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1.
J Nanosci Nanotechnol ; 20(2): 709-718, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383066

RESUMO

We report the preparation and characterization of a new heterostructured Ag-TiO2/ZnFe2O4 (ATZ) nanocomposite. X-ray diffraction (XRD) reveals the presence of spinel type ZnFe2O4 and anatase TiO2. Scanning electron microscope (SEM) images of ATZ nanocomposites show that Ag nanoparticles are successfully loaded on the composite Ag-TiO2 and is uniformly distributed on surface of ZnFe2O4 forming a nanocomposite with an approximate particle size of 44.8 nm. High-resolution transmission electron microscope (HR-TEM) analysis clearly indicates the particles with spherical and hexagonal structure and sizes of most of the particles are below 50 nm. Ultra violet-visible diffuse reflectance spectra (UV-vis-DRS) show that Ag-TiO2/ZnFe2O4 has increased visible absorption than TiO2. Photoluminescence (PL) spectra shows that the intensity of ATZ is low relative to prepared TiO2. The photocatalytic degradation of Reactive Yellow 86 (RY 86) dye was studied. Based on the band gap energies of TiO2 and ZnFe2O4, a mechanism of degradation is given. Photocatalytic activity results suggest that as-prepared ATZ shows higher photodegradation efficiency than pure TiO2. The main reactive oxidative species involved in the degradation and stability of photocatalyst were also investigated. ATZ shows higher electrocatalytic activity than TiO2 for methanol electrooxidation. The cytotoxicity of ATZ was analysed. Multifunctionality of ATZ makes it useful for environmental and biomedical applications.

2.
ACS Appl Mater Interfaces ; 11(1): 288-299, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30539634

RESUMO

In the field of nanomedicine, drug-loaded nanocarriers that integrate nanotechnology and chemotherapeutics are widely used to achieve synergistic therapeutic effects. Here, we prepared mesoporous silica nanoparticles capped with cerium oxide nanoparticles (COP@MSN) wherein a pH trigger-responsive mechanism was used to control drug release and intracellular drug delivery. We blocked the mesopores of the carboxyl-functionalized MSN with aminated COP. These pores could be opened in acidic conditions to release the loaded drug, thus establishing a pH-responsive drug release system. We loaded doxorubicin (DOX) as anticancer biomolecule into the pores of MSN and capped with COP. The COP@DOX-MSN system showed a typical drug release profile in an acidic medium, which, however, was not observed in a neutral medium. In vitro studies using cancer cell line (HeLa) proved that the COP@DOX-MSN entered efficiently into HeLa cells and released DOX to the level sufficient for cytotoxicity. The cytotoxic effect of COP in cancer cells was facilitated by the pro-oxidant property of COPs, which considerably raised the reactive oxygen species (ROS) level, thereby leading to cellular apoptosis. The combination of DOX with COP (COP@DOX-MSN) showed even higher ROS level, demonstrating a cytotoxic synergism of drug and nanoparticle in terms of ROS generation. Collectively, the COP@DOX-MSN is considered useful for cancer treatment with the combined capacity of pH-controlled drug delivery, chemotherapeutics, and redox activity.


Assuntos
Cério , Doxorrubicina , Portadores de Fármacos , Nanopartículas , Neoplasias , Sobrevivência Celular/efeitos dos fármacos , Cério/química , Cério/farmacocinética , Cério/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Oxirredução/efeitos dos fármacos , Dióxido de Silício
3.
3 Biotech ; 8(3): 144, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29484283

RESUMO

Twenty-five primer pairs developed from genomic simple sequence repeats (SSR) were compared with 25 expressed sequence tags (EST) SSRs to evaluate the efficiency of these two sets of primers using 59 sugarcane genetic stocks. The mean polymorphism information content (PIC) of genomic SSR was higher (0.72) compared to the PIC value recorded by EST-SSR marker (0.62). The relatively low level of polymorphism in EST-SSR markers may be due to the location of these markers in more conserved and expressed sequences compared to genomic sequences which are spread throughout the genome. Dendrogram based on the genomic SSR and EST-SSR marker data showed differences in grouping of genotypes. A total of 59 sugarcane accessions were grouped into 6 and 4 clusters using genomic SSR and EST-SSR, respectively. The highly efficient genomic SSR could subcluster the genotypes of some of the clusters formed by EST-SSR markers. The difference in dendrogram observed was probably due to the variation in number of markers produced by genomic SSR and EST-SSR and different portion of genome amplified by both the markers. The combined dendrogram (genomic SSR and EST-SSR) more clearly showed the genetic relationship among the sugarcane genotypes by forming four clusters. The mean genetic similarity (GS) value obtained using EST-SSR among 59 sugarcane accessions was 0.70, whereas the mean GS obtained using genomic SSR was 0.63. Although relatively lower level of polymorphism was displayed by the EST-SSR markers, genetic diversity shown by the EST-SSR was found to be promising as they were functional marker. High level of PIC and low genetic similarity values of genomic SSR may be more useful in DNA fingerprinting, selection of true hybrids, identification of variety specific markers and genetic diversity analysis. Identification of diverse parents based on cluster analysis can be effectively done with EST-SSR as the genetic similarity estimates are based on functional attributes related to morphological/agronomical traits.

4.
J Contemp Dent Pract ; 18(5): 399-404, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28512280

RESUMO

INTRODUCTION: The objectives of this study were to compare the qualitative and quantitative profiles of herpes simplex virus type I (HSV-1) in implant surfaces between participants with peri-implantitis (PI) and Healthy peri-implant tissues and to quantitatively assess the relation between HSV-1 and periopathogens inside the microbiological profile associated with PI. MATERIALS AND METHODS: A total of 40 patients with PI and 40 with healthy peri-implant tissues (HI) were recruited. Plaque samples from peri-implant sulcus and internal implant connections were analyzed using quantitative real-time polymerase chain reaction to detect and quantify HSV-1 and periodonto-pathogens. Frequencies of detection and levels of microorganisms were compared between PI and HI; the frequencies and levels of periodontopathogens were compared between HSV-1+ and HSV-1- PI to assess qualitative relations between HSV-1 and bacteria. Correlation between HSV-1 and periodontopatho-gens levels was assessed in PI and HI. RESULTS: A total of 77 dental implants affected by PI, and 113 HIs were included. The HSV-1 prevalence was slightly higher in PI compared with controls (33.3 vs 23.8%; p > 0.05); HSV-1 was detected in external samples more frequently compared with internal samples. The HSV-1-positive patients revealed higher median loads of Prevotella intermedia (Pi) and Campylobacter rectus (Cr) compared with HSV-1-negative patients. In the PI group, a significant positive correlation was evidenced between HSV-1 and Tannerella forsythia, Parvimonas micra (Pm), Fusobacterium nucleatum, and Cr levels, while in the HI, positive correlation between HSV-1 and Aggregatibacter actinomycetemcomitans, Pi, and Pm was established. CONCLUSION: The HSV-1 prevalence cannot be used to identify PI. The HSV-1 was found in similar levels of PI and HI patients after an average of 6 years of loaded implants. The HSV-1 prevalence cannot be used to identify implants with or without the presence of PI. CLINICAL SIGNIFICANCE: Although HSV-1 is detected in PI site, HSV-1 may represent an unspecific indicator for the host response to the bacterial challenge observed in PI.


Assuntos
Herpes Simples/complicações , Herpesvirus Humano 1/isolamento & purificação , Peri-Implantite/virologia , Idoso , Estudos de Casos e Controles , DNA Viral/isolamento & purificação , Feminino , Gengiva/microbiologia , Gengiva/virologia , Herpesvirus Humano 1/genética , Humanos , Masculino , Pessoa de Meia-Idade
5.
Acta Biomater ; 51: 330-340, 2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28110074

RESUMO

Clinically usable tissue-engineered constructs are currently limited due to their inability of forming microvascular networks necessary for adequate cellular oxygen and nutrient supply upon implantation. The aim of this study is to investigate the conditions necessary for microvascularization in a tissue-engineered construct using vascular endothelial growth factor (VEGF). The construct was made of gelatin methacrylate (GelMA) based cell-laden hydrogel system, which was then covalently linked with VEGF-mimicking peptide (AcQK), using human umbilical vein endothelial cells (HUVECs) as the model cell. The results of the mechanics and gene expression analysis indicated significant changes in mechanical properties and upregulation of vascular-specific genes. The major finding of this study is that the increased expression of vascular-specific genes could be achieved by employing AcQK in the GelMA based hydrogel system, leading to accelerated microvascularization. We conclude that GelMA with covalently-linked angiogenic peptide is a useful tissue engineered construct suitable for microvascularization. STATEMENT OF SIGNIFICANCE: (1) This study reports the conditions necessary for microvascularization in a tissue-engineered construct using vascular endothelial growth factor (VEGF). (2) The construct was made of gelatin methacrylate based cell-laden hydrogel system. (3) There is a significant change observed in mechanical properties and upregulation of vascular-specific genes, in particular CD34, when AcQK is used. (4) The major finding of this study is that the increased expression of vascular-specific genes, i.e., CD34 could be achieved by employing AcQK in the GelMA based hydrogel system, leading to accelerated microvascularization.


