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1.
Langmuir ; 40(1): 179-192, 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38112377

ABSTRACT

An effective strategy was employed for the rapid development of a supramolecular metallohydrogel of Mg(II) ion (i.e., Mg@PEHA) using pentaethylenehexamine (PEHA) as a low-molecular-weight gelator in aqueous medium under ambient conditions. The mechanical stability of the synthesized Mg@PEHA metallohydrogel was characterized by using rheological analysis, which showed its robustness across different angular frequencies and oscillator stress levels. The metallohydrogel exhibited excellent thixotropic behavior, which signifies that Mg@PEHA has a self-healing nature. Field emission scanning electron microscopy and transmission electron microscopy images were utilized to explore the rectangular pebble-like hierarchical network of the Mg@PEHA metallohydrogel. Elemental mapping through energy-dispersive X-ray spectroscopy analysis confirmed the presence of primary chemical constituents in the metallohydrogel. Fourier transform infrared spectroscopy spectroscopy provided insights into the possible formation strategy of the metallohydrogel. In this work, Schottky diode structures in a metal-semiconductor-metal geometry based on a magnesium(II) metallohydrogel (Mg@PEHA) were constructed, and the charge transport behavior was observed. Additionally, a resistive random access memory (RRAM) device was developed using Mg@PEHA, which displayed bipolar resistive switching behavior at room temperature. The researchers investigated the switching mechanism, which involved the formation or rupture of conduction filaments, to gain insights into the resistive switching process. The RRAM device demonstrated excellent performance with a high ON/OFF ratio of approximately 100 and remarkable endurance of over 5000 switching cycles. RRAM devices exhibit good endurance, meaning they can endure a large number of read and write cycles without significant degradation in performance. RRAM devices have shown promising reliability in terms of long-term performance and stability, making them suitable for critical applications that require reliable memory solutions. Significant inhibitory activity against the drug-resistant Klebsiella pneumonia strain and its biofilm formation ability was demonstrated by Mg@PEHA. The minimum inhibitory concentration value of the metallohydrogel was determined to be 3 mg/mL when it was dissolved in 1% DMSO. To study the antibiofilm activity, an MTT assay was performed, revealing that biofilm inhibition (60%) commenced at 1 mg/mL of Mg@PEHA when dissolved in 1% DMSO. Moreover, in the mouse excisional wound model, Mg@PEHA played a crucial role in preventing postoperative wound infections and promoting wound healing.

2.
Sci Rep ; 13(1): 22318, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38102201

ABSTRACT

A rapid metallohydrogelation strategy has been developed of magnesium(II)-ion using trimethylamine as a low molecular weight gelator in water medium at room temperature. The mechanical property of the synthesized metallohydrogel material is established through the rheological analysis. The nano-rose like morphological patterns of Mg(II)-metallohydrogel are characterized through field emission scanning electron microscopic study. The energy dispersive X-ray elemental mapping analysis confirms the primary gel forming elements of Mg(II)-metallohydrogel. The possible metallohydrogel formation strategy has been analyzed through FT-IR spectroscopic study. In this work, magnesium(II) metallohydrogel (Mg@TMA) based metal-semiconductor-metal structures have been developed and charge transport behaviour is studied. Here, it is confirmed that the magnesium(II) metallohydrogel (Mg@TMA) based resistive random access memory (RRAM) device is showing bipolar resistive switching behaviour at room temperature. We have also explored the mechanism of resistive switching behaviour using the formation (rupture) of conductive filaments between the metal electrodes. This RRAM devices exhibit excellent switching endurance over 10,000 switching cycles with a large ON/OFF ratio (~ 100). The easy fabrication techniques, robust resistive switching behaviour and stability of the present system makes these structures preferred candidate for applications in non-volatile memory design, neuromorphic computing, flexible electronics and optoelectronics etc.

3.
RSC Adv ; 13(4): 2561-2569, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36741164

ABSTRACT

A unique strategy for the synthesis of a supramolecular metallogel employing zinc ions and adipic acid in DMF medium has been established at room temperature. Rheological analysis was used to investigate the mechanical characteristics of the supramolecular Zn(ii)-metallogel. Field emission scanning electron microscopy and transmission electron microscopy were used to analyse the hexagonal shape morphological features of the Zn(ii)-metallogel. Interestingly, the electrical conductivity is observed in the electronic device with Zn(ii)-metallogel based metal-semiconductor (MS) junctions. All aspects of the metallogel's electrical properties were investigated. The electrical conductivity of the metallogel-based thin film device was 7.38 × 10-5 S m-1. The synthesised Zn(ii)-metallogel based device was investigated for its semi-conductive properties, such as its Schottky barrier diode nature.

