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1.
Molecules ; 26(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34361575

RESUMO

Glass ionomer cements and resin-based composites are promising materials in restorative dentistry. However, their limited mechanical properties and the risk of bulk/marginal fracture compromise their lifespan. Intensive research has been conducted to understand and develop new materials that can mimic the functional behavior of the oral cavity. Nanotechnological approaches have emerged to treat oral infections and become a part of scaffolds for tissue regeneration. Carbon nanotubes are promising materials to create multifunctional platforms for dental applications. This review provides a comprehensive survey of and information on the status of this state-of-the-art technology and describes the development of glass ionomers reinforced with carbon nanotubes possessing improved mechanical properties. The applications of carbon nanotubes in drug delivery and tissue engineering for healing infections and lesions of the oral cavity are also described. The review concludes with a summary of the current status and presents a vision of future applications of carbon nanotubes in the practice of dentistry.


Assuntos
Portadores de Fármacos , Teste de Materiais , Nanotubos de Carbono/química , Cimentos de Resina , Resinas Acrílicas/química , Resinas Acrílicas/uso terapêutico , Portadores de Fármacos/química , Portadores de Fármacos/uso terapêutico , Humanos , Cimentos de Resina/química , Cimentos de Resina/uso terapêutico , Dióxido de Silício/química , Dióxido de Silício/uso terapêutico , Propriedades de Superfície
2.
Molecules ; 26(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34443508

RESUMO

INTRODUCTION: Chemotherapy with anti-cancer drugs is considered the most common approach for killing cancer cells in the human body. However, some barriers such as toxicity and side effects would limit its usage. In this regard, nano-based drug delivery systems have emerged as cost-effective and efficient for sustained and targeted drug delivery. Nanotubes such as carbon nanotubes (CNT) and boron nitride nanotubes (BNNT) are promising nanocarriers that provide the cargo with a large inner volume for encapsulation. However, understanding the insertion process of the anti-cancer drugs into the nanotubes and demonstrating drug-nanotube interactions starts with theoretical analysis. METHODS: First, interactions parameters of the atoms of 5-FU were quantified from the DREIDING force field. Second, the storage capacity of BNNT (8,8) was simulated to count the number of drugs 5-FU encapsulated inside the cavity of the nanotubes. In terms of the encapsulation process of the one drug 5-FU into nanotubes, it was clarified that the drug 5-FU was more rapidly adsorbed into the cavity of the BNNT compared with the CNT due to the higher van der Waals (vdW) interaction energy between the drug and the BNNT. RESULTS: The obtained values of free energy confirmed that the encapsulation process of the drug inside the CNT and BNNT occurred spontaneously with the free energies of -14 and -25 kcal·mol-1, respectively. DISCUSSION: However, the lower value of the free energy in the system containing the BNNT unraveled more stability of the encapsulated drug inside the cavity of the BNNT comparing the system having CNT. The encapsulation of Fluorouracil (5-FU) anti-cancer chemotherapy drug (commercial name: Adrucil®) into CNT (8,8) and BNNT (8,8) with the length of 20 Å in an aqueous solution was discussed herein applying molecular dynamics (MD) simulation.


Assuntos
Antineoplásicos/farmacologia , Compostos de Boro/química , Composição de Medicamentos , Fluoruracila/farmacologia , Nanotubos de Carbono/química , Estabilidade de Medicamentos , Fluoruracila/química , Conformação Molecular , Simulação de Dinâmica Molecular , Termodinâmica
3.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445500

RESUMO

Cationic surfactants interact with DNA (Deoxyribonucleic acid), forming surfactant-DNA complexes that offer particularly efficient control for encapsulation and release of DNA from DNA gel particles. In the present work, DNA-based particles were prepared using CTAB (Cetyltrimethylammonium bromide) as the cationic surfactant and modified using two different additives: (Multi-Walled Carbon Nanotubes) MWNT or PEG (Poly Ethylene Glycol). The use of both additives to form composites increased the stability of the gel particles. The stability was monitored by the release of DNA and CTAB in different pH solutions. However, not much is known about the influence of pH on DNA-surfactant interaction and the release of DNA and surfactant from gel particles. It was observed that the solubilization of DNA occurs only in very acid media, while that of CTAB does not depend on pH and gets to a plateau after about 8 h. Within 2 h in contact with a pH = 2 solution, about 1% DNA and CTAB was released. Complete destruction for the gel particles was observed in pH = 2 solution after 17 days for PEG and 20 days for MWNT. The composite particles show a considerably enlarged sustained release span compared to the unmodified ones. The dehydration-rehydration studies show that the structure of the composite gel particles, as determined from SAXS (Small-Angle-X-Ray-Scattering) experiments, is similar to that of the unmodified ones. These studies will allow a better knowledge of these particles' formation and evolution in view of possible applications in drug delivery and release.


