scholarly journals Osseointegration of hydroxyapatite coatings doped with silver nanoparticles: scanning electron microscopy studies on a rabbit model

Author(s):  
Łukasz Łapaj ◽  
Waldemar Woźniak ◽  
Jacek Markuszewski
Author(s):  
S C Joshi ◽  
Utkarsh Kaushik ◽  
Aproova Upadhyaya ◽  
Priyanka Sharma

ABSTRACTObjective: The synthesis of nanoparticles from biological processes is evolving a new era of research interests in nanotechnology. Silver nanoparticlesare usually synthesized by chemicals and physical method, which are quite toxic and flammable in nature. This study deals with an environmentfriendly biosynthesis process of antibacterial silver nanoparticles using Momordica charantia fruit.Methods: AgNO3 (5 mM) was allowed to react with fruit extract of M. charantia. Biosynthesis of AgNPs was optimized by changing temperature,pH, and solvent. The silver nanoparticles so formed were characterized using ultraviolet-visible (UV-VIS) spectroscopy, Fourier transform infraredspectroscopy (FTIR), dynamic light scattering (DLS), atomic force microscope (AFM), and scanning electron microscopy (SEM).Results: UV-VIS spectra show absorption peak between 420 and 430 nm. The FTIR analysis showed the alcoholic, lactam, and nitro group presentin the plant extract, which were responsible for the reduction in AgNPs. The SEM images showed the size distribution of the nanoparticles and theaverage size was found to be 50-100 nm. By DLS analysis and AFM analysis, average sizes of the silver nanoparticles were of 150 nm. The results ofthese analyses confirmed the formation of silver nanoparticles. Silver nanoparticles were tested against Bacillus cereus and Staphylococcus epidermidisstrains using disc diffusion method and were found to be effective.Conclusion: Silver nanoparticles so synthesized in this study using fruit extract of M. charantia are simple, easy, and effective technique of nanoparticlesproduction.Keywords: Silver nanoparticles, Momordica charantia, Optimization, Antibacterial, Atomic force microscope, Scanning electron microscopy.


Nanomedicine ◽  
2019 ◽  
Vol 14 (21) ◽  
pp. 2783-2798
Author(s):  
Ajmal Khan ◽  
Ahmed Al-Harrasi ◽  
Najeeb Ur Rehman ◽  
Rizwana Sarwar ◽  
Touqeer Ahmad ◽  
...  

Aim: Acetyl-11-keto- β-boswellic acid (AKBA) is a potent anti-inflammatory compound limited by its low water solubility and bioavailability. To load AKBA on silver nanoparticles (AgNPs) to improve bioavailability and water solubility of the compound. Materials & methods: AKBA-AgNPs were chemically synthesized and characterized by UV–Vis spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. AKBA and AKBA-Ag were studied for their sedative-hypnotic and anti-inflammatory efficacies. Results: Pretreatment with AKBA or AKBA-Ag caused significant dose-dependent sedative-hypnotic effects at 5 and 10 mg/kg intraperitoneal. The effects of AKBA-loaded AgNPs caused pronounced changes in mice compared with those of AKBA, and the AKBA-AgNPs demonstrated anti-inflammatory effects that were superior to those of AKBA. Conclusion: The loading of AKBA on nanoparticles improved its pharmacokinetic effects, and capacity for drug delivery.


2018 ◽  
Vol 930 ◽  
pp. 224-229
Author(s):  
Marcos Antônio Guerra ◽  
Jeferson Prado Swerts ◽  
Mei Abe Funcia ◽  
Neide Aparecida Mariano ◽  
Maria Gabriela Nogueira Campos

Polyethylene terephthalate (PET) fiber is a very versatile fiber that can be produced with different properties, such as antimicrobial activity. This study aims to synthesize antimicrobial PET filaments incorporated with silver nanoparticles immobilized in silica (NPAg-Si) by bulk additive method. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) characterized the obtained filaments at concentrations (w/w) of 0.008%, 0.016%, 0.032%, 0.047% and 0.063% NPAg-Si, in order to identify the nanoparticles and analyze their dispersion in the polymeric matrix. Moreover, thermogravimetric analysis (TGA) was carry out to confirm the presence and concentration of the silver nanoparticles in the filaments as well as the thermal stability of the nanocomposites. The bulk addition method was efficient to produce PET-Silver filaments with silver nanoparticles homogeneously dispersed in the PET matrix.