Assuntos
Materiais Biomiméticos/farmacologia , Gelatina/química , Células Endoteliais da Veia Umbilical Humana/metabolismo , Proteínas Imobilizadas/farmacologia , Metacrilatos/química , Microvasos/metabolismo , Peptídeos/farmacologia , Fator A de Crescimento do Endotélio Vascular/farmacologia , Sequência de Aminoácidos , Animais , Antígenos CD34/metabolismo , Imunofluorescência , Perfilação da Expressão Gênica , Glicoproteínas/genética , Glicoproteínas/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Microvasos/efeitos dos fármacos , Peptídeos/química , Sus scrofa , Regulação para Cima/efeitos dos fármacos
6.
J Tissue Eng Regen Med ; 11(2): 582-595, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-25393357

RESUMO

Engineered muscle tissues demonstrate properties far from native muscle tissue. Therefore, fabrication of muscle tissues with enhanced functionalities is required to enable their use in various applications. To improve the formation of mature muscle tissues with higher functionalities, we co-cultured C2C12 myoblasts and PC12 neural cells. While alignment of the myoblasts was obtained by culturing the cells in micropatterned methacrylated gelatin (GelMA) hydrogels, we studied the effects of the neural cells (PC12) on the formation and maturation of muscle tissues. Myoblasts cultured in the presence of neural cells showed improved differentiation, with enhanced myotube formation. Myotube alignment, length and coverage area were increased. In addition, the mRNA expression of muscle differentiation markers (Myf-5, myogenin, Mefc2, MLP), muscle maturation markers (MHC-IId/x, MHC-IIa, MHC-IIb, MHC-pn, α-actinin, sarcomeric actinin) and the neuromuscular markers (AChE, AChR-ε) were also upregulated. All these observations were amplified after further muscle tissue maturation under electrical stimulation. Our data suggest a synergistic effect on the C2C12 differentiation induced by PC12 cells, which could be useful for creating improved muscle tissue. Copyright © 2014 John Wiley & Sons, Ltd.


Assuntos
Técnicas de Cocultura , Músculo Esquelético/fisiologia , Mioblastos/citologia , Engenharia Tecidual/métodos , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Linhagem Celular , Fibroblastos/citologia , Gelatina/química , Perfilação da Expressão Gênica , Hidrogéis/química , Camundongos , Contração Muscular , Desenvolvimento Muscular , Fibras Musculares Esqueléticas/citologia , Proteínas Musculares/metabolismo , Células PC12 , RNA Mensageiro/metabolismo , Ratos , Sarcômeros/metabolismo , Suínos
7.
J Mater Sci Mater Med ; 22(2): 209-16, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21153686

RESUMO

Double-step hydrothermal processing is a process where powder compacts of calcium phosphates are exposed to vapor of solvent solution, followed by being immersed in the solution. In the present study, we investigated the effects of ammonium carbonate on formation of calcium-deficient hydroxyapatite (CDHA) through double-step hydrothermal processing. The synthesized CDHA has high crystallinity when the solution has relatively low concentration of the ammonium carbonate ranging from 0.01 to 0.25 mol dm(-3). Carbonate content in the prepared samples were distinctly increased with increasing the concentration of ammonium carbonate to indicate formation of carbonate-containing calcium-deficient hydroxyapatite (CHAp) with low crystallinity. Morphology of the CHAp formed on the compacts varied progressively from rods and rosette-like shape to irregular shape with increase in the initial concentration of the ammonium carbonate in the solution. Application of ammonium carbonate in the double-step hydrothermal processing allows fabrication of irregular-shaped CDHA containing carbonate ions in both phosphate and hydroxide site, with low crystallinity, when the initial concentration of ammonium carbonate was 0.5 mol dm(-3) and more.


Assuntos
Cálcio/química , Durapatita/química , Compostos de Amônio Quaternário/química , Carbonatos/química , Cristalização , Desenho de Equipamento , Concentração de Íons de Hidrogênio , Hidróxidos/química , Íons , Teste de Materiais , Modelos Químicos , Fosfatos/química , Espectrofotometria Atômica/métodos , Temperatura Ambiente , Difração de Raios X
8.
Indian J Microbiol ; 51(4): 456-60, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23024407

RESUMO

A total of 128 faecal samples/rectal swabs were collected from dogs showing signs of diarrhea/enteritis in and around Puducherry, South India. Eighteen clinical samples, showing high HA titre of 1:512 and above and positivity by polymerase chain reaction (PCR) with CPV-2ab primers, were subjected to virus isolation in CRFK cell line. Of the 18 samples processed, 3 samples (16.6%) were positive for CPV and were confirmed by haemagglutination, dot-ELISA, and IFAT. The three cell culture isolates were characterized as CPV-2b types by multiplex PCR as well as by monoclonal antibody typing.

