Publications by authors named "Sherif E Emam"

Myricetin (MYR) is a natural flavonoid that has several biological functions. However, some of its beneficial effects are diminished due to low water solubility, stability, and bioavailability. Herein, several kinds of silica nanoparticles (MCM-41 and SBA-15) were loaded with MYR to improve its biological activity as an analgesic, antipyretic, and anti-inflammatory component, thereby overcoming its drawbacks.

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Poly(ethylene glycol) (PEG) is used in many common products, such as cosmetics. PEG, however, is also used to covalently conjugate drug molecules, proteins, or nanocarriers, which is termed PEGylation, to serve as a shield against the natural immune system of the human body. Repeated administration of some PEGylated products, however, is known to induce anti-PEG antibodies.

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Polyethylene glycol (PEG) is a versatile polymer that is used in numerous pharmaceutical applications like the food industry, a wide range of disinfectants, cosmetics, and many commonly used household products. PEGylation is the term used to describe the covalent attachment of PEG molecules to nanocarriers, proteins and peptides, and it is used to prolong the circulation half-life of the PEGylated products. Consequently, PEGylation improves the efficacy of PEGylated therapeutics.

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Modifying the surface of nanoparticles with polyethylene glycol (PEG) is a commonly used approach for improving the in vitro stability of nanoparticles such as liposomes and increasing their circulation half-lives. We have demonstrated that, in certain conditions, an intravenous (i.v.

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PEGylation is a crucial process for decorating the surface of liposomes with polyethylene glycol (PEG) for clinical use. This process endows the liposomes extended circulation time and improved stability in vivo. The post-insertion method is one of the well-established techniques for PEGylation.

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Polyethylene glycol (PEG) is a versatile polymer that is widely used as an additive in foods and cosmetics, and as a carrier in PEGylated therapeutics. Even though PEG is thought to be less immunogenic, or perhaps even non-immunogenic, with a variety of physicochemical properties, there is mounting evidence that PEG causes immunogenic responses when conjugated with other materials such as proteins and nanocarriers. Under these conditions, PEG with other materials can result in the production of anti-PEG antibodies after administration.

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Electrospinning (ES) has become a straightforward and customizable drug delivery technique for fabricating drug-loaded nanofibers (NFs) using various biodegradable and non-biodegradable polymers. One of NF's pros is to provide a controlled drug release through managing the NF structure by changing the spinneret type and nature of the used polymer. Electrospun NFs are employed as implants in several applications including, cancer therapy, microbial infections, and regenerative medicine.

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Three undescribed diterpenes including two ent-abietanes, euphomauritanol A, and euphomauritanol B, and one jatrophane, euphomauritanophane A, in addition to eight previously described metabolites were isolated from the MeOH-CHCl (1:1) extract of the Euphorbia mauritanica. The chemical structures of isolates were established based on the spectroscopic means including FT-IR, HRMS, 1D and 2D NMR. The absolute stereochemistry of the undescribed diterpenes was deduced by experimental and calculated TDDFT-electronic circular dichroism (ECD).

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The presence of anti-polyethylene glycol (PEG) antibodies in the systemic circulation might have potential implications for the therapeutic activity of PEGylated products in vivo in the clinic. In order to study the effect of pre-existing anti-PEG antibodies on the in vivo fate and the therapeutic efficiency of PEGylated therapeutics, we developed a BALB/c mouse model by virtue of the intraperitoneal (i.p.

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The purpose of this study was to develop a Bio-layer interferometry (BLI) system that could be an alternative approach for the direct evaluation of anti-polyethylene glycol (PEG) immunoglobulin M (IgM)-mediated complement activation of the accelerated blood clearance (ABC) phenomenon. Complement activation is well known to play an important role in the clearance of PEGylated and non-PEGylated nanomedicines following intravenous injection. This complement system is also thought to be responsible for the ABC phenomenon wherein repeated injections of PEGylated products are bound by anti-PEG antibodies.

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Palau'amine has received a great deal of attention as an attractive synthetic target due to its intriguing molecular architecture and significant immunosuppressive activity, and we achieved its total synthesis in 2015. However, the synthesized palau'amine has not been readily applicable to the mechanistic study of immunosuppressive activity, because it requires 45 longest linear steps from a commercially available compound. Here, we report the short-step construction of the ABCDEF hexacyclic ring core of palau'amine.

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Exosomes (EXOs) were given attention as an extracellular vesicle (EV) with a pivotal pathophysiological role in the development of certain neurodegenerative disorders (NDD), such as Parkinson's and Alzheimer's disease (AD). EXOs have shown the potential to carry pathological and therapeutic cargo; thus, researchers have harnessed EXOs in drug delivery applications. EXOs have shown low immunogenicity as natural drug delivery vehicles, thus ensuring efficient drug delivery without causing significant adverse reactions.

