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El-Sherbiny I.M.,Center for Materials Science | El-Shibiny A.,Biomedical Science | Salih E.,Center for Materials Science
Journal of Photochemistry and Photobiology B: Biology | Year: 2016

This study reports the photo-induced green synthesis and antimicrobial assessment of poly(ϵ-caprolactone)/curcumin/grape leaf extract-Ag hybrid nanoparticles (PCL/Cur/GLE-Ag NPs). PCL/Cur/GLE NPs were synthesized via emulsion-solvent evaporation in the presence of PVA as a capping agent, then used as active nano-supports for the green synthesis and stabilization of AgNPs on their surfaces. Both Cur and GLE were selected and incorporated into the PCL nano-supports due to their reported promising antimicrobial activity that would further enhance that of the synthesized AgNPs. The developed PCL/Cur/GLE NPs and PCL/Cur/GLE-Ag hybrid NPs were characterized using UV-visible spectrophotometry, high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). HRTEM images showed that the PCL/Cur/GLE NPs are monodispersed and spherical with size of about 270 nm, and the AgNPs were formed mainly on their surfaces with average size in the range 10-30 nm. The synthesized AgNPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220) and (311) planes. The antimicrobial characteristics of the newly developed NPs were investigated against gram-positive and gram-negative bacteria in addition to two fungal strains. The results demonstrated that the PCL/Cur/GLE-Ag hybrid NPs have a potential antimicrobial activity against pathogenic bacterial species and could be considered as an alternative antibacterial agent. © 2016 Elsevier B.V. All rights reserved.


PubMed | Biomedical Science and Center for Materials Science
Type: | Journal: Journal of photochemistry and photobiology. B, Biology | Year: 2016

This study reports the photo-induced green synthesis and antimicrobial assessment of poly(-caprolactone)/curcumin/grape leaf extract-Ag hybrid nanoparticles (PCL/Cur/GLE-Ag NPs). PCL/Cur/GLE NPs were synthesized via emulsion-solvent evaporation in the presence of PVA as a capping agent, then used as active nano-supports for the green synthesis and stabilization of AgNPs on their surfaces. Both Cur and GLE were selected and incorporated into the PCL nano-supports due to their reported promising antimicrobial activity that would further enhance that of the synthesized AgNPs. The developed PCL/Cur/GLE NPs and PCL/Cur/GLE-Ag hybrid NPs were characterized using UV-visible spectrophotometry, high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). HRTEM images showed that the PCL/Cur/GLE NPs are monodispersed and spherical with size of about 270nm, and the AgNPs were formed mainly on their surfaces with average size in the range 10-30nm. The synthesized AgNPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220) and (311) planes. The antimicrobial characteristics of the newly developed NPs were investigated against gram-positive and gram-negative bacteria in addition to two fungal strains. The results demonstrated that the PCL/Cur/GLE-Ag hybrid NPs have a potential antimicrobial activity against pathogenic bacterial species and could be considered as an alternative antibacterial agent.


Soliman A.B.,Center for Materials Science | Soliman A.B.,Ain Shams University | Haikal R.R.,Center for Materials Science | Hassan Y.S.,Center for Materials Science | Alkordi M.H.,Center for Materials Science
Chemical Communications | Year: 2016

A one-pot, bottom-up assembly of a pyrimidine-containing porous-organic polymer (PyPOP) was conducted to homogenously deposit the PyPOP atop unmodified graphene sheets, affording a composite material PyPOP@G. The PyPOP demonstrated an appreciable affinity toward CO2 capture but was found to be largely insulating, hindering its usage in potential electrochemical conversion of CO2. However, its composite with graphene was found to be microporous, with maintained affinity toward CO2 and furthermore demonstrated significant electrochemical activity toward CO2 reduction (5 mA cm-2 at -1.6 V), not observed in either of its two components separately. © 2016 The Royal Society of Chemistry.


