potential confounders, in a cross-sectional study of 102 workers. Multi-day exposure was measured by CNT/F structure count (SC) and elemental carbon (EC) air concentrations. Demographic, lifestyle and other occupational covariate data were obtained via questionnaire. Whole blood collected from each participant was incubated for 18 hours with and without two microbial stimulants (lipopolysaccharide/LPS and staphylococcal enterotoxin type B/SEB) using TruCulture technology to evaluate immune cell activity. Following incubation, supernatants were preserved and analyzed for protein concentrations. The stimulant:null response ratio for each individual protein was analyzed using multiple linear regression, followed by principal component (PC) analysis to determine whether patterns of protein response were related to CNT/F exposure. Adjusting for confounders, CNT/F metrics (most strongly, the SC-based) were significantly (p < 0.05) inversely associated with stimulant:null ratios of several individual biomarkers: GM-CSF, IFN-γ, interleukin (IL)-2, IL-4, IL-5, IL-10, IL-17, and IL-23. CNT/F metrics were significantly inversely associated with PC1 (a weighted mean of most biomarkers, explaining 25% of the variance in the protein ratios) and PC2 (a biomarker contrast, explaining 14%). Among other occupational exposures, only solvent exposure was significant (inversely related to PC2). CNT/F exposure metrics were uniquely related to stimulant responses in challenged whole blood, illustrating reduced responsiveness to a secondary stimulus. This approach, if replicated in other exposed populations, may present a relatively sensitive method to evaluate human response to CNT/F or other occupational exposures.


Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Citocinas/sangue , Exposição por Inalação/efeitos adversos , Nanofibras/toxicidade , Nanotubos de Carbono/toxicidade , Exposição Ocupacional/efeitos adversos , Adulto , Poluentes Ocupacionais do Ar/análise , Biomarcadores/sangue , Estudos Transversais , Feminino , Humanos , Exposição por Inalação/análise , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Nanofibras/análise , Nanotubos de Carbono/análise , Exposição Ocupacional/análise , Análise de Componente Principal , Escarro/química , Escarro/imunologia
2.
J Photochem Photobiol B ; 202: 111680, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31810038

RESUMO

Tissue engineering and stem cell rehabilitation are the hopeful aspects that are being investigated for the management of Myocardial Infarction (MI); cardiac patches have been used to start myocardial rejuvenation. In this study, we engineered p-phenylenediamine surface functionalized (modif-CQD) into the Silk fibroin/PLA (SF/PLA) nanofibrous bioactive scaffolds with improved physico-chemical abilities, mechanical and cytocompatibility to cardiomyocytes. The micrograph results visualized the morphological improved spherical modif-CQD have been equivalently spread throughout the SF/PLA bioactive cardiac scaffolds. The fabricated CQD@SF/PLA nanofibrous bioactive scaffolds were highly porous with fully consistent pores; effectively improved young modulus and swelling asset for the suitability and effective implantation efficacy. The scaffolds were prepared with rat cardiomyocytes and cultured for up to 7 days, without electrical incentive. After 7 days of culture, the scaffold pores all over the construct volume were overflowing with cardiomyocytes. The metabolic activity and viability of the cardiomyocytes in CQD@SF/PLA scaffolds were significantly higher than cardiomyocytes in Silk fibroin /PLA scaffolds. The integration of CQD also influenced greatly and increases the expression of cardiac-marker genes. The results of the present investigations evidently recommended that well-organized cardiac nanofibrous scaffold with greater cardiac related mechanical abilities and biocompatibilities for cardiac tissue engineering and nursing care applications.


