Poly (hydroxyethyl methacrylate-glycidyl methacrylate) films modified with different functional groups: In vitro interactions with platelets and rat stem cells

Cataloged from PDF version of article.Copolymerization of 2-hydroxyethylmethactylate (HEMA) with glycidylmethacrylate (GMA) in the presence of alpha-alpha'-azoisobisbutyronitrile (AIBN) resulted in the formation of hydrogel films carrying reactive epoxy groups. Thirteen kinds of different molecules with pendant -NH2 group were used for modifications of the p(HEMA-GMA) films. The -NH2 group served as anchor binding site for immobilization of functional groups on the hydrogel film via direct epoxy ring opening reaction. The modified hydrogel films were characterized by FTIR, and contact angle studies. In addition, mechanical properties of the hydrogel films were studied, and modified hydrogel films showed improved mechanical properties compared with the non-modified film, but they are less elastic than the non-modified film. The biological activities of these films such as platelet adhesion, red blood cells hemolysis, and swelling behavior were studied. The effect of modified hydrogel films, including -NH2, (using different aliphatic -CH2 chain lengths) -CH3, -SO3H, aromatic groups with substituted -OH and -COOH groups, and amino acids were also investigated on the adhesion, morphology and survival of rat mesenchymal stem cells (MSCs). The MTT colorimetric assay reveals that the p(HEMA-GMA)-GA-AB, p(HEMA-GMA)-GA-Phe, p(HEMA-GMA)-GA-Trp, p(HEMA-GMA)-GA-Glu formulations have an excellent biocompatibility to promote the cell adhesion and growth. We anticipate that the fabricated p(HEMA-GMA) based hydrogel films with controllable surface chemistry and good stable swelling ratio may find extensive applications in future development of tissue engineering scaffold materials, and in various biotechnological areas. (c) 2012 Elsevier B.V. All rights reserved

The effect of racemic gossypol and AT-101 on angiogenic profile of OVCAR-3 cells: a preliminary molecular framework for gossypol enantiomers

To compare the effect of racemic gossypol with its (–)/(–) enantiomer (AT-101) on expression profiles of angiogenic molecules by mRNA levels in human ovarian cancer cell line OVCAR-3. Methods: Cell viability assay (2,3-bis (2-methoxy-4-nitro-5- sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide) was used to detect cytotoxicity of gossypol enantiomers. DNA fragmentation by an enzyme-linked immunosorbent (ELISA) assay was used to evaluate the rate of apoptosis. The mRNA expression levels of angiogenic molecules were investigated by Human Angiogenesis RT2 ProfilerTM PCR Array (SuperArray, Frederick, MD). Results: Both racemic form and AT-101 resulted in a significant cytotoxicity and induced apoptosis. This effect was observed in a dose- and time dependent manner. However, AT-101 was much more potent. In addition, the treatment of 10 μM of racemic gossypol alone and 3 μM of AT-101 alone resulted in significant down-regulation (≥ 3 fold) in mRNA levels of some pivotal angiogenic molecules in OVCAR-3, but altered gene profiles were different by the treatment of each enantiomer. Conclusion: The efficacy of two gossypol enantiomers in OVCAR-3 cells showed distinction. AT-101 was much more potent than racemic gossypol, not only by means of cell death and apoptosis, but also by modulation of angiogenic molecules released from OVCAR-3 cells. Further studies with endothelial cells should be done to verify the anti-angiogenic effect of gossypol enantiomers in cancer treatment

A kinetic and thermodynamic investigation into the removal of methyl orange from wastewater utilizing fly ash in different process configurations

The removal of methyl orange using coal fly ash, which is a widely available low-cost adsorbent, has been investigated. Adsorption studies for dye removal were conducted using various configurations such as batch, column and heap adsorption at various temperatures and adsorbent dosages at neutral pH. The Langmuir, Freundlich and Tempkin isotherm models were used to describe the process. The Freundlich model best represented the adsorption. Kinetic studies show the adsorption followed pseudo-second-order kinetics. Thermodynamic studies show that the process is spontaneous, endothermic and random. Column configuration was found to be the most efficient with a dye removal percentage of 99.95%, followed by heap adsorption at 99.25% removal and lastly batch configuration with 96.68% removal. Economic analysis shows that column operation would be the most effective for practical implementation