Assuntos
Cetrimônio/química , DNA/química , Nanotubos de Carbono/química , Tensoativos/química , Géis , Concentração de Íons de Hidrogênio , Polietilenoglicóis , Espalhamento a Baixo Ângulo , Difração de Raios X
4.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361025

RESUMO

In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm-1 to 1415 cm-1 proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm-1 indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL) quenching process. An additional PL quenching process of the POPD-PVDF blends is reported to be induced in the presence of DWNTs. The studies of anisotropic PL highlight a change of the angle of the binding of the PVDF spheres onto the POPD fiber like structures surface from 50.2° to 38° when the carbon nanotubes concentration increases in the POPD-PVDF/DWNTs composites mass up to 2 wt.%.


Assuntos
Dimetilformamida/química , Nanotubos de Carbono/química , Polivinil/química , Anisotropia , Nanocompostos/química , Análise Espectral Raman
5.
Chem Commun (Camb) ; 57(59): 7215-7231, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34223844

RESUMO

Heavy metal ions are one of the main sources of water pollution. Most heavy metal ions are carcinogens that pose a threat to both ecological balance and human health. With the increasing demand for heavy metal detection, electrochemical detection is favorable due to its high sensitivity and efficiency. Here, after discussing the pollution sources and toxicities of Hg(ii), Cd(ii), As(iii), Pb(ii), UO2(ii), Tl(i), Cr(vi), Ag(i), and Cu(ii), we review a variety of recent electrochemical methods for detecting heavy metal ions. Compared with traditional methods, electrochemical methods are portable, fast, and cost-effective, and they can be adapted to various on-site inspection sites. Our review shows that the electrochemical detection of heavy metal ions is a very promising strategy that has attracted widespread attention and can be applied in agriculture, life science, clinical diagnosis, and analysis.


Assuntos
Técnicas Eletroquímicas/métodos , Metais Pesados/análise , Poluentes Químicos da Água/análise , Cádmio/análise , DNA de Cadeia Simples , Eletrodos , Íons/química , Limite de Detecção , Mercúrio/análise , Nanotubos de Carbono/química
6.
Int J Mol Sci ; 22(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299346

RESUMO

Research on carbon-based nanomaterials, such as carbon nanotubes, graphene and its derivatives, nanodiamonds, fullerenes, and other nanosized carbon allotropes, has experienced sharp exponential growth over recent years [...].


Assuntos
Nanoestruturas/química , Nanotubos de Carbono/química , Animais , Fulerenos/química , Grafite/química , Humanos , Nanodiamantes/química , Pontos Quânticos/química
7.
J Chem Phys ; 154(20): 204702, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34241160

RESUMO

The co-involvement of biological molecules and nanomaterials has increasingly come to the fore in modern-day applications. While the "bio-nano" (BN) interface presents physico-chemical characteristics that are manifestly different from those observed in isotropic bulk conditions, the underlying molecular reasons remain little understood; this is especially true of anomalies in interfacial hydration. In this paper, we leverage atomistic simulations to study differential adsorption characteristics of a small protein on the inner (concave) surface of a single-walled carbon nanotube whose diameter exceeds dimensions conducive to single-file water movement. Our findings indicate that the extent of adsorption is decided by the degree of foldedness of the protein conformational substate. Importantly, we find that partially folded substates, but not the natively folded one, induce reorganization of the protein hydration layer into an inner layer water closer to the nanotube axis and an outer layer water in the interstitial space near the nanotube walls. Further analyses reveal sharp dynamical differences between water molecules in the two layers as observed in the onset of increased heterogeneity in rotational relaxation and the enhanced deviation from Fickian behavior. The vibrational density of states reveals that the dynamical distinctions are correlated with differences in crucial bands in the power spectra. The current results set the stage for further systematic studies of various BN interfaces vis-à-vis control of hydration properties.


