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1.
Biofactors ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760074

RESUMO

Foam cell formation plays a pivotal role in atherosclerosis-associated cardiovascular diseases. Bioactive peptides generated from marine sources have been found to provide multifunctional health advantages. In the present study, we investigated the anti-atherosclerotic effects of LLRLTDL (Bu1) and GYALPCDCL (Bu2) peptides, isolated from ark shell protein hydrolysates by assessing their inhibitory effect on oxidized LDL (oxLDL)-induced foam cell formation. The two peptides showed a promising anti-atherosclerotic effect by inhibiting foam cell formation, which was evidenced by inhibiting lipid accumulation in oxLDL-treated RAW264.7 macrophages and oxLDL-treated primary human aortic smooth muscle cells (HASMC). Two peptides effectively reduced total cholesterol, free cholesterol, cholesterol ester, and triglyceride levels by upregulating cholesterol efflux and downregulating cholesterol influx. Expression of cholesterol influx-related proteins such as SR-A1 and CD36 were reduced, whereas cholesterol efflux-related proteins such as ATP-binding cassette transporter ABCA-1 and ABCG-1 were highly expressed. In addition, Bu1 and Bu2 peptides increased PPAR-γ and LXR-α expression. However, PPAR-γ siRNA transfection reversed the foam cell formation inhibitory activity of Bu1 and Bu2 peptides. Furthermore, the synergistic effect of Bu1 and Bu2 peptides on foam cell formation inhibition was observed with PPAR-γ agonist thiazolidinediones, indicating that PPAR-γ signaling pathway plays a key role in foam cell formation of macrophages. Beyond their impact on foam cell formation, Bu1 and Bu2 peptides demonstrated anti-inflammatory potential by inhibiting the generation of pro-inflammatory cytokines and nitric oxide and NF-κB nuclear activation. Taken together, these results suggest that Bu1 and Bu2 peptides may be useful for atherosclerosis and associated anti-inflammatory therapies.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38814156

RESUMO

The use of powered activated carbon is often limited by inconsistent particle sizes and porosities, leading to reduced adsorption efficiencies. In this study, we demonstrated a practical and environmentally friendly method for creating a 3D graphene nanostructure with highly uniform ultramicropores from wood-based biomass through a series of delignification, carbonization, and activation processes. In addition, we evaluated the capture characteristics of this structure for CO2, CH4, and N2 gases as well as its selectivity for binary-mixture gases. Based on textural and chemical analyses, the delignified monolith had a lamellar structure interconnected by cellulose-based fibers. Interestingly, applying the KOH vapor activation technique solely to the delignified samples led to the formation of a monolithic 3D network composed of interconnected graphene sheets with a high degree of crystallinity. Especially, the Act. 1000 sample exhibited a specific surface area of 1480 m2/g and a considerable pore volume of 0.581 cm3/g, featuring consistently uniform ultramicropores over 90% in the range of 3.5-11 Å. The monolithic graphene-based samples, predominantly composed of ultramicropores, demonstrated a notably heightened capture capacity of 6.934 mol/kg at 110 kPa for CO2, along with favorable selectivity within binary gas mixtures (CO2/N2, CO2/CH4, and CO2/CH4). Our findings suggest that this biomass-derived 3D structure has the potential to serve as a monolithic adsorbent in gas separation applications.

3.
Int J Biol Macromol ; 255: 128087, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37979743

RESUMO

Captopril (CTP) is an oral drug widely used to treat high blood pressure and congestive heart failure. In this study, CTP-incorporated biomaterials for antihypertensive therapy were synthesized from chitosan, carboxymethyl cellulose, and plasticizers. The physicochemical properties of the prepared biomaterials were characterized using FE-SEM, FT-IR analysis, and physical properties. CTP release experiments were carried out in buffer solutions at various pH values and temperatures. Results indicated that above 99.0 % of CTP was released within 180 min. Optimization of the experimental conditions for CTP release was analyzed by using response surface methodology (RSM). Results of CTP release through artificial skin indicated that CTP was continuously released above 95.0 % from the prepared biomaterials for 36.0 h. The CTP release mechanisms into a buffer and through artificial skin followed pseudo-Fickian diffusion mechanism and non-Fickian diffusion mechanisms, respectively. Moreover, angiotensin-converting enzyme (ACE) inhibition (related to cardiovascular disease) via the released CTP clearly reveals that the prepared biomaterials have a high potential as a transdermal drug delivery agent in antihypertensive therapy.


