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1.
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
2.
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
3.
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
4.
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
5.
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
7.
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
8.
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
9.
Mater Sci Eng C Mater Biol Appl ; 97: 602-612, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30678947

RESUMO

Biocompatible scaffolds have been used to promote cellular growth and proliferation in order to develop grafts, prostheses, artificial skins and cartilage. Electrospinning is widely studied as a method capable of producing nanofibers which enables cell attachment and proliferation, generating a functional scaffold that is suitable for many types of organs or tissues. In this study, electrospinning was used to obtain core-shell and monolithic fibers from the biocompatible poly (lactic acid) and poly (vinyl alcohol) polymers. The main purpose of this work is to produce core-shell nanofiber based scaffolds that works as a sustained delivery vehicle for BMP-2 protein, allowing those fibers to be used in the recovery of alveolar bone tissue without further bone surgery. Then, polymer nanofibers were manufactured by optimizing process parameters of coaxial electrospinning with emphasis on the most relevant ones: voltage, internal and external flows in an attempt to correlate fibers properties with protein releasing abilities. All nanofibers were characterized according to its morphology, thermal behaviour, crystallinity and release profile. For the release tests, bovine albumin was added into internal fiber for future periodontal restorage application. Obtained results demonstrate that fibers were formed with diameters up to 250 nm. According to electronic microscopy images, one could observe surface of nanofibers, thickness and core-shell morphology confirmed. X-ray diffraction analysis and contact angle tests showed fibers with low crystal degree and low hydrophobicity. Nanofibers structure affected in vitro release model tests and consequently the cellular assays.


Assuntos
Materiais Biocompatíveis/química , Proteína Morfogenética Óssea 2/química , Nanofibras/química , Poliésteres/química , Álcool de Polivinil/química , Regeneração , Fator de Crescimento Transformador beta/química , Animais , Materiais Biocompatíveis/farmacologia , Proteína Morfogenética Óssea 2/farmacologia , Osso e Ossos/fisiologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Humanos , Camundongos , Nanofibras/toxicidade , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologia , Regeneração/efeitos dos fármacos , Engenharia Tecidual , Fator de Crescimento Transformador beta/farmacologia
10.
Mater Sci Eng C Mater Biol Appl ; 97: 966-977, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30678985

RESUMO

Cancer is one of the most dangerous diseases which had been encountering the human beings since last several decades. In 2018, according to national cancer institute, about 609,640 people are expected to die from cancer and about 1,735,350 new patients are expected to be diagnosed with this lethal disease. Nanotechnology has played a significant role in almost every field of life including medical sciences. A controlled and sustained release of drug is much desirable and beneficial when one has to deal with cancer as such drugs do also harm to normal cells. General anticancer drugs, used in chemotherapy, are associated with severe side effects due to high dosage requirements. With the help of nanotechnology, great outcomes for instance, anticancer drug loaded nanofibers, have been achieved in cancer therapy requiring less amount of drug as drug is preserved in these nanofibers for prolonged time. Electrospun nanofibers have very large surface area, controllable pore size and tunable drug release profiles which make these nanofibers promising candidates in medical field. To promote green synthesis of nanofibers, researchers have also used water as an effective solvent instead of toxic chemicals and reduced the environmental burden. This green approach of nanofibers fabrication has a good potential to be used in regenerative medicine including cancer therapy because of environmental friendly characteristics. Though, there are numerous research reports available on the application of nanofibers. To the best of our knowledge, no review paper has been reported solely on the applications of nanofibers for cancer therapy. Therefore, this review paper describes some electrospun nanofibers of pure polymer, blends and block copolymers that have been reported for successful cancer therapy.


Assuntos
Antineoplásicos/uso terapêutico , Nanofibras/química , Neoplasias/tratamento farmacológico , Polímeros/química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Humanos , Nanofibras/toxicidade , Neoplasias/patologia , Peptídeos/química
11.
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
12.
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
13.
Mater Sci Eng C Mater Biol Appl ; 91: 502-511, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30033282

RESUMO

Electrospinning is a versatile and cost-effective method for fabricating nanofibers of different materials suitable for various applications. In this work, silica nanofibers have produced using the electrospinning method followed by the heat treatment. To fabricate silica nanofibers, polyvinylpyrrolidone (PVP), tetraethyl orthosilicate (TEOS) and Butanol were used to prepare the dope solutions. The optimized concentration for polymer in the dope solutions was then measured at 0.1 g/ml. The electrospinning process was conducted under the optimum circumstances of voltage, injection flow, tip to collector distance, ambient temperature (25 °C) and the humidity of 47%. Having conducted the thermal analysis (TG/DTA), electrospun fibers were exposed to thermal analysis in three different temperatures of 500, 700, and 1000 °C for 5 h. Following this, the morphology and the diameter of the fibers, as well as the chemical composition and the crystallinity of each sample were analyzed using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR), and x-ray diffractometry (XRD), respectively. The noteworthy conditions of 700 °C and 5 h of heat treatment (i.e., calcination) have provided satisfactory results in terms of silica nanofibers morphology and fibers; diameter, i.e., 110 and 600 nm. For cytotoxicity assay, murine fibroblast cells L929 were cultured on a mat of as-spun silica nanofibers. After 24 h and 48 h cultivation time, samples showed no evidence of cytotoxicity effect, which will be a promising result.