Assuntos
Simulação de Dinâmica Molecular , Nanotubos de Carbono/química , Proteínas/química , Adsorção
8.
J Chem Phys ; 154(20): 204704, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34241182

RESUMO

Carbon nanotube porins (CNTPs) are biomimetic membrane channels that demonstrate excellent biocompatibility and unique water and ion transport properties. Gating transport in CNTPs with external voltage could increase control over ion flow and selectivity. Herein, we used continuum modeling to probe the parameters that enable and further affect CNTP gating efficiency, including the size and composition of the supporting lipid membrane, slip flow in the carbon nanotube, and the intrinsic electronic properties of the nanotube. Our results show that the optimal gated CNTP device consists of a semiconducting CNTP inserted into a small membrane patch containing an internally conductive layer. Moreover, we demonstrate that the ionic transport modulated by gate voltages is controlled by the charge distribution along the CNTP under the external gate electric potential. The theoretical understanding developed in this study offers valuable guidance for the design of gated CNTP devices for nanofluidic studies, novel biomimetic membranes, and cellular interfaces in the future.


Assuntos
Simulação de Dinâmica Molecular , Nanotubos de Carbono/química , Porinas/química , Transporte de Íons , Eletricidade Estática
9.
Int J Biol Macromol ; 184: 538-550, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34175336

RESUMO

In this study, two kinds of form-stable multifunctional materials with thermal and electrical response (FPCMs: DP-E7U3-CNT, DP-E7T3-CNT) are composed of wood-based honeycomb-like celluloses micro-framework (DP), carbon nanotubes (CNT), erythritol-urea (E7U3) or erythritol-thiourea (E7T3). In FPCMs, DP acts as a skeleton structure to seal E7U3 and E7T3 and provide more pathways for heat conduction. The CNT acts as an extended surface to further improve thermal conductivity. FE-SEM showed that the honeycomb-like pore structure of DP was completely filled with E7U3, E7T3 and CNT. FTIR and XRD analysis show that there is only a combination of physical interactions between the components of FPCMs. DSC curves and thermal conductivity analysis results show that DP-E7U3-1.5CNT and DP-E7T3-1.5CNT with the mass fraction of carbon nanotubes (1.5 wt%) have the highest latent heat values (230.3 J/g, 272.2 J/g) and thermal conductivity (0.9832 W/(m·K), 0.9363 W/(m·K)). Both DP-E7U3-1.5CNT and DP-E7T3-1.5CNT exhibit high latent heat retention and thermal stability after 100 heating-cooling cycles. In addition, DP-E7U3-1.5CNT and DP-E7T3-1.5CNT show excellent performance in light-heat energy conversion-storage, actual latent heat storage and release, thermal and electrical response performance, which make it has great potential to be multifunctional materials with thermal storage sand electrical response.


Assuntos
Celulose/química , Eritritol/química , Tioureia/química , Ureia/química , Condutividade Elétrica , Desenho de Equipamento , Teste de Materiais , Estrutura Molecular , Nanotubos de Carbono/química , Transição de Fase , Condutividade Térmica , Madeira/química
10.
ACS Appl Mater Interfaces ; 13(26): 30295-30305, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34165969

RESUMO

As viruses have been threatening global public health, fast diagnosis has been critical to effective disease management and control. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is now widely used as the gold standard for detecting viruses. Although a multiplex assay is essential for identifying virus types and subtypes, the poor multiplicity of RT-qPCR makes it laborious and time-consuming. In this paper, we describe the development of a multiplex RT-qPCR platform with hydrogel microparticles acting as independent reactors in a single reaction. To build target-specific particles, target-specific primers and probes are integrated into the particles in the form of noncovalent composites with boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs). The thermal release characteristics of DNA, primer, and probe from the composites of primer-BNNT and probe-CNT allow primer and probe to be stored in particles during particle production and to be delivered into the reaction. In addition, BNNT did not absorb but preserved the fluorescent signal, while CNT protected the fluorophore of the probe from the free radicals present during particle production. Bicompartmental primer-incorporated network (bcPIN) particles were designed to harness the distinctive properties of two nanomaterials. The bcPIN particles showed a high RT-qPCR efficiency of over 90% and effective suppression of non-specific reactions. 16-plex RT-qPCR has been achieved simply by recruiting differently coded bcPIN particles for each target. As a proof of concept, multiplex one-step RT-qPCR was successfully demonstrated with a simple reaction protocol.