Assuntos
Fibroínas/química , Nanofibras/química , Pontos Quânticos/química , Engenharia Tecidual , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Carbono/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Raios Infravermelhos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Nanofibras/toxicidade , Poliésteres/química , RNA Mensageiro/metabolismo , Ratos , Troponina C/genética , Troponina C/metabolismo
3.
Carbohydr Polym ; 229: 115472, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826419

RESUMO

TEMPO oxidized cellulose nanofibers (T-CNF) were prepared from cellulose pulp which is extracted from bagasse. Soy protein hydrolysate (SPH) was grafted on T-CNF via amidation of carboxylic groups. Biomineralization was, then, assessed via calcium phosphates (CaP) precipitation in twice-simulated body fluid until formation of a new bioactive material. Protein was efficiently grafted without alteration of morphology and nanofibrils packing as reported by Fourier Transform infrared analysis /X Ray Diffraction /Scanning and Transmission Electron Microscopy / Atomic Force Microscopy. Highly crystalline calcium phosphate deposits - ca. 22.1% - were detected, with a Ca/P ratio equal to 1.63, in agreement with native bone apatite composition. In vitro response of human Mesenchymal Stem Cells confirmed the biocompatibility. No significant differences in terms of cell adhesion were recognized while a significant increase in cell proliferation was detected until 7 days. The presence of calcium phosphates tends to cover the nanofibrillar pattern, inducing the inhibition of cell proliferation and promoting the ex-novo precipitation of mineral phases. All the results suggest a promising use of these biomaterials in the repair and/or the regeneration of hard tissues such as bone.


Assuntos
Materiais Biocompatíveis/farmacologia , Calcificação Fisiológica/efeitos dos fármacos , Celulose/farmacologia , Nanofibras/química , Hidrolisados de Proteína/farmacologia , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/toxicidade , Fosfatos de Cálcio/síntese química , Fosfatos de Cálcio/farmacologia , Fosfatos de Cálcio/toxicidade , Proliferação de Células/efeitos dos fármacos , Celulose/análogos & derivados , Celulose/toxicidade , Óxidos N-Cíclicos/química , Géis/síntese química , Géis/farmacologia , Géis/toxicidade , Humanos , Nanocompostos/química , Nanocompostos/toxicidade , Nanofibras/toxicidade , Oxirredução , Hidrolisados de Proteína/química , Hidrolisados de Proteína/toxicidade , Soja/química
4.
Carbohydr Polym ; 229: 115544, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826435

RESUMO

Chitin is the second abundant natural polysaccharide, and the development of chitin and its derivatives have received more and more attention. Glucosamine sulfate (GAS) obtained by the hydrolysis of chitin can promote the growth of chondrocytes. The coaxial electrospinning technology had been utilized to encapsulated GAS into the core of polycaprolactone (PCL) nanofibers. It could protect the GAS from the environment and allow it to release sustainably over time. From the results of scanning electron microscopy (SEM), PCL/GAS nanofibers performed a typical fiber scaffold surface. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) results confirmed the feasibility to use coaxial electrospinning to load GAS. Tensile tests exhibited that PCL/GAS mats could be stretched more than twice its own length. Besides, the cell experiments illustrated that PCL/GAS had a significant effect on the proliferation and growth of rat articular chondrocytes, attesting its prospect for cartilage regeneration.


Assuntos
Quitina/química , Glucosamina/química , Nanofibras/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cartilagem/fisiologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/metabolismo , Expressão Gênica/efeitos dos fármacos , Glucosamina/metabolismo , Nanofibras/toxicidade , Poliésteres/química , Ratos , Regeneração/efeitos dos fármacos , Resistência à Tração
5.
Ecotoxicol Environ Saf ; 188: 109856, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31722800

RESUMO

In this study, we reported the design and the fabrication of Ag and TiO2 modified polycaprolactone (PCL) electrospun nanofiber (NF) mats. The as-prepared NF mats were fabricated by one-step electrospinning and it was exploited for three different purposes (i) reusable SERS substrate for quantitative analysis to trace organic pollutants, (ii) photocatalyst for degradation of organic pollutants and (iii) antibacterial agent for killing of bacteria. Three different nanofiber mats, PCL, PCL-TiO2, PCL/TiO2-Ag NFs. were fabricated and further investigated. The morphologies and structures of the as-prepared nanofiber mats were carried out using X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and fourier transform infrared spectroscopy (FT-IR) techniques. PCL/TiO2-Ag NFs served as a highly effective SERS platform with a detection limit of 10 nM for the detection of methylene blue dye (MB). A remarkable feature of the presented platform is the ability to reuse the PCL/TiO2-Ag NFs for SERS analysis of MB; availing from its capability for self-cleaning under UV light. By employing PCL/TiO2-Ag NFs nanocatalyst, complete photocatalytic degradation of the probe analytes MB and ibuprofen (Ibu) under UV irradiation was accomplished not more than 180 min. Moreover, PCL/TiO2-Ag NF mats showed a highly promising bactericidal feature against gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria, which immensely emerged due to the presence of Ag NPs. This new trending nanofiber is assumed to lead a bunch of changes in the field of photocatalytic, SERS and antibacterial studies.