Is it adaptive to disengage from demands of social change? Adjustment to developmental barriers in opportunity-deprived regions

This paper investigates how individuals deal with demands of social and economic change in the domains of work and family when opportunities for their mastery are unfavorable. Theoretical considerations and empirical research suggest that with unattainable goals and unmanageable demands motivational disengagement and self-protective cognitions bring about superior outcomes than continued goal striving. Building on research on developmental deadlines, this paper introduces the concept of developmental barriers to address socioeconomic conditions of severely constrained opportunities in certain geographical regions. Mixed-effects methods were used to model cross-level interactions between individual-level compensatory secondary control and regional-level opportunity structures in terms of social indicators for the economic prosperity and family friendliness. Results showed that disengagement was positively associated with general life satisfaction in regions that were economically devastated and has less than average services for families. In regions that were economically well off and family-friendly, the association was negative. Similar results were found for self-protection concerning domain-specific satisfaction with life. These findings suggest that compensatory secondary control can be an adaptive way of mastering a demand when primary control is not possible

Mild reductions in cytosolic NADP-dependent isocitrate dehydrogenase activity result in lower amino acid contents and pigmentation without impacting growth

Transgenic tomato (Solanum lycopersicum) plants were generated targeting the cytosolic NADP-dependent isocitrate dehydrogenase gene (SlICDH1) via the RNA interference approach. The resultant transformants displayed a relatively mild reduction in the expression and activity of the target enzyme in the leaves. However, biochemical analyses revealed that the transgenic lines displayed a considerable shift in metabolism, being characterized by decreases in the levels of the TCA cycle intermediates, total amino acids, photosynthetic pigments, starch and NAD(P)H. The plants showed little change in photosynthesis with the exception of a minor decrease in maximum photosynthetic efficiency (Fv/Fm), and a small decrease in growth compared to the wild type. These results reveal that even small changes in cytosolic NADP-dependent isocitrate dehydrogenase activity lead to noticeable alterations in the activities of enzymes involved in primary nitrate assimilation and in the synthesis of 2-oxoglutarate derived amino acids. These data are discussed within the context of current models for the role of the various isoforms of isocitrate dehydrogenase within plant amino acid metabolism

A multidisciplinary consensus on the morphological and functional responses to immunotherapy treatment

The implementation of immunotherapy has radically changed the treatment of oncological patients. Currently, immunotherapy is indicated in the treatment of patients with head and neck tumors, melanoma, lung cancer, bladder tumors, colon cancer, cervical cancer, breast cancer, Merkel cell carcinoma, liver cancer, leukemia and lymphomas. However, its efficacy is restricted to a limited number of cases. The challenge is, therefore, to identify which subset of patients would benefit from immunotherapy. To this end, the establishment of immunotherapy response criteria and predictive and prognostic biomarkers is of paramount interest. In this report, a group of experts of the Spanish Society of Medical Oncology (SEOM), the Spanish Society of Medical Radiology (SERAM), and Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM) provide an up-to-date review and a consensus guide on these issues

Bandwidth Estimation for Admission Control in MANET: Review and Conceptual MANET Admission Control Framework

The widespread of wireless mobile network have increased the demand for its applications. Providing a reliable QoS in wireless medium, especially mobile ad-hoc network (MANET), is quite challenging and remains an ongoing research trend. One of the key issues of MANET is its inability to accurately predict the needed and available resources to avoid interference with already transmitting traffic flow. In this work, we propose a resource allocation and admission control (RAAC) solution. RAAC is an admission control scheme that estimates the available bandwidth needed within a network, using a robust and accurate resource estimation technique. Simulation results obtained show that our proposed scheme for MANET can efficiently estimate the available bandwidth and outperforms other existing approaches for admission control with bandwidth estimation