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Minocycline Block Copolymer Micelles and their Anti-Inflammatory Effects on Microglia

Research Abstract
MH, a semisynthetic tetracycline antibiotic with promising neuroprotective properties, was encapsulated into PIC micelles of CMD-PEG as a potential new formulation of MH for the treatment of neuroinflammatory diseases. PIC micelles were prepared by mixing solutions of a Ca2+/MH chelate and CMD-PEG copolymer in a Tris-HCl buffer. Light scattering and 1H NMR studies confirmed that Ca2+/MH/CMD-PEG core-corona micelles form at charge neutrality having a hydrodynamic radius 100 nm and incorporating 50 wt.-% MH. MH entrapment in the micelles core sustained its release for up to 24 h under physiological conditions. The micelles protected the drug against degradation in aqueous solutions at room temperature and at 37°C in the presence of FBS. The micelles were stable in aqueous solution for up to one month, after freeze drying and in the presence of FBS and BSA. CMD-PEG copolymers did not induce cytotoxicity in human hepatocytes and murine microglia (N9) in concentrations as high as 15 mg.mL1 after incubation for 24 h. MH micelles were able to reduce the inflammation in murine microglia (N9) activated by LPS. These results strongly suggest that MH PIC micelles can be useful in the treatment of neuroinflammatory disorders.
Research Authors
Ghareb Mohamed Soliman, Angela O. Choi, Dusica Maysinger, Françoise M. Winnik
Research Department
Research Journal
Macromolecular Bioscience., DOI: 10.1002/mabi.200900259
Research Rank
1
Research Vol
Vol. 10 No.3
Research Year
2010

Tailoring the Efficacy of Nimodipine Drug Delivery using Nanocarriers Based on A2B Miktoarm Star Polymers

Research Abstract
We report a nanocarrier based on A2B type miktoarm polymers (A = polyethylene glycol (PEG); B = polycaprolactone (PCL)) for nimodipine (NIM), a hydrophobic drug with very poor aqueous solubility that is commonly prescribed for the prevention and treatment of delayed ischemic neurological disorders. The A2B star polymers were constructed on a core with orthogonal functionalities that facilitated the performance of “click” chemistry followed by ring-opening polymerization. These star polymers assemble into spherical micelles into which NIM can be easily loaded by the co-solvent evaporation method. The micelles obtained from the star polymer PEG7752-PCL5800 showed NIM encapsulation efficiency of up to 78 wt% at a feed weight ratio of 5.0%. The loading efficiency of the micelles was dependent on the length of the PCL arm in the A2B miktoarm polymers. Aqueous solubility of NIM was increased by ~200 fold via micellar encapsulation. The in vitro release of NIM from the micelles was found to occur at a much slower rate than from its solution. Lipopolysaccharide induced nitric oxide production in N9 microglia cells was reduced in the presence of micelle-encapsulated NIM, as well as in the presence of micelles alone. The treatment of microglia with micelle-encapsulated NIM reduced the release of TNF-, a pro-inflammatory cytokine. These results suggest that NIM-loaded miktoarm micelles could be useful in the treatment of neuroinflammation.
Research Authors
Ghareb M. Soliman, Rishi Sharma, Angela O. Choi, Sunil K. Varshney, Françoise M. Winnik, Ashok K. Kakkar, Dusica Maysinger
Research Department
Research Journal
Biomaterials, doi:10.1016/j.biomaterials.2010.07.039
Research Rank
1
Research Vol
Vol. 31
Research Year
2010

Solubility of Budesonide, Hydrocortisone, and Prednisolone in Ethanol + Water Mixtures at 298.2 K

Research Abstract
Experimental solubilities of budesonide, hydrocortisone, and prednisolone in ethanol + water mixtures at 298.2 K are reported. The solubility of drugs was increased with the addition of ethanol and reached the maximum values of the volume fractions of 90%, 80%, and 80% of ethanol. The Jouyban-Acree model was used to fit the experimental data, and the solubilities were reproduced using previously trained versions of the Jouyban-Acree model and the solubility data in monosolvents in which the overall mean relative deviations (OMRDs) of the models were 5.1%, 6.4%, 37.7%, and 35.9%, respectively, for the fitted model, the trained version for ethanol + water mixtures, and generally trained versions for various organic solvents + water mixtures. Solubilities were also predicted by a previously established log-linear model of Yalkowsky with the OMRD of 53.8 %.
Research Authors
Hany S. M. Ali1,2, Peter York1, Nicholas Blagden1, Shahla Soltanpour3, William E. Acree, Jr4, Abolghasem Jouyban4
Research Department
Research Journal
Journal of Chemical and Engineering Data.
Research Member
Research Rank
1
Research Vol
Vol. 55 - No. 1
Research Year
2010

Delivery of Nucleic Acids Through the Controlled Disassembly of Multifunctional Nanocomplexes

