scholarly journals Addition of Silver Nanoparticles to Composite Resin: Effect on Physical and Bactericidal Properties In Vitro

2014 ◽  
Vol 25 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Patrícia Bolzan Agnelli das Neves ◽  
José Augusto Marcondes Agnelli ◽  
Cristina Kurachi ◽  
Clovis Wesley Oliveira de Souza
Keyword(s):  
Silver Nanoparticles ◽  
Microscopic Analysis ◽  
Control Group ◽  
Biofilm Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Viable Cells ◽  
Bactericidal Properties ◽  
Sucrose Medium

The objectives of this study were to evaluate physical properties and antibacterial activity of a light-activated composite modified with silver nanoparticles. Discs were produced with unmodified resin (control group - CG) and modified resin with silver nanoparticles at two concentrations, 0.3% wt (MR03) and 0.6% wt (MR06). Streptococcus mutans and Lactobacillus acidophilus biofilms were induced in vitro by incubation of discs in a 20% sucrose medium, followed by sonication and counting of viable cells after 1, 4 and 7 days (n=9). The arithmetic roughness of all three groups was evaluated by atomic force microscopy (n=9). Compression assay was conducted in all groups to measure the compressive strength at failure and elasticity modulus (n=5). Data were subjected to ANOVA and Tukey's tests (α=0.05%). At all three time points the number of viable cells was statistically lower for MR03 and MR06 compared with CG, for both specimens. MR03 and MR06 showed no significant differences. Microscopic analysis demonstrated no significant differences for roughness among the three groups (p>0.05). The MR03 was stronger to compression than CG, and MR06 was statistically lower than CG and MR03. It was concluded that the MR03 were less conducive to biofilm growth, without compromising the strength in compression and surface roughness.

scholarly journals Silver Nanoparticles Embedded in Natural Rubber Films: Synthesis, Characterization, and Evaluation ofIn VitroToxicity

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Caroline S. Danna ◽  
Dalita G. S. M. Cavalcante ◽  
Andressa S. Gomes ◽  
Leandra E. Kerche-Silva ◽  
Eidi Yoshihara ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Natural Rubber ◽  
Chinese Hamster ◽  
Cell Lineage ◽  
Microscopic Analysis ◽  
Visible Spectrum ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force

Natural rubber (NR) films can reduce silver metal ions forming embedded metal nanoparticles, a process that could be described as green synthesis. The NR films acting as a reactor generate and incorporate silver nanoparticles (AgNPs). Organic acids and amino acids play a crucial role in the formation of AgNPs. The plasmon extinction obtained in the UV-visible spectrum shows the presence of nanoparticles in the film after dipping the NR film into a solution of silver nitrate at 80°C. Electron microscopic analysis confirms the presence of AgNPs in the NR film and characterization by atomic force microscopy shows a change in the roughness of the NR film with AgNPs. In addition, our preliminary results fromin vitrotoxicity studies (MTT and comet assays) of the NR films and NR films with silver nanoparticles (NR/Ag) show that they are not toxic to cell lineage CHO-K1 (cells from the ovary of a Chinese hamster), an important result for potential medical applications.

scholarly journals Ciliated columnar epithelium pathomorphosis in children with upper and lower respiratory infections: ultrastructural and nanoscopic analysis

2021 ◽  
Vol 18 (1) ◽  
pp. 69-79
Author(s):  
A. N. Astashonok ◽  
N. N. Poleshchuk ◽  
L. V. Rubanik ◽  
V. V. Bobrovnichiy ◽  
A. V. Petruchenya
Keyword(s):  
Lung Disease ◽  
Chronic Lung Disease ◽  
Respiratory Infections ◽  
Microscopic Analysis ◽  
Control Group ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Spatial Disorientation ◽  
Atomic Force ◽  
Respiratory Pathology

The cytomorphological profile of nasal epithelium in children with acute and chronic respiratory disorders was characterized. The redistribution of nasal ciliary epithelial cells in favor of the mucus-secreting (goblet) cells was observed (group with acute respiratory infection – ratio 2.3:1; group with chronic lung disease – 1:2.4) with normal values of these indicators 5:1 (control group). The mucosal metaplasia, against a background of local leukocyte infiltration, was detected among 28 patients (64.29 %). Using atomic force microscopy, the pathomorphosis of the cytoplasmic membrane ciliated epithelium was described, which characterized by the changes in roughness parameters (Ra, Rq, Rsk, Rmax, Rsk) and waviness (Wa) in group with chronic lung disease (Ra – 34.94 ± 7.8 nm, Rq – 41.26 ± 7.5, Rmax – 225.55 ± 44.43, Rsk – 1,2, Wa – 43.23 ± 12.4 nm) compared with control group (Ra – 7.22 ± 1.94 nm, Rq – 11.43 ± 1.83, Rmax – 111.83 ± 29.26, Rsk – 0.33, Wa – 83.81 ± 29.55 nm). Several deviations in microgeometry of the cilia form factor were revealed, which associated with formation of abnormally long cilia (10–12 μm), decreasing (0.095–0.15 μm) and/or a thickening (0.3–0.4 μm) of their diameter, as well as spatial disorientation like the “corkscrew twisting”. Based on the electron microscopic analysis, anomalies in external dynein arms of the cilia axoneme were revealed, which made it possible to confirmed in two patients the hereditary respiratory pathology.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Antimicrobial Activity of Silver Nanoparticles Synthesized by Streptomyces Species JF714876

