Atef S. Darwish

Ceria-containing uncoated and coated hydroxyapatite-based galantamine nanocomposites for formidable treatment of Alzheimer's disease in ovariectomized albino-rat model

This paper upraises delivery and therapeutic actions of galantamine drug (GAL) against Alzheimers disease (AD) in rat brain through attaching GAL to ceria-containing hydroxyapatite (GAL@Ce-HAp) as well ceria-containing carboxymethyl chitosan-coated hydroxyapatite (GAL@Ce-HAp/CMC) nanocomposites. Physicochemical features of such nanocomposites were analyzed by XRD, FT-IR, Raman spectroscopy, UV-vis spectrophotometer, N2-BET, DLS, zeta-potential measurements, SEM, and HR-TEM. Limited interactions were observed in GAL@Ce-HAp with prevailed existence of dispersed negatively charged rod-like particles conjugated with ceria nanodots. On contrary, GAL@Ce-HAp/CMC was well-structured developing aggregates of uncharged tetragonal-shaped particles laden with accession of ceria quantum dots. Such nanocomposites were i.p. injected into ovariectomized AD albino-rats at galantamine dose of 2.5mg/kg/day for one month, then brain tissues were collected for biochemical and histological tests. GAL@Ce-HAp adopted as a promising candidate for AD curativeness, whereas oxidative stress markers were successfully upregulated, degenerated neurons in hippocampal and cerebral tissues were wholly recovered and Aβ-plaques were vanished. Also, optimizable in-vitro release for GAL and nanoceria were displayed from GAL@Ce-HAp, while delayed in-vitro release for those species were developed from GAL@Ce-HAp/CMC. This proof of concept work allow futuristic omnipotency of rod-like hydroxyapatite particles for selective delivery of GAL and nanoceria to AD affected brain areas.

Sugarcane bagasse lignin, and silica gel and magneto-silica as drug vehicles for development of innocuous methotrexate drug against rheumatoid arthritis disease in albino rats.

The present study clarifies co-therapy action of deliveries from their textural changes point of view. Methotrexate (MTX) was immobilized onto biodegradable lignin, silica gel and iron/silica nanocomposite. Loaded-MTX was i.p. injected into albino rats at doses of 0.25 and 0.5mg/kg/week for 2.5months, after which spleen, liver, testes and knee joint tissues were collected for tests. IFN-γ and IL-17A mRNA gene expressions in spleen in all biological samples were determined by RT-PCR. Physicochemical features of drug carriers were monitored by XRD, BET-PSD, SEM and TEM. Drug inflammatory-site targeting was found to be closely related to the physico-features of deliverers. The interlayered lignin of micro- and meso-pore channels directed MTX toward concealed infected cells in liver and testes tissues, while meso-structured silica flacks satisfied by gathering MTX around knee joints. The magneto-silica nanocomposite targeted MTX toward spleen tissue, which is considered as a lively factory for the production of electron rich compounds.

Sustainable removal of Cu2+, Ni2+ and Zn2+ ions from severe contaminated water using kaolin/poly(glycine) composites, characterization and uptake studies

AbstractKaolinite clay of Saint Catharine, Sinai, was treated by glycine molecules and then modified by various diamino-compounds like ethylenediamine, phenyl hydrazine and polyoxypropylenediamine. The native and modified clays were structurally and texturally characterized by XRD, FTIR, XRF, BET, pore size distribution and SEM in addition to exchange capacity parameters. Phenyl hydrazine and polyoxypropylenediamine organo-modifiers proved superior in function compared to ethylenediamine with regard to in situ glycine polymerization forming large fragments of ordered polypeptides which acted as super clay sheet binders. Adsorption of Cu(II), Ni(II) and Zn(II) ions by the modified kaolinite under variable concentrations of metal ions and interacting time were studied. Adsorption isotherm investigation indicated that Freundlich equation was a better fit than Langmuir model reflecting surfaces of various accommodated active sites with analogue sites distribution. The adsorption rate constants sequence for al...

Exfoliated Egyptian kaolin immobilized heteropolyoxotungstate nanocomposite as an innovative antischistosomal agent: In vivo and in vitro bioactive studies.