Assuntos
Captopril , Quitosana , Captopril/química , Captopril/uso terapêutico , Anti-Hipertensivos/química , Quitosana/química , Carboximetilcelulose Sódica/química , Liberação Controlada de Fármacos , Materiais Biocompatíveis , Espectroscopia de Infravermelho com Transformada de Fourier , Portadores de Fármacos/química
4.
Int J Biol Macromol ; 232: 123382, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-36693604

RESUMO

The aim of this study was to prepare niacinamide (NA) imprinted biomaterials for treating hyperpigmentation using mungbean starch (MS), PVA, and plasticizers (glycerol (GL) and citric acid (CA)). Biomaterials and NA were characterized by FE-SEM, FT-IR, and 1H NMR. To evaluate the applicability of the NA imprinted biomaterials for a transdermal drug delivery system (TDDS), NA release experiment was conducted in different pH and temperature conditions. Results of NA release properties indicated that NA was released about 99 % rapidly in the initial 10 min. NA release in low pH and high temperature was also higher than that in high pH and low temperature. The determination of experimental conditions and the analysis of NA release results were achieved using response surface methodology (RSM). Results of NA release using artificial skin indicated that NA release from NA imprinted biomaterials was increased at a relatively steady rate for 90 min. To verify for treating hyperpigmentation of the prepared biomaterials, tyrosinase inhibitory and antioxidant inhibitory were performed. Results indicated that NA imprinted biomaterials with the addition of CA exhibited 55.8 % of tyrosinase inhibitory and 73.0 % of antioxidant inhibitory. In addition, their ability to inhibit melanin synthesis in B16F10 cells was evaluated.


Assuntos
Hiperpigmentação , Niacinamida , Humanos , Niacinamida/farmacologia , Amido/química , Materiais Biocompatíveis/química , Antioxidantes/uso terapêutico , Monofenol Mono-Oxigenase , Espectroscopia de Infravermelho com Transformada de Fourier , Hiperpigmentação/tratamento farmacológico , Melaninas
5.
Expert Rev Vaccines ; 21(10): 1363-1376, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35924678

RESUMO

INTRODUCTION: Vaccination continues to be the most effective method for controlling COVID-19 infectious diseases. Nonetheless, SARS-CoV-2 variants continue to evolve and emerge, resulting in significant public concerns worldwide, even after more than 2 years since the COVID-19 pandemic. It is important to better understand how different COVID-19 vaccine platforms work, why SARS-CoV-2 variants continue to emerge, and what options for improving COVID-19 vaccines can be considered to fight against SARS-CoV-2 variants and future pandemics. AREA COVERED: Here, we reviewed the innate immune sensors in the recognition of SARS-CoV-2 virus, innate and adaptive immunity including neutralizing antibodies by different COVID-19 vaccines. Efficacy comparison of the several COVID-19 vaccine platforms approved for use in humans, concerns about SARS-CoV-2 variants and breakthrough infections, and the options for developing future COIVD-19 vaccines were also covered. EXPERT OPINION: Owing to the continuous emergence of novel pathogens and the reemergence of variants, safer and more effective new vaccines are needed. This review also aims to provide the knowledge basis for the development of next-generation COVID-19 and pan-coronavirus vaccines to provide cross-protection against new SARS-CoV-2 variants and future coronavirus pandemics.


Assuntos
COVID-19 , Vacinas Virais , Anticorpos Neutralizantes , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Pandemias/prevenção & controle , SARS-CoV-2
6.
Int J Biol Macromol ; 209(Pt A): 1477-1485, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35469944

RESUMO

The main objective of this study was to prepare functional allopurinol (ALP) incorporated biomaterials using mungbean starch, polyvinyl alcohol, melanin (MEL), and plasticizers. Prepared biomaterials were characterized by FE-SEM and FT-IR analysis. Photothermal conversion efficiencies and ALP release properties of biomaterials were evaluated with NIR laser irradiation. When biomaterials were irradiated with the NIR laser, temperatures increase of MEL-added biomaterials were higher than those of MEL-non-added biomaterials. After NIR laser irradiation, ALP release rates of MEL-added biomaterials were 1.62 times faster than those of MEL-non-added biomaterials. In addition, ALP release using an artificial skin was increased by NIR laser irradiation. ALP release from biomaterials followed Fickian diffusion mechanism, while ALP release using an artificial skin followed a non-Fickian diffusion mechanism. Xanthine oxidase inhibitory (%) for MEL-added biomaterials with/without the addition of GL and XL were 47.5%, 61.7%, and 65.1%, respectively.