Assuntos
Nanofibras/química , Poliésteres/química , Prata/química , Titânio/química , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Poluentes Ambientais/química , Azul de Metileno/química , Nanofibras/toxicidade , Fotólise , Análise Espectral Raman/instrumentação
6.
Daru ; 27(2): 683-693, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31654377

RESUMO

BACKGROUND: The lemongrass (LG) leaves could be a useful source of cellulose after its oil extraction, which is still either dumped or burned, not considered as a cost-effective approach. The synthesis of cellulose nanofibers (CNF) from LG waste has emerged as a beneficial alternative in the value-added applications. The non-toxicity, biodegradability, and biocompatibility of CNF have raised the interest in its manufacturing. METHOD: In the present study, we have isolated and characterized CNFs using enzymatic hydrolysis. We also explored the cytotoxic properties of the final material. The obtained products were characterized using dynamic light scattering (DLS), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), and thermogravimetric/differential thermal gravimetric analysis (TG/DTG). The cytotoxicity of CNF was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay against three different cancer cell lines NCIH460, PA1, and L132 cells. RESULTS: The FT-IR results showed that the resulting sample was of cellulose species, and CNF was found free from the non-cellulosic components like lignin and hemicellulose. The SEM micrographs of the cellulose showed a bundle like structure. The TEM micrographs of CNF showed diverse long fibers structure with 105.7 nm particle size analysed using DLS. The TGA analysis revealed that the thermal stability was slightly lower, compared to cellulose. Additionally, CNF did not show the cytotoxic effect at the tested concentrations (~10-1000 µg/ml) in any of the cell lines. CONCLUSION: Overall, the results concluded that LG waste-derived CNF is a potential sustainable material and could be employed as a favourable reinforcing agent or nanocarriers in diverse areas, mainly in food and drug delivery sectors. Graphical abstract Systematic representation of the synthesis of the cellulose nanofibers: The lignocellulosic waste of lemongrass (after oil extraction) was pretreated for the isolation of raw cellulose, followed by enzyme hydrolysis for the synthesis of pure cellulose nanofibers.


Assuntos
Cymbopogon/química , Lignina/isolamento & purificação , Nanofibras/química , Biodegradação Ambiental , Biomassa , Linhagem Celular Tumoral , Humanos , Hidrólise , Lignina/toxicidade , Nanofibras/toxicidade , Tamanho da Partícula , Testes de Toxicidade
7.
ACS Appl Mater Interfaces ; 11(42): 38568-38577, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31584794

RESUMO

The influence of chirality on cell behavior is closely related with relevant biological events; however, many recent studies only focus on the apparent chiral influence of supramolecular nanofibers and ignore the respective effects of molecular chirality and supramolecular chirality in biological processes. Herein, the inherent molecular and supramolecular chiral effects on cell spreading and differentiation are studied. Left-handed nanofibers (referring to supramolecular chirality) assembled from l-amino acid derivatives can enhance cell spreading and proliferation compared to flat l-surfaces (referring to molecular chirality). However, compared to the d-surfaces (referring to molecular chirality), right-handed nanofibers (referring to supramolecular chirality) derived from d-amino acid suppress cell spreading and proliferation, overturning the conventional view that a fibrous morphology generally enhances cell adhesion. The results directly suggest that the amplification of chirality from chiral molecules to chiral assemblies significantly enhances the effect on regulated cell behavior by supramolecular helical handedness. Moreover, cell differentiation is found to be chirality dependent. It suggests that both the l-amino acid derivatives and the left-handed fibers facilitate osteogenic differentiation. This study provides useful insight into understanding the origin of chiral expression from the molecular to the macroscopic level in nature.