This study aims to manipulate an antischistosomal nanocomposite based on exfoliated clay immobilized heteropolyoxotungstate. The nanocomposites physicochemical characteristics were examined using XRD, Raman spectroscopy, FTIR, DLS, SEM, HR-TEM and AFM. Nano-sized spheroidal negatively charged Keggin-type heteropolyoxotungstate particles were developed along and between the exfoliated clay layers. The impact of the nanocomposite on Schistosoma mansoni-infected mice was studied through parasitological, physiological and histological analyses. Infected mice were orally vaccinated by a single nanocomposite dose (15mg/kg/day) for two weeks. The schistosomicidal activities of the nanocomposite in vitro were investigated by examining its dose- and time-dependent responses in terms of % worm mortality. The time-dependent morphological alterations in schistosomes at a nanocomposite dosage of 15μg/mL were followed by SEM. The nanocomposite exhibited potential schistosomicidal properties with a marked reduction in worm burden (~85% mortality), extensive deformities in the adult worm tegument and suckers, improvement of serum biochemical activities, and diminishment in granulomatous lesions. The in vitro release of heteropolyoxotungstate from exfoliated clay indicates the clays ability to embrace the heteropolytungstate until its liberation at the parasitic districts.

Artichoke as a non-conventional precursor for activated carbon: Role of the activation process

Abstract Artichoke peels were used to produce activated carbon using chemical activation methods. Two activation protocols were compared: a two-step method A and a one-step method B. As newly used activating agents, KCl, CrCl3 and TiCl4 were compared. The results show that method B is superior to A. KOH with method B had an area of 2321 m2/g and a total pore volume 1.0071 cm3/g, of which 0.9794 cm3/g was confined to micropores. The corresponding values for KCl are 1731, 0.6925 and 0.6718. TiCl4 had lower but comparable values with those of KCl. CrCl3 appeared to be the least successful among the three newly used activating agents. The post-activation washing step strongly affects the characteristics of the final product. The differences among the effects of Zn, Cr and Ti are discussed in terms of the differences in polarizing power.

Photoactivated water-disinfecting, and biological properties of Ag NPs@Sm-doped ZnO nanorods/cuttlefish bone composite: In-vitro bactericidal, cercaricidal and schistosomicidal studies

Herein, eco-friendly composite was synthesized by embedding silver (Ag) nanospheres onto aragonitic cuttlefish bone (CB)-stabilized samarium doped zinc oxide (Sm-doped ZnO) nanorods. The operating interaction profile and the photoactive behavior of this nanocomposite were assessed via XRD, FTIR, Raman, TEM, FE-SEM, DLS, DRS and PL techniques. Locality of Sm-doped ZnO and its attaching modes to the cuttlefish bone lamella were highly dominated by embedding Ag NPs that encouraged Zn2+ Lewis acid sites to electrostatically interact with aragonite carbonates in the channeled porous CB system. Such interacting approach enhanced photoactivity of Sm-doped ZnO by lowering its energy band gap (from 3.26 eV for Sm-doped ZnO/CB to 2.12 eV for Ag@Sm-doped ZnO/CB). Besides, plasmon-induced silver electrons provided Sm-doped ZnO by extra photosensitivity. Ag@Sm-doped ZnO/CB nanocomposite exhibited pronounced photo-activated disinfection efficiencies for Staphylococcus aureus (80%), Pseudomonas aeruginosa (60%), and Schistosoma mansoni cercariae (100%) linked with progressive demolition in cercarial body. Such nanocomposite also possessed exterminating action against Schistosoma mansoni adult worms serving near 100% worm-mortality accompanied by significant disintegration of worm body. These findings were successfully drawn Ag@Sm-doped ZnO/CB as an efficient weapon in the biocides arsenal being even capable of destructing pathogenic bacteria and parasites in dark- and photo- conditions.

Various Characteristics of Nanosized V2O5/TiO2 and MoO3–Modified V2O5/TiO2 Catalytic Systems Used in Redox-Initiated Polymerization of Methyl Methacrylate

Various samples of nanosized V2O5 (2–20 wt%)/TiO2 catalytic systems (of particle sizes ranged between 5 and 50 nm were characterized. The effect of addition of MoO3 (3–9 wt%), in different sequences, was followed up in view of competing interactions with titania surface. Characterization was performed through XRD, FTIR, BET, and TEM techniques. Catalytic activity of prepared samples was tested in redox-initiated polymerization of methyl methacrylate, in presence of NaHSO3 cocatalyst. The proposed polymerization mechanism indicated participation of radicals, primarily generated on a TiO2 surface, with V5+/V4+ and/or Mo6+/Mo5+ redox pairs to form active radical species with the monomer. In all cases, extremely high yields of reasonably high molecular weight polymers, of syndiotactic-structure, were functions of catalyst nanosized nature, rapid redox-initiation steps, and mode of MoO3 addition.