Assuntos
Materiais Biocompatíveis , Amido , Alopurinol/farmacologia , Liberação Controlada de Fármacos , Melaninas , Espectroscopia de Infravermelho com Transformada de Fourier
7.
J Nanosci Nanotechnol ; 21(9): 4974-4979, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33691902

RESUMO

In this study, we prepared chitosan beads cross-linked with epichlorohydrin (CB-ECH) to improve the removal of nitrate in groundwater. It was confirmed that CB-ECH exhibited higher thermal stability and well-developed nano-pores compared to the pure chitosan beads (CB) by the thermogravimetric analyzer, nitrogen gas adsorption and desorption isotherm, and field emission scanning microscopy analysis. The CB-ECH showed a higher nitrate adsorption amount than the pure CB. Nitrate adsorption behaviors of CB-ECH were further investigated using adsorption isotherm, adsorption kinetics, adsorption energy distribution, and Gibbs free energy distribution models. The adsorption equilibrium and kinetics of nitrate ion on CB-ECH were well explained by the Sips isotherm and homogeneous surface diffusion model, respectively. It was also found from the AED analysis that the CB-ECH represent the heterogeneous adsorption behaviors for nitrate.


Assuntos
Quitosana , Poluentes Químicos da Água , Adsorção , Epicloroidrina , Concentração de Íons de Hidrogênio , Cinética , Nitratos , Água
8.
Int J Biol Macromol ; 175: 217-228, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33548320

RESUMO

This study focuses on the synthesis of functional allopurinol (ALP) imprinted biomaterials for a transdermal drug delivery using mung bean starch (MBS), polyvinyl alcohol (PVA), sodium benzoate (SB) as a crosslinking agent, and poloxamer (PX) as a thermo-sensitive polymer. Prepared functional biomaterials were characterized and evaluated by SEM, FT-IR analysis, and physical properties. Results of ALP recognition properties indicated that adsorbed amounts (Q) of ALP on functional ALP imprinted biomaterials were 3.8 to 4.9-fold higher than that of non-ALP imprinted biomaterial. Results of ALP release revealed that the ALP release rate for PX added biomaterials was 1.10 (36.5 °C) or 1.30 (45 °C) times faster than that at 25 °C. These results indicate that functional ALP imprinted biomaterials have thermo-sensitive properties due to the addition of PX. Results of ALP release using artificial skin indicated that ALP release was increased at a relatively steady-state rate for 3 h and that the ALP release behavior followed the non-Fickian diffusion mechanism.


Assuntos
Alopurinol/química , Sistemas de Liberação de Medicamentos/métodos , Amido/farmacologia , Administração Cutânea , Adsorção , Alopurinol/farmacologia , Materiais Biocompatíveis/farmacologia , Difusão/efeitos dos fármacos , Hidrogéis , Polímeros/química , Álcool de Polivinil/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Adesivo Transdérmico
9.
Int J Biol Macromol ; 161: 763-770, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32553978

RESUMO

The main objective of this work was to prepare inulin (INL)/polyvinyl alcohol (PVA) biomaterials imprinted with arbutin (AR) as the target drug. INL from Jerusalem artichoke flour was extracted with hot water extraction method. INL/PVA biomaterials were synthesized with a casting method and a UV curing. The optimal UV curing time and sodium benzoate content were about 10 min and 0.1 wt%, respectively. The biomaterials were characterized by SEM and FT-IR analysis. Mechanical properties of prepared AR imprinted biomaterials were also investigated. AR release was examined with changes of pH at 36.5 °C. The AR release ratio was also investigated using artificial skin. It was found that AR was released constantly for 40 min. Results of drug release mechanism indicated that AR release followed the Fickian diffusion behavior, whereas drug release using artificial skin followed the non-Fickian diffusion behavior. Tyrosinase inhibitory (%) for AR imprinted biomaterials with/without the addition of GL were 58.8% and 79.2%, respectively.


