Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Bioprocess Biosyst Eng ; 44(7): 1461-1476, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33818638

RESUMO

Biomediated ecofriendly method for the synthesis of nickel oxide nanoparticles using plants extracts (Toona ciliata, Ficus carica and Pinus roxburghii) has been reported. The nanoparticles so obtained were characterized by various techniques such as ultraviolet-visible, powder X-ray diffraction, Fourier transform infrared spectroscopy, attenuated total reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis and fluorescence spectroscopy. Formation of nickel oxide nanoparticles was confirmed by Fourier transform infrared spectroscopy and X-ray diffraction where the former technique ascertains the formation of bond between nickel and oxygen. The nickel oxide nanoparticles were found to be crystalline cubic face centered and show intense photoluminescence emission at 416, 414 and 413 nm, respectively. The antibacterial activity was studied against gram positive and gram negative bacterial species by agar well diffusion method. The nickel oxide nanoparticles show better activity against some bacterial strains with reference to the standard drugs Ciprofloxacin and Gentamicin. The anthelmintic activity against Pheretima posthuma of nanomaterials obtained from Pinus roxburghii was found to be greater than that derived from Toona ciliata and Ficus carica using the standard drug Albendazole. This method takes the advantage of the sustainable and economic approach for the synthesis of metal oxide nanoparticles.


Assuntos
Biotecnologia/métodos , Ficus/metabolismo , Níquel/química , Pinus/metabolismo , Toona/metabolismo , Albendazol/química , Ciprofloxacina/química , Gentamicinas/química , Química Verde/métodos , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Oxigênio/química , Tamanho da Partícula , Extratos Vegetais/química , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios X
2.
Chem Biodivers ; 16(8): e1900145, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31207044

RESUMO

Copper oxide nanomaterials were synthesized by a facile sustainable biological method using two plant species (Zanthoxylum armatum DC. and Berberis lycium Royle). The formation of materials was confirmed by FT-IR, ATR, UV-visible, XRD, TEM, SEM, EDX, TGA and PL. The antibacterial activity was evaluated by agar well diffusion method to ascertain the efficacy of plant species extract and extract derived copper oxide nanomaterials against six Gram-positive bacteria namely Staphylococcus aureus, Streptococcus mutans, Streptococcus pyogenes, Corynebacterium diphtheriae, Corynebacterium xerosis, Bacillus cereus and four Gram-negative bacteria such as Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris against the standard drug, Ciprofloxacin for Gram-positive and Gentamicin for Gram-negative bacteria, respectively. In both cases, copper oxide nanomaterials were found to be sensitive in all the bacterial species. Sensitivity of copper oxide nanomaterials shows an be higher as compared to plant species extract against different bacteria. Scavenging activity of plant extracts along with nanomaterials have been accessed using previously reported protocols employing ascorbic acid as standard. Scavenging activity of copper oxide nanomaterials shows an increase with increase in concentration. The biological activity (bactericidal and scavenging efficiency) of plant derived copper oxide nanomaterials revealed that these materials can be used as potent antimicrobial agent and DPPH scavengers in industrial as well as pharmacological fields.


Assuntos
Antibacterianos/química , Berberis/química , Cobre/química , Sequestradores de Radicais Livres/química , Nanoestruturas/química , Zanthoxylum/química , Antibacterianos/farmacologia , Berberis/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Testes de Sensibilidade Microbiana , Nanoestruturas/toxicidade , Folhas de Planta/química , Espectroscopia de Infravermelho com Transformada de Fourier , Zanthoxylum/metabolismo
3.
Int J Biol Macromol ; 203: 292-301, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35074335

RESUMO

The present article reports the biogenic synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) from the extract of Acacia auriculiformis (AA) leaves using biogenic approach. Several spectral and morphological studies namely UV-vis, Fourier transform infrared (FT-IR), tunneling electron microscopy along with selected area electron diffraction (TEM/SAED), scanning electron microscopy along with energy dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) were carried out which ascertains the successful formation of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) starting from Silver nitrate and Chloroauric acid respectively. On the basis of TEM/SAED and SEM-EDX, AgNPs were found to be more regular with smaller particle size and hence they were selected for biological studies. Thermal techniques like thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) were also performed to study the comparative thermal stability of AgNPs and AuNPs where AgNPs were found to be thermally more stable. Several biophysical techniques including Thioflavin T assay, ANS assay, Rayleigh scattering method and turbidity assay were also performed. These assays confirm that AgNPs possess better inhibitory property. Moreover, antioxidant activity of AgNPs was also carried out using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and AgNPs were found to be good antioxidant.


