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1.
Crit Rev Food Sci Nutr ; : 1-27, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35943179

RESUMO

The natural bioactive or nutraceuticals exhibit several health benefits, including anti-inflammatory, anti-cancer, metal chelation, antiviral, and antimicrobial activity. The inherent limitation of nutraceuticals or bioactive ligand(s) in terms of poor pharmacokinetic and other physicochemical properties affects their overall therapeutic efficiency. The excess of iron in the physiological compartments and its varying dynamic oxidation state [Fe(II) and Fe(III)] precipitates various clinical conditions such as non-transferrin bound iron (NTBI), labile iron pool (LIP), ferroptosis, cancer, etc. Though several natural bioactive ligands are proposed to chelate iron, the efficiency of bioactive ligands is limited due to poor bioavailability, denticity, and other related physicochemical properties. The present review provides insight into the relevance of studying the dynamic oxidation state of iron(II) and iron(III) in the physiological compartments and its clinical significance for selecting diagnostics and therapeutic regimes. We suggested a three-pronged approach, i.e., diagnosis, selection of therapeutic regime (natural bioactive), and integration of novel drug delivery systems (NDDS) or nanotechnology-based principles. This systematic approach improves the overall therapeutic efficiency of natural iron chelators to manage iron overload-related clinical conditions.

2.
Biomacromolecules ; 19(4): 1340-1346, 2018 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-29489343

RESUMO

Chitosan derived from chitin is one of the most abundant naturally occurring biocompatible polymers obtained from fungi and arthropods. In this work, we report the enhancement in the bactericidal efficacy of CHI in the presence of a sharp nanotopography. High-aspect ratio nanostructured surface (NSS) was fabricated using a single-step deep reactive ion etching technique (DRIE). Post fabrication, CHI coating was carried out using a layer-by-layer (LBL) dip coating process on the flat and nanostructured surfaces. Antibacterial efficacy of the flat silicon surface coated with CHI (Si_CHI) and NSS coated with CHI (NSS_CHI) was tested against both Gram-negative (G-ve) bacteria E. coli and Gram-positive (G+ve) bacteria S. aureus. NSS_CHI exhibited superior antibacterial property against G-ve and G+ve microbes as compared with Si_CHI and NSS substrates. Scanning electron microscopy (SEM) and fluorescence microscopy were used to study the morphology and viability of the bacteria on all the surfaces. Also, biofilm quantification was carried out on all the engineered surfaces for both E. coli and S. aureus using crystal violet (CV) staining. NSS_CHI was found to have the minimum biofilm formation on its surface exhibiting its superior antibacterial property. This study shows that the antibacterial and antibiofilm efficiency of CHI can be augmented by combining it with a sharp nanotopography.


Assuntos
Antibacterianos/química , Biofilmes/efeitos dos fármacos , Quitosana/química , Nanoestruturas/química , Antibacterianos/farmacologia , Quitosana/farmacologia , Escherichia coli/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
3.
Environ Toxicol ; 32(5): 1617-1627, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28101988

RESUMO

The present study deals with the toxicity assessment of two differently synthesized zero valent iron nanoparticles (nZVI, chemical and biological) as well as Fe2+ ions on Artemia salina at three different initial concentrations of 1, 10, and 100 mg/L of these particles. The assessment was done till 96 h at time intervals of 24 h. EC50 value was calculated to evaluate the 50% mortality of Artemia salina at all exposure time durations. Between chemically and biologically synthesized nZVI nanoparticles, insignificant differences in the level of mortality were demonstrated. At even 24 h, Fe2+ ion imparted complete lethality at the highest exposure concentration (100 mg/L). To understand intracellular oxidative stress because of zero valent iron nanoparticles, ROS estimation, SOD activity, GSH activity, and catalase activity was performed which demonstrated that ionic form of iron is quite lethal at high concentrations as compared with the same concentration of nZVI exposure. Lower concentrations of nZVI were more toxic as compared with the ionic form and was in order of CS-nZVI > BS-nZVI > Fe2+ . Cell membrane damage and bio-uptake of nanoparticles were also evaluated for all three concentrations of BS-nZVI, CS-nZVI, and Fe2+ using adult Artemia salina in marine water; both of which supported the observations made in toxicity assessment. This study can be further explored to exploit Artemia salina as a model organism and a biomarker in an nZVI prone aquatic system to detect toxic levels of these nanoparticles. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1617-1627, 2017.