Assuntos
Arbutina , Sistemas de Liberação de Medicamentos , Helianthus/química , Inulina , Álcool de Polivinil , Arbutina/química , Arbutina/farmacocinética , Inulina/química , Inulina/farmacocinética , Álcool de Polivinil/química , Álcool de Polivinil/farmacocinética , Solubilidade
10.
ACS Appl Mater Interfaces ; 12(16): 18332-18341, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32239905

RESUMO

Shiga toxin-producing Escherichia coli (STEC) are critical foodborne pathogens, which cause serious human health issues, including hemolytic uremic syndrome. Illnesses caused by STEC lack effective treatments that target the elimination of these bacteria from the gastrointestinal tract without causing an adverse effect. Reducing this pathogen from a reservoir of STEC is an effective strategy, but the challenges remain due to the lack of efficient, selective antimicrobial agents. We developed specific antibody-conjugated chitosan nanoparticles (CNs) to selectively target and treat STEC in the gastrointestinal tract. Given the great broad-spectrum antimicrobial activity of CN, we conjugated antibodies to CN. Antibodies were raised and purified from egg yolks after immunization of hens with seven different O-side-chain antigens isolated from STEC (O26, O45, O103, O111, O121, O145, and O157). We prepared CN-immunoglobulin Y (IgY) conjugates by forming amide bonds at different ratios of CN:IgY (10:1, 10:2, and 10:4). The CN-IgY conjugated at a 10:2 ratio demonstrated significantly enhanced antimicrobial activity against E. coli O157:H7. Conjugates of CN and anti-STEC IgY antibodies killed corresponding STEC serotypes specifically and selectively, while showing no significant impact on nontargeted bacteria, including Salmonella enterica and Lactobacillus plantarum. The enhanced antimicrobial activity of CN-IgY against STEC was also confirmed in synthetic intestinal fluid, as well as an in vivo animal model of Caenorhabditis elegans. These results suggest that the CN-IgY conjugates have strong and specific antimicrobial activity and that they are also great candidates to eliminate pathogens selectively in the gastrointestinal tract without inhibiting beneficial bacteria.


Assuntos
Antibacterianos , Anticorpos Antibacterianos , Trato Gastrointestinal/microbiologia , Nanopartículas/química , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Anticorpos Antibacterianos/química , Anticorpos Antibacterianos/farmacologia , Caenorhabditis elegans/microbiologia , Galinhas , Quitosana/química , Modelos Animais de Doenças , Infecções por Escherichia coli/microbiologia , Gastroenteropatias/microbiologia , Viabilidade Microbiana/efeitos dos fármacos
11.
J Nanosci Nanotechnol ; 20(7): 4322-4326, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31968466

RESUMO

In this study, walnut-shaped V2O3 particles with high photocatalytic activity in the visible light were synthesized by hydrothermal process. The V2O3 samples synthesized with the various temperature conditions of the hydrothermal process were characterized using XRD, SEM, TEM, UV-Visible spectrometer and N2gas adsorption/desorption analysis. For investigating the photocatalytic performance of synthesized V2O3 particles in the visible light condition, photodegradation experiments of methylene blue (MB) solution under artificial sunlight irradiation was conducted. As a result, the V2O3 hydrothermal-synthesized at 280 °C was composed of pure V2O3 crystal structure and showed high photocatalytic activity for the degradation of MB dye in visible light.

12.
Carbohydr Polym ; 220: 86-94, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31196554

RESUMO

In this study, biodegradable biomaterials were prepared by using inulin (INL), PVA and plasticizers (citric acid (CA), glycerol (GL) and thiamine (TH)) with UV curing process. INL was extracted from Jerusalem artichoke flour using hot water extraction method. Extracted INL and INL/PVA biomaterials were characterized by TLC, FT-IR, and SEM analysis. Physical properties such as mechanical and water resistance properties of biomaterials prepared with UV curing time from 0 to 20 min and types of plasticizers were investigated. Their antimicrobial activities, biodegradability, and application of coating materials for foods were also determined. Results indicated that their physical properties were improved by the UV curing process. In addition, physical properties of TH-added biomaterials were 1.5 to 2 times higher than those of GL-added and CA-added biomaterials. Biodegradability in soil revealed that biomaterials were degraded by about 20-40% after 140 days.