Assuntos
Hidrogéis/química , Reação em Cadeia da Polimerase Multiplex/métodos , Nanotubos de Carbono/química , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Compostos de Boro/química , Coronavirus/química , Primers do DNA/química , DNA de Cadeia Simples/química , Corantes Fluorescentes/química , Grafite/química , Vírus da Influenza A/química , Vírus da Doença de Newcastle/química , Estudo de Prova de Conceito , RNA Viral/química , Viroses/diagnóstico
11.
ACS Appl Mater Interfaces ; 13(26): 30284-30294, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34170101

RESUMO

The facile and controlled fabrication of homogeneously grafted cationic polymers on carbon nanotubes (CNTs) remains poorly investigated, which further hinders the understanding of interactions between functionalized CNTs with different nucleic acids and the rational design of appropriate gene delivery vehicles. Herein, we describe the controlled grafting of cationic poly(2-dimethylaminoethylmethacrylate) brushes on CNTs via surface-initiated atom transfer radical polymerization integrated with mussel-inspired polydopamine chemistry. The binding of nucleic acids with different brush-CNT hybrids discloses the highly architectural-dependent behavior with dense short brush-coated CNTs displaying the highest binding among all the other hybrids, namely, dense long, sparse long, and sparse short brush-coated CNTs. Additionally, different chemistries of the brush coatings were shown to influence the biocompatibility, cellular uptake, and silencing efficiency in vitro. This platform provides great flexibility for the design of polymer brush-CNT hybrids with precise control over their structure-activity relationship for the rational design of nucleic acid delivery systems.


Assuntos
Antineoplásicos/farmacologia , Portadores de Fármacos/química , Metacrilatos/química , Nanotubos de Carbono/química , Nylons/química , RNA Interferente Pequeno/farmacologia , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/síntese química , Técnicas de Silenciamento de Genes , Inativação Gênica/efeitos dos fármacos , Técnicas de Transferência de Genes , Metacrilatos/síntese química , Camundongos , Nylons/síntese química
12.
ACS Appl Mater Interfaces ; 13(26): 31285-31297, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34170664

RESUMO

Wearable superwettable surfaces with dynamic tunable wettability and self-healability are promising for advanced wearable electronics, whereas have been rarely reported. Herein, a flexible superhydrophobic shape memory film (SSMF) with switchable surface wettability and high strain sensitivity has been conveniently fabricated. The surface topography of the SSMF can be finely adjusted by a reversible stretching (bending)/recovery way, which makes it feasible to control the surface-switchable adhesive superhydrophobicity by simple body movements, demonstrating great advantages in selective droplet manipulation and smart control of droplet movement. Moreover, benefitting from the hierarchical micro/nanostructures and outstanding sensing performance, the flexible SSMFs with good adaptivity and durability can serve as smart wearable sensors attached to human skin to achieve full-range and real-time detection of human motions and intelligent control of Internet of Things. More interestingly, the unique dynamic dewetting property enables the sensors to work in a humid environment or rainy days. Overall, this work successfully integrates dynamic tunable superwettability into design of intelligent wearable electronics with multifunctions. The obtained SSMF-based wearable surface with dynamic dewetting properties reveals great potential in versatile application fields such as liquid-repellent electronics, wearable droplet manipulators, and all-weather intelligent actuators.


Assuntos
Materiais Inteligentes/química , Dispositivos Eletrônicos Vestíveis , Condutividade Elétrica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Monitorização Fisiológica/métodos , Movimento , Nanotubos de Carbono/química , Nanofios/química , Maleabilidade , Poliésteres/química , Poliuretanos/química , Prata/química , Molhabilidade
13.
Molecules ; 26(9)2021 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-34063259

RESUMO

In this study, we combine magnetic solid phase extraction (MSPE), with the screen-printed carbon electrode (SPCE) modified by a molecular imprinted polymer (MIP) for sensitive and selective extraction and electrochemical determination of Rhodamine B in food samples. A magnetic solid phase extraction (MSPE) was carried out using magnetic poly(styrene-co-divinylbenzene) (PS-DVB) and magnetic nanoparticles (MNPs) synthetized on the surface of multiwalled carbon nanotubes (MWCNTs). An MIP was prepared on the surface of MWCNTs in the presence of titanium oxide nanoparticles (TiO2NPs) modifying the SPCE for the rapid electrochemical detection of Rhodamine B. The MIPs synthesis was optimized by varying the activated titanium oxide (TiO2) and multiwalled carbon nanotubes (MWCNTs) amounts. The MSPE and electrochemical detection conditions were optimized as well. The present method exhibited good selectivity, high sensitivity, and good reproducibility towards the determination of Rhodamine B, making it a suitable method for the determination of Rhodamine B in food samples.


