RESUMO
The present study demonstrated the preparation of three different acid-functionalised magnetic nanoparticles (MNPs) and evaluation for their catalytic efficacy in hydrolysis of cellobiose. Initially, iron oxide (Fe3O4)MNPs were synthesised, which further modified by applying silica coating (Fe3O4-MNPs@Si) and functionalised with alkylsulfonic acid (Fe3O4-MNPs@Si@AS), butylcarboxylic acid (Fe3O4-MNPs@Si@BCOOH) and sulphonic acid (Fe3O4-MNPs@Si@SO3H) groups. The Fourier transform infrared analysis confirmed the presence of above-mentioned acid functional groups on MNPs. Similarly, X-ray diffraction pattern and energy dispersive X-ray spectroscopy analysis confirmed the crystalline nature and elemental composition of MNPs, respectively. TEM micrographs showed the synthesis of spherical and polydispersed nanoparticles having diameter size in the range of 20-80â nm. Cellobiose hydrolysis was used as a model reaction to evaluate the catalytic efficacy of acid-functionalised nanoparticles. A maximum 74.8% cellobiose conversion was reported in case of Fe3O4-MNPs@Si@SO3H in first cycle of hydrolysis. Moreover, thus used acid-functionalised MNPs were magnetically separated and reused. In second cycle of hydrolysis, Fe3O4-MNPs@Si@SO3H showed 49.8% cellobiose conversion followed by Fe3O4-MNPs@Si@AS (45%) and Fe3O4-MNPs@Si@BCOOH (18.3%). However, similar pattern was reported in case of third cycle of hydrolysis. The proposed approach is considered as rapid and convenient. Moreover, reuse of acid-functionalised MNPs makes the process economically viable.
Assuntos
Celobiose/química , Nanopartículas de Magnetita/química , Ácidos Sulfônicos/química , Ácidos Carboxílicos/química , Celobiose/análise , Hidrólise , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Nanotechnology is widely used in biomedical applications, engineering sciences, and food technology. The application of nanocompounds play a pivotal role in food protection, preservation, and increasing its shelf life. The changing lifestyle, use of pesticides, and biological and/or chemical contaminants present in food directly affect its quality. Metallic nanoparticles (MNPs) are useful to develop products with antimicrobial activity and with the potential to improve shelf life of food and food products. Due to the prevention of microbial growth, MNPs have attracted the attention of researchers. Biopolymers/polymers can be easily combined with different MNPs which act as a vehicle not only for one type of particles but also as a hybrid system that allows a combination of natural compounds with metallic nanocompounds. However, there is a need for risk evaluation to use nanoparticles in food packaging. In this review, we aim to discuss how MNPs incorporated into polymers/biopolymers matrices can be used for food preservation, considering the quality and safety, which are desirable in food technology.
Assuntos
Conservação de Alimentos/métodos , Tecnologia de Alimentos/métodos , Nanopartículas Metálicas , Nanotecnologia/métodos , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Microbiologia de Alimentos , Armazenamento de Alimentos/métodosRESUMO
The authors report the comparative antibacterial activity of silver nanoparticles synthesised by biological (using Fusarium oxysporum) and chemical routes in the presence and absence of pluronic F68 as a stabilising agent. The production of silver nanoparticles was evidenced by UV-visible spectra, with absorbance at about 420 nm in the case of both biological and chemical synthesis. X-ray diffraction pattern confirmed the presence of face-centred cubic structure (FCC plane). The nanoparticles characterised by transmission and scanning electron microscopy showed spherical silver nanoparticles with size range of 5-40 and 10-70 nm in the case of biologically and chemically synthesised nanoparticles, respectively. Addition of pluronic F68 showed the stabilisation of silver nanoparticles. Antibacterial efficacy of silver nanoparticles demonstrated different inhibitory activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Overall, biologically synthesised silver nanoparticles showed higher activity as compared with chemically synthesised nanoparticles. Silver nanoparticles synthesised in the presence of pluronic F68 by the chemical route exhibited synergism in antibacterial activity as compared with those synthesised without pluronic F68. On the contrary, biogenic silver nanoparticles without pluronic F68 showed higher antibacterial potential.
