Fabrication of Wettability-Patterned Surface for Cellular Micropatterning Using Step-Wise Ion Beam Processing.

In this study, the fabrication of a wettability patterned surface for cellular micropatterning was investigated using step-wise ion beam processing. A perfluorinated poly(ethylene-co-propylene) (FEP) film was first irradiated using accelerated Xe+ ions with 100 keV of energy at the low current density of 1 µA/cm² over the entire surface. Second, its confined regions were irradiated at the higher current density of 15 µA/cm² at various ion fluences through the pattern mask to generate patterns with big differences in wettability. From the analytic results, it was clearly verified that the step-wise irradiation induced effective chemical and morphological changes on the FEP surface, resulting in the successful formation of well-defined micropatterns with relatively hydrophilic and superhydrophobic surfaces. Moreover, the results of in-vitro cell culture showed well-resolved formation of 200 µm cell micropatterns on the wettability patterned FEP surface due to the individual effects of the relatively hydrophilic and superhydrophobic properties on the cell adhesiveness and proliferation.

Electron beam-based fabrication of crosslinked hydrophilic carbon electrodes and their application for capacitive deionization.

In this research, we demonstrated that a crosslinked hydrophilic carbon electrode with better electrochemical performance than hydrophobic counterparts can easily be produced using room-temperature, quick electron-beam irradiation with a hydrophilic methacryloyl-substituted polyvinyl alcohol (SPVA) binder. The SPVA binder was effectively synthesized by trans-esterification of PVA with glycidyl methacrylate. The hydrophilic carbon electrode cast on a graphite sheet from a slurry of activated carbon (AC) and SPVA was irradiated with an electron beam to form a crosslinked structure. The analytical results in terms of the morphology, solvent resistance, chemical composition, and contact angle revealed that the carbon electrode was completely crosslinked by electron-beam irradiation even at the dose of 100 kGy (irradiation time = 180 s). The new electrode exhibited superior water-wettability due to the hydrophilic functionality of SPVA. Furthermore, the hydrophilic carbon electrode with an AC : SPVA composition of 90 : 10 and an absorbed dose of 200 kGy, exhibited a specific capacitance of 127 F g-1 (67% higher than the hydrophobic poly(vinylidene fluoride) (PVDF)-based counterpart with the same composition). The specific capacitance was further improved to 160 F g-1 with an increase in the AC content. The hydrophilic carbon electrode exhibited noticeably better desalination efficiency than the hydrophobic PVDF-based counterpart.

Acid-labile mPEG-vinyl ether-1,2-dioleylglycerol lipids with tunable pH sensitivity: synthesis and structural effects on hydrolysis rates, DOPE liposome release performance, and pharmacokinetics.

A family of 3-methoxypoly(ethylene glycol)-vinyl ether-1,2-dioleylglycerol (mPEG-VE-DOG) lipopolymer conjugates, designed on the basis of DFT calculations to possess a wide range of proton affinities, was synthesized and tested for their hydrolysis kinetics in neutral and acidic buffers. Extruded ∼100 nm liposomes containing these constructs in ≥90 mol % 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) produced dispersions that retained their calcein cargo for more than 2 days at pH 7.5, but released the encapsulated contents over a wide range of time scales as a function of the electronic properties of the vinyl ether linkage, the solution pH, and the mPEG-VE-DOG composition in the membrane. The in vivo performance of two different 90:10 DOPE:mPEG-VE-DOG compositions was also evaluated for blood circulation time and biodistribution in mice, using (125)I-tyraminylinulin as a label. The pharmacokinetic profiles gave a t(1/2) of 7 and 3 h for 90:10 DOPE:ST302 and 90:10 DOPE:ST502, respectively, with the liposomes being cleared predominantly by liver and spleen uptake. The behavior of these DOPE:mPEG-VE-DOG formulations is consistent with their relative rates of vinyl ether hydrolysis, i.e., the more acid-sensitive mPEG-VE-DOG derivatives produced faster leakage rates from DOPE:mPEG-VE-DOG liposomes, but decreased the blood circulation times in mice. These findings suggest that the vinyl ether-based PEG-lipid derivatives are promising agents for stabilizing acid-sensitive DOPE liposomes to produce formulations with a priori control over their pH responsiveness in vitro. Our data also suggest, however, that the same factors that contribute to enhanced acid sensitivity of the DOPE:mPEG-VE-DOG dispersions are also likely responsible for their reduced pharmacokinetic profiles.

Lance-adams syndrome.

It is not common for a patient who survives cardiac arrest to experience significant neurologic impairment such as acute and chronic post-hypoxic myoclonus, known as Lance-Adams syndrome. This syndrome is predominantly characterized by myoclonus that starts days to weeks after cardiopulmonary resuscitation in patients who regained consciousness. Although several cases of LAS were reported, the decisive treatment method has not been established. We report a 43 year old man with Lance-Adams syndrome who showed long-term improvement through treatment with anti-myoclonic agents and participation in a rehabilitation program.