Assuntos
Diferenciação Celular , Nanofibras/química , Citoesqueleto de Actina/efeitos dos fármacos , Adsorção , Aminoácidos/química , Animais , Bovinos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Dicroísmo Circular , Hidrogéis/química , Camundongos , Células NIH 3T3 , Nanofibras/toxicidade , Soroalbumina Bovina/química , Estereoisomerismo
8.
J Photochem Photobiol B ; 197: 111539, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31301638

RESUMO

Treatment of burn injury is clinically challenging one, therefore several steps and noteworthy approaches have been taken to improve wound mechanisms. Citrus pectin plays a stabilizing agent to synthesis of ZnO nanoparticles (ZnO NPs). The present study is focused on ZnO loaded collagen/chitosan nanofibrous were synthesized by electrospinning method using ZnO NPs. The chemical structure, phase purity and morphological observation were investigated under spectroscopic and mircoscopic techniques and demonstrated their suitable properties as a wound healing material. In addition, that prepared nanoparticles loaded biopolymeric fibrous nanomaterial showed suitable antibacterial activity against S. aureus and E. coli bacterial pathogens and also in vitro studies was confirmed the enhanced proliferation, cell viability and biocompatibility. In vitro evaluations have been exhibited acceptable cell proliferation is observed throughout the ZnO loaded Coll/CS nanofibrous within 3 days, which was comparable to the control material. In vivo wound healing ability was monitored on the rat wound experimental model. From the in vivo observations, revealed that the loaded of ZnO NPs with Coll/CS nanofibrous can effectively quicken wound healing mechanism, expressed in the initial stage healing process. These results suggest that ZnO loaded collagen/chitosan nanofibrous is a potential candidate for wound healing applications with enhanced biological properties.


Assuntos
Queimaduras/patologia , Quitosana/química , Colágeno/química , Nanopartículas Metálicas/química , Nanofibras/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriemia/prevenção & controle , Queimaduras/veterinária , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Nanofibras/uso terapêutico , Nanofibras/toxicidade , Ratos , Pele/efeitos dos fármacos , Pele/patologia , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Óxido de Zinco/química
9.
Environ Toxicol Chem ; 38(10): 2314-2325, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31343769

RESUMO

Manufactured nanomaterial production is outpacing the ability to investigate environmental hazard using current regulatory paradigms, causing a backlog of materials requiring testing. To ameliorate this issue, regulatory bodies have proposed integrating safety into the production of novel nanomaterials, allowing for hazards to be identified early in development rather than aftermarket release. In addition, there is a growing interest in short-term ecotoxicity testing to rapidly identify environmental hazards. In this sense, the present study investigated 3 carbon nanofibers (CNFs), created with different production methods, using short-term in vitro and in vivo exposures on fish cell lines, mussel hemocytes, crustacea, and algae. The present study investigated if differences in ecotoxicity hazard between the CNFs could be identified and, if so, which product could be considered less hazardous. A major challenge in assessing the potential hazards posed by manufactured nanomaterials is standardizing the preparation for testing. Standardized operating protocols have been proposed using protein to facilitate the preparation of stable stock suspension, which is not environmentally representative. As such, the study also assessed the potential impacts these standardized protocols (with or without the use of protein) could have on the interpretation of environmental hazard. The results demonstrated that there were clear differences between the 3 CNFs and that the dispersion protocol influenced the interpretation of hazard, demonstrating a need for caution when interpreting ecotoxicity in a regulatory context. Environ Toxicol Chem 2019;38:2314-2325. © 2019 SETAC.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Carbono/toxicidade , Ecotoxicologia , Nanofibras/toxicidade , Animais , Linhagem Celular , Daphnia/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Hemócitos/efeitos dos fármacos , Mytilus/efeitos dos fármacos , Nanofibras/ultraestrutura , Especificidade da Espécie
10.
Carbohydr Polym ; 219: 113-120, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151507