News Article | August 22, 2016
Site: www.nature.com

Questions are swirling over the future of Egypt’s first science city, after the death of the Nobel laureate who made the project his legacy. The Zewail City of Science and Technology, a campus outside Cairo comprising a non-profit university and several research institutes, is named for the man who spearheaded it: Egyptian-born US chemist Ahmed Zewail, the first Arab to win a science Nobel. But Zewail’s death at the age of 70 last week raises fresh doubts about the research hub's already precarious finances. The institute had relied heavily on Zewail’s star name and contacts to attract the support of scientific luminaries and millions of dollars in donations and government loans. It is now running out of money, has not yet raised enough cash to support a planned move to a new campus and will probably have to rely on more state support, say researchers working there. “Fundraising has always been a challenge, and I think it is likely to be affected by the loss of Dr Zewail in the short term,” says Sherif El-Khamisy, a molecular biologist at the University of Sheffield, UK, who is also director of Zewail City’s Center for Genomics. “But the logistical support envisaged from the state is expected to override the initial fear or uncertainty.” Uncertainty has plagued Zewail City since its inception. While working at the California Institute of Technology in Pasadena, Zewail proposed in 1999 to found the university and technology hub near Cairo as a flagship science project, essential for Egypt’s research development. But it was not until 2011 that the institute launched — a delay that Zewail has ascribed to political instability and bureaucracy. The young university was quickly plunged into controversy, after Egypt's first not-for-profit private research institution, Nile University — also outside Cairo — argued that it owned some of the buildings gifted to the science city. Nile University ultimately won the legal dispute — although it has allowed researchers from Zewail City to stay on in its buildings until a new campus is complete. Zewail City began accepting students in 2013; it currently has more 500 students and 150 academic professors and researchers. The first class of students will graduate next year, many of whom have received scholarships to cover their tuition fees. The project’s new campus is expected to be finished in 2019, at a cost of at least US$450 million; a first phase should be complete by July 2017, when many faculty and students are to move there. But Zewail City hasn’t raised enough money to finish even its first phase, says Sherif Fouad, a spokesperson for the institute. To pay for scholarships and campus construction, it has almost used up the 700 million Egyptian pounds (around US$80 million) raised from donors; its other funding comes in the form of a 1-billion-Egyptian-pound loan from the ministry of defence, which ultimately must be paid back. A shaky economy and the widely expected devaluation of Egypt’s currency is not helping matters. El-Khamisy and others affiliated with the institute say they are hopeful that it will survive — not least because it has the verbal backing of Egypt’s president, Abdel Fattah el-Sisi. In a speech on 6 August after Zewail’s death, el-Sisi asked Egyptians to continue to donate to the city, but vowed that Egypt’s armed forces — whose engineers are building the new campus — would finish construction even if no more money comes through. “The president’s speech was very reassuring for us all that Zewail City remains a priority for the government and is considered one of Egypt’s national projects,” says Fouad. It is likely that Egypt’s government will ultimately need to step in with support, says Salah Obayya, a physicist who is currently acting chairman of Zewail City until a replacement for Zewail is elected. How the state deals with that intervention could affect whether the institute can maintain the support of scientists whom Zewail sought to attract, says Ibrahim el-Sherbiny, joint director of the institute’s Center for Materials Science. “If they feel the reassurance on the ground, they will remain and attract others because they loved Dr Zewail, and I am sure they would love to support him after his death,” he says. Zewail City enjoys an unusual autonomy: unlike other Egyptian state-sponsored institutions, it has been granted a decree that allows the campus to outline its own structure and governance, guaranteeing its independence from the education ministry. Obayya says that he does not expect such autonomy to be affected by closer government intervention. At a meeting on 8 August, Zewail City’s board of directors vowed that their pioneer’s “national mission” would carry on. British-Egyptian cardiac surgeon Magdi Yacoub of Imperial College London is widely tipped to take Zewail’s place at the head of the project, says Fouad. “If Sir Magdi Yacoub is chosen to run the city, it will give the project the needed stability to soldier on,” says Sherif Sedky, a physicist and former academic president of Zewail City, who is now provost of the American University in Cairo.


PubMed | Imperial College London, A-Life Medical, Center for Materials Science and Heart Science Center
Type: Journal Article | Journal: Journal of cardiovascular translational research | Year: 2016

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease which continues to carry an unacceptably high mortality and morbidity. The nitric oxide (NO) pathway has been implicated in the pathophysiology and progression of the disease. Its extremely short half-life and systemic effects have hampered the clinical use of NO in PAH. In an attempt to circumvent these major limitations, we have developed a new NO-nanomedicine formulation. The formulation was based on hydrogel-like polymeric composite NO-releasing nanoparticles (NO-RP). The kinetics of NO release from the NO-RP showed a peak at about 120 min followed by a sustained release for over 8 h. The NO-RP did not affect the viability or inflammation responses of endothelial cells. The NO-RP produced concentration-dependent relaxations of pulmonary arteries in mice with PAH induced by hypoxia. In conclusion, NO-RP drugs could considerably enhance the therapeutic potential of NO therapy for PAH.


