Correction: Porous monoliths synthesized via polymerization of styrene and divinyl benzene in nonaqueous deep-eutectic solvent-based HIPEs

Correction for ‘Porous monoliths synthesized via polymerization of styrene and divinyl benzene in nonaqueous deep-eutectic solvent-based HIPEs’ by M. G. Pérez-García et al., RSC Adv., 2015, 5, 23255–23260.

The authors regret that there was an error in the results and discussion section of the original article. On page 23257, the text read, “The surfactant employed here was sorbitan monooleate”. This should have read, “The surfactant employed here was sorbitan stearate”.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Grafting of Chitosan with Styrene and Maleic Anhydride via Nitroxide‐Mediated Radical Polymerization in Supercritical Carbon Dioxide

A novel synthesis route is used to produce chitosan‐graft‐poly(styrene‐maleic anhydride)‐OH‐TEMPO (CTS‐g‐PSMA‐T). A three‐step reaction scheme is proposed: 1) bromine 4‐OH‐TEMPO oxoammonium salt is synthesized. 2) Hydroxyl‐targeted groups in the CTS molecule are reacted with the synthesized salt in aqueous acid solution. A functionalization of 18.9% is achieved. 3) Graft copolymerization of styrene and maleic anhydride is done via NMRP by a unimolecular initiation system. The reaction is run in a dispersion in supercritical carbon dioxide (scCO₂) in the presence of camphorsulfonic acid (CSA) to avoid autopolymerization. A modified CTS with a graft content of 68% in weight is obtained.

     

A phytotherapeutic extract of Equisetum myriochaetum is not genotoxic either in the in vivo wing somatic test of Drosophila or in the in vitro human micronucleus test

Equisetum myriochaetum is a Mexican plant used in folk medicine to treat kidney diseases and type 2 diabetes mellitus. The main constituents of the phytoextract are flavonol glycosides (kaempferol), phytoesterols and carbohydrates. In this study, phytotherapeutic extracts from Equisetum myriochaetum were investigated for genotoxicity in the in vivo wing spot test in Drosophila melanogaster and in the in vitro human micronucleus test. No acute toxicity of the phytoextract could be determined in Drosophila or in human lymphocytes in culture, ranging from 0.78 microg/ml to 3700 microg/ml for the wing assay and between 12.5 microg/ml and 500 microg/ml for the micronucleus test. The Drosophila wing somatic mutation and recombination test (SMART) was applied in the standard version with basal biotransformation activity as well as in a variant version with increased cytochrome P450-dependent bioactivation capacity. The ranges of exposure concentrations for these genotoxicity experiments were between 0.78 microg/ml and 500 microg/ml. The human micronucleus test in vitro was performed with cultured lymphocytes obtained from four healthy donors. The concentrations assayed for these experiments ranged from 12.5 microg/ml to 500 microg/ml. No statistically significant increase was observed between treated series when compared with a concurrent negative (water solvent) control series in either assay. The results demonstrate clearly that the phytotherapeutic extract from Equisetum myriochaetum, under the experimental conditions tested, is not genotoxic in the in vivo experiments or in the in vitro studies.     

DNA damage response of A549 cells treated with particulate matter (PM10) of urban air pollutants

We describe the events triggered by a sub-lethal concentration of airborne particulate matter (PM₁₀) in A549 cells, which include the formation DNA double-strand breaks, γH2A.X generation, and 53BP1 recruitment. To protect the genome, cells activated ATM/ATR/Chk1/Chk2/p53 pathway but, after 48 h, cells turned into a senescence-like state. Trolox, an antioxidant, was able to prevent most of the alterations observed after particulate matter exposure, demonstrating the important role of ROS as mediator of PM₁₀-induced genotoxicity and suggesting that DNA damage could be the mechanisms by which particulate matter augment the risk of lung cancer.     

Cytoplasmic p21, ERK1/2 activation,and cytoskeletal remodeling are associated with the senescence-like phenotype after airborne particulate matter (PM10) exposure in lung cells

The exposure to particulate matter with a mean aerodynamic diameter ≤10 μm (PM₁₀) from urban zones is considered to be a risk factor in the development of cancer. The aim of this work was to determine if PM₁₀ exposure induces factors related to the acquisition of a neoplastic phenotype, such as cytoskeletal remodeling, changes in the subcellular localization of p21^CIP1/WAF1, an increase in β-galactosidase activity and changes in cell cycle. To test our hypothesis, PM₁₀ from an industrial zone (IZ) and a commercial zone (CZ) were collected, and human adenocarcinoma lung cell cultures (A549) were exposed to a sublethal PM₁₀ concentration (10 μg/cm²) for 24 h and 48 h. The results showed that PM₁₀ exposure induced an increase in F-actin stress fibers and caused the cytoplasmic stabilization of p21^CIP1/WAF1 via phosphorylation at Thr¹⁴⁵ and Ser¹⁴⁶ and the phosphorylation of ERK1/2 on Thr²⁰². Changes in the cell cycle or apoptosis were not observed, but an increase in β-galactosidase activity was detected. The PM₁₀ from CZ caused more dramatic effects in lung cells. We conclude that PM₁₀ exposure induced cytoplasmic p21^CIP1/WAF1 retention, ERK1/2 activation, cytoskeleton remodeling and the acquisition of a senescence-like phenotype in lung cells. These alterations could have mechanistic implications regarding the carcinogenic potential of PM₁₀.