Translocation of positively and negatively charged polystyrene nanoparticles in an in vitro placental model

AbstractTo obtain insight in translocation of nanoparticles across the placental barrier, translocation was studied for one positively and two negatively charged polystyrene nanoparticles (PS-NPs) of similar size in an in vitro model. The model consisted of BeWo b30 cells, derived from a human choriocarcinoma grown on a transwell insert forming a cell layer that separates an apical from a basolateral compartment. PS-NPs were characterized with respect to size, surface charge, morphology and protein corona. Translocation of PS-NPs was not related to PS-NP charge. Two PS-NPs were translocated across the BeWo transwell model to a lower extent than amoxicillin, a model compound known to be translocated over the placental barrier to only a limited extent, whereas one PS-NP showed a slightly higher translocation. Studies on the effect of transporter inhibitors on the translocation of the PS-NPs indicated that their translocation was not mediated by known transporters and mainly dependent on passive diffusion. It is concluded that the BeWo b30 model can be used as an efficient method to get an initial qualitative impression about the capacity of NPs to translocate across the placental barrier and set priorities in further in vivo studies on translocation of NPs to the fetus

PERANAN WEBSITE DALAM AKTIVITAS PUBLIC RELATIONS SEBAGAI MEDIA PENGHUBUNG ANTARA MASYARAKAT DAN PEMERINTAH DI DISHUBKOMINFO KARANGANYAR

SUMMARY Ni Nyoman Ayu A.W, D1613067, Public Relations, Utilization Website Functions in Public Relations Activities as Media Communicator between the Community and the Government in Dishubkominfo Karanganyar, 2016. Kuliah Kerja Media (KKM) or we called Job Training do it by the author in Dishubkominfo Karanganyar. The reason why the author chose Dishubkominfo Karanganyar as a job training (KKM) in the field of communication and information technology, especially because it looks a lot of public relations activities or practice public speaking especially between government Karanganyar Regent and his Deputy with a lot of community. Here Public Relations is a communication method that is where the various forms of communication. Which in Punlic Relations that there is an attempt to realize the harmonious relationship between an organization and its publics. Public Relations is a deliberate effort, planned on an on going basis to create mutual understanding between an institution / organization with the public. Public Relations can also be regarded as an art as well as social science of analyzing trends, predicting their consequences, briefed the leaders of the institution / organization and implementing planned programs to meet the interests of both the institution / organization and the people involved. At the time of the job training writers do a lot of practice public relations or public relations starting from routine activities for official that morning assembly, socializing with office workers, mutual coordination with staff-related staff, and lobbied with related parties participating in activities , documenting coverage and must maintain good relations between the internal and external Dishubkominfo Karanganyar District. Even job training is very useful for writing because it can prepare for the world of work that requires professional workers and authors directly to gain knowledge related to the field of public relations in order practices. Based on reports from the job training the institution Dishubkominfo Karangayar District, the authors conclude that public relations activities are vital to maintaining good relations between the internal and external Dishubkominfo Karanganyar District

Highly cooperative stress relaxation in two-dimensional soft colloidal crystals

Stress relaxation in crystalline solids is mediated by the formation and diffusion of defects. Although it iswell established how externally generated stresses relax, through the proliferation and motion of dislocations in the lattice, it remains relatively unknown how crystals cope with internal stresses. We investigate, both experimentally and in simulations, how highly localized stresses relax in 2D soft colloidal crystals.When a single particle is actively excited, bymeans of optical tweezing, a rich variety of highly collective stress relaxation mechanisms results. These relaxation processes manifest in the form of open strings of cooperatively moving particles through the motion of dissociated vacancy-interstitial pairs, and closed loops of mobile particles, which either result from cooperative rotations in transiently generated circular grain boundaries or through the closure of an open string by annihilation of a vacancy-interstitial pair. Surprisingly, we find that the same collective events occur in crystals that are excited by thermal fluctuations alone; a large thermal agitation inside the crystal lattice can trigger the irreversible displacements of hundreds of particles. Our results illustrate how local stresses can induce largescale cooperative dynamics in 2D soft colloidal crystals and shed light on the stabilization mechanisms in ultrasoft crystals