Research Abstract
In this study, novel pH-responsive polyion complex micelles (PICMs) were developed for the efficient delivery of nucleic acid drugs, such as antisense oligonucleotide (AON) and short interfering RNA (siRNA). The PICMs consisted of a poly(amidoamine) (PAMAM) dendrimer–nucleic acid core and a detachable poly(ethylene glycol)-block-poly(propyl methacrylate-co-methacrylic acid) (PEG-b-P(PrMA-co-MAA)) shell. The micelles displayed a mean hydrodynamic diameter ranging from 50 to 70 nm, a narrow size distribution, and a nearly neutral surface charge. They could be lyophilized without any additives and stored in dried form. Upon redispersion in water, no change in complexation efficiency or colloidal properties was observed. Entry of the micelles into cancers cells was mediated by a monoclonal antibody fragment positioned at the extremity of the PEG segment via a disulfide linkage. Upon cellular uptake and protonation of the MAA units in the acidic endosomal environment, the micelles lost their corona, thereby exposing their positively charged endosomolytic PAMAM/nucleic acid core. When these pH-responsive targeted PICMs were loaded with AON or siRNAs that targeted the oncoprotein Bcl-2, they exhibited a greater transfection activity than nontargeted PICMs or commercial PAMAM dendrimers. Moreover, their nonspecific cytotoxicity was lower than that of PAMAM. The pH-responsive PICMs reported here appear as promising carriers for the delivery of nucleic acids.
Research Authors
Mahmoud Elsabahy, Nada Wazen, Núria Bayó-Puxan, Glen Deleavey, Marc Servant, Masad J. Damha, Jean-Christophe Leroux
Research Department
Research Journal
Advanced Functional Materials, DOI: 10.1002/adfm.200901139
Research Member
Research Rank
1
Research Vol
Vol. 19
Research Year
2009

Multi-Layered Nanoparticles for Penetrating the Endosome and Nuclear Membrane via a Step-Wise Membrane Fusion Process

Research Abstract
Efficient targeting of DNA to the nucleus is a prerequisite for effective gene therapy. The gene-delivery vehicle must penetrate through the plasma membrane, and the DNA-impermeable double-membraned nuclear envelope, and deposit its DNA cargo in a form ready for transcription. Here we introduce a concept for overcoming intracellular membrane barriers that involves step-wise membrane fusion. To achieve this, a nanotechnology was developed that creates a multi-layered nanoparticle, which we refer to as a Tetra-lamellar Multi-functional Envelope-type Nano Device (T-MEND). The critical structural elements of the T-MEND are a DNA-polycation condensed core coated with two nuclear membrane-fusogenic inner envelopes and two endosome-fusogenic outer envelopes, which are shed in stepwise fashion. A double-lamellar membrane structure is required for nuclear delivery via the stepwise fusion of double layered nuclear membrane structure. Intracellular membrane fusions to endosomes and nuclear membranes were verified by spectral imaging of fluorescence resonance energy transfer (FRET) between donor and acceptor fluorophores that had been dually labeled on the liposome surface. Coating the core with the minimum number of nucleus-fusogenic lipid envelopes (i.e., 2) is essential to facilitate transcription. As a result, the T-MEND achieves dramatic levels of transgene expression in non-dividing cells.
Research Authors
Hidetaka Akita, Asako Kudo, Arisa Minoura, Masaya Yamaguti, Ikramy A. Khalil, Rumiko Moriguchi, Tomoya Masuda, Radostin Danev, Kuniaki Nagayama, Kentaro Kogure, Hideyoshi Harashima
Research Department
Research Journal
Biomaterials, doi: 10.1016/j.biomaterials.2009.02.009
Research Rank
1
Research Vol
Vol. 30
Research Year
2009

Enhanced Gene Expression by a Novel Stearylated INF7 Peptide Derivative Through Fusion Independent Endosomal Escape

Research Abstract
An octaarginine-modified multifunctional envelope-type nano device (R8-MEND) was previously reported to be an efficient nonviral vector for the delivery of plasmid DNA, in vitro and after topical administration. We report herein on a novel stearylated derivative of the INF7 peptide, a derivative of the N-terminal domain of the HA2 protein of the influenza virus envelope, which enhances the endosomal escape of R8-MEND through a mechanism independent of fusion between the MEND coat and the endosomal membrane. The use of the novel peptide derivative would permit the gene expression of the R8-MEND to be improved, both in vitro and in vivo. R8-MEND modified with stearylated INF7 resulted in gene expression levels that were 77-fold higher than unmodified and 20-fold higher than the free INF7 peptide-modified R8-MEND with no cellular toxicity. Spectral imaging in live cells confirmed that the stearylated INF7 modification did not mediate fusion between liposomes and the endosomal membrane. The inclusion of DOPE to the R8-MEND coat was synergistic with the peptide in improving gene transfection. The intravenous injection of an R8-MEND modified with stearylated INF7 to ICR mice resulted in luciferase expression levels 240-fold higher in liver and 115-fold higher in spleen than that of the R8-MEND.
Research Authors
Ayman El-Sayed, Tomoya Masuda, Ikramy A. Khalil, Hidetaka Akita, Hideyoshi Harashima
Research Department
Research Journal
Journal of Controlled Release, doi: 10.1016/j.jconrel.2009.05.018
Research Rank
1
Research Vol
Vol.  138
Research Year
2009

Phytochemical and Biological Studies of Adiantum capillus-veneris L.