Assuntos
Materiais Biocompatíveis/química , Embalagem de Alimentos , Helianthus/metabolismo , Inulina/análogos & derivados , Plastificantes/química , Álcool de Polivinil/química , Tiamina/química , Biodegradação Ambiental , Ácido Cítrico/química , Glicerol/química , Solubilidade , Resistência à Tração
13.
Carbohydr Polym ; 208: 261-268, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30658799

RESUMO

In this work, biodegradable biomaterial films for sulindac (SLD) recognition are synthesized from mungbean starch (MBS), PVA, and plasticizers by using UV irradiation process and casting methods. The optimal UV irradiation time for the preparation of SLD imprinted biomaterials films was about 30 min. Mechanical properties, recognition ability, and SLD release property for prepared films were investigated. From the results of recognition ability, we verified that these SLD imprinted biomaterial films have the binding site for SLD. The release properties of SLD was examined with the change of pH and temperature. The results indicate that the SLD release in pH 10.0 was higher than in pH 4.0. SLD release was also evaluated using an artificial skin. Results of the artificial skin test verified that SLD was released constantly for 20 days.


Assuntos
Materiais Biocompatíveis/química , Amido/química , Sulindaco/química , Vigna/química , Sistemas de Liberação de Medicamentos/métodos , Membranas Artificiais , Solubilidade
14.
J Nanosci Nanotechnol ; 19(4): 2329-2333, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30486993

RESUMO

In this work, we prepared basalt based nanostructured zeolite 13X by alkali fusion and hydrothermal synthesis process. The sample prepared was characterized using XRD, SEM, and low-temperature nitrogen analysis. The adsorption equilibrium and kinetic characteristics of ammonia nitrogen (NH+4-N) and phosphate phosphorus (PO3-4-P) were investigated. It was found that the basalt based nanostructured zeolite 13X showed high adsorption capacities for NH+4-N (75 mg/g) and PO3-4-P (25 mg/g) under the experimental conditions used. Our results demonstrate that basalt based zeolite 13X can be a good alternative adsorbent for the simultaneously removal of NH+4-N and PO3-4-P from aqueous solution.

15.
Nanotechnology ; 29(41): 415101, 2018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30028309

RESUMO

Photothermal therapy requires a biocompatible material to absorb near-infrared (NIR) light and generate sufficient heat. Herein, we suggest natural melanin-loaded nanovesicles (melasicles) as photothermal therapeutic agents (PTA) for NIR mediated cancer therapy in vivo. The mean size of these melasicles was 140 ± 15 nm. They showed excellent colloidal stability. After irradiation from 808 nm NIR laser at 1.5 W cm-2, the melasicles showed good photothermal conversion efficiencies both in vitro and in vivo. In drug release study, laser irradiation increased fluidity of vesicle membrane due to photothermal generation from melanin. Initial drug release in the laser irradiation group was higher than that in the no laser irradiation group. After injecting the melasicles into tail veins of CT-26 bearing mice, tumors were suppressed or eliminated after irradiation at 1.5 W cm-2 for 5 min once or twice. These results suggest that melasicles could be used as attractive PTA for cancer therapy and localized drug release.

16.
J Photochem Photobiol B ; 176: 145-149, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29020661

RESUMO

Active blend films from chitosan-gallic acid (CGA) and polyvinyl alcohol (PVA) were prepared via a simple mixing and casting method through the addition of citric acid as a plasticizer. The CGA/PVA blend films were characterized using Fourier transform infrared spectroscopy (FT-IR). The mechanical properties including tensile strength (TS) and elongation at break (%E), degree of solubility (S) and swelling behavior (DS), water vapor adsorption, and antimicrobial activities of the CGA/PVA blend films with and without LED (light emitting diode)-UV irradiation were also investigated. The CGA/PVA blend films exposed to UV irradiation exerted a higher TS (43.5MPa) and lower %E (50.40), S (0.38) and DS (2.73) compared to the CGA/PVA blend films (TS=41.7MPa, %E=55.40, S=0.42, and DS=3.16) not exposed LED-UV irradiation, indicating that the cross-linkage between CGA and PVA had been strengthened by LED-UV irradiation. However, the water vapor adsorption in the CGA/PVA blend films increased due to the changes of surface roughness and pore volume after LED-UV irradiation, and all values increased by increasing the CGA concentrations in the CGA/PVA blend films. The antimicrobial activities of the CGA/PVA blend films showed that the efficient concentration of CGA in the CGA/PVA blend films was over 1.0%. Taken together, the CGA/PVA blend films have potential for use as food packing materials.


