scholarly journals Effects of Synthetic Procedures and Postsynthesis Incubation pH on Size, Shape, and Antibacterial Activity of Copper (I) Oxide Nanoparticles

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Vinh Tien Nguyen ◽  
Khanh Son Trinh

Copper (I) oxide nanoparticles (Cu2O NP) were synthesized by reducing CuSO4 with glucose in the presence of polyvinyl alcohol as a capping agent. We used three different synthetic procedures with a fast reaction (procedure 1p), a fast-then-slow reaction (procedure 2p), and a slow-then-fast reaction (procedure 3p). The reaction rates were controlled by changing the temperature and the speed of adding reagents. The synthesized Cu2O NP were subsequently incubated for 24 h in a pH 6 solution (Cu2O NP6) or a pH 8 solution (Cu2O NP8) at 5°C. XRD and SEM images analysis revealed that the 1p procedure produced smaller NP, while the 2p procedure produced larger but more uniform NP. The 3p procedure produced the largest NP with a higher size variation. The 24-hour acidic postsynthesis incubation resulted in an etching effect, which reduced the size and size variation of Cu2O NP6. To evaluate the antibacterial activity, E. coli suspensions were mixed with the obtained Cu2O NP (32, 96, or 160 ppm) for different time intervals (1 or 24 h) and then grown on Petri dishes at 37°C for 24 h. Higher doses, smaller sizes of Cu2O NP, and longer contact times with the bacterial suspension resulted in higher inactivation efficiencies. Cu2O NP6 showed higher antibacterial effects at low doses, possibly due to the etching effect and the positive surface charge. Increasing the Cu2O doses from 32 to 96 and 160 ppm noticeably increased the antibacterial effect of the Cu2O NP8, but not significantly for Cu2O NP6. We suggested that the Cu2O NP6 suffered from agglomeration at high doses due to their high surface activity and low surface charges.

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1393
Author(s):  
Carolina Ramos Hurtado ◽  
Gabriela Ramos Hurtado ◽  
Gabrielle Lupeti de Cena ◽  
Rafaela Campos Queiroz ◽  
Alexandre Vieira Silva ◽  
...  

Conjugation of photosensitizers (PS) with nanoparticles has been largely used as a strategy to stabilize PS in the biological medium resulting in photosensitizing nanoparticles of enhanced photoactivity. Herein, (Meso-5, 10, 15, 20-tetrakis (3-hydroxyphenyl) phorphyryn (mTHPP) was conjugated with diamond nanoparticles (ND) by covalent bond. Nanoconjugate ND-mTHPP showed suitable stability in aqueous suspension with 58 nm of hydrodynamic diameter and Zeta potential of −23 mV. The antibacterial activity of ND-mTHPP was evaluated against Escherichia coli for different incubation times (0–24 h). The optimal activity was observed after 2 h of incubation and irradiation (660 nm; 51 J/cm2) performed right after the addition of ND-mTHPP (100 μg/mL) to the bacterial suspension. The inhibitory activity was 56% whereas ampicillin at the same conditions provided only 14% of bacterial growth inhibition. SEM images showed agglomerate of ND-mTHPP adsorbed on the bacterial cell wall, suggesting that the antimicrobial activity of ND-mTHPP was afforded by inducing membrane damage. Cytotoxicity against murine embryonic fibroblast cells (MEF) was also evaluated and ND-mTHPP was shown to be noncytotoxic since viability of cells cultured for 24 h in the presence of the nanoconjugate (100 μg/mL) was 78%. Considering the enhanced antibacterial activity and the absence of cytotoxic effect, it is possible to consider the ND-mTHPP nanoconjugate as promising platform for application in antimicrobial photodynamic therapy (aPDT).


2016 ◽  
Vol 2 (1) ◽  
pp. 11-15 ◽  
Author(s):  
S. Begila David

Nanoparticles have made a steady progress in all the branches of science. It is used in biological applications including nanomedicine. Zinc oxide is also known as Zincite generally seen in a crystalline form. Zinc oxide nanoparticles are multifunctional. It has effective antibacterial activity. This study focuses on the synthesis of zinc oxide nanoparticle by the sonochemical and green method, characterized by XRD, SEM and to determine the antibacterial efficacy of green and chemical techniques.Results prove that green synthesized Zinc oxide nanoparticle shows the enhanced biocidal activity. In addition the current study has demonstrated that the particle size variation and surface area to volume ratio of green synthesized Zinc oxide nanoparticles are responsible for significant high antibacterial activity. From the result obtained it suggested that the biogenic green fabrication is a better choice due to eco-friendliness.


Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.


Author(s):  
Haider Qassim Raheem ◽  
Takwa S. Al-meamar ◽  
Anas M. Almamoori

Fifty specimens were collected from wound patients who visited Al-Hilla Teaching Hospital. The samples were grown on Blood and MacConkey agar for 24-48 hr at 37oC. The bacterial isolates which achieved as a pure and predominant growth from clinical samples as Pseudomonas fluorescens, were identified using morphological properties and Vitek2 system. The anti-bacterial activity of copper oxide nanoparticles (CuO NPs) against was tested by (disk diffusion assay) using dilutions of (400, 200, 100, 50, 25, and 12.5‎µ‎g/ml). The (MIC and MBC) of each isolate was determined. CuO NPs shows wide spectrum antibacterial activity against tested bacteria with rise zone of inhibition diameter that is proportionate with the increase in nanoparticle concentration. The MIC of CuO NPs extended from 100-200‎µ‎g/ml and the MBC ranged from 200-400‎µ‎g/ml. The antibiotic profile was determined by Viteck 2 compact system (Biomérieux). CuO NPs‎ found highly effective and safe in P. fluorescens wounds infections comparing with used antibiotics.