Assuntos
Nanofibras/química , Nanotecnologia/métodos , Dióxido de Silício/química , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Análise Diferencial Térmica , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/ultraestrutura , Camundongos , Nanofibras/toxicidade , Nanofibras/ultraestrutura , Povidona/química , Reologia , Dióxido de Silício/toxicidade , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Termogravimetria , Difração de Raios X
14.
J Agric Food Chem ; 66(24): 6219-6226, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29877707

RESUMO

In this study, chitosan/poly(ethylene oxide) (PEO)/lauric arginate (LAE) composite nanofibrous films were fabricated via electrospinning. The addition of LAE did not change the physical properties of chitosan/PEO in acetic aqueous solutions, but increased the fluorescent intensity of chitosan by electrostatic interactions, resulting in uniform and bead-free nanofibers with an average diameter of 150 nm. The Fourier transform infrared spectra and thermal analysis indicated that the LAE molecules were homogeneously dispersed within the chitosan/PEO nanofibers. The formation of electrostatic and hydrogen bonding interactions induced by the LAE addition changed the inter- and intramolecular interactions between PEO and chitosan and further affected the mobility of the polymer molecules, leading to the increased crystallinity and decreased melting point. The hydrophilicity of the nanofibrous films was significantly increased by the incorporation of LAE, as indicated by the decreasing water contact angle from 39° to 10°. Meanwhile, the chitosan/PEO/LAE nanofibrous films showed LAE concentration dependent antimicrobial activity against Escherichia coli and Staphylococcus aureus, suggesting enhanced antimicrobial activity. The fluorescent staining experiments demonstrated that the antimicrobial mechanism of the nanofibrous films was cell membrane damage.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Arginina/análogos & derivados , Embalagem de Alimentos/instrumentação , Nanofibras/química , Polietilenoglicóis/farmacologia , Antibacterianos/química , Arginina/síntese química , Arginina/química , Arginina/farmacologia , Quitosana/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Interações Hidrofóbicas e Hidrofílicas , Nanofibras/toxicidade , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Polímeros/síntese química , Polímeros/química , Polímeros/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Eletricidade Estática
15.
Part Fibre Toxicol ; 15(1): 22, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769147

RESUMO

BACKGROUND: Commercial use of carbon nanotubes and nanofibers (CNT/F) in composites and electronics is increasing; however, little is known about health effects among workers. We conducted a cross-sectional study among 108 workers at 12 U.S. CNT/F facilities. We evaluated chest symptoms or respiratory allergies since starting work with CNT/F, lung function, resting blood pressure (BP), resting heart rate (RHR), and complete blood count (CBC) components. METHODS: We conducted multi-day, full-shift sampling to measure background-corrected elemental carbon (EC) and CNT/F structure count concentrations, and collected induced sputum to measure CNT/F in the respiratory tract. We measured (nonspecific) fine and ultrafine particulate matter mass and count concentrations. Concurrently, we conducted physical examinations, BP measurement, and spirometry, and collected whole blood. We evaluated associations between exposures and health measures, adjusting for confounders related to lifestyle and other occupational exposures. RESULTS: CNT/F air concentrations were generally low, while 18% of participants had evidence of CNT/F in sputum. Respiratory allergy development was positively associated with inhalable EC (p=0.040) and number of years worked with CNT/F (p=0.008). No exposures were associated with spirometry-based metrics or pulmonary symptoms, nor were CNT/F-specific metrics related to BP or most CBC components. Systolic BP was positively associated with fine particulate matter (p-values: 0.015-0.054). RHR was positively associated with EC, at both the respirable (p=0.0074) and inhalable (p=0.0026) size fractions. Hematocrit was positively associated with the log of CNT/F structure counts (p=0.043). CONCLUSIONS: Most health measures were not associated with CNT/F. The positive associations between CNT/F exposure and respiratory allergies, RHR, and hematocrit counts may not be causal and require examination in other studies.


Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Sistema Cardiovascular/efeitos dos fármacos , Leucócitos/efeitos dos fármacos , Nanofibras/toxicidade , Nanotubos de Carbono/toxicidade , Exposição Ocupacional/análise , Sistema Respiratório/efeitos dos fármacos , Adulto , Idoso , Poluentes Ocupacionais do Ar/análise , Poluentes Ocupacionais do Ar/farmacocinética , Biomarcadores/sangue , Contagem de Células Sanguíneas , Estudos Transversais , Feminino , Humanos , Leucócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Nanofibras/análise , Nanotubos de Carbono/análise , Testes de Função Respiratória , Escarro/química , Inquéritos e Questionários
16.
Artigo em Inglês | MEDLINE | ID: mdl-29775400

RESUMO

Tin dioxide nanofibers (SnDNFs) are small fibers that have many applications. Tin dioxide nanofibers can be used in cosmetics, solar cells, toxic gas release sensors, and air pollution control. To date there have been few studies on the cytotoxicity of SnDNFs. The goal of this research is to determine if electrospun SnDNFs are toxic in a lung cancer cell line (A549). Considering the nano-scale size of the fibers, they can easily be inhaled and enter the pulmonary system and cause toxic effects in the lung. Occupational exposure to SnDNFs has been linked to pulmonary disease, making the A549 cell line important in this study. Nanofiber toxicity can vary based upon the characteristics of the fibers. Smaller nanofibers have been shown to have more toxic effects than their larger counterparts. The synthesized SnDNFs were characterized using SEM, Raman spectroscopy, and powder X-ray diffractometer (PXRD). SEM images showed the fibers to be 200-300 nm in diameter. Raman spectroscopy and PXRD indicated that the fibers were in the rutile phase. After quantifying the SnDNFs, the fibers were introduced to A549 cells at concentrations ranging from 0.02-500 µg mL-1 and incubated at 37°C. These cells were quantified with the MTT assay to measure cell proliferation (IC50 = 0.02 mg mL-1), while lactate dehydrogenase (LDH) leakage was used to determine cytotoxicity, and apoptosis assays to assess the mechanism of cell death. Increasing concentration of SnDNF generated a consequential decrease in cell proliferation and viability. The percent cytotoxicity of SnDNF was not significantly changed at the various concentrations and time frames. In order to gain additional insight about the mechanism of cytotoxicity of SnDNFs, genes with links to inflammation and apoptosis were evaluated and found to be over-expressed in treated cells. At the concentrations of SnDNF examined, SnDNF was mildly toxic to the A549 cells.


Assuntos
Apoptose/efeitos dos fármacos , Nanofibras/toxicidade , Compostos de Estanho/toxicidade , Células A549 , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Humanos , Teste de Materiais , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/análise , Testes de Toxicidade
17.
Chem Commun (Camb) ; 54(37): 4673-4676, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29675529

RESUMO

A novel forky peptide was designed and synthesized. The peptide self-assembled into supramolecular hydrogels triggered by zinc ions (ZIs). The hydrogels were designed for a drug delivery system (DDS), loaded with docetaxel and applied for the therapy of prostate cancer. In this research, we have discussed the response mechanism and evaluated the anticancer effect of the DDS.


Assuntos
Antineoplásicos/farmacologia , Portadores de Fármacos/química , Oligopeptídeos/química , Neoplasias da Próstata/tratamento farmacológico , Taxoides/farmacologia , Zinco/química , Antineoplásicos/química , Linhagem Celular Tumoral , Docetaxel , Portadores de Fármacos/toxicidade , Liberação Controlada de Fármacos , Humanos , Hidrogéis/química , Hidrogéis/toxicidade , Masculino , Nanofibras/química , Nanofibras/toxicidade , Oligopeptídeos/síntese química , Oligopeptídeos/toxicidade , Multimerização Proteica/efeitos dos fármacos , Taxoides/química , Substâncias Viscoelásticas/química , Substâncias Viscoelásticas/toxicidade
18.
Toxicol Lett ; 291: 173-183, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29679712

RESUMO

Cellulose nanofibrils (CNF) are manufactured nanofibres that hold impressive expectations in forest, food, pharmaceutical, and biomedical industries. CNF production and applications are leading to an increased human exposure and thereby it is of utmost importance to assess its safety to health. In this study, we screened the cytotoxic, immunotoxic and genotoxic effects of a CNF produced by TEMPO-mediated oxidation of an industrial bleached Eucalyptus globulus kraft pulp on a co-culture of lung epithelial alveolar (A549) cells and monocyte-derived macrophages (THP-1 cells). The results indicated that low CNF concentrations can stimulate A549 cells proliferation, whereas higher concentrations are moderately toxic. Moreover, no proinflammatory cytokine IL-1ß was detected in the co-culture medium suggesting no immunotoxicity. Although CNF treatment did not induce sizable levels of DNA damage in A549 cells, it leaded to micronuclei formation at 1.5 and 3 µg/cm2. These findings suggest that this type of CNF is genotoxic through aneugenic or clastogenic mechanisms. Noteworthy, cell overgrowth and genotoxicity, which are events relevant for cell malignant transformation, were observed at low CNF concentration levels, which are more realistic and relevant for human exposure, e.g., in occupational settings.