Research Abstract
Chromatographic fractionation of the alcoholic extract of the dried fronds of Adiantum capillus-veneris L. (Adiantaceae) yielded seven compounds: Four triterpenoidal compounds belonging to adiantane and filicane groups were isolated from the hexane fraction and identified as isoadiantone (1); isoadiantol-B (2); 3-methoxy-4-hydroxyfilicane (3) and 3,4-dihydroxyfilicane (4) and three flavonoids were isolated from the ethyl acetate fraction and identified as: quercetin (5), quercetin-3-O-glucoside (6) and quercetin-3-O-rutinoside (rutin) (7). The identification of the isolated compounds has been established through their physical, chemical and spectroscopic methods including IR, 1H-NMR, 13C-NMR, HSQC, HMBC, NOESY and MS. Biological studies of the total alcoholic extract, hexane fraction and some of the isolated compounds showed an anti-inflammatory activity while the hypoglycemic study of the total alcoholic extract showed a significant activity.
Research Authors
Zedan Z. Ibraheim, Amany S. Ahmed, Yaser G. Gouda
Research Department
Research Journal
Saudi Pharmaceutical Journal.
Research Member
Research Rank
2
Research Vol
Vol. 19 (2)
Research Year
2011

Phytochemical and Biological Studies of Adiantum capillus-veneris L.

Research Abstract
Chromatographic fractionation of the alcoholic extract of the dried fronds of Adiantum capillus-veneris L. (Adiantaceae) yielded seven compounds: Four triterpenoidal compounds belonging to adiantane and filicane groups were isolated from the hexane fraction and identified as isoadiantone (1); isoadiantol-B (2); 3-methoxy-4-hydroxyfilicane (3) and 3,4-dihydroxyfilicane (4) and three flavonoids were isolated from the ethyl acetate fraction and identified as: quercetin (5), quercetin-3-O-glucoside (6) and quercetin-3-O-rutinoside (rutin) (7). The identification of the isolated compounds has been established through their physical, chemical and spectroscopic methods including IR, 1H-NMR, 13C-NMR, HSQC, HMBC, NOESY and MS. Biological studies of the total alcoholic extract, hexane fraction and some of the isolated compounds showed an anti-inflammatory activity while the hypoglycemic study of the total alcoholic extract showed a significant activity.
Research Authors
Zedan Z. Ibraheim, Amany S. Ahmed, Yaser G. Gouda
Research Department
Research Journal
Saudi Pharmaceutical Journal.
Research Member
Zedan Zeid Ibraheim Hammad
Research Rank
2
Research Vol
Vol. 19 (2)
Research Year
2011

Cassava: An Appraisal of its Phtytochemistry and its Biotechnological Prospects

Research Abstract
The present state of knowledge of the phytochemistry of small molecules isolated from the roots and leaves of cassava, Manihot esculenta Crantz (Euphorbiaceae), is reviewed. Cassava roots are an important source of dietary and industrial carbohydrates, mainly eaten as a source of starch, forming the staple food to over 500 million; additionally, the roots have value as a raw material for industrial starch production and for animal feed giving the crop high economic value, but it suffers markedly from post-harvest physiological deterioration (PPD). The hydroxycoumarins scopoletin and its glucoside scopolin as well as trace quantities of esculetin and its glucoside esculin are identified from cassava roots during PPD. The biotechnological prospects for cassava are also reviewed including a critical appraisal of transgenic approaches for crop improvement, together with its use for bioethanol production, due to cassava's efficient ability to fix carbon dioxide into carbohydrate.
Research Authors
Ian S. Blagbrough1, Soad A.L. Bayoumi1,3, Michael G. Rowan1, John R. Beeching2
Research Department
Research Journal
Phytochemistry
Research Rank
1
Research Vol
Vol. 71
Research Year
2010

Constituents and Secondary Metabolite Natural Products in Fresh and Deteriorated Cassava Roots

Research Abstract
A phytochemical analysis of cassava (Manihot esculenta Crantz) fresh roots and roots suffering from post-harvest physiological deterioration (PPD) has been carried out. The first isolation and identification of galactosyl diacylglycerides from fresh cassava roots is reported as well as -carotene, linamarin, and -sitosterol glucopyranoside. The hydroxycoumarin scopoletin and its glucoside scopolin were identified from cassava roots during PPD, as well as trace quantities of esculetin and its glucoside esculin. There is no isoscopoletin in cassava roots during PPD.
Research Authors
Soad A.L. Bayoumi1,3, Michael G. Rowan1, John R. Beeching2, Ian S. Blagbrough1
Research Department
Research Journal
Phytochemistry.
Research Rank
1
Research Vol
Vol. 71
Research Year
2010
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