Nanoparticle-templated formation and growth mechanism of curved protein polymer fibrils

We investigated the growth of biosynthetic protein polymers with templated curvature on pluronic nanospheres. The protein has a central silk-like block containing glutamic residues (SE) and collagen-like end-blocks (C). The SE blocks stack into filaments when their charge is removed (pH <5). Indeed, at low pH curved and circular fibers are formed at the surface of the nanospheres, which keep their shape after removal of the pluronics. The data reveal the mechanism of the templated fibril-growth: The growth of protein assemblies is nucleated in solution; small protein fibrils adsorb on the nanospheres, presumably due to hydrogen bond formation between the silk-like blocks and the pluronic PEO blocks. The surface of the pluronic particles templates further growth. At relatively low protein/pluronic weight ratios, only a fraction of the nanospheres bears protein fibers, pointing to a limiting amount of nuclei in solution. Because the nanospheres capture fibrils at an early stage of growth, they can be used to separate growth and nucleation rates in protein fibril formation. Moreover, the nanoparticle-templated growth of stable curved fibers opens ways to build proteinaceous nanocapsules from designed protein polymers</p

Self-Assembly of Poly(ferrocenyldimethylsilane-b-methyl methacrylate) Block Copolymers in a Selective Solvent\ud

The self-assembly of poly(ferrocenyldimethylsilane-b-methyl methacrylate) block copolymers, with PFDMS contents of 9−61 wt % (block ratios 1:23−1:1.5), is described. PFDMS-b-PMMA block copolymers form remarkable cylindrical micelles with very narrow diameter distributions at block ratios in the range of 1:10−1:6 (18−26 wt % PFDMS) in the block-selective solvent acetone, which is a good solvent for PMMA and a nonsolvent for PFDMS. The micelles, with a PFDMS core and a PMMA corona, were studied in solution by means of dynamic light scattering, 1H NMR spectroscopy, and cryo-transmission electron microscopy. Micelles were also deposited on silicon substrates by dip-coating and characterized with atomic force microscopy and scanning electron microscopy. The micelles were over 3 μm long and had an overall diameter of around 22 nm. Dynamic light scattering experiments confirmed the formation of rodlike micellar aggregates in acetone. The cylindrical micelles exhibited a rod-to-sphere transition around 60 °C. When cooled below this transition temperature, the micelles reassembled back to their original aggregation state. Depolarized DLS experiments showed no rotational contribution to the measured decays of the autocorrelation functions. We ascribe this to the extreme length of the micelles, which arrests rotational movement. 1H NMR spectra recorded in acetone-d6 showed PFDMS signals, indicating that these blocks in the micellar cores have some mobility. This suggests that the cores are not in a crystalline state and that crystallization is not a driving force in the formation of these PFDMS-b-PMMA cylindrical micelles, but rather the contrast in solvophilicity between the blocks, which in the bulk are in the strong segregation limit. \u

Design of triphasic poly(lactic-co-glycolic acid) nanoparticles containing a perfluorocarbon phase for biomedical applications

Poly(lactic-co-glycolic acid) (PLGA) particles are very widely used, particularly for drug delivery, including commercial clinical formulations. Adding perfluorocarbon (PFC) enables in vivo imaging and quantification of the PLGA particles through 19F NMR, MRS or MRI. PFCs are both hydrophobic and lipophobic at the same time. This property makes their encapsulation in particles challenging, as it requires the addition of a third immiscible phase during the emulsification process. Here we explore how different parameters affect the miniemulsion formation of particles loaded with perfluoro-15-crown-5-ether (PFCE). By changing the concentration of surfactant and type of solvent, we were able to control the radius of synthesized particles, between 85-200 nm. We assessed stability and release from the particles at different pH values, showing that hydrophobic agents are released from the particles by diffusion rather than degradation. With cell experiments, we show that primary human dendritic cells take up the particles without any apparent effect, including on cell migration. In summary, the control of synthesis conditions leads to particles with sufficient PFCE encapsulation, which are suitable for drug loading and cell labeling, and do not affect cell viability or functionality. Finally, these nanoparticles can be produced at GMP-grade for clinical use