Assuntos
Acacia , Doença de Alzheimer , Nanopartículas Metálicas , Doença de Parkinson , Antibacterianos/farmacologia , Ouro/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Folhas de Planta/química , Prata/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
J Mater Chem B ; 10(2): 170-203, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34889937

RESUMO

Absorbent polymers or hydrogel polymer materials have an enhanced water retention capacity and are widely used in agriculture and medicine. The controlled release of bioactive molecules (especially drug proteins) by hydrogels and the encapsulation of living cells are some of the active areas of drug discovery research. Hydrogel-based delivery systems may result in a therapeutically advantageous outcome for drug delivery. They can provide various sequential therapeutic agents including macromolecular drugs, small molecule drugs, and cells to control the release of molecules. Due to their controllable degradability, ability to protect unstable drugs from degradation and flexible physical properties, hydrogels can be used as a platform in which various chemical and physical interactions with encapsulated drugs for controlled release in the system can be studied. Practically, hydrogels that possess biodegradable properties have aroused greater interest in drug delivery systems. The original three-dimensional structure gets broken down into non-toxic substances, thus confirming the excellent biocompatibility of the gel. Chemical crosslinking is a resource-rich method for forming hydrogels with excellent mechanical strength. But in some cases the crosslinker used in the synthesis of the hydrogels may cause some toxicity. However, the physically cross-linked hydrogel preparative method is an alternative solution to overcome the toxicity of cross-linkers. Hydrogels that are responsive to stimuli formed from various natural and synthetic polymers can show significant changes in their properties under external stimuli such as temperature, pH, light, ion changes, and redox potential. Stimulus-responsive hydrogels have a wider range of applications in biomedicine including drug delivery, gene delivery and tissue regeneration. Stimulus-responsive hydrogels loaded with multiple drugs show controlled and sustained drug release and can act as drug carriers. By integrating stimulus-responsive hydrogels, such as those with improved thermal responsiveness, pH responsiveness and dual responsiveness, into textile materials, advanced functions can be imparted to the textile materials, thereby improving the moisture and water retention performance, environmental responsiveness, aesthetic appeal, display and comfort of textiles. This review explores the stimuli-responsive hydrogels in drug delivery systems and examines super adsorbent hydrogels and their application in the field of agriculture.


Assuntos
Agricultura/métodos , Preparações de Ação Retardada/química , Hidrogéis/química , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/classificação , Hidrogéis/síntese química , Hidrogéis/classificação , Concentração de Íons de Hidrogênio , Oxirredução , Polímeros/química , Materiais Inteligentes/síntese química , Materiais Inteligentes/química , Materiais Inteligentes/classificação , Temperatura , Água/química
5.
Int J Biol Macromol ; 164: 526-539, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32682975

RESUMO

Chitin, a polysaccharide that occurs abundantly in nature after cellulose, has attracted the interest of the scientific community due to its plenty of availability and low cost. Mostly, it is derived from the exoskeleton of insects and marine crustaceans. Often, it is insoluble in common solvents that limit its applications but its deacetylated product, named chitosan is found to be soluble in protonated aqueous medium and used widely in various biomedical fields. Indeed, the existence of the primary amino group on the backbone of chitosan provides it an important feature to modify it chemically into other derivatives easily. In the present review, we present the structural properties of chitin, and its derivatives and highlighted their biomedical implications including, tissue engineering, drug delivery, diagnosis, molecular imaging, antimicrobial activity, and wound healing. We further discussed the limitations and prospects of this versatile natural polysaccharide.


Assuntos
Quitina/química , Crustáceos/química , Insetos/química , Exoesqueleto/química , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Configuração de Carboidratos , Quitina/farmacologia , Sistemas de Liberação de Medicamentos , Engenharia Tecidual , Cicatrização/efeitos dos fármacos
6.
J Photochem Photobiol B ; 185: 262-274, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29981488

RESUMO

A phytoextract mediated synthesis of iron oxide nanoparticles using Agrewia optiva (Dhaman or Biul) and Prunus persica (Peach) leaf extract as capping and stabilizing agent without using hazardous toxic chemicals via biogenic route has been studied. The biogenic method of synthesis is convenient, rapid, cost effective and ecofriendly. The green synthesized nanoparticles were characterized by Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, Attenuated total reflectance spectroscopy, X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and dynamic light scattering measurements. The antibacterial study was determined by agar well diffusion method to measure the efficiency of both phyto species extract and its mediated iron oxide nanoparticles against five gram positive bacterial stains such as Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus pyrogenes (S. pyrogenes), Corynebacterium diphtheriae (C. diphtheriae) and Corynebacterium xerosis (C. xerosis) and three gram negative bacterial stains such as Escherichia coli (E. coli), Klebsiella pneuomoniae (K. pneuomoniae) and Pseudomonas aeruginosa (P. aeruginosa). The antibiotic Ciprofloxacin and Gentamicin have been used as reference standard drugs for gram positive and gram negative bacterial stains, respectively. The antioxidant activity of the phyto extracts and prepared nanoparticles have been performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay employing l-ascorbic acid as a standard.


