Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate’s properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

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In this study, the fabrication of a metal oxide nanoparticles (NPs) dispersed catalytic electrode is described based on a new alternating current (AC) plasma deposition approach. The fabrication involves the treatment of AC plasma on a precursor solution comprised of metal salts such as CuCl 2 , FeCl 2 , and ZnCl 2 , and a monomer (acrylic acid) in the presence/absence of a cross-linker. Furthermore, the utility of such developed electrodes has been demonstrated for the electrochemical determination of hydrogen peroxide (H 2 O 2 ). The electrode materials obtained through plasma treatment was characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), contact angle measurements, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry. Among the metal oxide modified electrodes prepared by the AC plasma deposition method, the copper oxide (CuO) NPs catalytic electrode exhibited significant oxidation and reduction peaks for H 2 O 2 in phosphate-buffered saline solution. The catalytic electrode with CuO NPs exhibited a combination of good H 2 O 2 sensing characteristics such as good sensitivity (63.52 mA M −1 cm −2 ), good selectivity, low detection limits (0.6 µM), fast sensing response (5 s), a wide linear range (0.5-8.5 mM), and good stability over 120 cycles. Based on our results, it is well demonstrated that plasma deposition could be effectively utilized for the fabrication of the catalytic electrode for detection of H 2 O 2 concentrations. Further, the strategy of using AC plasma for fabrication of metal oxide-based modified electrodes could also be extended for the fabrication of other kinds of nanomaterials-based sensors.Catalysts 2019, 9, 888 2 of 16 selectivity, and high sensitivity [5][6][7][8][9][10]. It must be noted that a variety of electrochemical H 2 O 2 sensors reported in literature are predominantly based on enzymes. Knowing the intrinsic disadvantages of enzyme-based electrochemical sensors, non-enzymatic H 2 O 2 sensors are receiving considerable interest in recent years due to their advantages such as low cost, high stability, prompt response, ultra-low detection limit, and excellent sensitivity. Non-enzymatic electrochemical H 2 O 2 sensors are designed based on H 2 O 2 electro-oxidation/electroreduction and thus require electrocatalytic materials. Therefore, development of new electrode materials with high catalytic activity and catalytic stability is continuously being given priority and utmost importance.Several metal oxide nanostructures [11][12][13][14][15][16][17] have been utilized to modify the surface of electrodes and were demonstrated to exhibit excellent redox capabilities towards detection of H 2 O 2 with high reaction activity, catalytic efficiency, strong absorption ability, and low cost [18,19]. Particularly, copper oxide (CuO) has been extensively used in non-enzymatic electrochemical sensors, due to its excellent electrochemical properties (proper redox potentials), catalytic propert...

Carbon black (CB) particles tend to aggregate in aqueous solutions, and finding an optimum dispersing condition (e.g., selection of the type of dispersant) is one of the important tasks in related industries. In the present study, three types of styrene maleic acid (SMA) copolymer dispersants were synthesized, labeled respectively ‘SMA-1000’, ‘SMA-2000’, and ‘SMA-3000’, which have 1, 2, and 3 styrene groups in their repeating units. Then, asymmetrical flow field-flow fractionation (AsFlFFF) was employed to measure the particle size distributions of the aqueous CB dispersions. For the particle size analysis of the CB dispersions, dynamic light scattering (DLS) showed relatively lower reproducibility than AsFlFFF. AsFlFFF showed that the use of SMA-3000 yielded a CB dispersion with the most uniform particle size distribution. When the SMA-3000 dispersant was used, the particle size tended to increase after 1 h of milling as the milling time increased, probably due to the re-agglomeration of the particles by excessive milling. The particle size distributions from AsFlFFF were consistent with the colorimetric observations. With the SMA-3000 dispersant, the lowest L∗ value was observed after 1 h of milling. The AsFlFFF and colorimetric analyses suggest that a stable CB dispersion can be obtained by either 3-h of milling with the SMA-2000 or 1-h of milling with the SMA-3000.

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