Encapsulation of GFP in Complex Coacervate Core Micelles

Protein encapsulation with polymers has a high potential for drug delivery, enzyme protection and stabilization. Formation of such structures can be achieved by the use of polyelectrolytes to generate so-called complex coacervate core micelles (C3Ms). Here, encapsulation of enhanced green fluorescent protein (EGFP) was investigated using a cationic-neutral diblock copolymer of two different sizes: poly­(2-methyl-vinyl-pyridinium)₄₁-<i>b</i>-poly­(ethylene-oxide)₂₀₅ and poly­(2-methyl-vinyl-pyridinium)₁₂₈-<i>b</i>-poly­(ethylene-oxide)₄₇₇. Dynamic light scattering and fluorescence correlation spectroscopy (FCS) revealed a preferred micellar composition (PMC) with a positive charge composition of 0.65 for both diblock copolymers and micellar hydrodynamic radii of approximately 34 nm. FCS data show that at the PMC, C3Ms are formed above 100 nM EGFP, independent of polymer length. Mixtures of EGFP and nonfluorescent GFP were used to quantify the amount of GFP molecules per C3M, resulting in approximately 450 GFPs encapsulated per micelle. This study shows that FCS can be successfully applied for the characterization of protein-containing C3Ms

Monodisperse polymer-virus hybrid nanoparticles

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Multicore Liquid Perfluorocarbon-Loaded Multimodal Nanoparticles for Stable Ultrasound and ¹⁹F MRI Applied to In Vivo Cell Tracking

Ultrasound is the most commonly used clinical imaging modality. However, in applications requiring cell-labeling, the large size and short active lifetime of ultrasound contrast agents limit their longitudinal use. Here, 100 nm radius, clinically applicable, polymeric nanoparticles containing a liquid perfluorocarbon, which enhance ultrasound contrast during repeated ultrasound imaging over the course of at least 48 h, are described. The perfluorocarbon enables monitoring the nanoparticles with quantitative 19 F magnetic resonance imaging, making these particles effective multimodal imaging agents. Unlike typical core–shell perfluorocarbon-based ultrasound contrast agents, these nanoparticles have an atypical fractal internal structure. The nonvaporizing highly hydrophobic perfluorocarbon forms multiple cores within the polymeric matrix and is, surprisingly, hydrated with water, as determined from small-angle neutron scattering and nuclear magnetic resonance spectroscopy. Finally, the nanoparticles are used to image therapeutic dendritic cells with ultrasound in vivo, as well as with 19 F MRI and fluorescence imaging, demonstrating their potential for long-term in vivo multimodal imaging. </p

Multicore Liquid Perfluorocarbon-Loaded Multimodal Nanoparticles for Stable Ultrasound and ¹⁹F MRI Applied to In Vivo Cell Tracking

Ultrasound is the most commonly used clinical imaging modality. However, in applications requiring cell-labeling, the large size and short active lifetime of ultrasound contrast agents limit their longitudinal use. Here, 100 nm radius, clinically applicable, polymeric nanoparticles containing a liquid perfluorocarbon, which enhance ultrasound contrast during repeated ultrasound imaging over the course of at least 48 h, are described. The perfluorocarbon enables monitoring the nanoparticles with quantitative 19 F magnetic resonance imaging, making these particles effective multimodal imaging agents. Unlike typical core–shell perfluorocarbon-based ultrasound contrast agents, these nanoparticles have an atypical fractal internal structure. The nonvaporizing highly hydrophobic perfluorocarbon forms multiple cores within the polymeric matrix and is, surprisingly, hydrated with water, as determined from small-angle neutron scattering and nuclear magnetic resonance spectroscopy. Finally, the nanoparticles are used to image therapeutic dendritic cells with ultrasound in vivo, as well as with 19 F MRI and fluorescence imaging, demonstrating their potential for long-term in vivo multimodal imaging. </p