Assuntos
Antibacterianos/química , Antioxidantes/química , Grewia/química , Nanopartículas Metálicas/química , Prunus persica/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antioxidantes/síntese química , Difusão Dinâmica da Luz , Compostos Férricos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Grewia/metabolismo , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Prunus persica/metabolismo , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier
7.
J Obstet Gynaecol India ; 66(Suppl 1): 377-82, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27651633

RESUMO

PURPOSE: To detect whether ultrasonographic parameters and Doppler analysis of uterine blood flow can be of value in the prediction of endometrial receptivity in infertile female patients undergoing embryo transfer. METHODS: In this study, a total of 200 women with primary infertility undergoing embryo transfer were analyzed. Transvaginal ultrasonography was done on the 10th day of the menstrual cycle. To assess the uterine receptivity, we analyzed all the ultrasonographic and Doppler parameters. The slightly modified version of Applebaum Uterine Scoring System was used. This uterine scoring system included all the following parameters: endometrial thickness, endometrial morphology, endometrial blood flow within zone 3, myometrial echogenecity, uterine artery pulsatility index (PI), end diastolic blood flow, and myometrial blood flow internal to the arcuate vessels seen on gray-scale examination. RESULTS: The pregnancy rates were higher in women with thick, distinct five-line endometrium and multifocal endometrial vascularity within zone 3. Absent endometrial flow, despite highest values for the other parameters, was associated with no conception. In our study, no pregnancy occurred with uterine PI values of more than 2.8. Absence or reversal of end diastolic blood flow was associated with no conception. A maximum score of 20 was associated with the pregnancy rate of 97.4 %, whereas scores of 13 or less resulted in no pregnancies. CONCLUSION: Uterine scoring system will help to perform embryo transfers in only favorable uteri and postpone or cancel those cycles in which poor uterine score is demonstrated.

8.
Int J Biol Macromol ; 93(Pt A): 276-289, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27543347

RESUMO

Herein, we report the synthesis of a novel tri-component nanocomposite system incorporating ß-cyclodextrin (ß-CD) with nano-hydroxyapatite (n-HA) and chitosan (CS), (n-HA/ß-CD/CS) at three different temperatures via co-precipitation method. The chemical interactions and surface morphology have been evaluated by TEM, SEM and AFM techniques revealing the agglomerated nanoparticles in CS/n-HA-HA binary system whereas the ternary systems produced needle shaped nanoparticles dispersed homogeneously at low temperature with more porous and rougher surface. The addition of ß-CD in CS/n-HA at low temperature decreased the particle size and raised the thermal stability as compared to CS/n-HA. The comparative hemolytic, protein adsorption and platelet adhesion studies confirmed the better hemocompatibility of n-HA/ß-CD/CS-(RT,HT,LT) nanocomposites relative to CS/n-HA. The cell viability has been evaluated in vitro using MG-63 cell line which revealed superior non toxicity of n-HA/ß-CD/CS-LT nanocomposite in comparison to n-HA/ß-CD/CS-(RT,HT) and CS/n-HA nanocomposites. Thus it may be concluded that the orchestrated organic/inorganic n-HA/ß-CD/CS-(RT,HT,LT) nanocomposites exhibited relatively higher cell viability of human osteoblast cells, stimulated greater osteogenesis, controlled biodegradation, enhanced antibacterial activity with excellent in-vitro biomineralization and remarkable mechanical parameters as compared to CS/n-HA nanocomposite and thus may provide opportunities for potential use as an alternative biomaterial for Bone tissue engineering applications.