Assuntos
Celulose/toxicidade , Células Epiteliais/efeitos dos fármacos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Nanofibras/toxicidade , Células A549 , Sobrevivência Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Técnicas de Cocultura , Ensaio Cometa , Dano ao DNA , Eucalyptus/química , Humanos , Interleucina-1beta/efeitos dos fármacos , Interleucina-1beta/metabolismo , Testes para Micronúcleos , Testes de Mutagenicidade
19.
Mater Sci Eng C Mater Biol Appl ; 84: 123-129, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29519421

RESUMO

In this study, a poly (octanediol citrate) (POC)/bioglass nanofiber composite was prepared by incorporating electrospun bioglass nanofiber (5, 10, and 15% w/w) into the POC matrix. The bioglass nanofiber interacted with POC via physical adsorption and carboxylate formation, and thus the addition of bioglass nanofiber increased the glass transition temperature, modulus and strength; however, decreased the elongation at break when the amount of bioglass nanofiber was up to 15% w/w. Compared to the pure POC elastomer, the POC/bioglass nanofiber composites exhibited accelerated stimulation to the mouse bone marrow mesenchymal stem cells (MSCs) on the cell growth and osteogenic differentiation. The level of alkaline phosphatase activity and cellular mineralization was higher for the POC/bioglass composites compared to the pure POC and increased with increasing amount of bioglass nanofiber within 14-day culture period. The gene expression of collagen type I and osteocalcin was also proportional to the bioglass nanofiber content of the composite. The results of this study showed that the composite of POC/bioglass nanofiber supported the osteogenic differentiation of MSCs and would be an excellent biomaterial candidate for applications in bone regeneration.


Assuntos
Cerâmica/química , Nanofibras/química , Polímeros/química , Fosfatase Alcalina/metabolismo , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Células da Medula Óssea/citologia , Cálcio/metabolismo , Varredura Diferencial de Calorimetria , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo I/metabolismo , Módulo de Elasticidade , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Nanofibras/toxicidade , Osteocalcina/metabolismo , Osteogênese/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Mater Sci Eng C Mater Biol Appl ; 84: 80-89, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29519446

RESUMO

Long-term culture, passage and proliferation of human mesenchymal stem cells (hMSCs) cause loss of their stemness properties including self-renewal and multipotency. By optimizing the MSCs environment in vitro, maintaining the stemness state and better controlling the cell fate might be possible. We have recently reported the significant effects of bioactive Tat protein-derived peptide named R-peptide on hMSC adhesion, morphology and proliferation, which has demonstrated R-peptide enhanced MSC early adhesion and proliferation in comparison to other bioactive molecules including RGD peptide, fibronectin and collagen. In this study, R-peptide was used to evaluate stemness properties of MSCs after long-term passaging. R-peptide conjugated poly caprolactone (PCL) nanofibrous scaffold and unmodified nanofibrous scaffold were used to study the impact of R-peptide modified PCL nanofibers and PCL nanofibers on cell behavior. The results showed early formation of focal adhesion (FA) complex on R-peptide modified scaffolds at 30min after cell seeding. The rate of cell proliferation was significantly increased due to presence of R-peptide, and the MSCs marker analyses using flow cytometry and immunocytochemistry staining proved the ability of R-peptide to maintain mesenchymal stem cell properties (high proliferation, expression of multipotent markers and differentiation capacity) even after long-term passage culturing. Accordingly, our (The) results concluded that bioactive R-peptide in combination with nanofibrous scaffold can mimic the native ECM comprising micro/nano architecture and biochemical molecules in a best way. The designed scaffold can link extracellular matrix (ECM) to nucleus via formation of FA and organization of cytoskeleton, causing fast and strong attachment of MSCs and allowing integrin-mediated signaling to start.


Assuntos
Nanofibras/química , Oligopeptídeos/química , Células da Medula Óssea/citologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Matriz Extracelular/metabolismo , Adesões Focais/efeitos dos fármacos , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Microscopia Confocal , Nanofibras/toxicidade , Espectroscopia Fotoeletrônica , Poliésteres/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tecidos Suporte/química
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