Ternary Blend Strategy for Achieving High-Efficiency Organic Photovoltaic Devices for Indoor Applications.

Monomeric perylene diimide (PDI) small molecules display a high absorption coefficient and crystallinity in solid-state thin films due to strong π-π interactions between the molecules. To take advantage of these exciting properties of PDIs, N,N'-bis(1-ethylpropyl)perylene-3,4,9,10-tetracarboxylic diimide (EP-PDI) was mixed with a binary blend of PTB7 and PC71 BM to fabricate an efficient ternary blend, which were in turn used to produce organic photovoltaic (OPV) devices well suited to indoor applications (PTB7=poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}), PC71 BM=[6,6]-phenyl-C71 -butyric acid methyl ester). We varied the PC71 BM/EP-PDI weight ratio to investigate the influence of EP-PDI on the optical, electrical, and morphological properties of the PTB7:PC71 BM:EP-PDI ternary blend. Compared with the reference PTB7:PC71 BM binary blend, the ternary blends showed strong optical absorption in the wavelength range in which the spectra of indoor LED lamps show their strongest peaks. The addition of EP-PDI to the binary blend was found to play an important role in altering the morphology of the blend in such a way as to facilitate charge transport in the resulting ternary blend. Apparently, as a result, the optimal PTB7:PC71 BM:EP-PDI-based inverted OPV device exhibited a power conversion efficiency (PCE) of 15.68 %, a fill factor (FF) of 68.5 %, and short-circuit current density (JSC ) of 56.7 µA cm-2 under 500 lx (ca. 0.17 mW cm-2 ) indoor LED light conditions.

Transparent resistive switching memory using aluminum oxide on a flexible substrate.

Resistive switching memory (ReRAM) has attracted much attention in recent times owing to its fast switching, simple structure, and non-volatility. Flexible and transparent electronic devices have also attracted considerable attention. We therefore fabricated an Al2O3-based ReRAM with transparent indium-zinc-oxide (IZO) electrodes on a flexible substrate. The device transmittance was found to be higher than 80% in the visible region (400-800 nm). Bended states (radius = 10 mm) of the device also did not affect the memory performance because of the flexibility of the two transparent IZO electrodes and the thin Al2O3 layer. The conduction mechanism of the resistive switching of our device was explained by ohmic conduction and a Poole-Frenkel emission model. The conduction mechanism was proved by oxygen vacancies in the Al2O3 layer, as analyzed by x-ray photoelectron spectroscopy analysis. These results encourage the application of ReRAM in flexible and transparent electronic devices.

Amino acids in the polymerase complex of shorebird-isolated H1N1 influenza virus impact replication and host-virus interactions in mammalian models.

A diverse population of avian influenza A viruses (AIVs) are maintained in wild birds and ducks yet the zoonotic potential of AIVs in these environmental reservoirs and the host-virus interactions involved in mammalian infection are not well understood. In studies of a group of subtype H1N1 AIVs isolated from migratory wild birds during surveillance in North America, we previously identified eight amino acids in the polymerase genes PB2 and PB1 that were important for the transmissibility of these AIVs in a ferret model of human influenza virus transmission. In this current study we found that PB2 containing amino acids associated with transmissibility at 67, 152, 199, 508, and 649 and PB1 at 298, 642, and 667 were associated with more rapid viral replication kinetics, greater infectivity, more active polymerase complexes and greater kinetics of viral genome replication and transcription. Pathogenicity in the mouse model was also impacted, evident as greater weight loss and lung pathology associated with greater inflammatory lung cytokine expression. Further, these AIVs all contained the avian-type amino acids of PB2-E627, D701, G590, Q591 and T271. Therefore, our study provides novel insights into the role of the AIV polymerase complex in the zoonotic transmission of AIVs in mammals.

Preformulation and formulation of newly synthesized QNT3-18 for development of a skin whitening agent.

