scholarly journals Theranostic Nanoplatforms of Thiolated Reduced Graphene Oxide Nanosheets and Gold Nanoparticles

2020 ◽  
Vol 10 (16) ◽  
pp. 5529 ◽  
Author(s):  
Pascal Tomasella ◽  
Vanessa Sanfilippo ◽  
Carmela Bonaccorso ◽  
Lorena Maria Cucci ◽  
Giuseppe Consiglio ◽  
...  

In this study, graphene oxide (GO) and reduced-thiolated GO (rGOSH) were used as 2D substrate to fabricate nanocomposites with nanoparticles of gold nanospheres (AuNS) or nanorods (AuNR), via in situ reduction of the metal salt precursor and seed-mediated growth processes. The plasmonic sensing capability of the gold-decorated nanosheets were scrutinized by UV-visible (UV-VIS) spectroscopy. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analyses (TGA), and atomic force microscopy (AFM) were performed in order to prove the actual reduction that occurred concomitantly with the thiolation of GO, the increase in the hydrophobic character as well as the size, and preferential gathering of the gold nanoparticles onto the nanosheet substrates, respectively. Moreover, the theoretical electronic and infrared absorption (UV-VIS and IR) spectra were calculated within a time-dependent approach of density functional theory (DFT). Eventually, in vitro cellular experiments on human neuroblastoma cells (SH-SY5Y line) were carried out in order to evaluate the nanotoxicity of the nanocomposites by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction (MTT) colorimetric assay. Results pointed out the promising potential of these hybrids as plasmonic theranostic platforms with different hydrophilic or hydrophobic features as well as cytotoxic effects against cancer cells.

2019 ◽  
Vol 9 (4) ◽  
pp. 676 ◽  
Author(s):  
Lorena Cucci ◽  
Irina Naletova ◽  
Giuseppe Consiglio ◽  
Cristina Satriano

In this study, nanocomposites of spherical gold nanoparticles (AuNPs) and graphene oxide (GO) nanosheets were fabricated by a simple one-step reduction method. The characterisation by UV-visible spectroscopy of the plasmonic sensing properties pointed out to a strong interaction between graphene and metal nanoparticles in the hybrid GO-AuNP, as confirmed by nuclear magnetic resonance. Moreover, atomic force microscopy analyses demonstrated that the gold nanoparticles were mostly confined to the basal planes of the GO sheets. The response of the nanoassemblies at the biointerface with human neuroblastoma SH-SY5Y cell line was investigated in terms of nanotoxicity as well as of total and mitochondrial reactive oxygen species production. Confocal microscopy imaging of cellular internalization highlighted the promising potentialities of GO-AuNP nanoplatforms for theranostic (i.e., sensing/imaging + therapy) applications.


2015 ◽  
Vol 15 (05) ◽  
pp. 1550069 ◽  
Author(s):  
SHIJIA ZHAO ◽  
ALEX STAMM ◽  
JEONG SOON LEE ◽  
ALEXEI GRUVERMAN ◽  
JUNG YUL LIM ◽  
...  

Human neuroblastoma (SH-SY5Y) cells, with its ability to differentiate into neurons, have been widely used as the in vitro cell culture model for neuroscience research, especially in studying the pathogenesis of Parkinson's disease (PD) and developing therapeutic strategies. Cellular elasticity could potentially serve as a biomarker to quantitatively distinguish undifferentiated and differentiated SH-SY5Y cells. The goal of this work is to characterize the retinoic acid (RA) induced alternations of elastic properties of SH-SY5Y cells using atomic force microscopy (AFM). The elasticity was measured at multiple points of a single cell. Results have shown that the differentiation of SH-SY5Y cell led to a larger elastic modulus, which is three times more than that of undifferentiated cells. A higher indentation rate applied during AFM measurements led to a larger elastic modulus of the cell. This work provides new insights into the differentiation process identified by the elasticity marker, which could be extended to investigate the function, health and ageing of cells.