4.
Mol Cell Biochem ; 405(1-2): 149-58, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25893736

ABSTRACT

Non-small cell lung cancer (NSCLC) is known to be a difficult cancer to treat because of its poor prognosis, limited option for surgery, and resistance to chemo or radiotherapy. In this study, we have demonstrated that suppression of rictor expression in A549 and H1299 NSCLC cells by mahanine, a carbazole alkaloid, disrupted constitutive activation of mTOR and Akt. Mahanine suppression of rictor gene expression and consequent attenuation of its protein expression affected the inhibition of mTOR (Ser-2481) and Akt (Ser-473) phosphorylation. Since mahanine treatment revealed this new insight of rictor-mTOR relationship, we examined an association between mTOR activation with rictor expression. Interestingly, in rictor knockdown (KD) NSCLC cells, mTOR activation was significantly impaired. Transfection of rictor over-expression vector into the NSCLC cells reversed this situation. In fact, both rictor KD and mahanine treated cells showed considerably depleted phospho-mTOR level. These results indicate that rictor is required to maintain constitutive activation of mTOR in lung cancer cells. When mTOR kinase activity in rictor KD cells was examined with Akt as substrate, a significant reduction of Akt phosphorylation indicated impairment of mTOR kinase potentiality. Disruption of mTOR and Akt activation caused drastic mortality of NSCLC cancer cells through apoptosis. Hence, our study reveals a new dimension in mTOR-rictor relationship, where rictor stands to be a suitable therapeutic target for lung cancer.


Subject(s)
Alkaloids/pharmacology , Apoptosis/drug effects , Carbazoles/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Carrier Proteins/metabolism , Lung Neoplasms/drug therapy , TOR Serine-Threonine Kinases/metabolism , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , Humans , Lung Neoplasms/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Rapamycin-Insensitive Companion of mTOR Protein , Signal Transduction/drug effects
5.
Biochem Biophys Res Commun ; 452(3): 382-8, 2014 Sep 26.
Article in English | MEDLINE | ID: mdl-25157809

ABSTRACT

Skeletal muscle and adipose tissues are known to be two important insulin target sites. Therefore, lipid induced insulin resistance in these tissues greatly contributes in the development of type 2 diabetes (T2D). Ferulic acid (FRL) purified from the leaves of Hibiscus mutabilis, showed impressive effects in preventing saturated fatty acid (SFA) induced defects in skeletal muscle cells. Impairment of insulin signaling molecules by SFA was significantly waived by FRL. SFA markedly reduced insulin receptor ß (IRß) in skeletal muscle cells, this was affected due to the defects in high mobility group A1 (HMGA1) protein obtruded by phospho-PKCε and that adversely affects IRß mRNA expression. FRL blocked PKCε activation and thereby permitted HMGA1 to activate IRß promoter which improved IR expression deficiency. In high fat diet (HFD) fed diabetic rats, FRL reduced blood glucose level and enhanced lipid uptake activity of adipocytes isolated from adipose tissue. Importantly, FRL suppressed fetuin-A (FetA) gene expression, that reduced circulatory FetA level and since FetA is involved in adipose tissue inflammation, a significant attenuation of proinflammatory cytokines occurred. Collectively, FRL exhibited certain unique features for preventing lipid induced insulin resistance and therefore promises a better therapeutic choice for T2D.