Assuntos
Análise de Alimentos/métodos , Nanotubos de Carbono/química , Polímeros/química , Rodaminas/análise , Adsorção , Técnicas Eletroquímicas , Eletrodos , Concentração de Íons de Hidrogênio , Limite de Detecção , Magnetismo , Microscopia Eletrônica de Varredura , Impressão Molecular , Polímeros Molecularmente Impressos , Poliestirenos/química , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade , Extração em Fase Sólida/métodos , Análise Espectral Raman , Titânio/química
14.
Int J Biol Macromol ; 185: 66-76, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34146560

RESUMO

In this study calcium alginate-multiwall carbon nanotube (CA/MWCNTs) was synthesized using (CA) calcium alginate and multiwall carbon nanotube (MWCNTs), and its efficiency in adsorption of 4-Nitrophenol (4-NP) in aqueous solution was studied. The structure and properties of the synthesized adsorbent were investigated using scanning electron microscope (SEM), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The experimental design was performed using Box-Behnken design (BBD) in which variables pH, CA/MWCNTs, and temperature were examined. The results of the effect of temperature on the removal efficiency of 4-NP showed that the adsorption efficiency decreases with increasing temperature. The results of nonlinear isotherm and kinetics models showed that Langmuir and pseudo-second-order models were more consistent than other models. The maximum adsorption capacity of 4-NP in this study by CA, MWCNTs, and CA/MWCNTs was 136, 168.4, and 58.8 mg/g, respectively, which indicates that the use of MWCNTs on CA could increase the adsorption capacity. The results of reuse of the synthesized adsorbent at 4-NP removal also showed that after 5 reuse of the adsorbent, the removal of 4-NP using CA/MWCNTs is reduced by about 10%, which shows that the synthesized adsorbent can be used several times to adsorb contaminants without significant reduction in the efficiency.


Assuntos
Alginatos/síntese química , Nanotubos de Carbono/química , Nitrofenóis/química , Adsorção , Alginatos/química , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
15.
ACS Appl Mater Interfaces ; 13(24): 28010-28016, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34101422

RESUMO

The broad applications of implantable glucose biofuel cells (GBFCs) have become very attractive in biomedical sciences. The key challenge of GBFCs is eliminating the inevitable product H2O2 generated from the oxidation of glucose when glucose oxidase (GOx) is used as a catalyst while improving the performance of GBFCs. In this work, the cascade electrocatalyst, RBCs@NPDA was obtained through the in situ polymerization of dopamine to form nanopolydopamine (NPDA) on the surface of red blood cells (RBCs). The RBCs@NPDA can catalyze both fuels of H2O2 and O2, so as to generate a high cathodic current (0.414 mA cm-2). Furthermore, when RBCs@NPDA was used as a cathodic catalyst in the membraneless GBFC, it exhibited the cascade catalytic activity in the reduction of O2-H2O2 and minimized the damage to RBCs caused by the high concentration of H2O2. The mechanism research indicates that RBCs@NPDA integrates the property of NPDA and RBCs. Specifically, NPDA plays a catalase-like role in catalyzing the decomposition of H2O2, while RBCs play a laccase-like role in electrocatalyzing the O2 reduction reaction. This work offers the cascade catalyst for improving the performance of implantable GBFC and presents a strategy for constructing catalysts using living cells and nanomaterials to replace deformable and unstable enzymes in other biofuel cells.