2020 ◽  
Vol 17 (2) ◽  
pp. 169-183 ◽  
Author(s):  
İrem Bozbey ◽  
Suat Sari ◽  
Emine Şalva ◽  
Didem Kart ◽  
Arzu Karakurt

Background: Azole antifungals are among the first-line drugs clinically used for the treatment of systemic candidiasis, a deadly type of fungal infection that threatens mostly immunecompromised and hospitalized patients. Some azole derivatives were also reported to have antiproliferative effects on cancer cells. Objective: In this study, 1-(4-trifluoromethylphenyl)-2-(1H-imidazol-1-yl)ethanone (3), its oxime (4), and a series of its novel oxime ester derivatives (5a-v) were synthesized and tested for their in vitro antimicrobial activities against certain ATCC standard strains of Candida sp. fungi and bacteria. The compounds were also tested for their cytotoxic effects against mouse fibroblast and human neuroblastoma cell lines. Molecular modeling studies were performed to provide insights into their possible mechanisms for antifungal and antibacterial actions. Methods: The compounds were synthesized by the reaction of various oximes with acyl chlorides. Antimicrobial activity of the compounds was determined according to the broth microdilution method. For the determination of cytotoxic effect, we used MTS assay. Molecular docking and QM/MM studies were performed to predict the binding mechanisms of the active compounds in the catalytic site of C. albicans CYP51 (CACYP51) and S. aureus flavohemoglobin (SAFH), the latter of which was created via homology modeling. Results: 5d, 5l, and 5t showed moderate antifungal activity against C. albicans, while 3, 5c, and 5r showed significant antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa. Most of the compounds showed approximately 40-50% inhibition against the human neuroblastoma cells at 100 µM. In this line, 3 was the most potent with an IC50 value of 82.18 μM followed by 5a, 5o, and 5t. 3 and 5a were highly selective to the neuroblastoma cells. Molecular modelling results supported the hypothesis that our compounds were inhibitors of CAYP51 and SAFH. Conclusion: This study supports that oxime ester derivatives may be used for the development of new antimicrobial and cytotoxic agents.


2020 ◽  
Vol 16 (5) ◽  
pp. 793-804
Author(s):  
Naimeh Mahheidari ◽  
Jamal Rashidiani ◽  
Hamid Kooshki ◽  
Khadijeh Eskandari

Background: Today, nanoparticles hold great promise in biomedical researches and applications including bacteria detection. The rapid and sensitive outcomes of bacteria detection strategies using nanoparticle conjugates become determinative, especially in bacterial outbreaks. In the current research, we focused on detecting V. cholera bacteria and its toxin using a thiocyanate/Au nanoparticle. Thiocyanate adsorbed strongly on the surface of gold nanoparticles and changed the surface by enhancing surface plasmon resonance of gold nanoparticles. Objective: This method is tried to introduce a simple and fast procedure to assay vibrio cholera. So, it is observed by the naked eyes as well. Methods: We used two antibodies (Ab) for V. cholera detection: a) a primary antibody conjugated to magnetic nanoparticles (MNPs) for trapping V. cholera bacterial cells, and b) a secondary Abconjugated thiocyanate-GNPs as a colorimetric detector. Then, an immuno-magnetic separation system connected to a colorimetric assay was designed based on the GNPs. The results were measured by ultraviolet-visible (UV-Vis) spectroscopy. Results: The results showed that gold nanoparticles are an appropriate optical assay for detecting biological samples in a minimum concentration and also it can be easily seen by the naked eyes. The linear range of this biosensor is 3.2×104 to 28×104 cells per ml. Conclusion: In this research, a colorimetric immune assay based on gold nanoparticles was designed to improve the sensitivity of V. cholera detection. Also, this method can be used for the detection of other biological agents.


2020 ◽  
Vol 18 (1) ◽  
pp. 936-942
Author(s):  
Ardhmeri Alija ◽  
Drinisa Gashi ◽  
Rilinda Plakaj ◽  
Admir Omaj ◽  
Veprim Thaçi ◽  
...  

AbstractThis study is focused on the adsorption of hexavalent chromium ions Cr(vi) using graphene oxide (GO). The GO was prepared by chemical oxidation (Hummers method) of graphite particles. The synthesized GO adsorbent was characterized by Fourier transform infrared spectroscopy and UV-Vis spectroscopy. It was used for the adsorption of Cr(vi) ions. The theoretical calculations based on density functional theory and Monte Carlo calculations were used to explore the preferable adsorption site, interaction type, and adsorption energy of GO toward the Cr(vi) ions. Moreover, the most stable adsorption sites were used to calculate and plot noncovalent interactions. The obtained results are important as they give molecular insights regarding the nature of the interaction between GO surface and the adsorbent Cr(vi) ions. The found adsorption energy of −143.80 kcal/mol is indicative of the high adsorptive tendency of this material. The adsorption capacity value of GO toward these ions is q = 240.361 mg/g.


Gene Therapy ◽  
1997 ◽  
Vol 4 (2) ◽  
pp. 156-161 ◽  
Author(s):  
J-L Coll ◽  
E Wagner ◽  
V Combaret ◽  
K Metchler ◽  
H Amstutz ◽  
...  