Assuntos
Artemia/efeitos dos fármacos , Ferro/toxicidade , Nanopartículas Metálicas/toxicidade , Animais , Artemia/fisiologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Íons , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Análise de Sobrevida , Testes de Toxicidade
4.
Langmuir ; 32(22): 5460-7, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27175850

RESUMO

The measurement of molecular transport within polymer films yields information about the internal structural organization of the films and is useful in applications such as the design of polymeric capsules for drug delivery. Layer-by-layer assembly of polyelectrolyte multilayer films has been widely used in such applications where the multilayer structure often exhibits anisotropic transport resulting in different diffusivities in the lateral (parallel to the film) and transverse (normal to the film) directions. Although lateral transport can be probed using techniques such as fluorescence recovery after photobleaching (FRAP), it cannot be applied to probing transverse diffusivity in polymer films smaller than the diffraction limit of light. Here we present a technique to probe the transport of molecules tagged with fluorphores in polymer films thinner than the optical diffraction limit using the modulation of fluorescence emission depending on the distance of the tagged molecules from a metal surface. We have used this technique to probe the diffusion of proteins biotin and bovine serum albumin (BSA) in polyelectrolyte multilayer films. We also studied the interdiffusion of chains in multilayer films using this technique. We observed a 3 order of magnitude increase in interdiffusion as a function of the ionic strength of the medium. This technique, along with FRAP, will be useful in studying anisotropic transport in polymer films, even those thinner than the diffraction limit, because the signal in this technique arises only from transverse and not lateral transport. Finally, this technique is also applicable to studying the diffusion of chromophore-labeled species within a polymer film. We demonstrate this aspect by measuring the transverse diffusion of methylene blue in the PAH-PAA multilayer system.

5.
J Fluoresc ; 26(6): 2225-2235, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27592351

RESUMO

A comparative study on detection of melamine with different sized citrate capped AuNPs namely 15 nm (AuNPs-I), 30 nm (AuNPs-II), and 40 nm (AuNPs-III) was carried out by fluorescence spectroscopy. The AuNPs emitted strong fluorescence at 421 nm with different intensity at 116.122, 220.511 and 253.665 for AuNPs-I, AuNPs-II and AuNPs-III respectively on excitation with 308 nm. On interaction with melamine, the AuNPs aggregated resulting in the enhancement of the fluorescent intensity of AuNPs. The sensitivity of melamine detection was studied for three different sizes of AuNPs by drawing a calibration curve between the concentration of melamine and fluorescence intensity. A good sensitivity was observed for AuNPs-II having the detection limit as low as 0.66 nM (3σ) which was lower in comparison to the detection limit of AuNPs-I (2.78 nM) and AuNPs-III (7.74 nM). The cost of synthesis was low as the usage of HAuCl4 in the synthesis of AuNPs-II was lower compared to the other sizes of AuNPs resulting in low cost of chemicals. The AuNPs-II was further chosen for carrying out selectivity study and for detecting the concentration of melamine. The recovery percentage of melamine in raw milk, liquid milk and milk powder after pre-treatment was found to be 100 %, 97 % to 100 % and 94 % to 99 % respectively.