New molecules having the structure of (E)-2-(4-tert-butylbenzylidene) hydrazinecarbothioamide (QNT3-18) or 4-tert-butylphenylthiourea (QNT3-20) was synthesized and presupposed to inhibit melanogenesis through the inhibition of tyrosinase, which is involved in melanin formation. Therefore, we seek to develop these new molecules as skin whitening agents in topical formulations based on preformulation studies. QNT3-18 or QNT3-20 showed a strong single endothermic peak at 159.34°C with 10.79 µm-sized or at 150.69°C with 9.0 µm-sized aggregated particles, respectively. Both QNT3-18 and QNT3-20 did not show cytotoxicity at effective concentration range (0.4 µM) against keratinocyte cells and QNT3-18 was more retained than QNT3-20 in the skin instead of permeating through the skin. QNT3-18 or QNT3-20 was practically insoluble in water; the aqueous solubility was 3.8 ± 0.37 or 130.6 ± 2.52 µg/mL, respectively. Also, the partition coefficient value (log P) corresponding to the quotient between aqueous and octanol concentration of the molecule was 3.9 or 2.6, respectively. The skin retention amount of QNT3-18 was 1.7-fold higher than that of QNT3-20. When the optimal SLN cream (J3 formulation) containing 4 µM QNT3-18 was applied on the backs of hairless rats for 4 days after UV irradiation for 7 days and the skin color was checked by reflectance spectrophotometer, the rat skin treated with SLN cream with QNT3-18 quickly recovered to normal compared to skin treated with SLN cream without QNT3-18. Taken together, this study suggests that topical formulations such as creams including SLNs with QNT3-18 might be appropriate carriers for skin whitening agents.

Quantitative Verification of Concrete Formwork-Striking-Time Reduction by High Blaine Ordinary Portland Cement.

Type Ⅰ high Blaine ordinary Portland cement (IHB) possesses the same composition as that of type Ⅰ ordinary Portland cement; however, due to its high fineness, IHB exhibits properties that are similar to those of type Ⅲ rapid-hardening Portland cement, which can reduce the formwork striking time. However, to date, no quantitative research results regarding the construction-time-reduction effect of IHB have been reported. Therefore, this study conducted experiments to verify the formwork-striking-time reduction effect of concrete using IHB. Considering seasonal changes, the strength-development characteristics, according to the outside air temperature, were examined by modifying the curing temperature conditions (5, 10, and 20 °C). Furthermore, the achievable reduction in the concrete formwork striking time was quantitatively determined by comparing and analyzing with the linear interpolation and maturity methods for improving the accuracy of the formwork striking time. The experimental results indicated that, compared with ordinary cement, early formwork striking is possible using IHB, due to earlier strength development. Thus, IHB was confirmed to be effective for construction-time reduction through early formwork striking, and it can be used as a sufficient substitute for expensive rapid-hardening cement in sites and weather conditions where rapid hardening is required.

Structural basis for CEP192-mediated regulation of centrosomal AURKA.

Aurora kinase A (AURKA) performs critical functions in mitosis. Thus, the activity and subcellular localization of AURKA are tightly regulated and depend on diverse factors including interactions with the multiple binding cofactors. How these different cofactors regulate AURKA to elicit different levels of activity at distinct subcellular locations and times is poorly understood. Here, we identified a conserved region of CEP192, the major cofactor of AURKA, that mediates the interaction with AURKA. Quantitative binding studies were performed to map the interactions of a conserved helix (Helix-1) within CEP192. The crystal structure of Helix-1 bound to AURKA revealed a distinct binding site that is different from other cofactor proteins such as TPX2. Inhibiting the interaction between Helix-1 and AURKA in cells led to the mitotic defects, demonstrating the importance of the interaction. Collectively, we revealed a structural basis for the CEP192-mediated AURKA regulation at the centrosome, which is distinct from TPX2-mediated regulation on the spindle microtubule.

Surface-modified gemcitabine with mucoadhesive polymer for oral delivery.

Gemcitabine microparticles were prepared using chitosan, polyethylene oxide or carbopol as the mucoadhesive polymer and eudragit L100-55 as the enteric polymer by a double emulsion method. The particle size and zeta potential changed from 1338.3 ± 254.1 nm to 2459.4 ± 103.6 nm and -5.16 ± 1.62 mV to 2.84 ± 0.65 mV, respectively, with increasing chitosan to gemcitabine weight ratio from 0.25 to 1. The gemcitabine-loaded microparticles without mucoadhesive polymer (F50) showed the particle size and zeta potential of 671.3 ± 58.3 nm and - 16.7 ± 1.82 mV, respectively. The cellular uptake of gemcitabine into Caco-2 cells from gemcitabine-loaded microparticles with chitosan increased with increasing incubation time in Caco-2 cells compared to that of gemcitabine-loaded microparticles with polyethylene oxide or carbopol, suggesting that chitosan might be the optimal mucoadhesive polymer. Gemcitabine microparticles will be tested to identify whether the oral absorption could be increased in the future.