2020 ◽  
Vol 21 (1) ◽  
pp. 30
Author(s):  
Dewi Mustika Rahim ◽  
Netti Herawati ◽  
Hasri Hasri

ABSTRAK Telah dilakukan penelitian tentang sintesis nanopartikel perak menggunakan bioreduktor ekstrak daun teh hijau (Camellia Sinensis) dengan iradiasi microwave. yang untuk mengetahui pengaruh waktu sintesis dan pengaruh pH stabilizer terhadap sintesis nanopartikel perak ekstrak daun teh hijau dengan iradiasi microwave serta karakterisasinya. Larutan AgNO3 3 mM direduksi menggunakan ekstrak daun teh hijau dan di iradiasi microwave pada variasi waktu sintesis 1-5 menit. Penentuan waktu sintesis optimal menggunakan spektrofotometer UV-Vis diukur setiap 1 menit. Nanopartikel dengan waktu sistesis 4 menit, pH stabilizer menggunakan asam sitrat dan NaOH dengan pH 6-9. Karakterisasi nanopartikel menggunakan instrumen SEM-EDS (Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy) dan PSA (Particle Size Analyzer). Hasil penelitian menunjukkan bahwa waktu sintesis optimal adalah 4 menit. Morfologi nanopatikel perak yang dikarakterisasi menggunakan SEM (Scanning Electron Microscopy) yang dihasilkan cenderung beragregasi. Adanya kecenderungan nanopartikel untuk beragregasi menyebabkan ukuran atau diameter nanopartikel tidak seragam. Ukuran dan distribusi ukuran nanopartikel perak dikarakterisasi menggunakan PSA(Particle Size Analyzer) dihasilkan pada pH 6 antara 31,01 – 402,44 nm dengan rata-rata ukuran sebesar 91 nm, pH 7 antara 35,03 – 740,899 nm dengan rata-rata ukuran sebesar 106,3 nm, pH 8 antara 39,58 – 193,48 nm dengan rata-rata ukuran 71,7, dan pH 9 antara 35,03 – 171,25 nm dengan rata-rata ukuran sebesar 64,4 nm. Disimpulkan bahwa hasil sintesis nanopartikel perak terkecil diperoleh pada pH 9 dan waktu sintesis 4 menit. Kata kunci: Ekstrak Daun Teh Hijau, Nanopartikel Perak, Iradiasi Microwave ABSTRACT Research has been carried out on the synthesis of silver nanoparticles using a bioreductor of green tea leaf extract (Camellia Sinensis) by irradiation microwave.This research aimed to determine the effect of synthesis time and pH stabilizer on the synthesis of silver nanoparticles of green tea leaf extract by microwave irradiation and it’s characterization. The 3 mM AgNO3 solution was reduced using green tea leaf extract and microwave irradiated in a variation of the synthesis time 1-5 minutes. The determining optimum of sythesis time was done by analysis of UV-Vis spectrum for every minutes. Nanoparticles with a synthesis time of 4 minutes, the stabilizer of silver nanoparticles used citric acid and NaOH with a pH of 6-9. Characterization of nanoparticles using SEM-EDS instrument (Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy) and PSA (Particle Size Analyzer). The results showed that the optimal synthesis time was 4 minutes. The morphology of silver nanopaticles characterized using SEM produced tends to aggregate. The tendency of nanoparticles to aggregate causes size or diameter of nanoparticles was random. The size and distribution of size silver nanoparticles characterized using PSA were produced at pH 6 between 31.01 - 402.44 nm with an average size of 91 nm, pH 7 between 35.03 - 740,899 nm with an average size amounting to 106.3 nm, pH 8 between 39.58 - 193.48 nm with an average size of 71.7, and pH 9 between 35.03 - 171.25 nm with an average size of 64.4 nm. It was concluded that the synthesis of the smallest silver nanoparticles was obtained at pH 9 and synthesis time of 4 minutes. Keywords: Green Tea Leaf Extract, Silver Nanoparticles, Microwave Irradiation