Assuntos
Antibacterianos/síntese química , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Excipientes/química , Nanopartículas Metálicas/administração & dosagem , Poloxâmero/síntese química , Prata/administração & dosagem , Antibacterianos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Composição de Medicamentos/métodos , Sinergismo Farmacológico , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Prata/químicaRESUMO
Noble metals and their compounds have been used as therapeutic agents from the ancient time in medicine for the treatment of various infections. Recently, much progress has been made in the field of nanobiotechnology towards the development of different kinds of nanomaterials with a wide range of applications. Among the metal nanoparticles, noble metal nanoparticles have demonstrated potential biomedical applications. Due to the small size, nanoparticles can easily interact with biomolecules both at surface and inside cells, yielding better signals and target specificity for diagnostics and therapeutics. Noble metal nanoparticles inspired the researchers due to their remarkable role in detection and treatment of dreadful diseases. In this review, we have attempted to focus on the biomedical applications of noble metal nanoparticles particularly, silver, gold, and platinum in diagnosis and treatment of dreaded diseases such as cancer, human immunodeficiency virus (HIV), tuberculosis (TB), and Parkinson disease. In addition, the role of silver nanoparticles (AgNPs) such as novel antimicrobials, gold nanoparticles (AuNPs) such as efficient drug carrier, uses of platinum nanoparticles (PtNPs) in bone allograft, dentistry, etc. have been critically reviewed. Moreover, the toxicity due to the use of metal nanoparticles and some unsolved challenges in the field have been discussed with their possible solutions.
Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Tratamento Farmacológico , Ouro/química , Nanopartículas Metálicas/uso terapêutico , Platina/química , Prata/química , Animais , Ouro/farmacologia , Humanos , Medicina/instrumentação , Medicina/métodos , Nanopartículas Metálicas/química , Platina/farmacologia , Prata/farmacologiaRESUMO
The authors report extracellular mycosynthesis of silver nanoparticles (AgNPs) by Phoma capsulatum, Phoma putaminum and Phoma citri. The AgNPs thus synthesised were characterised by UV-visible spectrophotometer, Fourier transform infrared spectroscopy, Nanosight LM20 and transmission electron microscopy, which confirmed the synthesis of mostly spherical and polydisperse nanoparticles capped with proteins. The size of AgNPs was found in the range of 10-80 , 5-80 and 5-90 nm with an average size of 31.85, 25.43 and 23.29 nm by P. capsulatum, P. putaminum and P. citri, respectively. Further, potential antimicrobial activity was reported against Aspergillus niger, Candida albicans, Salmonella choleraesuis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. The lowest minimal inhibitory concentration (MIC) (0.85 µg/ml) was reported for AgNPs synthesised from P. citri against S. choleraesuis. However, AgNPs synthesised from P. capsulatum showed the highest MIC (10.62 µg/ml) against S. choleraesuis, P. aeruginosa and E. coli (clinical isolate). The same MIC values (10.62 µg/ml) were also reported against P. aeruginosa and both clinical and standard isolates of E. coli for AgNPs synthesised from P. citri. It was also observed that all the silver nanoparticles showed remarkable antifungal and antibacterial activity against these tested pathogens as compared with the commercially available antifungal and antibacterial agents.
Assuntos
Anti-Infecciosos/química , Ascomicetos/metabolismo , Nanopartículas Metálicas/química , Prata/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Biotecnologia , Fungos/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Prata/metabolismoRESUMO
The authors report the biological synthesis of silver nanoparticles (NPs) by Phoma gardeniae (ITCC 4554). The detection of silver NP formation was done by visual observation, and UV-vis spectrophotometer analysis. Further, these mycogenic silver NPs were characterised by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and nanoparticle tracking and analysis system. The TEM analysis revealed the formation of spherical and polydispersed NPs within the range of 10-30 nm. FTIR analysis confirmed the presence of proteins as capping agents. They also evaluated the antimicrobial activity of silver NPs against Candida albicans, Salmonella choleraesuis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. They found remarkable inhibition of Escherichia coli followed by Staphylococcus aureus, Candida albicans, Salmonella choleraesuis and Pseudomonas aeruginosa as compared with antibiotics. The main aim of the present study was to synthesise mycogenic silver NPs by P. gardeniae and to evaluate their antimicrobial activity in order to find their potential against human pathogenic microbes.