Sen T.,Center for Materials Science | Sen T.,University of Central Lancashire | Whittle J.,Center for Materials Science | Howard M.,Center for Materials Science
Chemical Communications | Year: 2012

A novel hierarchically ordered porous vanado-silicate nanocomposite with interconnecting macroporous windows and meso-microporous walls containing well dispersed vanadyl species has been fabricated and used as a heterogeneous catalyst for the oxidation of a bulky organic molecule, namely cyclooctene. © 2012 The Royal Society of Chemistry.


PubMed | Imperial College London and Center for Materials Science
Type: | Journal: Nanomedicine (London, England) | Year: 2017

Magnetic nanoparticles (MNPs) have gained much attention due to their unique properties such as biocompatibility and biodegradability as well as magnetic and heat-medicated characteristics. Due to these inherent properties, MNPs have been widely used in various biomedical applications including targeted drug delivery and hyperthermia-based therapy. Hyperthermia is a promising approach for the thermal activation therapy of several diseases, including pulmonary diseases. Additionally, due to their large loading capacity and controlled release ability, several MNP-based drug delivery systems have been emerged for treatment of cystic fibrosis and lung cancer. This review provides an overview on the unique properties of MNPs and magnetic-mediated hyperthermia with emphasis on the recent biomedical applications of MNPs in treatment of both lung cancer and cystic fibrosis.


El-Sherbiny I.M.,Center for Materials Science | Hefnawy A.,Center for Materials Science | Salih E.,Center for Materials Science
International Journal of Biological Macromolecules | Year: 2016

In this paper, preparation of new core-shell amino-terminated hyperbranched chitosan nanoparticles (HBCs-NH2) NPs is described. The synthesized nanoparticles were characterized using ninhydrin assay, FTIR, TGA, and FESEM. The newly prepared (HBCs-NH2) NPs were then used as a platform for facile and controlled synthesis of silver nanoparticles (AgNPs) which was confirmed using FTIR, UV-vis spectrometry, X-ray diffraction, SEM and HRTEM. Formation of the AgNPs was also noted upon changing the color of (HBCs-NH2) NPs suspension from colorless into yellow as well as through the appearance of surface plasmon resonance (SPR) peak at 400 nm. HRTEM showed a uniform and spherical morphology of the resulting HBCs-NH2 NPs with average size 400 nm, and the AgNPs were formed mainly on their surface with average size of 20-50 nm. The newly developed (HBCs-NH2) NPs-AgNPs showed a great potential as optical sensor for efficient detection of the ammonia concentration in solutions based on the change in the SPR. © 2016 Elsevier B.V.


El-Sherbiny I.M.,Center for Materials Science | Abbas Y.,Center for Materials Science
Current Pharmaceutical Biotechnology | Year: 2016

Research has been lately prospering in the field of Janus nanoparticles, focusing on new synthesis techniques and their application in various fields. This is due to the unique characteristics possessed by this type of particles such as their anisotropic nature, and their synergistic potential for combination therapy in addition to the multilevel targeting. These unique features are essential in several biomedical applications, especially the controlled drug delivery. Various techniques have been used for the synthesis of Janus nanoparticles including; masking, self-assembly, microfluidic and phase separation. They are all aiming at production of uniformly sized Janus particles with spatially separated functionalities. Herein, the main synthesis approaches of various Janus nanoparticles are briefly reviewed with the provision of examples of studies focusing on the potential applications of Janus particles in controlled drug delivery. © 2016 Bentham Science Publishers.


PubMed | Center for Materials Science
Type: | Journal: International journal of biological macromolecules | Year: 2016

In this paper, preparation of new core-shell amino-terminated hyperbranched chitosan nanoparticles (HBCs-NH2) NPs is described. The synthesized nanoparticles were characterized using ninhydrin assay, FTIR, TGA, and FESEM. The newly prepared (HBCs-NH2) NPs were then used as a platform for facile and controlled synthesis of silver nanoparticles (AgNPs) which was confirmed using FTIR, UV-vis spectrometry, X-ray diffraction, SEM and HRTEM. Formation of the AgNPs was also noted upon changing the color of (HBCs-NH2) NPs suspension from colorless into yellow as well as through the appearance of surface plasmon resonance (SPR) peak at 400 nm. HRTEM showed a uniform and spherical morphology of the resulting HBCs-NH2 NPs with average size 400 nm, and the AgNPs were formed mainly on their surface with average size of 20-50 nm. The newly developed (HBCs-NH2) NPs-AgNPs showed a great potential as optical sensor for efficient detection of the ammonia concentration in solutions based on the change in the SPR.

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