| 1. |
- Girgis, Emad, et al.
(författare)
-
Synthesis, magnetic and optical properties of core/shell Co(1-x)Zn(x)Fe(2)O(4)/SiO(2) nanoparticles
- 2011
-
Ingår i: Nanoscale Research Letters. - 1931-7573 .- 1556-276X. ; 6, s. 460-
-
Tidskriftsartikel (refereegranskat)abstract
- The optical properties of multi-functionalized cobalt ferrite (CoFe(2)O(4)), cobalt zinc ferrite (Co(0.5)Zn(0.5)Fe(2)O(4)), and zinc ferrite (ZnFe(2)O(4)) nanoparticles have been enhanced by coating them with silica shell using a modified Stober method. The ferrites nanoparticles were prepared by a modified citrate gel technique. These core/shell ferrites nanoparticles have been fired at temperatures: 400 degrees C, 600 degrees C and 800 degrees C, respectively, for 2 h. The composition, phase, and morphology of the prepared core/shell ferrites nanoparticles were determined by X-ray diffraction and transmission electron microscopy, respectively. The diffuse reflectance and magnetic properties of the core/shell ferrites nanoparticles at room temperature were investigated using UV/VIS double-beam spectrophotometer and vibrating sample magnetometer, respectively. It was found that, by increasing the firing temperature from 400 degrees C to 800 degrees C, the average crystallite size of the core/shell ferrites nanoparticles increases. The cobalt ferrite nanoparticles fired at temperature 800 degrees C; show the highest saturation magnetization while the zinc ferrite nanoparticles coated with silica shell shows the highest diffuse reflectance. On the other hand, core/shell zinc ferrite/silica nanoparticles fired at 400 degrees C show a ferromagnetic behavior and high diffuse reflectance when compared with all the uncoated or coated ferrites nanoparticles. These characteristics of core/shell zinc ferrite/silica nanostructures make them promising candidates for magneto-optical nanodevice applications.
|
|
| 2. |
- George, Riham F., et al.
(författare)
-
Design, synthesis and QSAR studies of dispiroindole derivatives as new antiproliferative agents
- 2013
-
Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 68, s. 339-351
-
Tidskriftsartikel (refereegranskat)abstract
- A variety of 4'-ary1-3-(arylmethylidene)-1 ''-[(cyclic-amino)methylene]-1'-methyl-dispiro[cyclohexane-1,3'-pyrrolidine-2',3 ''-[3H]indole]-2,2 ''(1H)-diones 4a-u were prepared via reaction of 2E,6E-bis(arylidene)-1-cyclohexanones 1a-i with azomethine ylides, generated in situ via a decarboxylative condensation of isatins 2a-c and sarcosine (3). Single crystal X-ray study of 4a, revealed structural and stereochemical features of these derivatives. While most of the synthesized compounds exhibit mild antitumor properties when tested against various human tumor cell lines (HEPG2 liver, HELA cervical and PD prostate cancers), three of them, 4d and 4p (active against HEPG2), and compound 4g (active against HELA), demonstrated higher activities, that were close or even higher than that of the reference standard Doxorubicin. QSAR studies revealed good predictive and statistically significant 3 descriptor models (r(2) = 0.903-0.812, r(adjusted)(2) = 0.855-0.672, r(prediction)(2) = 0.773-0.605).
|
|
| 3. |
- Girgis, Adel S., et al.
(författare)
-
Synthesis and QSAR study of novel cytotoxic spiro[3H-indole-3,2 '(1 ' H)-pyrrolo[3,4-c]pyrrole]-2,3 ',5 '(1H,2 ' aH,4 ' H)-triones
- 2012
-
Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 47, s. 312-322
-
Tidskriftsartikel (refereegranskat)abstract
- 1,3-Dipolar cycloaddition reaction of 1-aryl-1H-pyrrole-2,5-diones 1a-e with non-stabilized azomethine ylides, generated in situ via decarboxylative condensation of isatins 2a-c and sarcosine (3) in refluxing ethanol, afforded 4'-aryl-5'a,6'-dihydro-1'-methyl-spiro[3H-indole-3,2'(1 ' H)-pyrrolo[3,4-c]pyrrole]-2,3',5'(1H,2'aH,4'H)-triones 4a-o in good yields. Compound 4I exhibited high anti-tumor activity against HEPG2 (liver cancer) cell line (IC50 = 12.16 mu M) compared to that of Doxorubicin (IC50= 7.36 mu M), and the other synthesized compounds revealed moderate anti-tumor properties against HCT116 (colon), MCF7 (breast) and HEPG2 (liver) human tumor cell lines. 3D-Pharmacophore modeling and quantitative structure-activity relationship (QSAR) analysis were combined to explore the structural requirements controlling the observed anti-tumor properties. It was found that the major structural factors affecting potency of these compounds were related to their basic skeleton.
|
|
| 4. |
- Girgis, E., et al.
