Search

Chrysophsin-1, an amphipathic alpha-helical antimicrobial peptide, is isolated from the gills of the red sea bream and possesses different structure and mechanism(s) in comparison with traditional multidrug resistance (MDR) modulators. For the purpose of reducing off-target normal cell toxicity, it is rational to incorporate chrysophsin-1 and epirubicin in a PEGylated liposomal formulation. In the present study, we report a multifunctional liposomes with epirubicin as an antineoplastic agent and an apoptosis inducer, as well as chrysophsin-1 as a MDR transporter inhibitor and an apoptosis modulator in human cervical cancer HeLa cells. Co-incubation of HeLa cells with PEGylated liposomal formulation of epirubicin and chrysophsin-1 resulted in a significant increase in the cytotoxicity of epirubicin. The liposomal formulations of epirubicin and/or chrysophsin-1 were shown to considerably improve the intracellular H 2 O 2 and O 2 - levels of HeLa cells. Furthermore, these treatments were found to extensively reduce mRNA expression levels of MDR1, MRP1, and MRP2. The addition of chrysophsin-1 in liposomes was demonstrated to substantially enhance the intracellular accumulation of epirubicin in HeLa cells. Moreover, the PEGylated liposomes of epirubicin and chrysophsin-1 were also found to significantly increase the mRNA expressions of p53, Bax, and Bcl-2. The ratio of Bax to Bcl-2 was noticeably amplified in the presence of these formulations. Apoptosis induction was also validated by chromatin condensation, a reduction in mitochondrial membrane potential, the increased sub-G1 phase of cell cycle, and more populations of apoptosis using annexin V/PI assay. These formulations were verified to increase the activity and mRNA expression levels of caspase-9 and caspases-3. Collectively, our findings provide the first evidence that cotreatment with free or liposomal chrysophsin-1 and epirubicin leads to cell death in human cervical cancer cells through the ROS-mediated inhibition of P-gp and MRPs and concerted activation of mitochondrial apoptosis pathway. Thus, chrysophsin-1 represents a potential antimicrobial peptide to function as a new generation of MDR-reversing agent to enhance the activity of cancer chemotherapeutics. [ABSTRACT FROM AUTHOR]

Abstract: Surface plasmon resonance was observed to red shift in hexagonal nanohemisphere Ag array covered by double-walled carbon nanotubes. By altering the density of carbon nanotubes, the surface plasmon resonance can be tuned from 563nm to 586nm and the light scattering is enhanced in the spectral range from orange to red. This leads to improved performance of amorphous silicon solar cells deposited on top, which yields a short-circuit current density of 14.07mA/cm2 and a power conversion efficiency of 6.55% under the illumination of AM 1.5G. This carbon nanotubes'' density-dependent surface plasmon shift is attributed to the dielectric constant change around the periodic Ag nanostructure, which can be applied to other solar cell materials by fine-tuning the surface plasmon resonance to enhance the absorption at wavelength where the active layer is less absorptive. [Copyright &y& Elsevier]

Accurate characterization and reporting of organic photovoltaic (OPV) device performance remains one of the important challenges in the field. The large spread among the efficiencies of devices with the same structure reported by different groups is significantly caused by different procedures and equipment used during testing. The presented article addresses this issue by offering a new method of device testing using “suitcase sample” approach combined with outdoor testing that limits the diversity of the equipment, and a strict measurement protocol. A round robin outdoor characterization of roll-to-roll coated OPV cells and modules conducted among 46 laboratories worldwide is presented, where the samples and the testing equipment were integrated in a compact suitcase that served both as a sample transportation tool and as a holder and test equipment during testing. In addition, an internet based coordination was used via plasticphotovoltaics.org that allowed fast and efficient communication among participants and provided a controlled reporting format for the results that eased the analysis of the data. The reported deviations among the laboratories were limited to 5% when compared to the Si reference device integrated in the suitcase and were up to 8% when calculated using the local irradiance data. Therefore, this method offers a fast, cheap and efficient tool for sample sharing and testing that allows conducting outdoor measurements of OPV devices in a reproducible manner. [ABSTRACT FROM AUTHOR]

Solution processing of metal oxide semiconductors (MOS) is widely used for electronic and optoelectronic applications. However, the high-temperature annealing process that is required for device-quality films is incompatible with a flexible substrate because plastics can be thermally damaged. This study fabricates a p-type Cu 2 O flexible photodetector (PD) with a metal-semiconductor-metal structure on a polyethylene terephthalate (PET) substrate by irradiating a preheated precursor film with ultraviolet (UV) light. High-quality Cu 2 O crystals are formed on PET substrates by the charge transfer transition that is excited by the UV-irradiation at room temperature. An extremely high photo-to-dark current ratio (PDCR) of 1590 is achieved for a solution-processed Cu 2 O flexible PD. This flexible PD exhibits a relatively fast photoresponse (~0.2 s) and folds reproducibly after repeated bending for 500 cycles. This process does not require conventional high-temperature thermal annealing and is applicable to other solution-processed MOS, particularly those that are used for flexible electronic applications. [ABSTRACT FROM AUTHOR]