6.
Nanomedicine ; 11(4): 969-81, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25659647

RESUMO

Multidrug resistance is a major therapeutic challenge faced in the conventional chemotherapy. Nanocarriers are beneficial in the transport of chemotherapeutics by their ability to bypass the P-gp efflux in cancers. Most of the P-gp inhibitors under phase II clinical trial are facing failures and hence there is a need to develop a suitable carrier to address P-gp efflux in cancer therapy. Herein, we prepared novel protamine and carboxymethyl cellulose polyelectrolyte multi-layered nanocapsules modified with Fe3O4 nanoparticles for the delivery of doxorubicin against highly drug resistant HeLa cells. The experimental results revealed that improved cellular uptake, enhanced drug intensity profile with greater percentage of apoptotic cells was attained when doxorubicin loaded magnetic nanocapsules were used in the presence of external magnetic field. Hence, we conclude that this magnetic field assisted nanocapsule system can be used for delivery of chemotherapeutics for potential therapeutic efficacy at minimal dose in multidrug resistant cancers. FROM THE CLINICAL EDITOR: Many cancer drugs fail when cancer cells become drug resistant. Indeed, multidrug resistance (MDR) is a major therapeutic challenge. One way that tumor cells attain MDR is by over expression of molecular pumps comprising of P-glycoprotein (P-gp) and multidrug resistant proteins (MRP), which can expel chemotherapeutic drugs out of the cells. In this study, the authors prepared novel protamine and carboxymethyl cellulose polyelectrolyte multi-layered nanocapsules modified with Fe3O4 nanoparticles for the delivery of doxorubicin. The results show that there was better drug delivery and efficacy even against MDR tumor cells.


Assuntos
Carboximetilcelulose Sódica , Doxorrubicina , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Nanopartículas de Magnetita/química , Nanocápsulas/economia , Neoplasias/tratamento farmacológico , Protaminas , Carboximetilcelulose Sódica/química , Carboximetilcelulose Sódica/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacologia , Células HeLa , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Protaminas/química , Protaminas/farmacologia
7.
Environ Res ; 135: 333-45, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25462683

RESUMO

There is a persistent need to assess the effects of TiO2 nanoparticles on the aquatic ecosystem owing to their increasing usage in consumer products and risk of environmental release. The current study is focused on TiO2 nanoparticle-induced acute toxicity at sub-ppm level (≤1ppm) on the three different freshwater sediment bacterial isolates and their consortium under two different irradiation (visible light and dark) conditions. The consortium of the bacterial isolates was found to be less affected by the exposure to the nanoparticles compared to the individual cells. The oxidative stress contributed considerably towards the cytotoxicity under both light and dark conditions. A statistically significant increase in membrane permeability was noted under the dark conditions as compared to the light conditions. The optical and fluorescence microscopic images showed aggregation and chain formation of the bacterial cells, when exposed to the nanoparticles. The electron microscopic (SEM, TEM) observations suggested considerable damage of cells and bio-uptake of nanoparticles. The exopolysaccrides (EPS) production and biofilm formation were noted to increase in the presence of the nanoparticles, and expression of the key genes involved in biofilm formation was studied by RT-PCR.


Assuntos
Bactérias/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Lagos/química , Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Análise de Variância , Biofilmes/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Primers do DNA/genética , Índia , L-Lactato Desidrogenase/metabolismo , Nanopartículas Metálicas/análise , Microscopia Eletrônica , Microscopia de Fluorescência , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxido Dismutase/metabolismo , Titânio/análise , Testes de Toxicidade Aguda/métodos
8.
Ecotoxicol Environ Saf ; 108: 152-60, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25062447

RESUMO

Silver nanoparticles (AgNPs) pose a high risk of exposure to the natural environment owing to their extensive usage in various consumer products. In the present study we attempted to understand the harmful effect of AgNPs at environmentally relevant low concentration levels (≤1ppm) towards two different freshwater bacterial isolates and their consortium. The standard plate count assay suggested that the AgNPs were toxic towards the fresh water bacterial isolates as well as the consortium, though toxicity was significantly reduced for the cells in the consortium. The oxidative stress assessment and membrane permeability studies corroborated with the toxicity data. The detailed electron microscopic studies suggested the cell degrading potential of the AgNPs, and the FT-IR studies confirmed the involvement of the surface groups in the toxic effects. No significant ion leaching from the AgNPs was observed at the applied concentration levels signifying the dominant role of the particle size, and size distribution in bacterial toxicity. The reduced toxicity for the cells in the consortium than the individual isolates has major significance in further studies on the ecotoxicity of the AgNPs.


