Nanotechnology and global energy demand: challenges and prospects for a paradigm shift in the oil and gas industry.

The exploitation of new hydrocarbon discoveries in meeting the present global energy demand is a function of the availability and application of new technologies. The relevance of new technologies is borne out of the complex subsurface architecture and conditions of offshore petroleum plays. Conventional techniques, from drilling to production, for exploiting these discoveries may require adaption for such subsurface conditions as they fail under conditions of high pressure and high temperature. The oil and gas industry over the past decades has witnessed increased research into the use of nanotechnology with great promise for drilling operations, enhanced oil recovery, reservoir characterization, production, etc. The prospect for a paradigm shift towards the application of nanotechnology in the oil and gas industry is constrained by evolving challenges with its progression. This paper gave a review of developments from nano-research in the oil and gas industry, challenges and recommendations

Ecofriendly synthesis of silver nanoparticles from commercially available plant powders and their antibacterial properties

AbstractUse of various plant materials for the biosynthesis of nanoparticles is considered a green technology, as it does not involve any harmful chemicals. The present study reports that silver nanoparticles (Ag NPs) were synthesized from a silver nitrate solution by commercially available plant powders, such as Solanum tricobatum, Syzygium cumini, Centella asiatica and Citrus sinensis. Ag NPs were characterized by UV–vis spectrophotometer, X-Ray Diffractometer (XRD), Atomic Force Microscopy (AFM) and fourier transform infrared (FTIR) spectroscopy. The formation and stability of the reduced silver nanoparticles in the colloidal solution were monitored by UV–vis spectrophotometer analysis. The mean particle diameter of silver nanoparticles was calculated from the XRD pattern, according to the line width of the plane, and the refraction peak, using Scherrer’s equation. AFM showed the irregular shapes of Ag NPs, and the formation of silver nanoparticles was found to be 53, 41, 52 and 42 nm, corresponding to Syzygium cumini, Citrus sinensis, Solanum tricobatum and Centella asiatica, respectively. FTIR spectroscopy confirmed the presence of protein as the stabilizing agent surrounding the Ag NPs. Antimicrobial activity of the silver bio-nanoparticles was performed by a well diffusion method. The highest antimicrobial activity of Ag NPs synthesized by C. sinensis and C. asiatica was found against Pseudomonas aeruginosa (16 mm). The Ag NPs synthesized in this process were found to have efficient antimicrobial activity against pathogenic bacteria

Chronic oxidative stress increases resistance to doxorubicin-induced cytotoxicity in renal carcinoma cells potentially through epigenetic mechanism. Mol Pharmacol 89:27–41.

ABSTRACT Renal cell carcinoma is the most common form of kidney cancer and is highly resistant to chemotherapy. Although the role of oxidative stress in kidney cancer is known, the chemotherapeutic response of cancer cells adapted to chronic oxidative stress is not clear. Hence, the effect of oxidative stress on sensitivity to doxorubicin-induced cytotoxicity was evaluated using an in vitro model of human kidney cancer cells adapted to chronic oxidative stress. Results of MTT-and anchorage-independent growth assays and cell cycle analysis revealed significant decrease in sensitivity to doxorubicin in Caki-1 cells adapted to oxidative stress. Changes in the expression of genes involved in drug transport, cell survival, and DNA repair-dependent apoptosis further confirmed increased resistance to doxorubicin-induced cytotoxicity in these cells. Decreased expression of mismatch repair (MMR) gene MSH2 in cells exposed to oxidative stress suggests that loss of MMR-dependent apoptosis could be a potential mechanism for increased resistance to doxorubicin-induced cytotoxicity. Additionally, downregulation of HDAC1, an increase in the level of histone H3 acetylation, and hypermethylation of MSH2 promoter were also observed in Caki-1 cells adapted to chronic oxidative stress. DNA-demethylating agent 5-Aza-2dC significantly restored the expression of MSH2 and doxorubicin-induced cytotoxicity in Caki-1 cells adapted to chronic oxidative stress, suggesting the role of DNA hypermethylation in inactivation of MSH2 expression and consequently MMRdependent apoptosis in these cells. In summary, this study for the first time provides direct evidence for the role of oxidative stress in chemotherapeutic resistance in renal carcinoma cells potentially through epigenetic mechanism

Role of cellular reprogramming and epigenetic dysregulation in acquired chemoresistance in breast cancer

Acquired resistance to chemotherapy is a major limitation in clinical treatment for breast cancer. Accumulating evidence from in vitro, in vivo and clinical studies suggest that acquired chemoresistance is progressive, multifactorial and involve genetic and epigenetic aberrations. Among various mechanisms that contribute to chemoresistance, cellular reprogramming has extensively been implicated in breast cancer resistance lately. Cellular reprogramming events such as acquisition of epithelial to mesenchymal transition (EMT) and cancer stemness (CSCs) not only provide cancer cells with reversible phenotypic plasticity and survival advantage against cytotoxicity but also leads to aggressiveness, metastasis, clinical resistance, tumor recurrence and poor survival. The transient and reversible nature of cellular reprogramming processes and their controlled interaction with epigenetic regulatory complexes strongly support the involvement of dynamic epigenetic regulatory network in governing the cellular reprogramming and associated acquired chemoresistance. Further, epigenetic modulations are also gaining interest as promising interventions addressing the cancer cell reprogramming machinery to overcome acquired chemoresistance. This review discusses the previous reports and our recent findings that lead to current understanding of epigenetic dysregulation dictating the cellular reprogramming processes such as acquisition of EMT and CSCs phenotype and how they co-ordinate to establish acquired drug resistance in breast cancer