2017 ◽  
Vol 41 (1) ◽  
pp. 60-65
Author(s):  
Ahmad N. A. Salih ◽  
Mohammad J. Eesa

     This study was conducted for the synthesis of silver nanoparticles by using olive leaves aqueous extract and evaluate its antibacterial activity against Pseudomonas aeruginosa in vitro. The synthesis and characterization of silver nanoparticles was confirmed by Ultra Violet Visible – spectrophotometer and Scanning Electron Microscopy. Well diffusion method was used to show the antibacterial action of silver nanoparticles against Pseudomonas aeruginosa in vitro in comparison with standard antibacterial silver sulfadiazine by using different concentrations of each agent ranged from 12.5-200 μg/ml. The results of this study showed it possible to produce silver nanoparticles in eco-friendly and easy process and UV-Visible absorption spectra of the silver nanoparticles revealed maximum absorbance at 420 and 430 nm. The Scanning Electron Microscopy analysis demonstrated the mean of the silver particles diameter was 26 nm. The antibacterial findings of the synthesized silver nanoparticles against Pseudomonas aeruginosa in vitro showed that the silver nanoparticles were more effective than silver sulfadiazine against Pseudomonas aeruginosa. It could be concluded that olive leaves extract can be used effectively in the production of silver nanoparticles and these synthesized nanoparticles had considerable antibacterial activity against Pseudomonas aeruginosa in vitro.                                                        


2021 ◽  
Vol 41 (03) ◽  
pp. 393-399
Author(s):  
Parwin Jalal Jalil

Spillage of protoscoleces within hydatid fluid during surgery for hydatid cyst is the main reason for its recurrence. Therefore, to inactivate the protoscoleces, various scolicidal substances have been tested. However, novel and more efficient agents are needed owing to several associated complications. This study focused on the effects of green synthetic Silver Nanoparticles (AgNPs) from Zizyphus spina- christi leaves on Echinococcus granulosus protoscoleces. Also, to evaluate the blood compatibility of Ag NPs. The Ag NPs were identified by ultraviolet-visible (UV-Visible) spectrophotometer, X-ray diffraction (XRD), Scanning electron microscopy imaging, and Energy-dispersive X-ray spectroscopy (EDX). Hydatid fluid was aspirated aseptically from cysts of infected sheep liver. The protoscoleces were exposed to Ag NPs at several concentrations. Also, scanning electron microscopy for ultrastructural changes and in vitro erythrocytes lysis was performed. The Ag NPs were spherical; the particles' size reached 50 nm, and presented a surface plasmon peak around 460 nm. The current study's findings indicated the powerful in vitro scolicidal efficacy of the green biosynthesized AgNPs. Several morphological alterations were observed on the protoscoleces by optical and scanning electron microscopy. Lysis of RBCs at different doses of Ag NPs was significantly (P≤0.05) less than the positive control value, thus proposing its biocompatibility. This work suggests that chemicals like polyphenols present in the extract of Z. spina- christi act as reducing and stabilizers agents to create Ag NPs Nevertheless, further investigations are needed to investigate the Ag NPs scolicidial effects in animal models.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Toga Khalid Mohamed ◽  
Marivt Osman Widdatallah ◽  
Maida Musa Ali ◽  
Afraa Mubarak Alhaj ◽  
DhiaEldin AbdElmagied Elhag

An extremely worrying and alarming increase in the level of multiple drug resistance is reported in Sudan, in which bacterial strains are becoming resistant to many commonly available antibiotics. Eventually, it is becoming extremely difficult to treat debilitating infections. In search of promising solutions to this arising crisis, Camellia sinensis silver nanoparticles were synthesized using the green synthesis method. The synthesis of the Camellia sinensis silver nanoparticles is confirmed using analytical methods as ultraviolet-visible spectroscopy, X-ray diffractometer, and scanning electron microscopy. Using the ultraviolet-visible spectroscopy, an absorption band of 412 nm was observed. Furthermore, scanning electron microscopy revealed the presence of silver nanoparticles which fell within the range of 1–100 nm, and X-ray diffractometer analysis showed three intense peaks with a maximum intense peak at 24.3 theta. Nanoparticles distribution between 12 nm and 64 nm was observed with an average diameter of 18.115 nm. It also revealed orthorhombic-shaped nanoparticles. The synthesized nanoparticles showed antimicrobial activity against Staphylococcus aureus with a zone of inhibition of 7 mm, but none was detected against Escherichia coli. The obtained physicochemical properties were correlated with the antibacterial activity of the silver nanoparticles.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Asma Shahzad ◽  
Hamid Saeed ◽  
Mehwish Iqtedar ◽  
Syed Zajif Hussain ◽  
Afshan Kaleem ◽  
...  