Author(s):  
Hams H. H. Alfattli ◽  
Ghufran Zuhair Jiber ◽  
Ghaidaa Gatea Abbass

This study which designed to evaluate the inhibitory effect of Ethanolic extract of (Quercusrobur) and Zinc oxide nanoparticles on the growth of one genus of enterobacteriacae (Salmonella). In vitro. For this purpose graduate concentrates for plant extract (50, 100, 200, 400 )mg/ml which prepared and compared with Zinc oxide nanoparticles of different concentration (2, 1, 0.5, 0.25) μg/ml,and examined. The result showed that the studied medicinal plant has antibacterial activity against this bacteria which used. The result showed that the plant has good activity in decrease the growth of this bacteria. The results of the study also showed that the nano-ZnO has very effective antibacterial action against the studied bacteria which was Salmonella,nanoparticles concentrations lead to increasing in the inhibition zones of tested bacterial growth. We also study the effect of three antibiotics Lomefloxacin (LOM), Ciprofloxacin (SIP) and Rifampin (RA) and the result showed,in a comparison within the tested bacteria,Salmonella had a significant inhibition increase in Lomefloxacin ; the ciprofloxacin showed effect on tested bacteria. However,Rifampin does not show any effect on tested bacteria.


2020 ◽  
Vol 13 ◽  
Author(s):  
Selin Yılmaz ◽  
Çiğdem İçhedef ◽  
Kadriye Buşra Karatay ◽  
Serap Teksöz

Backgorund: Superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively used for targeted drug delivery systems due to their unique magnetic properties. Objective: In this study, it’s aimed to develop a novel targeted 99mTc radiolabeled polymeric drug delivery system for Gemcitabine (GEM). Methods: Gemcitabine, an anticancer agent, was encapsulated into polymer nanoparticles (PLGA) together with iron oxide nanoparticles via double emulsion technique and then labeled with 99mTc. SPIONs were synthesized by reduction–coprecipitation method and encapsulated with oleic acid for surface modification. Size distribution and the morphology of the synthesized nanoparticles were caharacterized by dynamic light scattering(DLS)and scanning electron microscopy(SEM), respectively. Radiolabeling yield of SPION-PLGAGEM nanoparticles were determined via Thin Layer Radio Chromatography (TLRC). Cytotoxicity of GEM loaded SPION-PLGA were investigated on MDA-MB-231 and MCF7 breast cancer cells in vitro. Results: SEM images displayed that the average size of the drug-free nanoparticles was 40 nm and the size of the drug-loaded nanoparticles was 50 nm. The diameter of nanoparticles were determined as 366.6 nm by DLS, while zeta potential was found as-29 mV. SPION was successfully coated with PLGA, which was confirmed by FTIR. GEM encapsulation efficiency of SPION-PLGA was calculated as 4±0.16 % by means of HPLC. Radiolabeling yield of SPION-PLGA-GEM nanoparticles were determined as 97.8±1.75 % via TLRC. Cytotoxicity of GEM loaded SPION-PLGA were investigated on MDA-MB-231 and MCF7 breast cancer cells. SPION-PLGA-GEM showed high uptake on MCF-7, whilst incorporation rate was increased for both cell lines which external magnetic field application. Conclusion: 99mTc labeled SPION-PLGA nanoparticles loaded with GEM may overcome some of the obstacles in anti-cancer drug delivery because of their appropriate size, non-toxic, and supermagnetic characteristics.


2020 ◽  
Vol 10 (2) ◽  
pp. 166-174
Author(s):  
Mehdi Khoshneviszadeh ◽  
Sarah Zargarnezhad ◽  
Younes Ghasemi ◽  
Ahmad Gholami

Background: Magnetic cell immobilization has been introduced as a novel, facile and highly efficient approach for cell separation. A stable attachment between bacterial cell wall with superparamagnetic iron oxide nanoparticles (SPIONs) would enable the microorganisms to be affected by an outer magnetic field. At high concentrations, SPIONs produce reactive oxygen species in cytoplasm, which induce apoptosis or necrosis in microorganisms. Choosing a proper surface coating could cover the defects and increase the efficiency. Methods: In this study, asparagine, APTES, lipo-amino acid and PEG surface modified SPIONs was synthesized by co-precipitation method and characterized by FTIR, TEM, VSM, XRD, DLS techniques. Then, their protective effects against four Gram-positive and Gram-negative bacterial strains including Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were examined through microdilution broth and compared to naked SPION. Results: The evaluation of characterization results showed that functionalization of magnetic nanoparticles could change their MS value, size and surface charges. Also, the microbial analysis revealed that lipo-amino acid coated magnetic nanoparticles has the least adverse effect on microbial strain among tested SPIONs. Conclusion: This study showed lipo-amino acid could be considered as the most protective and even promotive surface coating, which is explained by its optimizing effect on cell penetration and negligible reductive effects on magnetic properties of SPIONs. lipo-amino acid coated magnetic nanoparticles could be used in microbial biotechnology and industrial microbiology.


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