Larvicidal activity of Myrtaceae essential oils and their components against Aedes aegypti, acute toxicity on Daphnia magna, and aqueous residue.

The larvicidal activity of 11 Myrtaceae essential oils and their constituents was evaluated against Aedes aegypti L. Of the 11, Melaleuca linariifolia Sm., Melaleuca dissitiflora F. Muell., Melaleuca quinquenervia (Cav.) S. T. Blake, and Eucalyptus globulus Labill oils at 0.1 mg/ml exhibited > or = 80% larval mortality. At this same concentration, the individual constituents tested, allyl isothiocyanate, alpha-terpinene, p-cymene, (+)-limonene, (-)-limonene, gamma-terpinene, and (E)-nerolidol, resulted in > or = 95% mortality. We also tested the acute toxicity of these four active oils earlier mentioned and their constituents against Daphnia magna Straus. M. linariifolia and allyl isothiocyanate was the most toxic to D. magna. Twodays after treatment, residues of M. dissitiflora, M. linariifolia, M. quinquenervia, and E. globulus oils in water were 55.4, 46.6, 32.4, and 14.8%, respectively. Less than 10% of allyl isothiocyanate, alpha-terpinene, p-cymene, (-)-limonene, (+)-limonene, and gamma-terpinene was detected in the water at 2 d after treatment. Our results indicated that oils and their constituents could easily volatilize in water within a few days after application, thus minimizing their effect on the aqueous ecosystem. Therefore, Myrtaceae essential oils and their constituents could be developed as control agents against mosquito larvae.

Enhanced local anesthetic action of mepivacaine from the bioadhesive gels.

Mepivacaine, an amide-type local anesthetic, has been used to relieve local pain. Among the many drug delivery systems, transdermal drug delivery has some advantages, as it provides controlled drug delivery for an extended period of time. To develop new gel formulations that have suitable bioadhesion, the bioadhesive force of hydroxypropyl methylcellulose (HPMC) was assessed using an auto-peeling tester. The effect of drug concentration on drug release from 2% HPMC gel was studied using synthetic cellulose membrane at 37±0.5°C. The drug concentrations tested were 0.5, 1, 1.5, 2, and 2.5%. The effect of temperature on drug release from the 2% drug gel was evaluated at 27, 32, 37 and 42°C. To increase the skin permeation of mepivacaine from HPMC gel, enhancers such as saturated and unsaturated fatty acids, pyrrolidones, propylene glycol derivatives, glycerides, and non-ionic surfactants were incorporated into the mepivacaine-HPMC gels. The enhancing effect of the enhancer on drug permeation was then examined in the modified Keshary-Chien cell. For the efficacy study, the anesthetic action of the formulated mepivacaine gel containing enhancer and vasoconstrictor was evaluated with the tail-flick analgesimeter. Among the various kinds of HPMC, HPMC-K100M gel showed the highest viscosity and bioadhesive force. As the viscosity of the HPMC gels increased, the bioadhesive forces increased. Increasing the drug concentration or temperature increased the drug release rate. Among the enhancers used, polyoxyethylene 2-oleyl ether showed the greatest enhancement of permeation. Based on the area under the efficacy curve of the rat tail flick test curve, mepivacaine gel containing polyoxyethylene 2-oleyl ether and tetrahydrozoline showed prolonged and increased local anesthetic action compared to the control. For bioadhesive mepivacaine gels with enhanced local anesthetic action, mepivacaine gels containing penetration enhancer and vasoconstrictor could be developed with the bioadhesive polymer, HPMC.

An Evaluation of the Physical and Chemical Stability of Dry Bottom Ash as a Concrete Light Weight Aggregate.

Compared to the bottom ash obtained by a water-cooling system (wBA), dry process bottom ash (dBA) makes hardly any unburnt carbon because of its stay time at the bottom of the boiler and contains less chloride because there is no contact with seawater. Accordingly, to identify the chemical stability of dBA as a lightweight aggregate for construction purposes, the chemical properties of dBA were evaluated through the following process of the reviewing engineering properties of a lightweight aggregate (LWA). Typically, river gravel and crushed gravel have been used as coarse aggregates due to their physical and chemical stability. The coal ash and LWA, however, have a variety of chemical compositions, and they have specific chemical properties including SO3, unburnt coal and heavy metal content. As the minimum requirement to use the coal ash and lightweight aggregate with various chemical properties for concrete aggregate, the loss on ignition, the SO3 content and the amount of chloride should be examined, and it is also necessary to examine heavy metal leaching even though it is not included in the standard specifications in Korea. Based on the results, it is believed that there are no significant physical and chemical problems using dBA as a lightweight aggregate for concrete.

Preparation and evaluation of solid lipid nanoparticles with JSH18 for skin-whitening efficacy.

A new molecule having the structure of 6-methyl-3-phenethyl-3,4-dihydro-1H-quinazoline-2-thione (JSH18) was synthesized and it was possibly presupposed to show depigmentation through the inhibition of tyrosinase which is involved in the formation of melanin. Therefore, we are going to develop JSH18 as an inhibitor of melanin synthesis with topical formulations to show its optimal efficiency for skin whitening. Solid lipid nanoparticles (SLNs) play an important role as drug delivery systems for intravenous, peroral, parenteral, or ocular administration and for topical delivery. The particle size of prepared SLNs of JSH18 was variable from 59.8-919.6 nm. When the optimal SLNs cream (PU3) including 4 uM of JSH18 was applied to the backs of hairless rats for four days after the backs were irradiated by UV ray for seven days and the skin color was checked by reflectance spectrophotometer, the rat skin applied with PU3 cream quickly recovered to normal compared to SLNs cream without JSH18. Taken together, this study suggests topical formulations such as creams including SLNs with JSH18 might be an appropriate carrier for skin-whitening agents.

Effects of epigallocatechin gallate on the oral bioavailability and pharmacokinetics of tamoxifen and its main metabolite, 4-hydroxytamoxifen, in rats.

The effects of epigallocatechin gallate (EGCG) on the oral bioavailability and pharmacokinetics of tamoxifen and its metabolite, 4-hydroxytamoxifen, were investigated in rats. A single dose of tamoxifen was administered intravenously (2 mg/kg) and orally (10 mg/kg) with or without epigallocatechin (0.5, 3 and 10 mg/kg) to rats. The presence of EGCG significantly altered the pharmacokinetics of orally administered tamoxifen. Compared with the oral control group (given tamoxifen alone), the area under the plasma concentration-time curve and the peak plasma concentration of tamoxifen significantly (P<0.05 for 3 mg/kg of EGCG, P<0.01 for 10 mg/kg of EGCG) increased 48.4-77.0 and 57.1-89.7%, respectively. Consequently, the absolute bioavailability of tamoxifen in the presence of EGCG (3 and 10 mg/kg) was 48.9-78.1%, which was significantly enhanced (P<0.05 for 3 mg/kg of EGCG, P<0.01 for 10 mg/kg of EGCG) compared with the oral control group (23.7%). Moreover, the relative bioavailability of tamoxifen was 1.48-1.77-fold greater than that of the control group. EGCG at a dose of 10 mg/kg significantly increased the area under the plasma concentration-time curve (P<0.05, 40.3%) of 4-hydroxytamoxifen, but the metabolite-parent ratio of 4-hydroxytamoxifen was also significantly altered (P<0.05 for 10 mg/kg of EGCG), implying that the formation of 4-hydroxytamoxifen was considerably affected by EGCG. The increase in bioavailability of tamoxifen is likely to be due to the decrease in first-pass metabolism in the intestine and liver by inhibition of P-glycoprotein and CYP3A by EGCG. The increase in oral bioavailability of tamoxifen in the presence of EGCG should be taken into consideration of potential drug interactions between tamoxifen and EGCG.

Regulation of resin acid synthesis in Pinus densiflora by differential transcription of genes encoding multiple 1-deoxy-D-xylulose 5-phosphate synthase and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase genes.

Pinus densiflora Siebold et Zucc. is the major green canopy species in the mountainous area of Korea. To assess the response of resin acid biosynthetic genes to mechanical and chemical stimuli, we cloned cDNAs of genes encoding enzymes involved in the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway (1-deoxy-d-xylulose 5-phosphate synthase (PdDXS), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (PdDXR) and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (PdHDR)) by the rapid amplification of cDNA ends (RACE) technique. In addition, we cloned the gene encoding abietadiene synthase (PdABS) as a marker for the site of pine resin biosynthesis. PdHDR and PdDXS occurred as two gene families. In the phylogenetic trees, PdDXSs, PdDXR and PdHDRs each formed a separate clade from their respective angiosperm homologs. PdDXS2, PdHDR2 and PdDXR were most actively transcribed in stem wood, whereas PdABS was specifically transcribed. The abundance of PdDXS2 transcripts in wood in the resting state was generally 50-fold higher than the abundance of PdDXS1 transcripts, and PdHDR2 transcripts were more abundant by an order of magnitude in wood than in other tissues, with the ratio of PdHDR2 to PdHDR1 transcripts in wood being about 1. Application of 1 mM methyl jasmonate (MeJA) selectively enhanced the transcript levels of PdDXS2 and PdHDR2 in wood. The ratios of PdDXS2 to PdDXS1 and PdHDR2 to PdHDR1 reached 900 and 20, respectively, on the second day after MeJA treatment, whereas the transcript level of PdABS increased twofold by 3 days after MeJA treatment. Wounding of the stem differentially enhanced the transcript ratios of PdDXS2 to PdDXS1 and PdHDR2 to PdHDR1 to 300 and 70, respectively. The increase in the transcript levels of the MEP pathway genes in response to wounding was accompanied by two orders of magnitude increase in PdABS transcripts. These observations indicated that resin acid biosynthesis activity, represented by PdABS transcription, was correlated with the selective transcriptions of PdDXS2 and PdHDR2. Introduction of PdDXS2, PdHDR1 and PdHDR2 rescued their respective knockout Escherichia coli mutants, confirming that at least these three genes were functionally active. Intracellular targeting of the green fluorescent protein fused to the N-terminal 100 amino acid residues of these genes in the Arabidopsis transient expression system showed that the proteins were all targeted to the chloroplasts. Our results suggest that the MEP pathway regulates resin biosynthesis in the wood of P. densiflora by differential transcription of the multiple PdDXS and PdHDR genes.

Enhanced transdermal absorption and pharmacokinetic evaluation of pranoprofen-ethylene-vinyl acetate matrix containing penetration enhancer in rats.

To increase the skin permeation of pranoprofen from the ethylene-vinyl acetate (EVA) matrix, different types of enhancers were added to an EVA matrix containing 2% pranoprofen. The pharmacokinetics and bioavailability of pranoprofen, an anti-inflammatory drug, were examined to determine the feasibility of an enhanced transdermal delivery system for pranoprofen from an EVA matrix containing caprylic acid as the enhancer in rats. The effects of the enhancers on the level of pranoprofen permeation through the skin were evaluated using Franz diffusion cells that were fitted with the intact excised rat skin. Among the enhancers used, including the fatty acids (saturated, unsaturated), the glycols, the glycerides, and the pyrrolidones, caprylic acid showed the best enhancement. A pranoprofen-EVA matrix system was formulated containing caprylic acid as an enhancer. The pranoprofen-EVA matrix system (8 mg/kg) was applied to the abdominal skin of rats. The blood samples were collected through the femoral artery for 24 h and the plasma concentrations of pranoprofen were determined by HPLC. The pharmacokinetic parameters were calculated using the MULTI computer program. The area under the curve (AUC) was significantly higher in the enhancer group (55.49 +/- 13.87 ng/mL.h) than in the control group (22.48 +/- 5.63 ng/mL.h), which was treated transdermally without the enhancer, showing about 246% increased bioavailability (p<0.05). As the pranoprofen-EVA matrix containing caprylic acid as an enhancer was administered to rats via the transdermal routes, the relative bioavailability increased about 2.46-fold compared to the control group, showing a relatively constant, sustained blood concentration. These results show that a pranoprofen-EVA matrix containing a permeation enhancer could be developed as a transdermal delivery system to provide a sustained plasma concentration.

Studies on the formation of hydrophobic ion-pairing complex of alendronate.

A hydrophobic ion-pairing (HIP) concept considering the high dissociation property of alendronate was used as a strategy to improve the bioavailability of alendronate. Alendronate, which has a negative charge, was ion-paired with organic cations, such as tetraheptylammonium bromide (THAB) or tetrabutylammonium iodide (TBAI), to confer hydrophobicity to alendronate, and increase its intestinal permeability. Solutions containing various concentrations (0.5 to 100 mM) of organic cations were combined with an alendronate solution (5 mM) at molar ratios from 0.1:1 to 20:1 under various pHs (pH 2.2, 6.3 and 10.3). Alendronate exhibited high hydrophobicity when coupled with THAB at a molar ratio of 1:10 in pH 2.2. On the other hand, HIP complexes between alendronate and TBAI showed the maximum hydrophobicity at the same molar ratio at pH 10.3. The zeta potentials of alendronate from the aqueous layer of the HIP complex between alendronate and THAB or TBAI increased gradually with increasing alendronate to THAB molar ratio at pH 2.2 or pH 10.3, respectively. This is the first report of the production of hydrophobic ion-paired alendronate.

Development of the loratadine gel for enhanced transdermal delivery.

BACKGROUND: The oral administration of loratadine, an antihistamine, can have a variety of adverse side effects, such as headache, fatigue, and nausea, because of the transient high blood concentration. To avoid these effects, loratadine can be administered using a transdermal drug delivery system. METHOD: This study examined the effects of the drug concentration on drug release from prepared hydroxypropyl methylcellulose gels using a synthetic cellulose membrane at 37 degrees C. The drug concentrations tested were 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% (w/w). The effect of temperature on drug release from the 0.3% loratadine gels was evaluated at 27 degrees C, 32 degrees C, 37 degrees C, and 42 degrees C. Various types of penetration enhancers, such as glycols, glycerides, propylene glycol derivatives, nonionic surfactants, and fatty acids, were incorporated in the gel formulation to increase the level of drug permeation. RESULTS: The rate of drug release increased with increasing drug concentration or temperature. The activation energy for the release of the drug was 5.714 kcal/mol for 0.3% loratadine gel. Among all the enhancers used in this study, polyoxyethylene 2-stearyl ether showed the best enhancing effect. The enhancement factor of the loratadine gel containing the polyoxyethylene 2-stearyl ether was 2.03 compared with that of the loratadine system containing no enhancer. CONCLUSIONS: These results suggest that the topical gel formulation of loratadine containing a penetration enhancer could be developed to enhance the penetration of loratadine.

Highly Efficient Indoor Organic Solar Cells by Voltage Loss Minimization through Fine-Tuning of Polymer Structures.

Herein, we report a detailed study on the optoelectronic properties, photovoltaic performance, structural conformation, morphology variation, charge carrier mobility, and recombination dynamics in bulk heterojunction solar cells comprising a series of donor-acceptor conjugated polymers as electron donors based on benzodithiophene (BDT) and 5,8-bis(5-bromothiophen-2-yl)-6,7-difluoro-2,3-bis(3-(octyloxy)phenyl)quinoxaline as a function of the BDT's thienyl substitution (alkyl (WF3), alkylthio (WF3S), and fluoro (WF3F)). The synergistic positive effects of the fluorine substituents on the minimization of the bimolecular recombination losses, the reduction of the series resistances (RS), the increment of the shunt resistances (RSh), the suppression of the trap-assisted recombination losses, the balanced charge transport, the finer nanoscale morphology, and the deeper highest occupied molecular orbital (EHOMO) are manifested versus the alkyl and alkylthio substituents. According to these findings, the WF3F:[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM)-based organic photovoltaic device is a rare example that features a high power conversion efficiency (PCE) of 17.34% under 500 lx indoor light-emitting diode light source with a high open-circuit voltage (VOC) of 0.69 V, due to the suppression of the voltage losses, and a PCE of 9.44% at 1 sun (100 mW/cm2) conditions, simultaneously.

Influence of the delivery systems using a microneedle array on the permeation of a hydrophilic molecule, calcein.

Despite the advantages of drug delivery through the skin, such as easy accessibility, convenience, prolonged therapy, avoidance of the liver first-pass metabolism and a large surface area, transdermal drug delivery is only used with a small subset of drugs because most compounds cannot cross the skin at therapeutically useful rates. Recently, a new concept was introduced known as microneedles and these could be pierced to effectively deliver drugs using micron-sized needles in a minimally invasive and painless manner. In this study, biocompatible polycarbonate (PC) microneedle arrays with various depths (200 and 500 microm) and densities (45, 99 and 154 ea/cm2) were fabricated using a micro-mechanical process. The skin permeability of a hydrophilic molecule, calcein (622.5D), was examined according to the delivery systems of microneedle, drug loading, depth of the PC microneedle, and density of the PC microneedle. The skin permeability of calcein was the highest when the calcein gel was applied to the skin with the 500 microm-depth PC microneedle, simultaneously. In addition, the skin permeability of calcein was the highest when 0.1g of calcein gel was coupled to the 500 microm-depth PC microneedle (154 ea/cm2) as well as longer microneedles and larger density of microneedles. Taken together, this study suggests that a biocompatible PC microneedle might be a suitable tool for transdermal drug delivery system of hydrophilic molecules with the possible applications to macromolecules such as proteins and peptides.

Effects of morin on the bioavailability of tamoxifen and its main metabolite, 4-hydroxytamoxifen, in rats.

This study examined the effect of morin on the bioavailability and pharmacokinetics of tamoxifen and its metabolite, 4-hydroxytamoxifen, in rats. A single dose of tamoxifen was administered to rats intravenously (2 mg/kg) or orally (10 mg/kg), with or without morin (3 or 10 mg/kg). The presence of morin significantly altered the pharmacokinetics of the orally administered tamoxifen. Compared with the oral control group (given tamoxifen alone), the total body clearance (CL/F) of tamoxifen in the presence of morin was significantly reduced (by 35.9-40.8%, p<0.01). The area under the plasma concentration-time curve (AUC(0-infinity)) and the peak plasma concentration (Cmax) of tamoxifen significantly (p<0.05 for 3 mg/kg of morin, p<0.01 for 10 mg/kg of morin) increased by 50.6-68.9% and 65.1-80.9%, respectively. Consequently, the absolute bioavailability (AB) of tamoxifen in the presence of morin was 37.4-40.5%, which was enhanced significantly (p<0.05) compared with the oral control group (23.9%). The relative bioavailability (RB) of tamoxifen was 1.56 to 1.68 times higher than the control group. The increased bioavailability of tamoxifen is likely to be due to the decrease in the first-pass metabilism by the intestines and liver. Morin at a dose of 10 mg/kg significant increased the AUC(0-infinity), of 4-hydroxytamoxifen (by 50.9%, p<0.05) but the metabolite:parent ratio (MR) of 4-hydroxytamoxifen was not altered significantly, suggesting that the formation of 4-hydroxytamoxifen is not affected considerably by morin. The increased bioavailability of tamoxifen in the presence of morin should be taken into consideration for dosage regimens due to potential drug interaction.

Preparation and evaluation of procaine gels for the enhanced local anesthetic action.

To develop the new procaine gel formulations with a suitable bioadhesive property, the gel was formulated using hydroxypropyl methylcellulose (HPMC) and poloxamer containing an enhancer and the local anesthetic action were evaluated. As the drug concentration in the gels and the temperature of surrounding solutions increased, the drug release increased. The activation energy of drug permeation was 4.35 kcal/mol for procaine. The effects of permeation enhancers on the permeation rate of drug through skin were studied using various enhancers, such as the glycols, the non-ionic surfactants, and the bile salts. Among the enhancers used, polyoxyethylene 2-oleyl ether Showed the most enhancing effects on drug permeation through skin. The analgesic activity was examined using a tail-flick analgesimeter. From the area under the efficacy curve of the rat-tail flick tests, procaine gel containing polyoxyethylene 2-oleyl ether showed about 1.77-fold increase in analgesic activity compared with the control. These results support that the enhanced local anesthetic gels containing an enhancer could be developed using the bioadhesive polymer gels based on HPMC and poloxamer.