The biogenesis of silver nanoparticles by fungi is an ecologically clean and nontoxic method compared to other physical and chemical methods. Thus, we aimed to discuss the mycosynthesis of extracellular size-controlled AgNPs. After comprehensive screening, Aspergillus fumigatus BTCB10 (KY486782) was selected for the synthesis of AgNPs of controlled size. Characterization was performed by UV-Vis spectrophotometer, Zetasizer, X-Ray Diffraction (XRD), FTIR (Fourier-transform infrared), Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) along with functional assays—antibacterial and MTT assays. Data suggested that under optimized conditions, i.e., temperature 25°C, AgNO3 concentration 1 mM, biomass 7 g, fungal culture age 7 days, pH 6, ratio of cell-free filtrate (CFF)/silver nitrate (3 : 2), NaCl 20%, and under dark light, the smallest size AgNPs of 0.681 nm with 100% monodispersity was obtained as evident by a zeta potential of -23.4 mV, UV-Vis band at 400 nm, and the presence of O-H and C=O groups confirmed by ATR-FTIR; XRD revealed the crystalline nature of AgNPs; additionally, cube-shaped AgNPs were revealed by Scanning Electron Microscopy (SEM). Moreover, synthesized AgNPs exhibited antibacterial activity against multidrug-resistant bacterial strains, notably, Klebsiella pneumoniae BTCB04, Acinetobacter BTCB05, Pseudomonas aeruginosa BTCB01, and Escherichia coli BTCB03, while maximum 7-fold was observed with Acinetobacter BTCB05. AgNPs demonstrated no cytotoxic activity against HepG2 cells; however, in combination with cisplatin, antiproliferative and cytotoxic effects became more evident and significant in comparison to control and as single agent. Taken together, the data suggested that economical and smallest size AgNPs can be biosynthesized from Aspergillus fumigatus BTCB10 and be used as antibacterial and antiproliferative agents in combination with current drugs against clinically relevant multiple drug-resistant bacterial and tumoral cells. Further studies are required to confirm their effects employing in vivo disease models.


Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582095134
Author(s):  
Pamela Nair Silva-Holguín ◽  
Simón Yobanny Reyes-López

Innovative and improved antimicrobial agents by nanotechnology are developed to control and mitigation of resistant microorganisms. Nanoparticles of metals or oxide metals be able to be toxic to bacteria, demonstrating biocidal behaviors at low concentrations. The integration of silver nanoparticles in ceramic matrices has enhanced the antimicrobial performance, resulting in the search for new composites with improved bactericidal properties. The aim of this study was to prepare and characterize hydroxyapatite-silver nanocomposite and evaluate its antimicrobial properties against various Gram-positive and negative bacteria related to drug-resistance infections. Hydroxyapatite nanopowders were produced by sol-gel and silver nanoparticles were synthesized by reduction of Ag+ions with the simple addition of gallic acid. Hydroxyapatite-silver composite (HAp-AgNPs) was prepared by adsorption of AgNPs at several concentrations. The results of UV–visible spectroscopy, dynamic light scattering, and transmission scanning electron microscopy revealed the existence of AgNPs with diameters around 6 nm. Scanning electron microscopy and energy dispersive X-ray spectroscopy corroborated the presence of silver disseminated over the surface of hydroxyapatite nanopowders. All HAp-AgNPs composites demonstrated excellent antibacterial effect even at lower silver concentration. HAp-AgNPs composites have a higher possibility for medical applications focused no the control of microorganisms with drug-resistance.


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