Assuntos
Nanopartículas Metálicas/toxicidade , Consórcios Microbianos/efeitos dos fármacos , Prata/toxicidade , Permeabilidade da Membrana Celular/efeitos dos fármacos , Água Doce/microbiologia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Testes de Toxicidade
9.
ACS Appl Mater Interfaces ; 16(9): 11324-11335, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38406881

RESUMO

This study reports the preparation of a novel porous 3D scaffold from agarose-snail mucus (AGSMu) for cartilage tissue repair applications. AG is reported for its unique thermal and mechanical properties, biocompatibility, and biodegradability, making it suitable for biomedical applications. Still, it lacks the cell adhesion properties required for tissue engineering applications. SMu is a complex substance identified to contain glycosaminoglycans (GAGs) and other bioactive molecules that promote wound healing and reduce cartilage deterioration and inflammation. Hence, porous 3D blend scaffolds containing AG and SMu were prepared by the freeze-drying method, characterized, and investigated for bioactive effects on human chondrocyte (C28/I2) cells. The scaffolds had a microporous structure with an average pore size of 245 µm. FTIR spectroscopy showed that SMu was successfully incorporated into the scaffolds. The SMu increased the mechanical strength of the composite scaffolds by more than 80% compared to the pristine AG scaffold. The scaffolds were found to be biocompatible with tunable degradation. The human chondrocyte cells attached and proliferated well on the 3D scaffolds in a few days, demonstrating a marked improvement in adhesion due to the presence of SMu. Enhanced cell adhesion and mechanical properties of 3D porous AG scaffolds could make them suitable for articular cartilage repair and regeneration.


Assuntos
Cartilagem Articular , Condrócitos , Humanos , Sefarose , Alicerces Teciduais/química , Porosidade , Engenharia Tecidual
10.
ACS Appl Bio Mater ; 7(3): 1671-1681, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38447193

RESUMO

Copper sulfide nanoparticles (CuS) hold tremendous potential for applications in photothermal therapy (PTT) and photoacoustic imaging (PAI). However, the conventional chemical coprecipitation method often leads to particle agglomeration issues. To overcome this challenge, we utilized polyvinylpyrrolidone (PVP) as a stabilizing agent, resulting in the synthesis of small PVP-CuS nanoparticles named PC10, PCK30, and PC40. Our study aimed to investigate how different molecular weights of PVP influence the nanoparticles' crystalline characteristics and essential properties, especially their photoacoustic and photothermal responses. While prior research on PVP-assisted CuS nanoparticles has been conducted, our study delves deeper into this area, providing insights into optical properties. Remarkably, all synthesized nanoparticles exhibited a crystalline structure, were smaller than 10 nm, and featured an absorbance peak at 1020 nm, indicating their robust photoacoustic and photothermal capabilities. Among these nanoparticles, PC10 emerged as the standout performer, displaying superior photoacoustic properties. Our photothermal experiments demonstrated significant temperature increases in all cases, with PC10 achieving an impressive efficiency of 51%. Moreover, cytotoxicity assays revealed the nanoparticles' compatibility with cells, coupled with an enhanced incidence of apoptosis compared to necrosis. These findings underscore the promising potential of PVP-stabilized CuS nanoparticles for advanced cancer theranostics.


Assuntos
Nanopartículas , Neoplasias , Humanos , Povidona , Peso Molecular , Fototerapia , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Nanopartículas/uso terapêutico
11.
ACS Appl Bio Mater ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38996006

RESUMO

3D printing can revolutionize personalized medicine by allowing cost-effective, customized tissue-engineering constructs. However, the limited availability and diversity of biopolymeric hydrogels restrict the variety and applications of bioinks. In this study, we introduce a composite bioink for 3D bioprinting, combining a photo-cross-linkable derivative of Mucin (Mu) called Methacrylated Mucin (MuMA) and Hyaluronic acid (HA). The less explored Mucin is responsible for the hydrogel nature of mucus and holds the potential to be used as a bioink material because of its plethora of features. HA, a crucial extracellular matrix component, is mucoadhesive and enhances ink viscosity and printability. Photo-cross-linking with 405 nm light stabilizes the printed scaffolds without damaging cells. Rheological tests reveal shear-thinning behavior, aiding cell protection during printing and improved MuMA bioink viscosity by adding HA. The printed structures exhibited porous behavior conducive to nutrient transport and cell migration. After 4 weeks in phosphate-buffered saline, the scaffolds retain 70% of their mass, highlighting stability. Biocompatibility tests with lung epithelial cells (L-132) confirm cell attachment and growth, suggesting suitability for lung tissue engineering. It is envisioned that the versatility of bioink could lead to significant advancements in lung tissue engineering and various other biomedical applications.