Assuntos
Fontes de Energia Bioelétrica , Eritrócitos/metabolismo , Glucose/metabolismo , Indóis/química , Polímeros/química , Animais , Catálise , Eletrodos , Eritrócitos/química , Glucose/química , Glucose Oxidase/química , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Nanotubos de Carbono/química , Oxirredução , Oxigênio/química , Oxigênio/metabolismo , Suínos
16.
Int J Mol Sci ; 22(9)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34063012

RESUMO

Single-walled carbon nanotubes (SWCNTs) emerge as promising novel carbon-based nanoparticles for use in biomedicine, pharmacology and precision agriculture. They were shown to penetrate cell walls and membranes and to physically interact and exchange electrons with photosynthetic complexes in vitro. Here, for the first time, we studied the concentration-dependent effect of foliar application of copolymer-grafted SWCNTs on the structural and functional characteristics of intact pea plants. The lowest used concentration of 10 mg L-1 did not cause any harmful effects on the studied leaf characteristics, while abundant epicuticular wax generation on both leaf surfaces was observed after 300 mg L-1 treatment. Swelling of both the granal and the stromal regions of thylakoid membranes was detected after application of 100 mg L-1 and was most pronounced after 300 mg L-1. Higher SWCNT doses lead to impaired photosynthesis in terms of lower proton motive force generation, slower generation of non-photochemical quenching and reduced zeaxanthin content; however, the photosystem II function was largely preserved. Our results clearly indicate that SWCNTs affect the photosynthetic apparatus in a concentration-dependent manner. Low doses (10 mg L-1) of SWCNTs appear to be a safe suitable object for future development of nanocarriers for substances that are beneficial for plant growth.


Assuntos
Cloroplastos/ultraestrutura , Nanotubos de Carbono/química , Ervilhas/fisiologia , Ervilhas/ultraestrutura , Fotossíntese , Folhas de Planta/anatomia & histologia , Dióxido de Carbono/metabolismo , Carotenoides/metabolismo , Permeabilidade da Membrana Celular , Clorofila/metabolismo , Fluorescência , Nanotubos de Carbono/ultraestrutura , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/ultraestrutura , Prótons , Tilacoides/metabolismo , Fatores de Tempo , Xantofilas/metabolismo
17.
Molecules ; 26(10)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34068851

RESUMO

Solubilization of carbon nanotubes (CNTs) is a fundamental technique for the use of CNTs and their conjugates as nanodevices and nanobiodevices. In this work, we demonstrate the preparation of CNT suspensions with "green" detergents made from coconuts and bamboo as fundamental research in CNT nanotechnology. Single-walled CNTs (SWNTs) with a few carboxylic acid groups (3-5%) and pristine multi-walled CNTs (MWNTs) were mixed in each detergent solution and sonicated with a bath-type sonicator. The prepared suspensions were characterized using absorbance spectroscopy, scanning electron microscopy, and Raman spectroscopy. Among the eight combinations of CNTs and detergents (two types of CNTs and four detergents, including sodium dodecyl sulfate (SDS) as the standard), SWNTs/MWNTs were well dispersed in all combinations except the combination of the MWNTs and the bamboo detergent. The stability of the suspensions prepared with coconut detergents was better than that prepared with SDS. Because the efficiency of the bamboo detergents against the MWNTs differed significantly from that against the SWNTs, the natural detergent might be useful for separating CNTs. Our results revealed that the use of the "green" detergents had the advantage of dispersing CNTs as well as SDS.


Assuntos
Detergentes/química , Nanotubos de Carbono/química , Centrifugação , Nanotubos de Carbono/ultraestrutura , Suspensões
18.
Biosensors (Basel) ; 11(6)2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34072661

RESUMO

This work reports the design of a novel plastic antibody for cystatin C (Cys-C), an acute kidney injury biomarker, and its application in point-of-care (PoC) testing. The synthetic antibody was obtained by tailoring a molecularly imprinted polymer (MIP) on a carbon screen-printed electrode (SPE). The MIP was obtained by electropolymerizing pyrrole (Py) with carboxylated Py (Py-COOH) in the presence of Cys-C and multiwall carbon nanotubes (MWCNTs). Cys-C was removed from the molecularly imprinted poly(Py) matrix (MPPy) by urea treatment. As a control, a non-imprinted poly(Py) matrix (NPPy) was obtained by the same procedure, but without Cys-C. The assembly of the MIP material was evaluated in situ by Raman spectroscopy and the binding ability of Cys-C was evaluated by the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) electrochemical techniques. The MIP sensor responses were measured by the DPV anodic peaks obtained in the presence of ferro/ferricyanide. The peak currents decreased linearly from 0.5 to 20.0 ng/mL of Cys-C at each 20 min successive incubation and a limit of detection below 0.5 ng/mL was obtained at pH 6.0. The MPPy/SPE was used to analyze Cys-C in spiked serum samples, showing recoveries <3%. This device showed promising features in terms of simplicity, cost and sensitivity for acute kidney injury diagnosis at the point of care.