RESUMO

Honey is an ancient natural wound-healing agent and has been reintroduced to modern clinical wound care as it has various bioactivities. In this study, honey was incorporated into an alginate/PVA-based electrospun nanofibrous membrane to develop an efficient wound dressing material. The morphology and chemical composition of the nanofibrous membrane were observed by scanning electron microscopy and characterized via Fourier transform infrared spectroscopy, respectively, demonstrating that honey was successfully introduced to the nanofibers. The nanofibrous membranes with increasing honey content showed enhanced antioxidant activity, suggesting the ability to control the overproduction of reactive oxygen species. Disc diffusion assay and dynamic contact assay proved the antibacterial activity of the honey loaded nanofibers towards Gram-positive bacterium (Staphylococcus aureus) and Gram-negative bacterium (Escherichia coli). The cytotoxicity assay illustrated the non-cytotoxicity and biocompatibility of the nanofibrous membranes. Therefore, the developed honey/alginate/PVA nanofibrous membranes are promising for wound dressings.


Assuntos
Alginatos , Antibacterianos , Antioxidantes , Mel , Membranas/química , Nanofibras , Alginatos/química , Alginatos/uso terapêutico , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Apiterapia , Escherichia coli/efeitos dos fármacos , Humanos , Camundongos , Células NIH 3T3 , Nanofibras/química , Nanofibras/uso terapêutico , Nanofibras/toxicidade , Curativos Oclusivos , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Cicatrização
11.
Int J Nanomedicine ; 14: 3669-3678, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190818

RESUMO

Background: Electrospun gelatin/polycaprolactone (Gt/PCL) nanofibrous scaffolds loaded with graphene are novel nanomaterials with the uniquely strong property of electrical conductivity, which have been widely investigated for their potential applications in cardiovascular tissue engineering, including in bypass tracts for atrioventricular block. Purpose: Electrospun Gt/PCL/graphene nanofibrous mats were successfully produced. Scanning electron micrography showed that the fibers with graphene were smooth and homogeneous. In vitro, to determine the biocompatibility of the scaffolds, hybrid scaffolds with different fractions of graphene were seeded with neonatal rat ventricular myocytes. In vivo, Gt/PCL scaffolds with different concentrations of graphene were implanted into rats for 4, 8 and 12 weeks. Results: CCK-8 assays and histopathological staining (including DAPI, cTNT, and CX43) indicated that cells grew and survived well on the hybrid scaffolds if the mass fraction of graphene was lower than 0.5%. After implanting into rats for 4, 8 or 12 weeks, there was no gathering of inflammatory cells around the nanomaterials according to the HE staining results. Conclusion: The results indicate that Gt/PCL nanofibrous scaffolds loaded with graphene have favorable electrical conductivity and biological properties and may be suitable scaffolds for use in the treatment of atrioventricular block. These findings alleviate safety concerns and provide novel insights into the potential applications of Gt/PCL loaded with graphene, offering a solid foundation for comprehensive in vivo studies.


Assuntos
Gelatina/toxicidade , Grafite/toxicidade , Nanofibras/toxicidade , Poliésteres/toxicidade , Engenharia Tecidual , Tecidos Suporte/química , Testes de Toxicidade , Animais , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Processamento de Imagem Assistida por Computador , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Ratos , Suínos
12.
Int J Biol Macromol ; 135: 698-705, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31145955

RESUMO

Resveratrol loaded chitosan:gellan (CS:Gel) nanofibers (NFs) were prepared for the first time using electrospinning technique. The NFs were prepared with CS (9% w/v) in trifloroacetic acid and Gel (2.5% w/v) at a concentration ratio of 95:5% w/v. Based on the scanning electron microscopy (SEM) images, the diameters of CS-Gel fibers at a ratio of 95:5 and 90:10% w/v were 166 ±â€¯37 and 291 ±â€¯41 nm, respectively. Resveratrol (0.05% w/v) was loaded in NFs of CS-Gel at a ratio of 95:5. Encapsulation efficiency (EE) of resveratrol in NFs of CS-Gel were 86 ±â€¯6%. The amount of resveratrol delivered in intestine region was in the range of 43-51% of the total encapsulated resveratrol (equivalent to ~840 µM). Antioxidant activities of resveratrol loaded NFs were significantly higher than that of free resveratrol. Furthermore, the resveratrol releasing ability of the NFs was proved through the MTT assay and revealed that the resveratrol NFs have almost the same cytotoxicity against HT29 cancer cells compared to free resveratrol. Based on the obtained results, the prepared NFs hold great potential as drug delivery carriers for resveratrol delivery.