12.
Nanotheranostics ; 8(2): 150-162, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38328615

RESUMO

Developing a biocompatible and biodegradable graphene-based fluorescent nanoprobe with the ability to visualize live cells could be interesting for intracellular imaging and monitoring the efficiency of chemotherapy. Herein, we report a biodegradable and biocompatible hybrid fluorescent graphene oxide (GO)-ZnS(Mn) composite synthesized via in situ growth of ZnS(Mn) quantum dots (QDs) on the surface of GO in the aqueous medium. The prepared 'GO-ZnS(Mn)' composite was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and high-resolution transmission electron microscopy (HR-TEM) along with selected area electron diffraction (SAED). Further, the fluorescence properties of the GO-ZnS(Mn) composite were studied using fluorescence emission spectroscopy. The composite material exhibited a strong and broad visible light fluorescence from 500 to 600 nm by excitation with 365 nm (UV) light. The cytotoxic experiments of folic acid (FA) conjugated GO-ZnS(Mn) using MTT [(3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide)] assay revealed that the composite had excellent biocompatibility even at higher concentrations up to 200 µg/mL in HeLa cell lines. Next, the bioimaging experiments carried out using confocal fluorescence laser scanning microscopy (CLSM) revealed that GO-ZnS(Mn) composite was taken up by the HeLa cells effectively within 12 h of incubation via receptor (folate) mediated endocytosis with strong fluorescence throughout the cell surface. Finally, the biodegradability of GO-ZnS(Mn) composite was studied by treating it with human myeloperoxidase enzyme (hMPO) isolated from the primary immune cells, neutrophils, which is important to understand the in vivo fate of GO-Zns(Mn). The HR-TEM and Raman analyses confirmed the biodegradation of GO-ZnS(Mn) within 15 h of hMPO treatment. Thus, the biodegradable GO-ZnS (Mn) composite could be helpful for chemotherapy and bioimaging applications.


Assuntos
Grafite , Nanocompostos , Pontos Quânticos , Humanos , Pontos Quânticos/química , Células HeLa , Grafite/química , Nanocompostos/química
13.
Antimicrob Agents Chemother ; 57(10): 4945-55, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23877702

RESUMO

The emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapy in vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activity in vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand the in vivo relevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activities in vivo against Salmonella infection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes.


Assuntos
Anti-Infecciosos/farmacologia , Nanopartículas Metálicas/química , Soroalbumina Bovina/química , Prata/química , Animais , Bovinos , Citometria de Fluxo , Nanopartículas Metálicas/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Salmonella enterica/efeitos dos fármacos
14.
J Antimicrob Chemother ; 68(11): 2576-86, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23798672

RESUMO

OBJECTIVES: The ability to target conventional drugs efficiently inside cells to kill intraphagosomal bacteria has been a major hurdle in treatment of infective diseases. We aimed to develop an efficient drug delivery system for combating infection caused by Salmonella, a well-known intracellular and intraphagosomal pathogen. Chitosan-dextran sulphate (CD) nanocapsules were assessed for their efficiency in delivering drugs against Salmonella. METHODS: The CD nanocapsules were prepared using the layer-by-layer method and loaded with ciprofloxacin or ceftriaxone. Antibiotic-loaded nanocapsules were analysed in vitro for their ability to enter epithelial and macrophage cells to kill Salmonella. In vivo pharmacokinetics and organ distribution studies were performed to check the efficiency of the delivery system. The in vivo antibacterial activity of free antibiotic and antibiotic loaded into nanocapsules was tested in a murine salmonellosis model. RESULTS: In vitro and in vivo experiments showed that this delivery system can be used effectively to clear Salmonella infection. CD nanocapsules were successfully employed for efficient targeting and killing of the intracellular pathogen at a dosage significantly lower than that of the free antibiotic. The increased retention time of ciprofloxacin in the blood and organs when it was delivered by CD nanocapsules compared with the conventional routes of administration may be the reason underlying the requirement for a reduced dosage and frequency of antibiotic administration. CONCLUSIONS: CD nanocapsules can be used as an efficient drug delivery system to treat intraphagosomal pathogens, especially Salmonella infection. This delivery system might be used effectively for other vacuolar pathogens including Mycobacteria, Brucella and Legionella.


