RSC Advances

Dar, Ovas Ahmad; Lone, Shabir Ahmad; Malik, Manzoor Ahmad; Wani, Mohmmad Younus; Ahmad, Aijaz; Hashmi, Athar Adil

doi: 10.1039/c9ra02600bpmid: 35514852

Development of new chemotherapeutic agents to treat multidrug-resistant fungal infections to augment the current treatment options is a must. In this direction, a series of mixed ligand complexes was synthesized from a Schiff base (L) obtained by the condensation of 2-hydroxynapthaldehyde and tryptamine, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. Based on spectral characterization and physical measurements an octahedral geometry was assigned to [Co(phen)LClH2O] (C2), [Ni(phen)LClH2O](C3), and [Zn(phen)LClH2O](C4) complexes while a distorted octahedral geometry was assigned to the [Cu(phen)LClH2O](C1) complex. All the synthesized compounds were tested for antifungal activity against 11 Candida albicans isolates, including fluconazole (FLC) resistant isolates, by determining minimum inhibitory concentrations and studying growth curves. MIC results suggest that all the newly synthesized compounds have potent antifungal activity at varying levels. The rapid action of these compounds on fungal cells suggested a membrane-located target for their action.

Guima, Katia-Emiko; Souza, Victor H. R.; Martins, Cauê Alves

doi: 10.1039/c9ra01436epmid: 35514849

We turned printed plastic pieces into a conductive material by electrochemical polymerization of aniline on the plastic surface assisted by graphite. The conductive piece was then turned into a metallic electrode by potentiodynamic electrodeposition. As a proof-of-concept, we built indirect-3D-printed Pd, Pt and Au electrodes, which were used for glycerol electrooxidation.

Wang, Yuting; Hu, Huiyu; McClements, David Julian; Nie, Shaoping; Shen, Mingyue; Li, Chang; Huang, Yousheng; Chen, Jie; Zeng, Maomao; Xie, Mingyong

doi: 10.1039/c9ra01410apmid: 35514805

Lysine-derived advanced glycation end-products (AGEs), including Nε-carboxymethyllysine (CML), Nε-carboxyethyllysine (CEL) and pyrraline, are prevalent in processed foods. The impact of lipids on AGE formation is still contentious and most of our current knowledge is based only on CML. Little is known about how lipids impact the formation of CEL and pyrraline, or their involvement in formation pathways. This study investigated the effect of lipids (fatty acids and triglycerides) on the formation of CML, CEL and pyrraline simultaneously in model systems subjected to frying temperature. The results showed the presence of the lipids promoted the formation of CML, CEL and pyrraline. The promotion effects on CML and CEL were not dependent on the unsaturation degree and addition level (50, 100 or 150 μmol) of lipid, while pyrraline formation depended on lipid type (fatty acids vs. triglycerides) and level. The concentration of CML and CEL was statistically correlated with the concentration of glyoxal (GO) and methylglyoxal (MGO), respectively. The pyrraline concentration was statistically correlated with fructoselysine concentration. These results suggested that lipids promote the formation of lysine-derived AGEs by impacting the generation of Amadori products and α-dicarbonyl compounds. This information may be useful for optimizing the formulation and processing conditions to create tastier and healthier foods.

Inoue, Asuka; Sugimoto, Hiroshi; Fujii, Minoru

doi: 10.1039/c9ra02559fpmid: 35514861

The antimicrobial activity of a hybrid nanoparticle (NP) composed of a silver (Ag) NP core decorated with silicon (Si) nanocrystals (NCs) on the exterior (Ag/Si NPs) is evaluated. The shell of Si NCs effectively protects the surface of Ag NPs, thus the particles are more stable in water and in air compared to conventional organic-capped Ag NPs. The bacterial growth kinetic analysis reveals that the Si NC shell does not suppress the release of Ag ions from the Ag NP surface due probably to the porous structure. For the antimicrobial coating application, a thin film of the hybrid Ag/Si NPs is produced by drop coating the solution on a cover glass. Thanks to the Si NC shell, agglomeration of Ag NPs in the film is prevented and the film shows a very similar optical absorption spectrum to that of the solution. The film exhibits a larger zone of inhibition in an agar diffusion assay of Escherichia coli compared to a film produced from organic-capped Ag NPs.

