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1.
J Biomater Sci Polym Ed ; 34(1): 72-88, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35924835

RESUMO

Kiwi extract (KE) including different components such as quercetin, vitamins C and E, and actinides has been known as a debridement agent for burn wounds. In this study, electrospun poly(ɛ-caprolactone)/cellulose acetate blend nanofibers incorporating KE (PCL/CA/KE) were prepared and their performance was evaluated for healing acceleration of burn wounds. The physicochemical characterization of PCL/CA/KE nanofibers showed an average diameter of ∼420 nm, porosity of 70%, water contact angle of 61°, and water uptake of ∼220%. Moreover, the continuous release trend of KE from PCL/CA blend nanofibers happened during 24 h and the release mechanism was governed by the Fickian diffusion. Besides the cytocompatibility of PCL/CA/KE nanofibers, their in vivo experiments revealed that the bioactive wound dressing based on the sample has higher wound closure compared to KE after 21 days. Histopathology of wounds dressed by PCL/CA/KE nanofibers indicated epidermal formation along with a fully extended layer. Eventually, the obtained results confirmed that the PCL/CA/KE nanofibrous sample was a promising wound dressing for burn wound healing.


Assuntos
Queimaduras , Nanofibras , Humanos , Nanofibras/química , Cicatrização , Queimaduras/terapia , Poliésteres/química , Água/química
2.
Chem Pharm Bull (Tokyo) ; 56(6): 749-52, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18520075

RESUMO

Novel fluorescent molecules were synthesized by designing an environmentally friendly method involving the bulk electrolysis technique. This electrochemical treatment process helps protect the environment by minimizing the toxic waste component of effluent. The electrochemical oxidation of 3,6-dihydroxybenzene-1,2-dinitrile (DBD) in the presence of benzenesulfinic acids was studied in an aqueous solution (H(2)O : AN, 90 : 10), which included an acetate buffer (pH=5.0). This research utilized a variety of experimental techniques, including cyclic voltammetry, controlled-potential electrolysis as well as spectroscopic identification of compounds produced as products. In addition, our fluorescent studies offered results in line with existing findings. At the wavelength of 205 nm, DBD and compound (6) were excited and their fluorescent emissions were monitored.


Assuntos
Corantes Fluorescentes/síntese química , Hidroquinonas/síntese química , Nitrilas/síntese química , Soluções Tampão , Eletroquímica , Eletrólise , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Hidroquinonas/química , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Nitrilas/química , Fosfatos/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
3.
J Mol Model ; 14(4): 325-33, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18274794

RESUMO

The electrode potential of 2-(4,5-dihydroxy-2-methylphenyl)-2-phenyl-2H-indene-1,3-dione (DMPID) in acetonitrile has been calculated. The calculations were performed using ab initio molecular orbital calculations (HF), and density functional theory (DFT) with the inclusion of entropic and thermochemical corrections to yield free energies of redox reactions. The electrode potential of DMPID was also obtained experimentally with the aid of an electrochemical technique (cyclic voltammetry). The values for geometric parameters and the vibrational frequencies of DMPID and 2-(6-methyl-3,4-dioxocyclohexa-1,5-dienyl)-2-phenyl-2H-indene-1,3-dione (MDPID) were also computed using the same levels with the basis set of 6-31G(d). The calculated IR spectrum of DMPID used for the assignment of IR frequencies was observed in the experimental FT-IR spectrum and the calculated IR and FT-IR observed spectra of DMPID were compared with correlation factor of 0.996. It should be mentioned that the present work is the first research on coagulant derivative molecules in which the electrode potential of a molecule is calculated. Optimized structures of 2-(6-methyl-3,4-dioxocyclohexa-1,5-dienyl)-2-phenyl-2H-indene-1,3-dione (MDPID).


Assuntos
Indenos/química , Modelos Moleculares , Eletroquímica , Eletrodos , Conformação Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração
4.
Biophys Chem ; 134(1-2): 25-33, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18243488

RESUMO

Prosperity of information on the reactions of redox-active sites in proteins can be attained by voltammetric studies in which the protein sample is located on a suitable surface. This work reports the presentation of myoglobin/nickel oxide nanoparticles/glassy carbon (Mb/NiO NPs/GC) electrode, ready by electrochemical deposition of the NiO NPs on glassy carbon electrode and myoglobin immobilization on their surfaces by the potential cycling method. Images of electrodeposited NiO NPs on the surface of glassy carbon electrode were obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM). A pair of well-defined redox peaks for Mb(Fe(III)-Fe(II)) was obtained at the prepared electrode by direct electron transfer between the protein and nanoparticles. Electrochemical parameters of immobilized myoglobin such as formal potential (E(0')), charge transfer coefficient (alpha) and apparent heterogeneous electron transfer rate constant (k(s)) were estimated by cyclic voltammetry and nonlinear regression analysis. Biocatalytic activity was exemplified at the prepared electrode for reduction of hydrogen peroxide.