Assuntos
Quitosana/química , Portadores de Fármacos/química , Trato Gastrointestinal/metabolismo , Nanofibras/química , Polissacarídeos Bacterianos/química , Resveratrol/química , Portadores de Fármacos/toxicidade , Liberação Controlada de Fármacos , Células HT29 , Humanos , Teste de Materiais , Nanofibras/toxicidade , Resveratrol/metabolismo
13.
Colloids Surf B Biointerfaces ; 180: 212-220, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31054461

RESUMO

The objective of this study was to synthesize a novel antimicrobial cellulose nanofibril/silver nanoparticle (CNF/AgNP) nanocomposite by an ultraviolet (UV) irradiation method and evaluate the toxicity of the nanocomposite to human colon cells. AgNPs coated on CNFs have an average size of ˜28 nm and exhibited a surface plasma resonance absorption peak at 402 nm. Coating AgNPs on CNFs interfered with the formation of intra-chain and inter-chain hydrogen bonds of cellulose. Moreover, the CNF/AgNP nanocomposite exhibited significant antimicrobial activities against two important food-borne pathogens, including Escherichia coli O157:H7 and Staphylococcus aureus. No apparent toxicity of the CNF/AgNP nanocomposite to Caco-2 and FHC human colon cells was observed, except when a high content of (≥500 µg/m L) of the nanocomposite was used for which a significant decrease of cell viability was observed. The nanocomposite's toxicity was related to the content, size, and surface charge of UV-synthesized AgNPs on CNFs. These results indicate that the antimicrobial CNF/AgNP nanocomposite prepared by UV irradiation method can be potentially used as an active filler applied in food packaging materials.


Assuntos
Antibacterianos/farmacologia , Celulose/farmacologia , Nanopartículas Metálicas/toxicidade , Nanocompostos/toxicidade , Nanofibras/toxicidade , Prata/farmacologia , Testes de Toxicidade , Raios Ultravioleta , Células CACO-2 , Celulose/ultraestrutura , Colo/citologia , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/ultraestrutura , Humanos , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Nanofibras/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
14.
Carbohydr Polym ; 215: 130-136, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30981337

RESUMO

Neutral polysaccharides such as konjac glucomannan, starch and pullulan are abundant in nature and have unique property. Their nanofibers hold great potential for biomedicine, which however, are seldom applied in the field due to the lack of crosslinking method. In this work, we report a periodate oxidation - adipic acid dihydrazide (ADH) crosslinking strategy to prepare robust and biocompatible neutral polysaccharide nanofibers. Neutral polysaccharides with adjacent dihydroxyl groups are firstly partially oxidized with periodate to give dialdehyde polysaccharides, and their electrospun nanofibers are then crosslinked with ADH to form dihydrazone crosslinkers. The resulting crosslinked neutral polysaccharide nanofibers exhibit high water resistance and excellent mechanical properties because of the high reactivity of Schiff base crosslinking reaction. Moreover, the crosslinked neutral polysaccharide nanofibers show good biocompatibility due to the low toxicity of ADH. These robust and biocompatible neutral polysaccharide nanofibers are expected to seek extensive applications in a variety of biomedical fields.


Assuntos
Materiais Biocompatíveis/química , Mananas/química , Nanofibras/química , Adipatos/química , Adipatos/toxicidade , Animais , Materiais Biocompatíveis/toxicidade , Linhagem Celular Tumoral , Reagentes para Ligações Cruzadas/química , Mananas/toxicidade , Camundongos , Nanofibras/toxicidade
16.
Nanoscale ; 11(18): 8906-8917, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31016299