Assuntos
Antibacterianos/metabolismo , Quitosana/metabolismo , Ciprofloxacina/metabolismo , Sulfato de Dextrana/metabolismo , Sistemas de Liberação de Medicamentos , Nanocápsulas/administração & dosagem , Salmonella/efeitos dos fármacos , Animais , Antibacterianos/farmacocinética , Linhagem Celular , Quitosana/farmacocinética , Ciprofloxacina/farmacocinética , Sulfato de Dextrana/farmacocinética , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Fagossomos/metabolismo , Fagossomos/microbiologia , Salmonelose Animal/tratamento farmacológico , Resultado do Tratamento
15.
J Nanosci Nanotechnol ; 13(7): 4934-42, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23901513

RESUMO

Metal-doped anatase nanosized titania photocatalysts were successfully synthesized using a sol-gel process. Different amounts of the dopants (0.2, 0.4, 0.6, 0.8 and 1.0%) of the metals (Ag, Ni, Co and Pd) were utilized. The UV-Vis spectra (solid state diffuse reflectance spectra) of the doped nanoparticles exhibited a red shift in the absorption edge as a result of metal doping. The metal-doped nanoparticles were investigated for their photocatalytic activity under visible-light irradiation using Rhodamine B (Rh B) as a control pollutant. The results obtained indicate that the metal-doped titania had the highest activity at 0.4% metal loading. The kinetic models revealed that the photodegradation of Rh B followed a pseudo first order reaction. From ion chromatography (IC) analysis the degradation by-products Rhodamine B fragments were found to be acetate, chloride, nitrite, carbonate and nitrate ions.


Assuntos
Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Rodaminas/química , Rodaminas/isolamento & purificação , Titânio/química , Corantes Fluorescentes/química , Corantes Fluorescentes/isolamento & purificação , Corantes Fluorescentes/efeitos da radiação , Luz , Teste de Materiais , Nanopartículas Metálicas/efeitos da radiação , Tamanho da Partícula , Fotoquímica/métodos , Rodaminas/efeitos da radiação
16.
ACS Biomater Sci Eng ; 9(7): 4208-4222, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37294579

RESUMO

This study reports the novel use of Achatina fulica (A. fulica) mucus as a potential therapeutic repair agent in osteoarthritis and cartilage tissue repair in vitro. Snail mucus was isolated, sterilized, and characterized using FTIR, XPS, rheology, and LC-MS/MS. The GAGs, sugar, phenol, and protein contents were estimated using standard assays. The LC-MS/MS identified 6-gingerol and some other small molecules. The effects of the sterilized mucus were studied on human chondrocytes using the C28/I2 cell as a model for the in vitro assays. The MTT assay indicates that mucus extracted from the pedal of A. fulica is biocompatible with the cells up to a concentration of 50 µg/mL. The mucus promoted cell migration and proliferation and completely closed the wound within 72 h, as indicated in the in vitro scratch assay. In addition, the snail mucus reduced apoptosis significantly (p < 0.05) in the treated cells by 74.6%. It preserved the cytoskeletal integrity of the C28/I2 cells, attributed mainly to GAGs and 6-gingerol content of the mucus. In conclusion, this present study suggests that GAGs and 6-gingerol conferred wound-healing and antiapoptotic properties on the mucus secretion from A. fulica and can be explored for therapeutic repair and cartilage tissue engineering.


Assuntos
Materiais Biocompatíveis , Condrócitos , Animais , Humanos , Cromatografia Líquida , Espectrometria de Massas em Tandem , Caramujos , Muco/metabolismo
17.
ACS Omega ; 8(36): 32294-32310, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37720748

RESUMO

Shape memory-assisted self-healing polymers have drawn attention over the past few years owing to their interdisciplinary and wide range of applications. Self-healing and shape memory are two approaches used to improve the applicability of polymers in the biomedical field. Combining both these approaches in a polymer composite opens new possibilities for its use in biomedical applications, such as the "close then heal" concept, which uses the shape memory capabilities of polymers to bring injured sections together to promote autonomous healing. This review focuses on using shape memory-assisted self-healing approaches along with their respective affecting factors for biomedical applications such as tissue engineering, drug delivery, biomaterial-inks, and 4D printed scaffolds, soft actuators, wearable electronics, etc. In addition, quantification of self-healing and shape memory efficiency is also discussed. The challenges and prospects of these polymers for biomedical applications have been summarized.