Song, Taeyoung; Cheong, Jun Young; Cho, Hyunjin; Kim, Il-Doo; Jeon, Duk Young

doi: 10.1039/c9ra01462dpmid: 35514803

Recently, quantum dots based light-emitting diodes (QLEDs) have received huge attention due to the properties of quantum dots (QDs), such as high photoluminescence quantum yield (PLQY) and narrow emission. To improve the performance of QLEDs, reducing non-radiative energy transfer is critical. So far, most conventional methods required additional chemical treatment like giant shell and/or ligands exchange. However that triggers unsought shifted emission or reduced PLQY of QDs. In this work, we have firstly suggested a novel approach to improve the efficiency of QLEDs by introducing inorganic nanoparticles (NPs) spacer between QDs, without additional chemical treatment. As ZnS NPs formed a mixture layer with QDs, the energy transfer was reduced and the distance between the QDs increased, leading to improved PLQY of mixture layer. As a result, current efficiency (CE) of the QLED device was improved by twice compared with one using only QDs layer. This is an early report on utilizing ZnS NPs as an efficient spacer, which can be utilized to other compositions of QDs.

Liao, Yu; Zhang, Rui; Wang, Hongxia; Ye, Shuangli; Zhou, Yihua; Ma, Taolin; Zhu, Junqing; Pfefferle, Lisa D.; Qian, Jun

doi: 10.1039/c9ra01721fpmid: 35514818

Carbon-based conductive inks are one of the most important materials in the field of printing electronics. However, most carbon-based conductive inks with small electrical resistance are expensive, such as graphene. It limits the commercial use of carbon inks in the fields of flexible electronics and printed electronics. Here, we propose a low-cost and environmentally friendly formula based on dihydroxyphenyl-functionalized multi-walled carbon nanotubes (MWNT-f-OH)/carbon black/graphite as conductive fillers and waterborne acrylic resins as binders for preparing highly conductive carbon-based aqueous inks (HCCA-inks). Our study showed that when the mass fraction of carbon black, graphite and MWNT-f-OH was 3.0%, 10.2% and 4.1%, respectively, on a thickness of 40 μm, optimal conductivity (sheet resistance up to 29 Ω sq−1) was achieved, and the printed HCCA-inks on a paper could withstand extremely high folding cycles (>2000 cycles) while the resistance value of the flexible circuit only increased by 11%. The carbon-based aqueous inks showed high electrical conductivity and excellent mechanical stability, which makes it possible for them to be used as flexible wearable electronics, electroluminescent (EL) devices and printed capacitive sensors.

Bag, Braja G.; Garai, Chhabi; Ghorai, Subrata

doi: 10.1039/c9ra02801cpmid: 35514858

Corosolic acid, a natural ursane-type 6-6-6-6-6 pentacyclic dihydroxy triterpenic acid, is a well known antidiabetic compound extractable from leaves of Psidium guajava. In this manuscript we have reported the self-assembly properties of corosolic acid in different liquids. The compound undergoes self-assembly to give vesicular morphology in different aqueous organic liquids. Supramolecular gels were also obtained in some aqueous binary liquids such as ethanol–water and dimethyl formamide–water. The morphology of the self-assemblies of corosolic acid were characterized by using different microscopic techniques like optical microscopy, field emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy as well as XRD and FTIR studies. We also demonstrated the application of vesicular self-assemblies for the entrapment and release of fluorophores including an anticancer drug.