The availability of radiological measurement of tibial torsion: three-dimensional computed tomography reconstruction.

OBJECTIVE: To assess the intra-rater and inter-rater reliability for measuring tibial torsion measurements by a radiographic method using three-dimensional computed tomography reconstruction (3D-CT) and to compare the physical measures to those of 3D-CT. METHOD: The study included 33 children who presented with intoeing gait. Tibial torsion was measured by 3D-CT. Distal reference point was the bimalleolar axis. Proximal reference points were the transtibial axis and posterior condylar axis. Physical measurements included thigh-foot angle (TFA) and bimalleolar angle (BMA). 3D-CT measurement and physical measurement were performed twice at both lower extremities by each rater. The intra-rater and inter-rater reliability were calculated by intraclass correlation coefficiency (ICC). The relationship between radiological and physical examination was calculated by Spearman correlation coefficient. RESULTS: The 3D-CT measures for tibial torsion were reliable within individual raters and between different raters. However, physical measures for tibial torsion were reliable within an individual rater but not reliable between raters. The 3D-CT measures by any proximal reference axis were more reliable within a rater and between raters than physical measurements. There was no significant impact introduced by the selection of the proximal reference axis. The correlation coefficiency between 3D-CT and physical measurement methods was low. CONCLUSION: Because the 3D-CT measurements for tibial torsion are more reliable than physical measurements, we recommend that accurate diagnosis of internal tibial torsion should be detected by using 3D-CT measurements. Also, considering the disadvantages of radiological measurements, physical measurement may be used for short term follow-up by same raters, as intra-rater reliability is relatively good.

Improved plasmalogen synthesis using organobarium intermediates.

An improved synthesis of plasmalogen type lipids is described. Transmetalation of lithioalkoxy allyl intermediates with BaI(2) and subsequent alkylation with 1-iodoalkanes enables the stereoselective formation of O-(Z)-alkenyl ether as precursors for the synthesis of plasmenyl- and bisplasmenylcholines. This method provides a simple and adaptable approach for the stereocontrolled synthesis of plasmenyl derivatives with variations at the sn-1, sn-2, and sn-3 positions of the glycerol backbone.

Direct synthesis of plasmenylcholine from allyl-substituted glycerols.

We report a new method for the facile preparation of plasmenylcholine via reaction of lithioalkoxy allyl intermediates with 1-iodoalkanes as the key step in the stereoselective formation of 1'-(Z)-alkenyl glyceryl ethers. The allyl anion intermediate is prepared by treating mono- or disiloxy-protected 1-allylglycerol precursors with s-BuLi at -65 to -80 degrees C. Subsequent addition of 1-iodoalkane solutions at low temperature gives moderate yields of gamma-coupled, Z-vinyl ethers as the major product and alpha-coupled product as the minor component. Several different preparative strategies for the total synthesis of plasmalogens are enabled by this simple transformation.

Acid-triggered release via dePEGylation of DOPE liposomes containing acid-labile vinyl ether PEG-lipids.

Four structurally related, acid-labile polyethylene glycol (PEG) conjugated vinyl ether lipids have been synthesized and used at low molar ratios to stabilize the nonlamellar, highly fusogenic lipid, dioleoylphosphatidyl ethanolamine, as unilamellar liposomes. Acid-catalyzed hydrolysis of the vinyl ether bond destabilized these liposomes by removal of the sterically-stabilizing PEG layer, thereby promoting contents release on the hours timescale at pH<5. Structure-property correlations of these compounds suggested that single vinyl ether linkages between the PEG headgroup and the lipid backbone produce faster leakage rates. These studies also suggested that the presence of a slight negative charge at the membrane surface can accelerate the acid-catalyzed leakage process.

Facile synthesis of plasmalogens via Barbier-type reactions of vinyl dioxanes and vinyl dioxolanes with alkyl halides in LiDBB solution.

Plasmalogens (i.e. plasmenylcholines or plasmenylethanolamines) are a biologically important class of glycerophospholipids that have been difficult to synthesize due to the presence of an acid and oxidatively labile (Z)-vinyl ether substituent at the sn-1 position and a base-labile sn-2 acyl substituent that easily migrates during silica gel purification. We report two facile synthetic methods for the preparation of racemic plasmenylcholines via a tandem reductive vinyl dioxane/dioxolane ring opening and alkyliodide coupling process that proceeds in a single pot reaction. The key step in the formation of (Z)-vinyl ether precursors for the production of plasmenylcholines is accomplished using LiDBB under Barbier-type conditions to give the corresponding TBDMS-protected 1-O-Z'-vinylglycerol intermediate in moderate yields. This pathway is the most direct synthetic route for the formation of plasmenylcholines to date, requiring a total of six transformations from acrolein and glycerol or solketal as inexpensive starting materials, to generate glycerophosphocholine-type plasmalogens in 4% overall yield.