(författare)
-
Nanotoxicity of Gold and Gold-Cobalt Nanoalloy
- 2012
-
Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 25:5, s. 1086-1098
-
Tidskriftsartikel (refereegranskat)abstract
- Nanotoxicology test of gold nanoparticles (Au NPs) and gold-cobalt (Au-Co) nanoalloy is an important step in their safety evaluation for biomedical applications. The Au and Au-Co NPs were prepared by reducing the metal ions using sodium borohydride (NaBH4) in the presence of polyvinyl pyrrolidone (PVP) as a capping material. The average size and shape of the nanoparticles (NPs) were characterized using high resolution transmission electron microscopy (HRTEM). Cobalt presence in the nanoalloy was confirmed by energy dispersive X-ray spectroscopy (EDX) analysis, and the magnetic properties of these particles were determined using a vibrating sample magnetometer (VSM). The Gold and gold-cobalt NPs of average size 15 +/- 1.5 nm were administered orally to mice with a dose of 80, 160, and 320 mg/kg per body weight (bw) using gavages. Samples were collected after 7 and 14 days of the treatment. The results indicated that the Au-Co NPs were able to induce significant alteration in the tumor-initiating genes associated with an increase of micronuclei (MNs) formation and generation of DNA adduct (8-hydroxy-2-deoxyguanosine, 8-OHdG) as well as a reduction in the glutathione peroxidase activity. This action of Au-Co NPs was observed using 160 and 320 mg/kg bw at both time intervals. However, Au NPs had much lower effects than Au-Co NPs on alteration in the tumor-initiating genes, frequency of MNs, and generation of 8-0HdG as well as glutathione peroxidase activity except with the highest dose of Au NPs. This study suggests that the potential to cause in vivo genetic and antioxidant enzyme alterations due to the treatment by Au-Co nanoalloy may be attributed to the increase in oxidative stress in mice.
|
|
| 5. |
- Khalil, W. K. B., et al.
(författare)
-
Genotoxicity Evaluation of Nanomaterials : DNA Damage, Micronuclei, and 8-Hydroxy-2-deoxyguanosine Induced by Magnetic Doped CdSe Quantum Dots in Male Mice
- 2011
-
Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 24:5, s. 640-650
-
Tidskriftsartikel (refereegranskat)abstract
- Quantum dots (QDs) are a novel class of inorganic fluorophores which are gaining widespread recognition as a result of their exceptional photophysical properties and their applications as a biomarker and in molecular biomedical imaging. The aim of this study was to evaluate the in vivo genotoxicity in mice exposed to CdSe quantum dots of average size 5.0 +/- 0.2 nm and CdSe doped with 1% cobalt ions of similar size. The quantum dots are surface modified using mercaptoacetic acid (MAA) in order to be biocompatible and water-soluble. The MAA-QDs were given to the mice orally at doses of 500, 1000, and 2000 mg/kg by weight of MAA-QDs. Bone marrow and liver samples were collected after two and seven days of treatment. The results indicated that after two days of treatment, the high dose of doped MAA-QDs was significantly able to induce DNA damage, formation of micronuclei (MNs), and generation of DNA adduct (8-hydroxy-2-deoxyguanosine, 8-OHdG). However, increasing DNA damage and the frequency of MNs formation as well as the generation of DNA adducts were observed with both the undoped MAA-QDs (2000 mg/kg) and doped MAA-QDs (1000 and 2000 mg/kg) after seven days of treatment. The results of our study indicate that exposure to high doses of pure MAA-QDs or MAA-QDs doped with cobalt has the potential to cause indirect in vivo genetic damage, which may be attributed to free radical-induced oxidative stress in mice.
|
|