RESUMO

Biomimetic functional scaffolds for tissue engineering should fulfil specific requirements concerning structural, bio-chemical and electro-mechanical characteristics, depending on the tissue that they are designed to resemble. In bone tissue engineering, piezoelectric materials based on poly(vinylidene fluoride) (PVDF) are on the forefront, due to their inherent ability to generate surface charges under minor mechanical deformations. Nevertheless, PVDF's high hydrophobicity hinders sufficient cell attachment and expansion, which are essential in building biomimetic scaffolds. In this study, PVDF nanofibrous scaffolds were fabricated by electrospinning to achieve high piezoelectricity, which was compared with drop-cast membranes, as it was confirmed by XRD and FTIR measurements. Oxygen plasma treatment of the PVDF surface rendered it hydrophilic, and surface characterization revealed a long-term stability. XPS analysis and contact angle measurements confirmed an unparalleled two-year stability of hydrophilicity. Osteoblast cell culture on the permanently hydrophilic PVDF scaffolds demonstrated better cell spreading over the non-treated ones, as well as integration into the scaffold as indicated by SEM cross-sections. Intracellular calcium imaging confirmed a higher cell activation on the piezoelectric electrospun nanofibrous scaffolds. Combining these findings, and taking advantage of the self-stimulation of the cells due to their attachment on the piezoelectric PVDF nanofibers, a 3D tissue-like functional self-sustainable scaffold for bone tissue engineering was fabricated.


Assuntos
Nanofibras/química , Polivinil/química , Tecidos Suporte/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cálcio/análise , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Estimulação Elétrica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Microscopia Confocal , Nanofibras/toxicidade , Osteoblastos/citologia , Gases em Plasma/química , Propriedades de Superfície
17.
Nanoscale ; 11(13): 6422-6430, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30888347

RESUMO

In this work, nano-hybrid electrospun non-woven mats made of wool keratin combined with diclofenac loaded hydrotalcites (HTD) were prepared and characterized as potential drug delivery systems and scaffolds for fibroblast cell growth. Nano-hybrid electrospun non-woven mats showed a good adaptability to wet skin, effortlessly conforming to the three-dimensional topography of the tissue. Nanosized HTD exercised an overall reinforcing action on the electrospun non-woven mats since the nanohybrid samples displayed a reduced swelling ratio and a slower degradation profile compared to keratin-based nanofiber non-woven mats containing free diclofenac, without negative effects on drug release. The cell viability test indicated a decreased toxicity of the drug when loaded into nanofibers and confirmed the biocompatibility of keratin/HTD electrospun non-woven mats; moreover, a controlled diclofenac release within the first 24 hours does not compromise the fibroblast cell growth in a significant manner.


Assuntos
Hidróxido de Alumínio/química , Bandagens , Queratinas/química , Hidróxido de Magnésio/química , Nanofibras/química , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Diclofenaco/química , Diclofenaco/metabolismo , Liberação Controlada de Fármacos , Camundongos , Microscopia de Fluorescência , Células NIH 3T3 , Nanofibras/toxicidade , Resistência ao Cisalhamento , Viscosidade , Lã/metabolismo
18.
Environ Toxicol Pharmacol ; 66: 116-125, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30665014

RESUMO

We studied if the pulmonary and systemic toxicity of nanofibrillated celluloses can be reduced by carboxylation. Nanofibrillated celluloses administered at 6 or 18 µg to mice by intratracheal instillation were: 1) FINE NFC, 2-20 µm in length, 2-15 nm in width, 2) AS (-COOH), carboxylated, 0.5-10 µm in length, 4-10 nm in width, containing the biocide BIM MC4901 and 3) BIOCID FINE NFC: as (1) but containing BIM MC4901. FINE NFC administration increased neutrophil influx in BAL and induced SAA3 in plasma. AS (-COOH) produced lower neutrophil influx and systemic SAA3 levels than FINE NFC. Results obtained with BIOCID FINE NFC suggested that BIM MC4901 biocide did not explain the lowered response. Increased DNA damage levels were observed across materials, doses and time points. In conclusion, carboxylation of nanofibrillated cellulose was associated with reduced pulmonary and systemic toxicity, suggesting involvement of OH groups in the inflammatory and acute phase responses.


