Characterization and gamma radiation effects on poly(methyl methacrylate) doped with some benzylidene polymers

Sayyah, S. M.; EI-Ahdal, M. A.; El-Shafiey, Z. A.; El‐Sockary, Maher A.; Kandil, Usama F.

doi:10.1007/s10965-006-0109-9

Cited by 7 publications

(7 citation statements)

References 17 publications

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“…Elemental analyses were performed at Al-Azhar University at the regional center for mycology and biotechnology. Compounds ( 1a–b 23 − 2a 43 − 2b 44 − 3a 45 − 4 26 − 5a 46 − 5b,d,e 47 − 5c 48 − 6a 49 − 6b,c 50 − 6e 51 − 7a,b,c,e,h 52 − 7i 53 − 8a 54 − 8e 55 − 9a,b 56 − 9d 57 − 9h 58 − 10 30 − 17 33 − 18 34 − 19 35 ) were prepared according to the reported procedures.…”

Section: Methodsmentioning

confidence: 99%

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

Aziz

Serya

Lasheen

et al. 2016

Sci Rep

137

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Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a crucial role in cancer angiogenesis. In this study, a series of novel furo[2,3-d]pyrimidine and thieno[2,3-d]pyrimidine based-derivatives were designed and synthesized as VEGFR-2 inhibitors, in accordance to the structure activity relationship (SAR) studies of known type II VEGFR-2 inhibitors. The synthesized compounds were evaluated for their ability to in vitro inhibit VEGFR-2 kinase enzyme. Seven compounds (15b, 16c, 16e, 21a, 21b, 21c and 21e) demonstrated highly potent dose-related VEGFR-2 inhibition with IC50 values in nanomolar range, of which the thieno[2,3-d]pyrimidine based-derivatives (21b, 21c and 21e) exhibited IC50 values of 33.4, 47.0 and 21 nM respectively. Moreover, furo[2,3-d]pyrimidine-based derivative (15b) showed the strongest inhibition of human umbilical vein endothelial cells (HUVEC) proliferation with 99.5% inhibition at 10 μM concentration. Consistent with our in vitro findings, compounds (21b and 21e) orally administered at 5 and 10 mg/kg/day for 8 consecutive days demonstrated potent anticancer activity in Erhlich ascites carcinoma (EAC) solid tumor murine model. Such compounds blunted angiogenesis in EAC as evidenced by reduced percent microvessel via decreasing VEGFR-2 phosphorylation with subsequent induction of apoptotic machinery. Furthermore, Miles vascular permeability assay confirmed their antiangiogenic effects in vivo. Intriguingly, such compounds showed no obvious toxicity.

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Section: Methodsmentioning

confidence: 99%

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

Aziz

Serya

Lasheen

et al. 2016

Sci Rep

137

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“…However, the far UV limit of the experimental spectra (l o 300 nm) displays a strong absorbance edge produced by electronic excitations within the carboxyl (CQO) chromophore in the PMMA structure. 16 The most intense absorption feature in the 200-230 nm region is attributed to the pp* transitions in the CQO system while the 270-300 nm absorption feature is attributed to 'forbidden' np* transitions that possess a lower absorption intensity.…”

Section: Irradiation Conditionsmentioning

confidence: 98%

Mechanistical studies on the electron-induced degradation of polymethylmethacrylate and Kapton

Ennis

Kaiser

2010

Phys. Chem. Chem. Phys.

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Mechanisms for the electron-induced degradation of poly(methyl methacrylate) (PMMA) and Kapton polyimide (PMDA-ODA), both of which are commonly used in aerospace applications, were examined over a temperature range of 10 K to 300 K under ultra high vacuum (∼10(-11) Torr). The experiments were designed to simulate the interaction between the polymer materials and secondary electrons produced by interaction with galactic cosmic ray particles in the near-Earth space environment. Chemical alterations of the samples were monitored on line and in situ by Fourier-transform infrared spectroscopy and mass spectrometry during irradiation with 5 keV electrons and also prior and after the irradiation exposure via UV-vis. The irradiation-induced degradation of PMMA resulted in the formation and unimolecular decomposition of methyl carboxylate radicals (CH(3)OCO) forming carbon monoxide (k = 4.60 × 10(-3) s(-1)) and carbon dioxide (k = 1.29 × 10(-3) s(-1)). Temperature dependent gas-phase abundances for carbon monoxide, carbon dioxide, and molecular hydrogen were also obtained for the PMMA and Kapton samples. The lower gas yields detected for irradiated Kapton were typically one or two orders of magnitude less than PMMA suggesting a higher degradation resistance to energetic electrons. In addition, UV-vis spectroscopy revealed the propagation of conjugated bonds induced by the irradiation of PMMA and indicated a decrease in the optical band gap by an increase in absorbance above 500 nm in irradiated Kapton.

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“…The radiation doses (5,15,25,35,50,75, and 100 kGy) were measured with a radio chromic dye film and Perspex. The overall error in the dose measurements did not exceed 64%.…”

Section: Determination Of M Vmentioning

confidence: 99%

“…The UV spectra of a pure PMMA film before and after g irradiation with different accumulated exposure doses (5,15,25,35,50,75, and 100 kGy) was investigated by Sayyah et al 35 They found that the absorbance increased with increasing g ray doses, and the linear part of the relationship between the absorbance and g-exposure dose lay between 0 and 50 kGy. This means that a pure PMMA film can be used as a dosimeter in this range of exposure doses.…”

Section: Tlc Analysismentioning

confidence: 99%

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Molecular weight studies of the γ‐irradiation degradation of poly(methyl methacrylate) doped with poly(p‐sulfanilamide)

Sayyah

Khaliel

El‐Salam

2007

J of Applied Polymer Sci

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The protection of some poly(methyl methacrylate) (PMMA) samples against c rays was investigated in the absence and presence of poly(p-sulfanilamide). Pure PMMA (without additives) and PMMA-poly(p-sulfanilamide) blend samples were irradiated with c rays for different exposure doses (5,15,25,35, 50, 75, and 100 kGy). The viscosity-average molecular weights were determined and thin-layer chromatography measurements were carried out after each irradiation dose. The maximum protection against c rays was found when 1% poly(p-sulfanilamide) was used. The radiation chemical yield for main scission (G s ) was calculated and had lower values in the case of 1% poly(p-sulfanilamide). The energy absorption per scission was maximum for 1% poly(p-sulfanilamide), and this confirmed the obtained G s data. From thin-layer chromatography studies, it was observed that both the retention factor (R f ) values and polydispersity of the PMMA samples increased with an increasing exposure dose. The effect of c irradiation on PMMA films doped with 1% poly(p-sulfanilamide) was investigated with UV spectroscopy after the extraction of the additives. A change in the intensity of the absorption bands with an increasing irradiation dose was recorded. It is suggested that PMMA films doped with this type of polymer can be used as dosimeters.

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Characterization and gamma radiation effects on poly(methyl methacrylate) doped with some benzylidene polymers

Cited by 7 publications

References 17 publications

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

Mechanistical studies on the electron-induced degradation of polymethylmethacrylate and Kapton

Molecular weight studies of the γ‐irradiation degradation of poly(methyl methacrylate) doped with poly(p‐sulfanilamide)

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