9.
Indian J Virol ; 21(1): 86-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23637484

RESUMO

The present study was aimed at molecular typing of Canine parvovirus (CPV) occurring in Pondicherry using PCR based assays. CPV-2a and CPV-2b types were detected by PCR in 68 (53.12%) out of 128 faecal samples/rectal swabs. All the 68 samples found positive by PCR assay were subjected to multiplex PCR assay with CPV-2ab and CPV-2b primer pairs. Sixty-seven (98.52%) samples were characterized as CPV-2b type and one sample (1.47%) was categorized as CPV-2a type. Sixty clinical samples found negative by CPV-2ab primers were subjected to another PCR assay with CPV-555 primer pair for detecting CPV-2c. Though three samples (5%) responded to this PCR, subsequent RFLP of these PCR products with MboII did not show any cleavage indicating the absence of CPV-2c in Pondicherry. It was inferred that CPV-2b was the most prevalent CPV type in Pondicherry. It was further concluded that the CPV-2 variants (CPV-2a, CPV-2b and CPV-2c) currently circulating in the field worldwide could be diagnosed by employing multiplex PCR and PCR-RFLP assays.

10.
J Mater Sci Mater Med ; 20 Suppl 1: S77-83, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18543086

RESUMO

Thermally stable hydroxyapatite (HAp) was synthesized by hydrothermal method in the presence of malic acid. X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) was done on the synthesized powders. These analyses confirmed the sample to be free from impurities and other phases of calcium phosphates, and were of rhombus morphology along with nanosized particles. IR and Raman analyses indicated the adsorption of malic acid on HAp. Thermal stability of the synthesized HAp was confirmed by DTA and TGA. The synthesized powders were thermally stable upto 1,400 degrees C and showed no phase change. The proposed method might be useful for producing thermally stable HAp which is a necessity for high temperature coating applications.


Assuntos
Substitutos Ósseos/síntese química , Engenharia Química/métodos , Durapatita/síntese química , Nanopartículas , Substitutos Ósseos/química , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/química , Durapatita/química , Galvanoplastia/métodos , Teste de Materiais , Modelos Biológicos , Nanopartículas/química , Porosidade , Pós/síntese química , Pós/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Água/farmacologia , Difração de Raios X
11.
J Mater Sci Mater Med ; 20 Suppl 1: S43-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18560768

RESUMO

A novel, porous triphasic calcium phosphate composed of nonresorbable hydroxyapatite (HAp) and resorbable tricalcium phosphate (alpha- and beta-TCP) has been synthesized hydrothermally at a relatively low temperature. The calcium phosphate precursor for hydrothermal treatment was prepared by gel method in the presence of ascorbic acid. XRD, FT-IR, Raman analyses confirmed the presence of HAp/TCP. The surface area and average pore size of the samples were found to be 28 m2/g and 20 nm, respectively. The samples were found to be bioactive in simulated body fluid (SBF).


Assuntos
Substitutos Ósseos/síntese química , Fosfatos de Cálcio/síntese química , Engenharia Química/métodos , Durapatita/síntese química , Algoritmos , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Líquidos Corporais/fisiologia , Substitutos Ósseos/química , Fosfatos de Cálcio/química , Durapatita/química , Galvanoplastia/métodos , Temperatura Alta , Teste de Materiais , Porosidade , Água/farmacologia , Difração de Raios X
12.
J Mater Sci Mater Med ; 20 Suppl 1: S271-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19089600

RESUMO

The effect of swift heavy oxygen ion irradiation of hydroxyapatite on its in vitro bioactivity was studied. The irradiation experiment was performed using oxygen ions at energy of 100 MeV with 1 x 10(12) and 1 x 10(13) ions/cm2 fluence range. The irradiated samples were characterized by glancing angle X-ray diffraction (GXRD), photoluminescence spectroscopy (PL) and scanning electron microscopy (SEM). GXRD showed that irradiated samples exhibited better crystallinity. The irradiated samples revealed an increase in PL intensity. In addition, the irradiated hydroxyapatite was found to have enhanced bioactivity.


Assuntos
Durapatita/química , Durapatita/efeitos da radiação , Oxigênio/farmacologia , Líquidos Corporais/fisiologia , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Substitutos Ósseos/efeitos da radiação , Durapatita/farmacologia , Íons Pesados , Concentração de Íons de Hidrogênio , Teste de Materiais , Microscopia Eletrônica de Varredura , Modelos Biológicos , Propriedades de Superfície , Difração de Raios X
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