2019 ◽  
Author(s):  
Aida Revilla-García ◽  
Cristina Fernández ◽  
María Moreno-del Álamo ◽  
Vivian de los Ríos ◽  
Ina M. Vorberg ◽  
...  

AbstractRepA is a bacterial protein that builds intracellular amyloid oligomers acting as inhibitory complexes of plasmid DNA replication. When carrying a mutation enhancing its amyloidogenesis (A31V), the N-terminal domain (WH1) generates cytosolic amyloid particles that are inheritable within a bacterial lineage. Such amyloids trigger in bacteria a lethal cascade reminiscent to mitochondria impairment in human cells affected by neurodegeneration. To fulfil all the features of a prion-like protein, horizontal (intercellular) transmissibility remains to be demonstrated for RepA-WH1. Since this is experimentally intractable in bacteria, here we transiently expressed in a murine neuroblastoma cell line the soluble, barely cytotoxic RepA-WH1(WT) and assayed its response to co-incubation with in vitro assembled RepA-WH1(A31V) amyloid fibres. In parallel, cells releasing RepA-WH1(A31V) aggregates were co-cultured with human neuroblastoma cells expressing RepA-WH1(WT). Both the assembled fibres and the extracellular RepA-WH1(A31V) aggregates induce, in the cytosol of recipient cells, the formation of cytotoxic amyloid particles. Mass spectrometry analyses of the proteomes of both types of injured cells point to alterations in mitochondria, protein quality triage, signalling and intracellular traffic.Summary blurbThe horizontal, cell-to-cell spread of a bacterial prion-like protein is shown for the first time in mammalian cells. Amyloid cross-aggregation of distinct variants, and their associated toxicities, follow the same trend found in bacteria, underlining the universality of prion biology.


Author(s):  
Ghassan Mohammad Sulaiman ◽  
Hanaa M. Waheeba ◽  
Hanady AL-Shmgani ◽  
Hamsa A. Eassa ◽  
Ahmed A. Al-Amiery ◽  
...  

The flavonoglycone hesperidin is recognized as a potent anti-inflammatory, anticancer, and antioxidant agent. However, its poor bioavailability is a crucial bottleneck regarding its therapeutic activity. Gold nanoparticles are widely used in drug delivery because of its unique properties that differ from bulk metal. Hesperidin loaded gold nanoparticles were successfully prepared to enhance its stability and bioactive potential, as well as to minimize the problems associated with its absorption. The free radical scavenging activities of hesperidin, gold nanoparticles, and hesperidin loaded gold nanoparticles were compared with that of Vitamin C and subsequently evaluated in vitro using 2,2-diphenyl-1-picrylhydrazyl assay. The antioxidant pharmacophore-based structure-activity relationship analysis was assessed by the density functional theory as well as quantum chemical calculations. Moreover, the structural properties were utilized using Becke’s three-parameter hybrid exchange and Lee-Yang-Parr’s correction of functional approaches. Hesperidin-loaded gold nanoparticles were found to decrease hydrogen peroxide (H2O2) and thus induce Deoxyribonucleic acid (DNA) instability. In addition, hesperidin-gold nanoparticles were observed to display important antioxidant potential as well as ameliorate the functional activity of macrophages against Escherichia coli, possibly protecting DNA. These particles might be appropriate for clinical trials and could prove useful for the treatment of various life-threatening disorders.


Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 113 ◽  
Author(s):  
Chia-Chen Chang ◽  
Tsz-Lian Hsu ◽  
Chie-Pein Chen ◽  
Chen-Yu Chen

A colorimetric assay was developed for the detection of biothiols, based on the peroxidase-like activity of iodine-capped gold nanoparticles (AuNPs). These AuNPs show a synergetic effect in the form of peroxidase-mimicking activity at the interface of AuNPs, while free AuNPs and iodine alone have weak catalytic properties. Thus, iodine-capped AuNPs possess good intrinsic enzymatic activity and trigger the oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB), leading to a change in color from colorless to yellow. When added to solution, biothiols, such as cysteine, strongly bind to the interface of AuNPs via gold-thiol bonds, inhibiting the catalytic activity of AuNPs, resulting in a decrease in oxidized TMB. Using this strategy, cysteine could be linearly determined, at a wide range of concentrations (0.5 to 20 μM), with a detection limit of 0.5 μM using UV-Vis spectroscopy. This method was applied for the detection of cysteine in diluted human urine.


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