scholarly journals Silica-Supported Assemblage of CuII Ions with Carbon Dots for Self-Boosting and Glutathione-Induced ROS Generation

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 97
Author(s):  
Olga Bochkova ◽  
Alexey Dovjenko ◽  
Rustem Zairov ◽  
Kirill Kholin ◽  
Rinata Biktimirova ◽  
...  

The present work introduces coordinative binding of CuII ions with both amino-functionalized silica nanoparticles (SNs) and green-emitting carbon dots (CDs) as the pregrequisite for the CuII-assisted self-assembly of the CDs at the surface of the SNs. The produced composite SNs exhibit stable in time stimuli-responsive green fluorescence derived from the CuII-assisted assemblage of CDs. The fluorescence response of the composite SNs is sensitive to the complex formation with glutathione (GSH), enabling them to detect it with the lower limit of detection of 0.15 μM. The spin-trap-facilitated electron spin resonance technique indicated that the composite SNs are capable of self-boosting generation of ROS due to CuII→CuI reduction by carbon in low oxidation states as a part of the CDs. The intensity of the ESR signals is enhanced under the heating to 38 °C. The intensity is suppressed at the GSH concentration of 0.35 mM but is enhanced at 1.0 mM of glutathione, while it is suppressed once more at the highest intracellular concentration level of GSH (10 mM). These tendencies reveal the concentrations optimal for the scavenger or reductive potential of GSH. Flow cytometry and fluorescence and confocal microscopy methods revealed efficient cell internalization of SNs-NH2-CuII-CDs comparable with that of “free” CDs.

2019 ◽  
Vol 4 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Ryan T. Shafranek ◽  
Joel D. Leger ◽  
Song Zhang ◽  
Munira Khalil ◽  
Xiaodan Gu ◽  
...  

Directed self-assembly in polymeric hydrogels allows tunability of thermal response and viscoelastic properties.


e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 317-327
Author(s):  
Chenliang Shi ◽  
Ling Lin ◽  
Yukun Yang ◽  
Wenjia Luo ◽  
Maoqing Deng ◽  
...  

AbstractThe influence of density of amino groups, nanoparticles dimension and pH on the interaction between end-functionalized polymers and nanoparticles was extensively investigated in this study. PS–NH2 and H2N–PS–NH2 were prepared using reversible addition–fragmentation chain transfer polymerization and atom transfer radical polymerization. Zero-dimensional carbon dots with sulfonate groups, one-dimensional cellulose nanocrystals with sulfate groups and two-dimensional graphene with sulfonate groups in the aqueous phase were added into the toluene phase containing the aminated PS. The results indicate that aminated PS exhibited the strongest interfacial activity after compounding with sulfonated nanoparticles at a pH of 3. PS ended with two amino groups performed better in reducing the water/toluene interfacial tension than PS ended with only one amino group. The dimension of sulfonated nanoparticles also contributed significantly to the reduction in the water/toluene interfacial tension. The minimal interfacial tension was 4.49 mN/m after compounding PS–NH2 with sulfonated zero-dimensional carbon dots.


2020 ◽  
Vol 2020 ◽  
pp. 1-24 ◽  
Author(s):  
Carmen Cretu ◽  
Loredana Maiuolo ◽  
Domenico Lombardo ◽  
Elisabeta I. Szerb ◽  
Pietro Calandra

The involvement of metal ions within the self-assembly spontaneously occurring in surfactant-based systems gives additional and interesting features. The electronic states of the metal, together with the bonds that can be established with the organic amphiphilic counterpart, are the factors triggering new photophysical properties. Moreover, the availability of stimuli-responsive supramolecular amphiphile assemblies, able to disassemble in a back-process, provides reversible switching particularly useful in novel approaches and applications giving rise to truly smart materials. In particular, small amphiphiles with an inner distribution, within their molecular architecture, of various polar and apolar functional groups, can give a wide variety of interactions and therefore enriched self-assemblies. If it is joined with the opportune presence and localization of noble metals, whose chemical and photophysical properties are undiscussed, then very interesting materials can be obtained. In this minireview, the basic concepts on self-assembly of small amphiphilic molecules with noble metals are shown with particular reference to the photophysical properties aiming at furnishing to the reader a panoramic view of these exciting problematics. In this respect, the following will be shown: (i) the principles of self-assembly of amphiphiles that involve noble metals, (ii) examples of amphiphiles and amphiphile-noble metal systems as representatives of systems with enhanced photophysical properties, and (iii) final comments and perspectives with some examples of modern applications.


2021 ◽  
Vol 12 (1) ◽  
pp. 270-281
Author(s):  
Stefan Bitter ◽  
Moritz Schlötter ◽  
Markus Schilling ◽  
Marina Krumova ◽  
Sebastian Polarz ◽  
...  

The self-organization properties of a stimuli responsive amphiphile can be altered by subjecting the paramagnetic oxidized form to a magnetic field of 0.8 T and monitored in real time by coupling optical birefringence with dynamic light scattering.