Assuntos
Reação de Fase Aguda/induzido quimicamente , Ácidos Carboxílicos/química , Celulose/toxicidade , Desinfetantes/toxicidade , Pulmão/efeitos dos fármacos , Nanofibras/toxicidade , Animais , Líquido da Lavagem Broncoalveolar/citologia , Contagem de Células , Celulose/química , Dano ao DNA , Feminino , Inflamação/induzido quimicamente , Inflamação/patologia , Pulmão/patologia , Camundongos Endogâmicos C57BL , Nanofibras/química
19.
Carbohydr Polym ; 207: 169-179, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599996

RESUMO

The potential use of cellulose nanofibers (CNFs) as a reinforcing agent in banana starch-based nanocomposite films was investigated. CNFs were isolated from banana peel (Musa paradisiaca) by enzymatic hydrolysis. Banana starch-based nanocomposite films were prepared with CNFs using the casting method. CNFs effect on cell viability and on nanocomposite films properties' was investigated. The cytotoxicity of CNFs was assessed on Caco-2 cell line. CNFs were not cytotoxic at 50-2000 µg/mL. However, CNFs above 2000 µg/mL significantly decreased cell viability. Topography analysis showed that the incorporation of CNFs modified the film structure. The nanocomposites exhibited a complex structure due to strong interactions between CNFs and starch matrix, promoting a remarkable improvement on mechanical and water barrier properties, opacity and UV light barrier compared to the control film. CNFs can offer a great potential as reinforcing material for starch-based nanocomposite films, producing a value-added food packaging from a waste material.


Assuntos
Celulose/toxicidade , Frutas/química , Musa/química , Nanocompostos/toxicidade , Nanofibras/toxicidade , Amido/toxicidade , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Celulose/química , Módulo de Elasticidade , Embalagem de Alimentos/instrumentação , Humanos , Hidrólise , Nanocompostos/química , Nanofibras/química , Permeabilidade , Amido/química , Resistência à Tração , Água/química
20.
Carbohydr Polym ; 207: 276-287, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30600010

RESUMO

Hyaluronic acid (HA) is widely investigated due to its high potential for wound dressing applications. The fabrication of biomimetic HA-based scaffolds by electrospinning is thus extensively studied. However, HA is often dissolved in toxic organic solvents to allow the efficient production of electrospun nanofibers. Indeed, although HA is soluble in water, its ionic nature leading to long-range electrostatic interactions and the presence of counter ions induce a dramatic increase of the viscosity of aqueous HA solutions without insuring enough chain entanglements necessary for a stable and efficient electrospinning. In this study, biocompatible insoluble HA-based nanofibers were fabricated by electrospinning in pure water. To this end, poly(vinyl alcohol) (PVA) was added as a carrier polymer and it was found that the addition of hydroxypropyl-ßcyclodextrin (HPßCD) stabilized the process of electrospinning and led to the efficient formation of uniform nanofibrous scaffolds. An in situ crosslinking process of the scaffolds is also proposed, insuring a whole fabrication process without any toxicity. Furthermore, the beneficial presence of HPßCD in the HA-based scaffolds paves the way for wound dressing applications with controlled drug encapsulation-release properties. As a proof of concept, naproxen (NAP), a non-steroidal anti-inflammatory drug was chosen as a model drug. NAP was impregnated into the scaffolds either in aqueous solution or under supercritical CO2. The resulting functional scaffolds showed a regular drug release profile along several days without losing the fibrous structure. This study proposes a simple approach to form stable HA-based nanofibrous scaffolds embedding HPßCD using water as the only solvent, enabling the development of safe functional wound dressings.


Assuntos
Bandagens , Ácido Hialurônico/química , Nanofibras/química , Álcool de Polivinil/química , beta-Ciclodextrinas/química , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Dióxido de Carbono/química , Bovinos , Reagentes para Ligações Cruzadas/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Módulo de Elasticidade , Etildimetilaminopropil Carbodi-Imida/química , Ácido Hialurônico/toxicidade , Cinética , Camundongos , Células NIH 3T3 , Nanofibras/toxicidade , Naproxeno/administração & dosagem , Naproxeno/química , Álcool de Polivinil/toxicidade , Succinimidas/química , Água/química , beta-Ciclodextrinas/toxicidade
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