Assuntos
Antibacterianos/síntese química , Ácido Gálico/química , Álcool de Polivinil/química , Raios Ultravioleta , Adsorção , Antibacterianos/farmacologia , Quitosana/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração/efeitos da radiação , Água/química
17.
Food Res Int ; 100(Pt 1): 377-386, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28873700

RESUMO

This paper reports on a method of preparing chitosan-based films to which sulfosuccinic acid (SSA) is added for crosslinking agent with/without UV curing treatment and applications of a coating materials for foods. The physical, thermal, and optical properties of the UV cured chitosan-based films are investigated including their tensile strength (TS), elongation at break (%E), degree of swelling (DS), solubility (S), and water vapor absorption as well as their biodegradability in soil and applicability of the coating on a fruit. We also evaluated the physical properties of the prepared films to which glycerol (GL), xylitol (XL), and sorbitol (SO) are added to be used as plasticizers. The surface and topography of the prepared films are investigated by scanning electronic microscopy (SEM) and atomic force microscopy analysis (AFM). The results indicate that the films UV cured for 20min possess optimal physical and thermal properties compared to that of non-cured films. The mechanical, thermal, and water barrier properties of SO-added film are also found to be superior to other films with added GL and XL. The degree of biodegradability revealed that the films are degraded by about 40-65% after 220days.


Assuntos
Quitosana/química , Reagentes de Ligações Cruzadas/química , Embalagem de Alimentos/métodos , Álcool de Polivinil/química , Succinatos/química , Raios Ultravioleta , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/efeitos da radiação
18.
Int J Biol Macromol ; 104(Pt A): 1150-1157, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28687389

RESUMO

In this study, nanocomposite films were synthesized by chitosan (CH), PVA, ZnS, sulfosuccinic acid, and plasticizers. The nanocomposite films were cross-linked by the heat curing process. ZnS was synthesized by the reaction of Zn(CH3COO)2 and Na2S2O3·5H2O in aqueous solution via a template-free hydrothermal process. The prepared ZnS and CH/PVA nanocomposite films were characterized by X-ray diffraction, Fourier transform IR spectroscopy, and scanning electronic microscopy. The results of this study confirmed the presence of specific peaks of ZnS in the prepared nanocomposite films, and the intensity of these peaks increased with increasing ZnS contents. Tensile strength, elongation at break, water barrier properties, and thermal properties of the prepared nanocomposite films were also investigated, indicating that the addition of ZnS nanoparticles improved the physical and thermal properties. In addition, the photocatalytic degradability of the prepared films containing ZnS nanoparticles was evaluated using 2,4-dichlorophenoxyacetic acid and methyl orange.


Assuntos
Quitosana/química , Nanocompostos/química , Nanopartículas/química , Sulfetos/química , Compostos de Zinco/química , Ácido 2,4-Diclorofenoxiacético/química , Compostos Azo/química , Catálise , Processos Fotoquímicos , Resistência à Tração , Água/química
19.
Int J Biol Macromol ; 103: 839-844, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28551442

RESUMO

The photothermal effect is used in a new drug release system to control drug delivery in a specific region. Melanin absorbs near-infrared (NIR) light with a high photothermal conversion efficiency, and as a result, an NIR laser can be used to induced drug release from alginate microparticles containing melanin (ALG-Mel microparticles). The temperature of the ALG-Mel microparticle solution at a concentration of 5mg/mL increased to 38.1°C from 26.0°C after irradiation with 808nm NIR at 1.5W/cm2 for 5min, and this increase in temperature was found to be independent of the ALG-Mel microparticle concentration. After the NIR laser irradiation, 5-fluorouracil (5-FU) was released from the ALG-Mel microparticles to 87.4±0.5% of the total loaded drug for 24h. Without NIR laser irradiation, 5-FU was released from the ALG-Mel microparticles to 60.8±1.5% of the total loaded drug for 24h. These results indicate that NIR laser irradiation can be used with ALG-Mel microparticles as a drug delivery system for release within a target region.


Assuntos
Alginatos/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Raios Infravermelhos , Lasers , Melaninas/química , Microesferas , Ácido Glucurônico/química , Ácidos Hexurônicos/química
20.
J Nanosci Nanotechnol ; 15(7): 5224-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26373111

RESUMO

In this work, ZnS microspheres consisting of nanoblocks were synthesized by a simple, template-free approach employing a hydrothermal reaction at different temperatures, using Zn(CH3COO)2 and Na2S2O3 · 5H2O as starting materials in the aqueous solution. The synthesized samples were characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET). The photocatalysts were evaluated using photodecomposition of methylene blue under UV-C light. The photocatalytic degradation rate followed a pseudo-first-order equation. The kinetic constant (k1) of the ZnS microspheres was 5.43 x 10(-2) min(-1).

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