2021 ◽  
Vol 9 (1) ◽  
pp. 38-50
Author(s):  
Hien Phan ◽  
Vincenzo Taresco ◽  
Jacques Penelle ◽  
Benoit Couturaud

Stimuli-responsive amphiphilic block copolymers obtained by PISA have emerged as promising nanocarriers for enhancing site-specific and on-demand drug release in response to a range of stimuli such as pH, redox agents, light or temperature.


2011 ◽  
Vol 2011 ◽  
pp. 1-11
Author(s):  
Shinobu Ito ◽  
Tomohisa Mori ◽  
Hideko Kanazawa ◽  
Toshiko Sawaguchi

Electron spin resonance (ESR) method is a simple method for detecting various free radicals simultaneously and directly. However, ESR spin trap method is unsuited to analyze weak ESR signals in organs because of water-induced dielectric loss (WIDL). To minimize WIDL occurring in biotissues and to improve detection sensitivity to free radicals in tissues, ESR cuvette was modified and used with 5,5-dimethtyl-1-pyrroline N-oxide (DMPO). The tissue samples were mouse brain, hart, lung, liver, kidney, pancreas, muscle, skin, and whole blood, where various ESR spin adduct signals including DMPO-ascorbyl radical (AsA∗), DMPO-superoxide anion radical (OOH), and DMPO-hydrogen radical (H) signal were detected. Postmortem changes in DMPO-AsA∗and DMPO-OOH were observed in various tissues of mouse. The signal peak of spin adduct was monitored until the 205th day postmortem. DMPO-AsA∗in liver (y=113.8–40.7 log (day),R1=-0.779,R2=0.6,P<.001) was found to linearly decrease with the logarithm of postmortem duration days. Therefore, DMPO-AsA∗signal may be suitable for detecting an oxidation stress tracer from tissue in comparison with other spin adduct signal on ESR spin trap method.


Soft Matter ◽  
2021 ◽  
Author(s):  
Michael Meleties ◽  
Priya Katyal ◽  
Bonnie Lin ◽  
Dustin Britton ◽  
Jin Kim Montclare

Owing to their tunable properties, hydrogels comprised of stimuli sensitive polymers are one of the most appealing scaffolds with applications in tissue engineering, drug delivery and other biomedical fields. We...


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 502
Author(s):  
Liangliang Yue ◽  
Haolan Li ◽  
Qi Sun ◽  
Xiaogang Luo ◽  
Fengshou Wu ◽  
...  

Cancer is one of the major diseases threatening human health. Traditional cancer treatments have notable side-effects as they can damage the immune system. Recently, phototherapy, as a potential strategy for clinical cancer therapy, has received wide attention due to its minimal invasiveness and high efficiency. Herein, a small organic molecule (PTA) with a D-A-D structure was prepared via a Sonogashira coupling reaction between the electron-withdrawing dibromo-perylenediimide and electron-donating 4-ethynyl-N,N-diphenylaniline. The amphiphilic organic molecule was then transformed into nanoparticles (PTA-NPs) through the self-assembling method. Upon laser irradiation at 635 nm, PTA-NPs displayed a high photothermal conversion efficiency (PCE = 43%) together with efficient reactive oxygen species (ROS) generation. The fluorescence images also indicated the production of ROS in cancer cells with PTA-NPs. In addition, the biocompatibility and photocytotoxicity of PTA-NPs were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead cell co-staining test. Therefore, the as-prepared organic nanomaterials were demonstrated as promising nanomaterials for cancer phototherapy in the clinic.


Author(s):  
Ali Ghafarloo ◽  
Reza Sabzi ◽  
Naser Samadi ◽  
Hamed Hamishehkar

Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (HCTZ) via inner filter effect (IFE) and resonance Rayleigh scattering (RRS). The as-prepared CDs had wide emission spectra, excitation-dependent emission, high solubility, high stability, and visible fluorescence light with a quantum yield of up to 11%. The absorption of HCTZ overlapped with the excitation spectra of CDs. Therefore, CDs represented excellent quenching due to IFE when HCTZ was gradually added. Furthermore, this fluorescent sensor was successfully used to quantify HCTZ in the linear ranges (0.17-2.50 μg mL-1) with the limit of detection of 0.11 μg mL-1. The sensing system was simple as no surface functionalization was required for CDs, leading to less laborious steps and more cost-effective synthesis. The reaction time was short, i.e., less than 2 min, indicating a simple approach for rapid analysis of HCTZ. By optimizing conditions, successful measurements were carried out on pharmaceutical tablets.


2020 ◽  
Author(s):  
Amin Reza Zolghadr ◽  
Behnam Rostami

We describe a systematic investigation of carbon dots (C-dots) assemblies fabricated at the liquid/air interface because of the surface tension gradient. This gradient is originally created by capillary action and increased by addition of sodium dodecyl sulfate (SDS) surfactant or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) phospholipid to the surface of C-dots aqueous mixture. The arrangement of carbon dots in liquid bulk phase (before self-assembly) and at the surface region (after self-assembly) was examined by TEM microscopy. The presence of SDS surfactant and POPC phospholipid at the air/water interface induced the C-dots compression. In addition, molecular dynamics simulation was conducted to obtain the structure of C-dots at liquid/vapor interface. The orientation of C-dots is evaluated quantitatively at water/vapor surface by using bivariate analysis.


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