Assuntos
Galvanoplastia , Nanopartículas Metálicas/química , Mioglobina/química , Níquel/química , Carbono/química , Catálise , Eletrodos , Peróxido de Hidrogênio/química , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Oxirredução , Ligação Proteica
5.
Artigo em Inglês | MEDLINE | ID: mdl-17768082

RESUMO

Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of 2-(1-oxo-1 H-inden-3-yl)-2H-indene-1,3-dione (OID). Experimental studies were conducted on these parameters, including X-ray, FT-IR and 13C NMR spectroscopy. The optimized geometries of OID and its bonding characteristics as well as IR and NMR spectra have been calculated and analyzed. It was observed that the bond lengths and angles in the molecule, obtained by X-ray, IR and NMR at the level of theory, were in a good agreement with those of the experiment. The correlation between the theoretical and the experimental vibrational frequencies and the chemical shifts of the OID molecule were 0.994 and 0.991, respectively. The agreement mutually verified the accuracy of the experimental method and the validity of the applied mathematical model.


Assuntos
Indenos/química , Espectroscopia de Ressonância Magnética/métodos , Modelos Moleculares , Espectrofotometria Infravermelho/métodos , Cristalografia por Raios X , Modelos Teóricos , Conformação Molecular , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Vibração
6.
Biophys Chem ; 129(2-3): 259-68, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17628321

RESUMO

This work describes the performance of cytochrome c/nickel oxide nanoparticles/glassy carbon electrode, prepared by the electrochemical deposition of the nickel oxide nanoparticles (NiO NPs) on the glassy carbon (GC) electrode surface and the cytochrome c immobilization on the nickel oxide nanoparticle surfaces. An extensive sample examination with the help of the SEM and AFM presented the existence of different geometrical shapes of the nickel oxide particles. These geometrical structures could lead to the better immobilization of proteins on their surfaces. The resulting electrode displayed an excellent behavior for the redox of the cytochrome c. Also, the resulting heme protein exhibited a direct electrical contact with the electrode because of the structural alignment of the heme protein on the nanometer-scale nickel oxide surfaces. This method could be suitable for applications to nanofabricated devices. In the end, it was concluded that the cytochrome c could be tethered to the nanometer-scale nickel oxide surfaces.


Assuntos
Citocromos c/química , Enzimas Imobilizadas/química , Nanopartículas/química , Nanotecnologia/métodos , Níquel/química , Carbono/química , Eletrodos , Vidro/química , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanotecnologia/instrumentação , Oxirredução , Potenciometria , Propriedades de Superfície
7.
Biophys Chem ; 128(1): 30-7, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17389147

RESUMO

The performance of a single-walled carbon nanotube:graphite-based electrode, prepared by mixing single-walled carbon nanotubes (SWCNTs) and graphite powder, is described. The resulting electrode shows an excellent behavior for the redox of caffeic acid (CA), an important biological molecule. Due to the existing resemblance between electrochemical and biological reactions, it can be assumed that the oxidation mechanisms on the electrode and in the body share similar principles. SWCNT:graphite-based electrode presents a significant decrease in the overvoltage for the CA oxidation as well as a dramatic improvement in the reversibility of the CA redox behavior in comparison with the graphite-based and glassy carbon (GC) electrodes.


Assuntos
Ácidos Cafeicos/química , Grafite/química , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Eletroquímica , Microeletrodos , Microscopia Eletrônica de Varredura , Modelos Químicos , Modelos Moleculares , Oxirredução
8.
Chem Pharm Bull (Tokyo) ; 54(10): 1391-6, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17015975

RESUMO

This is an environmentally friendly method in the field of electroorganic reactions under controlled potential electrolysis, without toxic reagents at a carbon electrode in an undivided cell which involves the (EC) mechanism reaction and comprises two steps alternatively; (i) electrochemical oxidation and (ii) chemical reaction. In particular, the electrochemical oxidation of 4-tert-butylcatechol, 4-methylcatechol and 2,3-dihydroxybenzoic acid in the presence of 2-phenyl-1,3-indandione has been studied in a water-acetonitrile (90 : 10) mixture. The research includes the use of a variety of experimental techniques, such as cyclic voltammetry, controlled-potential electrolysis, and spectroscopic identification of products (FT-IR, (1)H-NMR, and MS spectrometry).


Assuntos
Indanos/síntese química , Carbono , Catecóis/síntese química , Catecóis/química , Eletroquímica , Eletrodos , Eletrólise , Hidroxibenzoatos/síntese química , Hidroxibenzoatos/química , Indanos/química , Estrutura Molecular , Oxirredução , Estereoisomerismo
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