For the fast droplet transportation on an open surface, a new magnetic elastomer with a superhydrophobic surface has been developed. Because the surface is superhydrophobic, the water droplet can easily roll off on the surface. The movement of the droplet was controlled by a deliberate local deformation of the surface of the elastomer induced by magnetic actuation. The direction and speed of the droplet motion was easily controlled by changing the surface topography using magnetic force. We also demonstrate the applicability of the devices as a new type of open-surface digital microfluidics using a simple chemical reaction.
Zinc oxide (ZnO) and cerium oxide (CeO2) nanoparticles were deposited on the surface of preformed silica spheres with diameters ranging from 60 to 750 nm. Ultrasonic irradiation was employed to promote the deposition of the metal oxide nanoparticles on the surface of silica. Silica-supported zinc oxide or cerium oxide was used as a catalyst in the glycolysis of polyethylene terephthalate, one of the key processes in the depolymerization of polyethylene terephthalate. The effect of the support size on the catalytic activity was studied in terms of monomer yield, and the monomer concentration was analyzed via high-performance liquid chromatography (HPLC). The morphologies and surface properties of the catalysts were characterized using a scanning electron microscope, a transmission electron microscope, and a BET surface area analyzer, while the monomer was characterized via HPLC and nuclear-magnetic-resonance spectroscopy. Both the zinc oxide and cerium oxide deposited on a smaller support showed better distribution and less aggregation. The high specific surface area of the smaller support catalysts provided a large number of active sites. The highest monomer yield was obtained with a catalyst of 60-nm silica support.
Silica nanorods were successfully prepared through a sol-gel process in the presence of carboxylic-functionalized single-walled carbon nanotubes (C-SWCNTs). The effect of chemical functionalization of single-walled carbon nanotubes (SWCNTs) on the growth of the silica layer was investigated using pristine SWCNTs (P-SWCNTs) and C-SWCNTS. The C-SWCNTs served as a unique template to fabricate silica hybrid composite materials. The crystalline formation and growing mechanism of the silica layer on C-SWCNTs were explained by the hydrolysis and chemical bonding between silica precursors and carboxylated SWCNTs. The C-SWCNTs, as templates, were successfully encapsulated using silica, and used templates were removed by oxidation at high temperature. Finally, silica nanorods/nanowires were synthesized in forms of mold, and this silica fabrication mechanism could be applied for large-scale production of silica nanomaterials and highly flexible nanocomposites. The sequence of a silica encapsulation process of C-SWCNTs and removed C-SWCNTs was characterized using SEM, TEM, EDX, FT-IR and Raman spectroscopy, XRD, and electrical analysis.
Fluorescent silica nanoparticles deposited with highly monodisperse gold nanoparticles (1-2 nm) were synthesized via the W/O method and intensive ultrasound irradiation. A large surface area of gold-doped fluorescent silica nanoparticle serves as a platform to immobilize a specific binding protein for biomolecules interaction in bioimaging applications.
A Reduced reduced graphene oxide (RGO)-gold (Au) nanoparticle (NP) nanocomposite was synthesized by simultaneously reducing the Au ions and depositing Au NPs on onto the surface surface of the RGOsRGO simultaneously. To facilitate the reduction of Au ions and the generation of oxygen functionalities for anchoring the Au NPs on the RGOsRGO, ultrasound irradiation was applied to the mixture of reactants. The functional groups were investigated with FT-IR spectra. From the Raman and XPS spectra, the oxygen groups were identified as hydroxyl, epoxy, and carboxyl groups, the same as the one from graphene oxide (GO). As a result, the dense and uniform deposition of nanometer-sized Au NPs with nanometer size was observed on the RGO sheets sheet was observed with from the TEM imagesimage. The Oxygen oxygen functional groups that formed on the surface surface of the RGOs RGO seemed to have served serve as links for Au NPs NP attachment, through the electrostatic attraction of Au ions. Hybrid materials could thus be produced in a short time, with a high yield, by via ultrasound application. Besides, it ultrasound application could can readily take goldAu- binding- peptide (GBP)-modified biomolecules, readily implying its possibility in possible biological applications.
A new method is proposed for the fabrication of fluorescence-labeled and amine-modified silica nanoparticles for application as nonviral vectors in gene delivery. Highly monodisperse, stable fluorescent silica nanoparticles were prepared using 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene and the water-in-oil microemulsion method. The green-fluorescent-protein gene can be easily combined onto the positively charged surfaces of nanoparticles to form a nanoparticle-DNA complex. The nanoparticle-DNA complex successfully passed through various barriers into the HeLa and HEK 293 K cells. The cytotoxicity of the PEI-coated and BBOT-encapsulated silica nanoparticles on both the HeLa and HEK 293T cell lines was found to be at an acceptable level for use as gene carriers when the particle concentration was below 125 microg/ml. The fluorescence intracellular images confirm the successful delivery of the nanoparticle-DNA complex and gene expression. The present work suggests the potential use of dye-incorporated silica nanoparticles in nonviral gene delivery.
Liposomes are small lipid vesicles that mimic biological membranes and have been spotlighted in the clinical field due to their ability to enclose a biologically active substance of any structure and to release it into the host's body. This study compares the physicochemical properties and biological activity of nano-liposomes with different compositions to determine the most effective formulation for further in vivo application. Nano-scale liposomes composed of different ratios of 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), dihexadecyl phosphate (DCP), and cholesterol (Chol): DMPE, DMPE/DCP, DMPE/Chol, and DMPE/DCP/Chol were produced. The thermal phase transition was assessed via differential scanning calorimetry (DSC); the particle size, via dynamic light scattering (DLS); the colloidal stability, via the zeta potential; the direct morphological characterization, via transmission electron microscopy (TEM); and the protein encapsulation efficiency. The bioavailability was also investigated with respect to the immunological responses via porcine interferon gamma (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay in peripheral blood mononuclear cells (PBMC) of immunocompetent pigs. All the liposomes can be expected to be stable in an in vivo physiological temperature, and the liposomes that were prepared from DMPE/DCP showed the best efficiency in the in vitro model that mimicked the release of a bioactive substance in vivo. In the result of DLS and the zeta potential for the investigation of the colloidal stability in the system, DMPE/DCP/Chol appeared better than the other formulations. The porcine IFN-gamma ELISPOT assay results postulated that DMPE/DCP most potently induced the IFN-gamma secretion by PBMC, followed by DMPE/DCP/Chol and DMPE alone, in that order.
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