Assuntos
Técnicas Biossensoriais , Cistatina C/análise , Nanotubos de Carbono/química , Polímeros/química , Pirróis/química , Espectroscopia Dielétrica , Técnicas Eletroquímicas , Eletrodos , Humanos , Limite de Detecção , Impressão Molecular , Plásticos
19.
ACS Appl Mater Interfaces ; 13(18): 21007-21017, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33934601

RESUMO

In this study, regenerated silk (RS) obtained from Bombyx Mori cocoons is compounded with carboxyl-functionalized carbon nanotubes (f-CNTs) in an aqueous environment for the fabrication of functional bio-adhesives. Molecular interactions between RS and carboxyl groups of CNTs result in structural increase of the ß-sheet formation, obtaining a resistant adhesive suitable for a wet biological substrate. Moreover, the functionalization of CNTs promotes their dispersion in RS, thus enabling the production of films with controlled electrical conductivity. The practical utility of such a property is demonstrated through the fabrication of a piezoelectric device implanted in a rat to monitor the breathing in vivo and to be used as a self-powered system. Finally, RS/f-CNTs were used as a printable biomaterial ink to three dimensionally print bilayer hollow tubular structures composed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and RS. Initial tests carried out by seeding and growing human skin fibroblasts demonstrated that the 3D printed bilayer hollow cylindrical structures offer a suitable surface for the seeded cells to attach and proliferate. In general, the herein proposed RS/f-CNT composite serves as a versatile material for solvent-free dispersion processing and 3D printing, thus paving a new approach to prepare multifunctional materials with potential applications of great interest in sealing biological substrates and implantable devices for regenerative medicine.


Assuntos
Adesivos/química , Tinta , Nanotubos de Carbono/química , Impressão Tridimensional , Seda/química , Animais , Materiais Biocompatíveis/química , Proliferação de Células , Humanos , Ratos , Tecidos Suporte
20.
ACS Appl Mater Interfaces ; 13(21): 24505-24523, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34027653

RESUMO

Polyacrylamide-based hydrogels are widely used as potential candidates for cartilage replacement. However, their bioapplicability is sternly hampered due to their limited mechanical strength and puncture resistance. In the present work, the strength of polyacrylamide (PAM) hydrogels was increased using titanium oxide (TiO2) and carbon nanotubes (CNTs) separately and a combination of TiO2 with CNTs in a PAM matrix, which was interlinked by the bonding between nanoparticles and polymers with the deployment of density functional theory (DFT) approach. The synergistic effect and strong interfacial bonding of TiO2 and CNT nanoparticles with PAM are attributed to high compressive strength, elastic modulus (>0.43 and 2.340 MPa, respectively), and puncture resistance (estimated using the needle insertion test) for the PAM-TiO2-CNT hydrogel. The PAM-TiO2-CNT composite hydrogel revealed a significant self-healing phenomenon along with a sign toward the bioactivity and cytocompatibility by forming the apatite crystals in simulated body fluid as well as showing a cell viability of ∼99%, respectively. Furthermore, for new insights on interfacial bonding and structural and electronic features involved in the hydrogels, DFT was used. The PAM-TiO2-CNT composite model, constructed by two interfaces (PAM-TiO2 and PAM-CNT), was stabilized by H-bonding and van der Waals-type interactions. Employing the NCI plot, HOMO-LUMO gap, and natural population analysis tools, the PAM-TiO2-CNT composite has been found to be most stable. Therefore, the prepared polyacrylamide hydrogels in combination with the TiO2 and CNT can be a remarkable nanocomposite hydrogel for cartilage repair applications.


Assuntos
Cartilagem/crescimento & desenvolvimento , Hidrogéis/química , Nanocompostos/química , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Teoria da Densidade Funcional , Interações Hidrofóbicas e Hidrofílicas , Cinética , Teste de Materiais , Camundongos , Microscopia Eletrônica de Varredura , Nanotubos de Carbono/química , Espectroscopia de Infravermelho com Transformada de Fourier , Titânio/química , Difração de Raios X
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