Compartmentalization of Gold Nanocrystals in Polymer Microparticles using Electrohydrodynamic Co-Jetting

Polymer particles with micro- and nanoscale anisotropy have received increasing interest for their ability to simultaneously present different physical- and chemical properties. In this communication, we demonstrate that gold nanocrystals (NCs) can be selectively incorporated into one compartment of anisotropic polymer particles. Stable bicompartmental particles were prepared via electrohydrodynamic co-jetting of aqueous nanoparticle suspensions followed by thermal cross-linking. Bicompartmental particle populations with different NC densities were obtained by varying the NC concentration in the jetting suspension. While NC-loaded polymer particles showed different optical properties depending on the NC density, they still maintained discrete interfaces between two compartments. Moreover, the fraction of the bicompartmental particles was higher than 98% based on flow cytometry. This study delineates a new approach for preparation of inorganic/organic composite particles with precisely engineered, anisotropic nanoparticle distributions and may contribute to further developments in emerging scientific areas, such as smart materials or particle-based diagnostics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64928/1/176_ftp.pd

A physiological signal database of children with different special needs for stress recognition

This study presents a new dataset AKTIVES for evaluating the methods for stress detection and game reaction using physiological signals. We collected data from 25 children with obstetric brachial plexus injury, dyslexia, and intellectual disabilities, and typically developed children during game therapy. A wristband was used to record physiological data (blood volume pulse (BVP), electrodermal activity (EDA), and skin temperature (ST)). Furthermore, the facial expressions of children were recorded. Three experts watched the children's videos, and physiological data is labeled "Stress/No Stress" and "Reaction/No Reaction", according to the videos. The technical validation supported high-quality signals and showed consistency between the experts.Scientific and Technological Research Council of Turkey Technology and Innovation Funding Programmes Directorat

Phenological, Pomological and Technological Characteristics of Seedless White Mulberry in Mulberry Genetic Resources of Turkey

This study carried out in 2015 and 2016 to determine phenological, pomological and some technological characteristics of 19 seedless mulberry genotypes of the Malatya Apricot Research Institute. Full-bloom periods of the genotypes varied between 27th of April (Poser 24-07) and 3rd of May (24 MRK 02); start of harvest dates varied between 15th of May (Poser 24-07) and 31st of May (Yediveren 24-08); end of harvest dates varied between 5th of July (Angut 009) and 30th of August (Yediveren 24-08). Fruiting durations varied between 50 days (Angut 009) and 95 days (Gemirgap Dutu 24-05). Of the pomological characteristics, average fruit weights varied between 0.77 g (Angut 009) and 2.46 g (Poser 24-07); water soluble dry matter (WSDM) contents varied between 15.50% (Topu Beyaz 1) and 29.60% (Angut 009). Of the technological characteristics, drying efficiency values varied between 15.79% (44 KE 10) and 39.94% (Angut 009), dry fruit color L values varied between 25.97 (Poser 24-07) and 50.20 (İstanbul Dutu 24-12). Based on present findings, Poser 24-07 genotype was found to be prominent with early fruiting and availability for fresh consumption; Yediveren 24-08 genotype with late fruiting; İstanbul Dutu 24-12 genotype with drying efficiency and Gemirgap Dutu 24-05 and Gemirgap Dutu 24-06 genotypes with their longer fruiting durations. Current findings may be beneficial in mulberry breeding programs

Surface-structure-regulated cell-membrane penetration by monolayer-protected nanoparticles

Nanoscale objects are typically internalized by cells into membrane-bounded endosomes and fail to access the cytosolic cell machinery. Whereas some biomacromolecules may penetrate or fuse with cell membranes without overt membrane disruption, no synthetic material of comparable size has shown this property yet. Cationic nano-objects pass through cell membranes by generating transient holes, a process associated with cytotoxicity. Studies aimed at generating cell-penetrating nanomaterials have focused on the effect of size, shape and composition. Here, we compare membrane penetration by two nanoparticle 'isomers' with similar composition (same hydrophobic content), one coated with subnanometre striations of alternating anionic and hydrophobic groups, and the other coated with the same moieties but in a random distribution. We show that the former particles penetrate the plasma membrane without bilayer disruption, whereas the latter are mostly trapped in endosomes. Our results offer a paradigm for analysing the fundamental problem of cell-membrane-penetrating bio- and macro-molecules

Deterministic encapsulation of single cells in thin tunable microgels for niche modeling and therapeutic delivery

Existing techniques to encapsulate cells into microscale hydrogels generally yield high polymer-to-cell ratios and lack control over the hydrogel’s mechanical properties1. Here, we report a microfluidic-based method for encapsulating single cells in a ~6 micron layer of alginate that increases the proportion of cell-containing microgels by 10-fold, with encapsulation efficiencies over 90%. We show that in vitro cell viability was maintained over a three-day period, that the microgels are mechanically tractable, and that for microscale cell assemblages of encapsulated marrow stromal cells cultured in microwells, osteogenic differentiation of encapsulated cells depends on gel stiffness and cell density. We also show that intravenous injection of singly-encapsulated marrow stromal cells into mice delays clearance kinetics and sustains donor-derived soluble factors in vivo. The encapsulation of single cells in tunable hydrogels should find use in a variety of tissue engineering and regenerative medicine applications

Stability of Surface-Immobilized Lubricant Interfaces under Flow

The stability and longevity of surface-stabilized lubricant layers is a critical question in their application as low- and nonfouling slippery surface treatments in both industry and medicine. Here, we investigate lubricant loss from surfaces under flow in water using both quantitative analysis and visualization, testing the effects of underlying surface type (nanostructured versus flat), as well as flow rate in the physiologically relevant range, lubricant type, and time. We find lubricant losses on the order of only ng/cm2 in a closed system, indicating that these interfaces are relatively stable under the flow conditions tested. No notable differences emerged between surface type, flow rate, lubricant type, or time. However, exposure of the lubricant layers to an air/water interface did significantly increase the amount of lubricant removed from the surface, leading to disruption of the layer. These results may help in the development and design of materials using surface-immobilized lubricant interfaces for repellency under flow conditions.Chemistry and Chemical BiologyEngineering and Applied Science

Hierarchical structures through molecular recognition and self -assembly

Hierarchy and complexity are typical features of many self-assembled biological structures and are emerging as an important characteristic in the development of supramolecular materials. The scientific and technological impact of any new class of mesoscale material depends on the ability to control the size, morphology and aggregate structure of their nanoscale components. Nanoparticles, with their unique size dependent electronic, magnetic and optical properties, can be used as the primary building block for the construction of supramolecular materials. As a secondary component, synthetic polymers utilizing noncovalent interactions can be used for the design and construction of materials with tunable properties. In order to achieve this goal, we have used a reversible polymer side chain modification method and showed that this approach can be used to control the size of nanoparticle aggregates, interparticle spacing between nanoparticles, surface properties and polymer aggregate microstructure