18.
Polymers (Basel) ; 15(7)2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-37050250

RESUMO

Dielectric properties for nanocomposites with metallic fillers inside a polymer matrix were determined using CST STUDIO SUITE-Electromagnetic field simulation software followed by the free-space Nicolson-Ross-Weir procedure. The structure is randomly generated to simulate the intrinsic non-uniformity of real nanomaterials. Cubic insertions were equated to corresponding spherical particles in order to provide either the same volume index or the same exterior surface index. The energy concentration around the inserts and within the entire material was determined as useful information in practice in order to design materials tailored to avoid exceeding the field/temperature limit values. The paper successfully associated the dialectic measurements with the results from the computer simulations, which are mainly based on energetic effects in electromagnetic applications. The experimental results are comparable with the software simulation in terms of precision. The conclusions outline the practical applications of the method for both electromagnetic shielding and microwave domain/telecommunications applications.

19.
J Agric Food Chem ; 70(49): 15474-15486, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36456189

RESUMO

This study evaluated the potency of zein-alginate-phosphatidylcholine nanoparticles (NPs) on bioaccessibility/intestinal uptake of encapsulated lycopene (LY) and lutein (LT) versus dietary absorption using simulated digestion and human intestinal Caco-2 cells. LY-zein-alginate-PC (LYZAP) and LT-zein-alginate-PC (LTZAP) NPs yield desired properties, which exhibit sustained release and are suitable for oral administration. Interestingly, co-treatment of LYZAP + LTZAP showed better release of carotenoids instead of individual treatment at intestinal pH. Bioaccessibility, cellular uptake, and basolateral secretion of LY and LT from NPs were significantly enhanced than micellar carotenoids (dietary mode of absorption). The increased absorption of carotenoids from NPs correlated with triglyceride levels. The intestinal cell uptake of carotenoids by nanoencapsulation may be due to endocytosis, paracellular, and SRB-1 protein-mediated transport. Overall, LYZAP and LTZAP NPs possess superior properties to control the release and cellular uptake of unique or distinct carotenoids. The inclusion of alginate and phosphatidylcholine in zein-based nanoencapsulation could be a promising strategy to improve carotenoid bioavailability.


Assuntos
Luteína , Zeína , Humanos , Células CACO-2 , Luteína/metabolismo , Licopeno , Micelas , Alginatos , Carotenoides/metabolismo , Disponibilidade Biológica , Lecitinas
20.
Nanoscale Adv ; 3(10): 2741-2776, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-36134191

RESUMO

High-performance epoxy composites find application in the aerospace industry. Although epoxy is a high-performance polymer, its fracture toughness is compromised due to its highly cross-linked nature. Nanomaterials such as carbon nanotubes (CNTs), graphene derivatives, and inorganic 2-dimensional (2D) nanomaterials are being explored to improve epoxy composites' mechanical properties. Graphene is one of the most popular 2D nano-reinforcing agents for epoxy composites. Following graphene discovery, the research community's attention was brought to various other few-atom thick 2D nanomaterials. Hence, apart from graphene, inorganic nanosheets such as transition metal dichalcogenides (TMDs), hexagonal boron nitride (hBN), etc., are also being studied as modifiers for enhancing the mechanical performance of epoxy composites. Graphene, TMDs and hBN are known to possess a high aspect ratio, high specific surface area and inherently high mechanical strength and stiffness, contributing to a stronger and tougher composite. Despite that, the challenges associated with these nanomaterials, such as dispersion issues, lack of standardization, underlying health hazards, etc., have hampered their commercialization. It has been long past a decade since the discovery of graphene, yet there are concerns regarding the lab to industry scale-up, and health and environmental hazards associated with nanomaterials for the fabrication of aerospace composites. This review offers a comprehensive literature survey and a perspective into the possible ways of bridging the gaps between the laboratory research and industrialization of 2D nanosheet-filled epoxy composites.

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