Hong, Yun; Mao, Dongsen; Wu, Rui; Gao, Zhe; Meng, Tingting; Wang, Rongrong; Liu, Lin; Miao, Jing

doi: 10.1039/c9ra00330dpmid: 35514820

DNAzymes have the potential to suppress gene expression through sequence-specific mRNA cleavage and can therefore play an important role in various gene therapies. Hepatitis B virus (HBV) is still one of the most serious liver infections in people around the world and is difficult to treat. We previously designed a 10-23 DNAzyme called DrzBS, which targets HBV S gene expression, but this enzyme depends on exogenous delivery, and so its application has been limited. To overcome this limitation, we have now developed a chitosan-based nanocarrier (chitosan-g-stearic acid, CSO–SA) for intracellular delivery of DrzBS, then compared the inhibition effect of our CSO–SA/DrzBS complex to a common transfection reagent, Lipofectamine™ 2000/DrzBS, on hepatitis B surface antigen expression. The synthesized CSO–SA assembles into micelles in an aqueous solution and exhibits excellent cytoplasmic targeting, and could protect DrzBS from degradation by ribonuclease. CSO–SA/DrzBS showed a higher inhibition rate (IR) than Lipofectamine™ 2000/DrzBS. Moreover, at the same DrzBS concentration (1.2 μmol L−1), the maximum IR of CSO–SA/DrzBS micelles was 2.4-fold that of the Lipofectamine™ 2000/DrzBS complex, and held on for 96 hours. Compared with Lipofectamine™ 2000/DrzBS, CSO–SA/DrzBS achieved a higher HBV inhibition effect. This study demonstrates that CSO–SA micelles can serve as a potential vector for DrzBS and that CSO–SA/DrzBS micelles are a promising application for anti-HBV gene therapy.

Wei, Yu; Xu, Xuehui; Shang, Yingxu; Jiang, Qiao; Li, Can; Ding, Baoquan

doi: 10.1039/c9ra01769kpmid: 35514862

Rolling circle amplification (RCA) and rolling circle transcription (RCT) can be used to fabricate various structures and organize functional materials for biological applications. The full understanding of the interactions between RCA/RCT-derived structures and live cells is urgently demanded. Here, we present a label-free fluorescent strategy to study the intracellular location and stability of RCA-based DNA flowers in live cells. The DNA flower structures are co-assembled with carbazole-based biscyanine fluorophores, which are DNA detecting molecules and characterized by restriction of intramolecular rotation (RIR) induced strong fluorescent emission. When biscyanine molecules are encapsulated in the DNA flowers via electrostatic attraction, these confined RIR dyes can produce strong luminescent emission. Using this advantage, we use the RIR enhanced technique for direct visualization of the distribution and degradation of DNA flowers in live cellular systems. Our current research could be adapted to other advanced DNA-based materials, providing a new strategy to fabricate fluorescent DNA materials and realize controllable release of payloads.

Deng, Mingxiang; Li, Sijie; Hong, Wanwan; Jiang, Yunling; Xu, Wei; Shuai, Honglei; Li, Hui; Wang, Wenlei; Hou, Hongshuai; Ji, Xiaobo

doi: 10.1039/c9ra02301apmid: 35514828

Antimony sulfide (Sb2S3) has drawn widespread attention as an ideal candidate anode material for sodium-ion batteries (SIBs) due to its high specific capacity of 946 mA h g−1 in conversion and alloy reactions. Nevertheless, volume expansion, a common flaw for conversion-alloy type materials during the sodiation and desodiation processes, is bad for the structure of materials and thus obstructs the application of antimony sulfide in energy storage. A common approach to solve this problem is by introducing carbon or other matrices as buffer material. However, the common preparation of Sb2S3 could result in environmental pollution and excessive energy consumption in most cases. To incorporate green chemistry, natural stibnite ore (Sb2S3) after modification via carbon sheets was applied as a first-hand material in SIBs through a facile and efficient strategy. The unique composites exhibited an outstanding electrochemical performance with a higher reversible capacity, a better rate capability, as well as an excellent cycling stability compared to that of the natural stibnite ore. In short, the study is expected to offer a new approach to improve Sb2S3 composites as an anode in SIBs and a reference for the development of natural ore as a first-hand material in energy storage.