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The nanotechnology approach has been recently adopted to provide more reliable, effective, controlled, and safe drug delivery systems. Nanostructured materials have gained great interest, including siliceous and carbonaceous nanoparticles. The effectiveness of mesoporous carbon nanoparticles (MCNs) in tumor imaging, targeting, and treatment is urging for more future studies.

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Acidic extracellular pH (pHe) is characteristic of the tumor microenvironment. Several reports suggest that increasing pHe improves the response of immune checkpoint inhibitors in murine models. To increase pHe, either sodium bicarbonate (NaHCO) or citric acid/potassium-sodium citrate (KNa-cit) was chronically administered to mice.

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Recently, there is an increasing interest in exosomes or extracellular vesicles as potential candidates for delivering RNAs, proteins, genes, and anticancer agents. Engineering of exosome properties is rapidly evolving as a means of expanding exosome applications. PEGylation of exosomes is a technique used to improve their in vivo stability, circulation half-lives, and sometimes to allow the binding targeting ligands to the exosome exterior.

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Gangliosides (glycosphingolipids) reduce antibody production by inhibiting B-cell receptor (BCR) signaling. We have shown that a copresentation of gangliosides and polyethylene glycol (PEG) on the same liposomes suppresses anti-PEG IgM production in mice. In addition, we recently observed that pDNA incorporated in PEGylated cationic liposomes (PCLs) induces anti-DNA IgM, which could be a hurdle to the development of efficient gene delivery systems.

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Protein-based therapeutics are beginning to be widely used in various clinical settings. Conjugation of polyethylene glycol (PEGylation) to protein therapeutics improves their circulation half-lives in the body. However, we and other groups observed that the initial dose of some PEGylated protein-based therapeutics may induce anti-PEG antibodies (primarily immunoglobulin M (IgM)), resulting in the accelerated clearance of a second dose.

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PEGylation had been used successfully to improve the circulation half-lives and some physicochemical properties of protein therapeutics. However, anti-polyethylene glycol (anti-PEG) antibodies, either pre-existing or treatment-induced, can negatively affect the pharmacokinetics and pharmacological efficacy of PEGylated proteins. We have examined anti-PEG immune responses in mice for peginterferon alfa-2a (Pegasys), a clinically approved PEGylated protein therapeutic, at both the recommended dose (equivalent to 3 μg/kg in mice) and at higher doses (150 μg/kg) for single or repeated subcutaneous (s.

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Pegfilgrastimis a recombinant PEGylated human granulocyte colony-stimulating factor (G-CSF) analog filgrastim (trade names Neulasta® or G-Lasta®) that stimulates the production of white blood cells (neutrophils). It is employed as an alternative to filgrastim (G-CSF) for chemotherapy-induced neutropenia in patients due to its longer half-life. In clinical settings, PEG-G-CSF is administered to cancer patients via both the s.

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Exosomes are gaining increasing attention as drug delivery vehicles due to their low toxicity and ability to functionally transfer biological cargos between cells. However, the therapeutic applicability of exosomes is partially hampered by a lack of cell-type specificity. In this study, therefore, we investigated the impact of cell-type tropism on the in vivo systemic delivery of exosomes to tumor tissues.

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We recently showed that in vitro incubation of cells with liposomes of varying compositions can increase exosome secretion and increase the yield of harvested exosomes (extracellular vesicles, EVs). This might foster their potential therapeutic implementations. In the current study, we investigated the surface proteins and the uptake of the harvested exosomes (EVs) to see if the incubation of cells with liposomes would change the biological properties of these exosomes (EVs).

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Modulation of tumor immunity is a known factor in the antitumor activity of many chemotherapeutic agents. Exosomes are extracellular nanometric vesicles that are released by almost all types of cells, which includes cancer cells. These vesicles play a crucial role in tumor immunity.

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Exosomes are tiny extracellular vesicles that are usually harvested in small quantities. Such small yield has been an obstacle for the expansion of the basic research regarding exosome analysis and applications in drug delivery. To increase exosome yield, we attempted to stimulate tumor cells via the addition of liposomes in vitro.

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Pharmaceutical development was adopted in the current study to propose a pediatric rectal formulation of sulpiride as a substitute to the available oral or parenteral formulations in the management of Tourette syndrome (TS). The goal was to formulate a product that is easy to use, stable, and highly bioavailable and to achieve a rapid clinical efficacy. Towards this aim, sulpiride solid dispersion (SD) with tartaric acid at a weight ratio of 1:0.

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