Gelation in Photoinduced ATRP with Tuned Dispersity of the Primary Chains.

We investigated gelation in photoinduced atom transfer radical polymerization (ATRP) as a function of Cu catalyst loading and thus primary chain dispersity. Using parallel polymerizations of methyl acrylate with and without the addition of a divinyl crosslinker (1,6-hexanediol diacrylate), the approximate values of molecular weights and dispersities of the primary chains at incipient gelation were obtained. In accordance with the Flory-Stockmayer theory, experimental gelation occurred at gradually lower conversions when the dispersity of the primary chains increased while maintaining a constant monomer/initiator/crosslinker ratio.

Fluorescent Patterns by Selective Grafting of a Telechelic Polymer.

The preparation of patterned ultrathin films (sub-10 nm) composed of end-anchored fluorescently labeled poly(methyl methacrylate) (PMMA) is presented. Telechelic PMMA was synthesized utilizing activator regenerated by electron transfer atom transfer radical polymerization and consecutively end-functionalized with alkynylated fluorescein by Cu-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. The polymers were grafted via the α-carboxyl groups to silica or glass substrates pretreated with (3-aminopropyl)triethoxysilane (APTES).

Facile Aqueous Route to Nitrogen-Doped Mesoporous Carbons.

An aqueous-based approach for the scalable synthesis of nitrogen-doped porous carbons with high specific surface area (SSA) and high nitrogen content is presented. Low molecular weight polyacrylonitrile (PAN) is solubilized in water in the presence of ZnCl that also acts as a volatile porogen during PAN pyrolysis to form mesoporous structures with significantly increased SSA. By templating with commercial SiO nanoparticles, nanocellulose fillers or filter paper, nanocarbons with SSA = 1776, 1366, and 1501 m/g, respectively and 10 wt % N content were prepared.

In-Situ Platinum Deposition on Nitrogen-Doped Carbon Films as a Source of Catalytic Activity in a Hydrogen Evolution Reaction.

Copolymer-templated nitrogen-doped carbon (CTNC) films deposited on glassy carbon were used as electrodes to study electrochemically driven hydrogen evolution reaction (HER) in 0.5 M H2SO4. The activity of these materials was extremely enhanced when a platinum counter electrode was used instead of a graphite rod and reached the level of commercial Pt/C electrodes.

Polyelectrolyte multilayers with perfluorinated phthalocyanine selectively entrapped inside the perfluorinated nanocompartments.

A novel perfluorinated magnesium phthalocyanine (MgPcF64) was synthesized and employed to probe nanodomains in hydrophobically modified, amphiphilic cationic polyelectrolytes bearing alkyl and/or fluoroalkyl side chains. MgPcF64 was found to be solubilized exclusively in the aqueous solutions of the fluorocarbon modified polycations, occupying the perfluorinated nanocompartments provided, while analogous polyelectrolytes with alkyl side chains forming hydrocarbon nanocompartments could not host the MgPcF64 dye. Multilayer films were fabricated by means of the layer-by-layer (LbL) deposition method using sodium poly(styrene sulfonate) as a polyanion.

[Regeneration of corneal epithelium using keratin modified chitosan membranes].

The cornea is a transparent front layer of the eye. It functions like a window that controls and focuses the light entering into the eye. The cornea contributes to 65-75% of the eye's total focusing power and it acts as a physical barrier against pathogenic microorganisms, dirt and other noxious physical factors.

Potentiated antitumor effects of a combination therapy with a farnesyltransferase inhibitor L-744,832 and butyrate in vitro.

Farnesyltransferase inhibitors, butyrate and butyric acid derivatives have previously been reported to exert anti-tumor activity in experimental models in vitro and in vivo and have recently gained acceptance as potential anticancer agents. In our study, we examined antitumor effects of a combination of a farnesyltransferase inhibitor L-744,832 and butyrate in vitro against MDA-MB-231 and MIA PaCa-2 human cancer cells. This combination therapy showed synergistic antitumor activity against MDA-MB-231 cells, which was at least in part due to induction of p27KIP1 expression.

Cerivastatin demonstrates enhanced antitumor activity against human breast cancer cell lines when used in combination with doxorubicin or cisplatin.

Competitive inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase are commonly used in the clinic to treat hypercholesterolemia and have been reported to exert antitumor effects. Cerivastatin is a novel, synthetic and the most pharmacologically potent inhibitor of HMG-CoA reductase. We decided to examine the cytostatic/cytotoxic activity of cerivastatin against human breast cancer cell lines and to test whether the effects of cerivastatin could be potentiated by doxorubicin and cisplatin.

Antitumor effects of photodynamic therapy are potentiated by 2-methoxyestradiol. A superoxide dismutase inhibitor.

Photodynamic therapy (PDT), a promising therapeutic modality for the management of solid tumors, is a two-phase treatment consisting of a photosensitizer and visible light. Increasing evidence indicates that tumor cells in regions exposed to sublethal doses of PDT can respond by rescue responses that lead to insufficient cell death. We decided to examine the role of superoxide dismutases (SODs) in the effectiveness of PDT and to investigate whether 2-methoxyestradiol (2-MeOE(2)), an inhibitor of SODs, is capable of potentiating the antitumor effects of this treatment regimen.