Subject(s)
Adipose Tissue/drug effects , Coumaric Acids/pharmacology , Diabetes Mellitus, Experimental/drug therapy , Hibiscus/chemistry , Hypoglycemic Agents/pharmacology , Muscle, Skeletal/drug effects , Adipocytes/drug effects , Adipocytes/metabolism , Adipose Tissue/metabolism , Animals , Coumaric Acids/isolation & purification , Diabetes Mellitus, Experimental/etiology , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/metabolism , Diet, High-Fat , Fatty Acids/adverse effects , Gene Expression Regulation , HMGA1a Protein/agonists , HMGA1a Protein/genetics , HMGA1a Protein/metabolism , Hypoglycemic Agents/isolation & purification , Insulin Resistance , Male , Muscle, Skeletal/metabolism , Plant Leaves/chemistry , Promoter Regions, Genetic , Protein Kinase C-epsilon/antagonists & inhibitors , Protein Kinase C-epsilon/genetics , Protein Kinase C-epsilon/metabolism , Rats , Rats, Sprague-Dawley , Receptor, Insulin/agonists , Receptor, Insulin/antagonists & inhibitors , Receptor, Insulin/genetics , Receptor, Insulin/metabolism , Signal Transduction , alpha-2-HS-Glycoprotein/antagonists & inhibitors , alpha-2-HS-Glycoprotein/genetics , alpha-2-HS-Glycoprotein/metabolism
6.
J Biol Chem ; 288(39): 28324-30, 2013 Sep 27.
Article in English | MEDLINE | ID: mdl-23943623

ABSTRACT

Macrophage infiltration into adipose tissue during obesity and their phenotypic conversion from anti-inflammatory M2 to proinflammatory M1 subtype significantly contributes to develop a link between inflammation and insulin resistance; signaling molecule(s) for these events, however, remains poorly understood. We demonstrate here that excess lipid in the adipose tissue environment may trigger one such signal. Adipose tissue from obese diabetic db/db mice, high fat diet-fed mice, and obese diabetic patients showed significantly elevated fetuin-A (FetA) levels in respect to their controls; partially hepatectomized high fat diet mice did not show noticeable alteration, indicating adipose tissue to be the source of this alteration. In adipocytes, fatty acid induces FetA gene and protein expressions, resulting in its copious release. We found that FetA could act as a chemoattractant for macrophages. To simulate lipid-induced inflammatory conditions when proinflammatory adipose tissue and macrophages create a niche of an altered microenvironment, we set up a transculture system of macrophages and adipocytes; the addition of fatty acid to adipocytes released FetA into the medium, which polarized M2 macrophages to M1. This was further confirmed by direct FetA addition to macrophages. Taken together, lipid-induced FetA from adipocytes is an efficient chemokine for macrophage migration and polarization. These findings open a new dimension for understanding obesity-induced inflammation.


Subject(s)
Adipocytes/cytology , Adipose Tissue/metabolism , Macrophages/cytology , alpha-2-HS-Glycoprotein/metabolism , Aged , Animals , Cell Movement , Endotoxins/metabolism , Female , Humans , Inflammation , Lipids/chemistry , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Middle Aged , Obesity/metabolism , Signal Transduction
7.
PLoS One ; 7(10): e47014, 2012.
Article in English | MEDLINE | ID: mdl-23091605

ABSTRACT

Non-small cell lung carcinoma (NSCLC) is a major killer in cancer related human death. Its therapeutic intervention requires superior efficient molecule(s) as it often becomes resistant to present chemotherapy options. Here we report that vapor of volatile oil compounds obtained from Litsea cubeba seeds killed human NSCLC cells, A549, through the induction of apoptosis and cell cycle arrest. Vapor generated from the combined oils (VCO) deactivated Akt, a key player in cancer cell survival and proliferation. Interestingly VCO dephosphorylated Akt at both Ser(473) and Thr(308); through the suppression of mTOR and pPDK1 respectively. As a consequence of this, diminished phosphorylation of Bad occurred along with the decreased Bcl-xL expression. This subsequently enhanced Bax levels permitting the release of mitochondrial cytochrome c into the cytosol which concomitantly activated caspase 9 and caspase 3 resulting apoptotic cell death. Impairment of Akt activation by VCO also deactivated Mdm2 that effected overexpression of p53 which in turn upregulated p21 expression. This causes enhanced p21 binding to cyclin D1 that halted G1 to S phase progression. Taken together, VCO produces two prong effects on lung cancer cells, it induces apoptosis and blocked cancer cell proliferation, both occurred due to the deactivation of Akt. In addition, it has another crucial advantage: VCO could be directly delivered to lung cancer tissue through inhalation.


Subject(s)
Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Litsea/chemistry , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Seeds/chemistry , Carcinoma, Non-Small-Cell Lung/metabolism , Caspases/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Cyclin D1/metabolism , Humans , Lung Neoplasms/metabolism , Oils, Volatile/isolation & purification , Phosphorylation/drug effects , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Oils/isolation & purification , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects
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