Generation of acid sites by incorporation of cobalt in the AFR structure

Pure CoAPO4-40 and CoAPSO-40 samples have been synthesized. The CoII <=> CoIII framework transformation, and hence the number of potential acid sites has been evaluated by spectroscopic techniques and using m-xylene isomerization as model reaction.

From polymer precursors to metal oxides

We report on a strategy to prepare metal oxides including binary oxide and mixed metal oxide (MMO) in form of nanometer-sized particles using polymer as precursor. Zinc oxide nanoparticles are prepared as an example. The obtained zinc polyacrylate precursor is amorphous as confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The conversion from polymer precursor to ZnO nanocrystals by thermal pyrolysis was investigated by means of XRD, thermogravimetric analysis (TGA) and electron microscopy. The as-synthesized ZnO consists of many individual particles with a diameter around 40 nm as shown by scanning electron microscopy (SEM). The photoluminescence (PL) and electron paramagnetic (EPR) properties of the material are investigated, too. Employing this method, ZnO nanocrystalline films are fabricated via pyrolysis of a zinc polyacrylate precursor film on solid substrate like silicon and quartz glass. The results of XRD, absorption spectra as well as TEM prove that both the ZnO nanopowder and film undergo same evolution process. Comparing the PL properties of films fabricated in different gas atmosphere, it is assigned that the blue emission of the ZnO films is due to crystal defect of zinc vacancy and green emission from oxygen vacancy. Two kinds of ZnO-based mixed metal oxide (Zn1-xMgxO and Zn1-xCoxO) particles with very precise stoichiometry are prepared by controlled pyrolysis of the corresponding polymer precursor at 550 oC. The MMO crystal particles are typically 20-50 nm in diameter. Doping of Mg in ZnO lattice causes shrinkage of lattice parameter c, while it remains unchanged with Co incorporation. Effects of bandgap engineering are seen in the Mg:ZnO system. The photoluminescence in the visible is enhanced by incorporation of magnesium on zinc lattice sites, while the emission is suppressed in the Co:ZnO system. Magnetic property of cobalt doped-ZnO is checked too and ferromagnetic ordering was not found in our samples. An alternative way to prepare zinc oxide nanoparticles is presented upon calcination of zinc-loaded polymer precursors, which is synthesized via inverse miniemulsion polymerization of the mixture of the acrylic acid and zinc nitrate. The as-prepared ZnO product is compared with that obtained from polymer-salt complex method. The obtained ZnO nanoparticles undergo surface modification via a phosphate modifier applying ultrasonication. The morphology of the modified particles is checked by SEM. And stability of the ZnO nanoparticles in aqueous dispersion is enhanced as indicated by the zeta-potential results.

Foreign glycoproteins expressed from recombinant vesicular stomatitis viruses are incorporated efficiently into virus particles.

In a previous study we demonstrated that vesicular stomatitis virus (VSV) can be used as a vector to express a soluble protein in mammalian cells. Here we have generated VSV recombinants that express four different membrane proteins: the cellular CD4 protein, a CD4-G hybrid protein containing the ectodomain of CD4 and the transmembrane and cytoplasmic tail of the VSV glycoprotein (G), the measles virus hemagglutinin, or the measles virus fusion protein. The proteins were expressed at levels ranging from 23-62% that of VSV G protein and all were transported to the cell surface. In addition we found that all four proteins were incorporated into the membrane envelope of VSV along with the VSV G protein. The levels of incorporation of these proteins varied from 6-31% of that observed for VSV G. These results suggest that many different membrane proteins may be co-incorporated quite efficiently with VSV G protein into budding VSV virus particles and that specific signals are not required for this co-incorporation process. In fact, the CD4-G protein was incorporated with the same efficiency as wild type CD4. Electron microscopy of virions containing CD4 revealed that the CD4 molecules were dispersed throughout the virion envelope among the trimeric viral spike glycoproteins. The recombinant VSV-CD4 virus particles were about 18% longer than wild type virions, reflecting the additional length of the helical nucleocapsid containing the extra gene. Recombinant VSVs carrying foreign antigens on the surface of the virus particle may be useful for viral targeting, membrane protein purification, and for generation of immune responses.

Dual stimulation of antigen presenting cells using carbon nanotube-based vaccine delivery system for cancer immunotherapy

Although anti−cancer immuno−based combinatorial therapeutic approaches have shown promising results, efficient tumour eradication demands further intensification of anti−tumour immune response. With the emerging field of nanovaccinology, multi−walled carbon nanotubes (MWNTs) have manifested prominent potentials as tumour antigen nanocarriers. Nevertheless, the utilization of MWNTs in co−delivering antigen along with different types of immunoadjuvants to antigen presenting cells (APCs) has not been investigated yet. We hypothesized that harnessing MWNT for concurrent delivery of cytosine−phosphate−guanine oligodeoxynucleotide (CpG) and anti-CD40 Ig (αCD40), as immunoadjuvants, along with the model antigen ovalbumin (OVA) could potentiate immune response induced against OVA−expressing tumour cells. We initially investigated the effective method to co−deliver OVA and CpG using MWNT to the APC. Covalent conjugation of OVA and CpG prior to loading onto MWNTs markedly augmented the CpG−mediated adjuvanticity, as demonstrated by the significantly increased OVA−specific T cell responses in vitro and in C57BL/6 mice. αCD40 was then included as a second immunoadjuvant to further intensify the immune response. Immune response elicited in vitro and in vivo by OVA, CpG and αCD40 was significantly potentiated by their co−incorporation onto the MWNTs. Furthermore, MWNT remarkably improved the ability of co−loaded OVA, CpG and αCD40 in inhibiting the growth of OVA−expressing B16F10 melanoma cells in subcutaneous or lung pseudo−metastatic tumour models. Therefore, this study suggests that the utilization of MWNTs for the co−delivery of tumour−derived antigen, CpG and αCD40 could be a competent approach for efficient tumours eradication.

Incorporation of novel 1-alkylcarbonyloxymethyl prodrugs of 5-fluorouracil into poly(lactide-co-glycolide) nanoparticles

Incorporation of 1-alkylcarbonyloxymethylprodrugs of 5FU into poly(lactide-co-glycolide) nanoparticles using nanoprecipitation methods gave increased loading efficiencies over that obtained using the parent drug substance. SEM studies revealed spherical nanoparticles of around 200 nm in diameter, corresponding well with measurements made using photon correlation spectroscopy. The C-7 prodrug gave the best mean loading of 47.23%, which compared favourably to 3.68% loading achieved with 5FU. Loading efficiency was seen to follow the hydrophilic-lipophilic balance in the homologue series, where increases in lipophilicities alone were not good predictors of loading. Drug release, in terms of resultant 5FU concentration, was monitored using a flow-through dissolution apparatus. Cumulative drug release from nanoparticles loaded with the C-5 prodrug was linear over 6h, with approximately 14% of the total available 5FU dose released and with no evidence of a burst effect. The flux profile of the C-5-loaded nanoparticles showed an initial peak in flux in the first sampling interval, but became linear for the remainder of the release phase. C-7-loaded nanoparticles released considerably less (4% in 6 h) with a similar flux pattern to that seen with the C-5 prodrug. The C-9-loaded nanoparticles released less than 1% of the available 5FU over 6 h, with a similar zero-order profile. The C7 prodrug was deemed to be the prodrug of choice, achieving the highest loadings and releasing 5FU, following hydrolysis, in a zero-order fashion over a period of at least 6 h. Given the lack of burst effect and steady-state flux conditions, this nanoparticulate formulation offers a better dosing strategy for sustained intravenous use when compared to that arising from nanoparticles made by direct incorporation of 5FU. (c) 2007 Elsevier B.V. All rights reserved.

Acts of incorporation and amendments of the Niagara Falls Suspension Bridge Co'y and the Niagara Falls International Bridge Co'y, also articles of association, leases, agreements, etc. (1900)

Contains "Acts of Parliament of Province of Canada and Acts of Parliament of Dominion of Canada."

Cobalt incorporation in calcite: Thermochemistry of (Ca,Co)CO3 solid solutions from density functional theory simulations

The incorporation of cobalt in mixed metal carbonates is a possible route to the immobilization of this toxic element in the environment. However, the thermodynamics of (Ca,Co)CO3 solid solutions are still unclear due to conflicting data from experiment and from the observation of natural ocurrences. We report here the results of a computer simulation study of the mixing of calcite (CaCO3) and spherocobaltite (CoCO3), using density functional theory calculations. Our simulations suggest that previously proposed thermodynamic models, based only on the range of observed compositions, significantly overestimate the solubility between the two solids and therefore underestimate the extension of the miscibility gap under ambient conditions. The enthalpy of mixing of the disordered solid solution is strongly positive and moderately asymmetric: calcium incorporation in spherocobaltite is more endothermic than cobalt incorporation in calcite. Ordering of the impurities in (0001) layers is energetically favourable with respect to the disordered solid solution at low temperatures and intermediate compositions, but the ordered phase is still unstable to demixing. We calculate the solvus and spinodal lines in the phase diagram using a sub-regular solution model, and conclude that many Ca1-xCoxCO3 mineral solid solutions (with observed compositions of up to x=0.027, and above x=0.93) are metastable with respect to phase separation. We also calculate solid/aqueous distribution coefficients to evaluate the effect of the strong non-ideality of mixing on the equilibrium with aqueous solution, showing that the thermodynamically-driven incorporation of cobalt in calcite (and of calcium in spherocobaltite) is always very low, regardless of the Co/Ca ratio of the aqueous environment.

Production of fungal lipases using wheat bran and soybean bran and incorporation of sugarcane bagasse as a co-substrate in solid-state fermentation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A plea for the incorporation of co-operative loan and building associations. Submitted to the Joint special labor committee of the Massachusetts Legislature,

Mode of access: Internet.

Precipitation casting of drug-loaded microporous PCL matrices:incorporation of progesterone by co-dissolution

Microporous, poly(ε-caprolactone) (PCL) matrices were loaded with progesterone by precipitation casting using co-solutions of PCL and progesterone in acetone. Progesterone loadings up to 32% w/w were readily achieved by increasing the drug content of the starting PCL solution. The kinetics of steroid release in PBS at 37°C over 10 days could be described effectively by a diffusional release model although the Korsmeyer-Peppas model indicated the involvement of multiple release phenomena. The diffusion rate constant (D) increased from 8 to 24 μg/mg matrix/day0.5 as the drug loading increased from 3.6 to 12.4% w/w. A total cumulative release of 75%-95% indicates the high efficiency of steroid delivery. Increasing the matrix density from 0.22 to 0.39 g/cm3, by increasing the starting PCL solution concentration, was less effective in changing drug release kinetics. Retention of anti-proliferative activity of released steroid was confirmed using cultures of breast cancer epithelial (MCF-7) cells. Progesterone released from PCL matrices into PBS at 37°C over 14 days retarded the growth of MCF-7 cells by a factor of at least 3.5 compared with progesterone-free controls. These findings recommend further investigation of precipitation-cast PCL matrices for delivery of bioactive molecules such as anti-proliferative agents from implanted, inserted or topical devices.

Changes in [18F]Fluoro-2-deoxy-D-glucose incorporation induced by doxorubicin and anti-HER antibodies by breast cancer cells modulated by co-treatment with metformin and its effects on intracellular signalling

Peer reviewed

Changes in [18F]Fluoro-2-deoxy-D-glucose incorporation induced by doxorubicin and anti-HER antibodies by breast cancer cells modulated by co-treatment with metformin and its effects on intracellular signalling

Peer reviewed

Changes in [18F]Fluoro-2-deoxy-D-glucose incorporation induced by doxorubicin and anti-HER antibodies by breast cancer cells modulated by co-treatment with metformin and its effects on intracellular signalling

Peer reviewed

The effects of bioactive akermanite on physiochemical, drug-delivery and biological properties of poly (lactide-co-glycolide) beads

Poly(lactide-co-glycolide) (PLGA) beads have been widely studied as a potential drug/protein carrier. The main shortcomings of PLGA beads are that they lack bioactivity and controllable drug-delivery ability, and their acidic degradation by-products can lead to pH decrease in the vicinity of the implants. Akermanite (AK) (Ca(2) MgSi(2) O(7) ) is a novel bioactive ceramic which has shown excellent bioactivity and degradation in vivo. This study aimed to incorporate AK to PLGA beads to improve the physiochemical, drug-delivery, and biological properties of PLGA beads. The microstructure of beads was characterized by SEM. The effect of AK incorporating into PLGA beads on the mechanical strength, apatite-formation ability, the loading and release of BSA, and the proliferation, and differentiation of bone marrow stromal cells (BMSCs) was investigated. The results showed that the incorporation of AK into PLGA beads altered the anisotropic microporous structure into homogenous one and improved their compressive strength and apatite-formation ability in simulated body fluids (SBF). AK neutralized the acidic products from PLGA beads, leading to stable pH value of 7.4 in biological environment. AK led to a sustainable and controllable release of bovine serum albumin (BSA) in PLGA beads. The incorporation of AK into PLGA beads enhanced the proliferation and alkaline phosphatase activity of BMSCs. This study implies that the incorporation of AK into PLGA beads is a promising method to enhance their physiochemical and biological property. AK/PLGA composite beads are a potential bioactive drug-delivery system for bone tissue repair.

CaSiO3 microstructure modulating the in vitro and in vivo bioactivity of poly (lactide-co-glycolide) microspheres

Poly (lactide-co-glycolide) (PLGA) microspheres have been used for regenerative medicine due to their ability for drug delivery and generally good biocompatibility, but they lack adequate bioactivity for bone repair application. CaSiO3 (CS) has been proposed as a new class of material suitable for bone tissue repair due to its excellent bioactivity. In this study, we set out to incorporate CS into PLGA microspheres to investigate how the phase structure (amorphous and crystal) of CS influences the in vitro and in vivo bioactivity of the composite microspheres, with a view to the application for bone regeneration. X-ray diffraction (XRD), N2 adsorption-desorption analysis and scanning electron microscopy (SEM) were used to analyze the phase structure, surface area/pore volume, and microstructure of amorphous CS (aCS) and crystal CS (cCS), as well as their composite microspheres. The in vitro bioactivity of aCS and cCS – PLGA microspheres was evaluated by investigating their apatite-mineralization ability in simulated body fluids (SBF) and the viability of human bone mesenchymal stem cells (BMSCs). The in vivo bioactivity was investigated by measuring their de novo bone-formation ability. The results showed that the incorporation of both aCS and cCS enhanced the in vitro and in vivo bioactivity of PLGA microspheres. cCS/PLGA microspheres improved better in vitro BMSC viability and de novo bone-formation ability in vivo, compared to aCS/PLGA microspheres. Our study indicates that controlling the phase structure of CS is a promising method to modulate the bioactivity of polymer microsphere system for potential bone tissue regeneration.