Assuntos
Osso e Ossos/citologia , Quitosana/química , Durapatita/química , Nanocompostos/química , Engenharia Tecidual , beta-Ciclodextrinas/química , Fosfatase Alcalina/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Força Compressiva , Dureza , Hemólise/efeitos dos fármacos , Humanos , Nanocompostos/toxicidade , Alicerces Teciduais/química
9.
Int J Biol Macromol ; 72: 1196-204, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25450541

RESUMO

The covalent binding of yeast alcohol dehydrogenase (YADH) enzyme complex in a series of magnetic crystalline Ni-Co nanoferrites, synthesized via sol-gel auto combustion technique was investigated. The structural analysis, morphology and magnetic properties of Ni-Co nanoferrites were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), vibrating-sample magnetometer (VSM), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). The comparative analysis of the HRTEM micrographs of bare magnetic nanoferrite particles and particles immobilized with enzyme revealed an uniform distribution of the particles in both the cases without undergoing change in the size which was found to be in the range 20-30 nm. The binding of YADH to Ni-Co nanoferrites and the possible binding mechanism have been suggested by comparing the FTIR results. The binding properties of the immobilized YADH enzyme were also studied by kinetic parameters, optimum operational pH, temperature, thermal stability and reusability. The immobilized YADH exhibits enhanced thermal stability as compared to the free enzyme over a wide range of temperature and pH, and showed good durability after recovery by magnetic separation for repeated use.


Assuntos
Cobalto/química , Enzimas Imobilizadas/metabolismo , Compostos Férricos/química , Fenômenos Magnéticos , Nanopartículas/química , Níquel/química , Saccharomyces cerevisiae/enzimologia , Álcool Desidrogenase , Amidas/metabolismo , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Magnetometria , Nanopartículas/ultraestrutura , Reciclagem , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Temperatura , Difração de Raios X
10.
Int J Biol Macromol ; 80: 282-92, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26116779

RESUMO

A novel ternary nanocomposite system incorporating hydroxyapatite, chitosan and starch (n-HA/CS-ST) has been synthesized by co-precipitation method at room temperature, addressing the issues of biocompatibility, mechanical strength and cytotoxicity required for bone tissue engineering. The interactions, crystallite size, surface morphology and thermal stability against n-HA/CS nanocomposite have been obtained by comparing the results of FTIR, SEM, TEM, DLS, XRD and TGA/DTA. A comparative study of bioactivity and thermal stability of n-HA/CS and n-HA/CS-ST nanocomposites revealed that the incorporation of starch as templating agent enhanced these properties in n-HA/CS-ST nanocomposite. A lower swelling rate of n-HA/CS-ST relative to n-HA/CS indicates a higher mechanical strength supportive of bone tissue ingrowths. The MTT assay on murine fibroblast L929 and human osteoblasts-like MG-63 cells and in vitro bioactivity of n-HA/CS-ST matrix referred superior non-toxic nature of n-HA/CS-ST nanocomposite and greater possibility of osteointegration in vivo respectively. Furthermore n-HA/CS-ST exhibited improved antibacterial property against both Gram-positive and Gram-negative bacteria relative to n-HA/CS.


Assuntos
Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Osso e Ossos/efeitos dos fármacos , Quitosana/química , Durapatita/química , Nanocompostos/química , Amido/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Biomimética , Osso e Ossos/citologia , Linhagem Celular , Técnicas de Química Sintética , Escherichia coli/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Fenômenos Mecânicos , Camundongos , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Alicerces Teciduais/química
11.
J Photochem Photobiol B ; 153: 20-32, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26386641

RESUMO

A polycarbazole-titanium dioxide (PCz/TiO2-8) nanocomposite was synthesized for the first time by in-situ oxidative polymerization with APS as an oxidizing agent in the presence of TiO2 nanoparticles which was characterized by SEM, TEM, FT-IR, DTA and TGA techniques. The SEM and TEM results showed that PCz has polymerized on the surface of the TiO2. The results confirmed the incorporation of TiO2 in PCz indicating the formation of nanocomposite due to strong interaction between TiO2 and PCz matrix affecting the properties as compared to pristine PCz. The PCz/TiO2-8 nanocomposite was tested for antimicrobial activity and found to exhibit activity against gram negative and gram positive strains at micromolar concentrations. The four types of 3D molecular field descriptors or field points as extrema of electrostatic, steric, and hydrophobic fields were explained. These field points were used to define the properties necessary for a molecule to bind in a characteristic way into a specified active site. A molecular docking simulation was used to predict the modes of interactions of the drugs (PCz and PCz/TiO2-8) with DNA. The molecular docking conclusion indicated that the modes of interactions between two (PCz and PCz/TiO2-8) and DNA helix can be regarded as minor groove binder. The K value (3.55 × 10(4) M(-1) and 2.13 × 10(5) M(-1)) obtained from fluorescence data are indicative of binding of PCz and PCz/TiO2-8 with DNA helix.


Assuntos
Anti-Infecciosos/química , DNA/química , Nanopartículas Metálicas/química , Simulação de Acoplamento Molecular , Polímeros/química , Anti-Infecciosos/farmacologia , Sítios de Ligação , Carbazóis/química , Dicroísmo Circular , DNA/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Conformação de Ácido Nucleico , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termogravimetria , Titânio/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA