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Nano carrier systems were prepared by forming self-assembled liposomes having a size distribution in the nano range through use of an ultrasonic homogenizer. Phosphatidylcholine and cholesterol were utilized as an amphiphilic compound and a shape stabilizer, respectively. The size of prepared samples was decreased (up to 150 nm) by elevating ratio of lecithin and extending homogenization time (2 to approximately 6 min). After secondary coating with alginic acid (0.1, 0.3 and 0.5%, W/V), size was remarkably changed in the range of +/-30 nm and zeta-potential was altered (only chitosan coating (molecular weight: 30 000 Da, 0.2%, W/V): 10.3 mV, Alginic acid coating (0.5%, W/V) after the chitosan coating: -21.8 mV). The low molecular weight chitosan (0.1%, W/V)-coated nano-liposomes had a lower absolute value of zeta-potential than the high molecular weight chitosan (0.1%, W/V)-coated nano-liposomes. The encapsulation efficiency was measured by gas chromatography. The efficiency was decreased slightly by elevating chitosan concentration (0.1 to approximately 0.5%, W/V).

Two mechanisms dominate the clinical pipeline for oligonucleotide-based gene silencing, namely, the antisense approach that recruits RNase H to cleave target RNA and the RNAi approach that recruits the RISC complex to cleave target RNA. Multiple chemical designs can be used to elicit each pathway. We compare the silencing of the asthma susceptibility gene ADAM33 in MRC-5 lung fibroblasts using four classes of gene silencing agents, two that use each mechanism: traditional duplex small interfering RNAs (siRNAs), single-stranded small interfering RNAs (ss-siRNAs), locked nucleic acid (LNA) gapmer antisense oligonucleotides (ASOs), and novel hexadecyloxypropyl conjugates of the ASOs. Of these designs, the gapmer ASOs emerged as lead compounds for silencing ADAM33 expression: several gapmer ASOs showed subnanomolar potency when transfected with cationic lipid and low micromolar potency with no toxicity when delivered gymnotically. The preferential susceptibility of ADAM33 mRNA to silencing by RNase H may be related to the high degree of nuclear retention observed for this mRNA. Dynamic light scattering data showed that the hexadecyloxypropyl ASO conjugates self-assemble into clusters. These conjugates showed reduced potency relative to unconjugated ASOs unless the lipophilic tail was conjugated to the ASO using a biocleavable linkage. Finally, based on the lead ASOs from (human) MRC-5 cells, we developed a series of homologous ASOs targeting mouse Adam33 with excellent activity. Our work confirms that ASO-based gene silencing of ADAM33 is a useful tool for asthma research and therapy.

High quality ZnTe epilayers have been grown on semi-insulating GaAs(100) substrates by hot-wall epitaxy, and the photoluminescence characteristics were investigated. The free exciton binding energy is found to be 12.7 meV and the free exciton reduced mass to be 0.095m0 from the clearly resolved excitonic peaks. From the temperature dependence of the free exciton line, the room temperature energy gap of ZnTe epilayer is found to be 2.278 eV. The longitudinal optical phonon energy from the resonance Raman shift is determined as 26.2 meV. The binding energy of the exciton bound to the neutral acceptor is found to be 4.9 meV. The temperature dependence of the bound exciton peak intensity is explained with a two-step thermal quenching mechanism. Deep level emissions such as donor–acceptor pair emission, Y-band, and oxygen-bound emission are also studied.

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The relaxation of strain in the ZnS epilayers grown on (100) GaP was investigated with resonant Raman scattering measurement. The single LO phonon resonant Raman shift and the intensity increased but the full width at half maximum decreased with the increasing ZnS epilayer thickness. These were attributed to the relaxation of the biaxial tensile strain with the generating misfit dislocations. Finally, the critical thickness of ZnS/GaP epilayer was found to be around 35 nm.

The present work demonstrates via numerical analysis that the presence of a thin InGaAs ternary layer around InAs quantum dots (QDs) reinforces the in-plane (εrr) and vertical (εzz) strain components of InAs quantum dots as compared to the QDs embedded directly in GaAs matrix, contrary to the general belief of strain relief. It has been further shown that such reinforced εrr and εzz states yields a decreased band-gap energy, i.e., the experimentally observed redshift in the literature.