2012 ◽  
Vol 5 (1) ◽  
pp. 1638-1642 ◽  
Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Ions ◽  
Human Beings ◽  
Streptomyces Species ◽  
Force Microscopy ◽  
E Coli ◽  
Extracellular Synthesis ◽  
Atomic Force ◽  
Uv Visible

Microorganisms like fungi, actinomycetes and bacteria are considered nanofactories and are helpful in the production of nanoparticles useful in the welfare of human beings. In the present study, we investigated the production of silver nanoparticles from Streptomyces species JF714876. Extracellular synthesis of silver nanoparticles by Streptomyces species was carried out using two different media. Silver nanoparticles were examined using UV-visible, IR and atomic force microscopy. The size of silver nanoparticles was in the range of 80-100 nm. Antimicrobial activity of silver nanoparticle against bacteria such as E. coli, S. aureus, and dermatophytes like T. rubrum and T. tonsurans was determined. Thus, this study suggests that the Streptomyces sp. JF741876 can produce silver ions that can be used as an antimicrobial substance.

Targeting Breast Cancer Cells with G4 PAMAM Dendrimers and Valproic Acid Derivative Complexes

2020 ◽  
Vol 20 (15) ◽  
pp. 1857-1872
Author(s):  
Alberto M. Muñoz ◽  
Manuel J. Fragoso-Vázquez ◽  
Berenice P. Martel ◽  
Alma Chávez-Blanco ◽  
Alfonso Dueñas-González ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Cell Lines ◽  
Water Solubility ◽  
Md Simulations ◽  
Pamam Dendrimer ◽  
Pamam Dendrimers ◽  
Force Microscopy ◽  
Micromolar Concentration ◽  
Atomic Force

Background: Our research group has developed some Valproic Acid (VPA) derivatives employed as anti-proliferative compounds targeting the HDAC8 enzyme. However, some of these compounds are poorly soluble in water. Objective: Employed the four generations of Polyamidoamine (G4 PAMAM) dendrimers as drug carriers of these compounds to increase their water solubility for further in vitro evaluation. Methods: VPA derivatives were subjected to Docking and Molecular Dynamics (MD) simulations to evaluate their affinity on G4 PAMAM. Then, HPLC-UV/VIS, 1H NMR, MALDI-TOF and atomic force microscopy were employed to establish the formation of the drug-G4 PAMAM complexes. Results: The docking results showed that the amide groups of VPA derivatives make polar interactions with G4 PAMAM, whereas MD simulations corroborated the stability of the complexes. HPLC UV/VIS experiments showed an increase in the drug water solubility which was found to be directly proportional to the amount of G4 PAMAM. 1H NMR showed a disappearance of the proton amine group signals, correlating with docking results. MALDI-TOF and atomic force microscopy suggested the drug-G4 PAMAM dendrimer complexes formation. Discussion: In vitro studies showed that G4 PAMAM has toxicity in the micromolar concentration in MDAMB- 231, MCF7, and 3T3-L1 cell lines. VPA CF-G4 PAMAM dendrimer complex showed anti-proliferative properties in the micromolar concentration in MCF-7 and 3T3-L1, and in the milimolar concentration in MDAMB- 231, whereas VPA MF-G4 PAMAM dendrimer complex didn’t show effects on the three cell lines employed. Conclusion: These results demonstrate that G4 PAMAM dendrimers are capableof transporting poorly watersoluble aryl-VPA derivate compounds to increase its cytotoxic activity against neoplastic cell lines.

scholarly journals Antibacterial Activity of Silver Nanoparticles Synthesized by Bark Extract of Syzygium cumini

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ram Prasad ◽  
Vyshnava Satyanarayana Swamy
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Cost Effective ◽  
Diffusion Method ◽  
Bark Extract ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cost Effective Method ◽  
Uv Visible ◽  
Major Attention

The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Azotobacter chroococcum WR 9, and Bacillus licheniformis (MTCC 9555).

scholarly journals Osteoblast-Like Cell Behavior on Porous Scaffolds Based on Poly(styrene) Fibers

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Andrada Serafim ◽  
Romain Mallet ◽  
Florence Pascaretti-Grizon ◽  
Izabela-Cristina Stancu ◽  
Daniel Chappard
Keyword(s):  
Interference Microscopy ◽  
Porous Scaffolds ◽  
Allogenic Bone ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dry Spinning ◽  
Bone Trabeculae ◽  
Large Bone

Scaffolds of nonresorbable biomaterials can represent an interesting alternative for replacing large bone defects in some particular clinical cases with massive bone loss. Poly(styrene) microfibers were prepared by a dry spinning method. They were partially melted to provide 3D porous scaffolds. The quality of the material was assessed by Raman spectroscopy. Surface roughness was determined by atomic force microscopy and vertical interference microscopy. Saos-2 osteoblast-like cells were seeded on the surface of the fibers and left to proliferate. Cell morphology, evaluated by scanning electron microscopy, revealed that they can spread and elongate on the rough microfiber surface. Porous 3D scaffolds made of nonresorbable poly(styrene) fibers are cytocompatible biomaterials mimicking allogenic bone trabeculae and allowing the growth and development of osteoblast-like cellsin vitro.

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