Homogeneous Shape Research Articles

Inelastic effects in bulge formation of inflated polymer tubes.

When a soft tube is inflated, it may sometimes show a bulge instability wherein a portion of the tube inflates much more than the rest. The bulge instability is well-understood for hyperelastic materials. We examine inflation of polyurethane tubes whose material behavior is not strictly hyperelastic. Upon inflating at constant rate, the tubes deform into a variety of shapes including irregular axisymmetric shapes with multiple localized bulges, a single axially-propagating bulge, or homogeneous cylindrical shapes. In all cases regardless of the inflation mode, the pressure first rises to a maximum, and then gradually reduces towards a plateau. We document numerous differences as compared to hyperelastic tubes. Most notably a pressure maximum can appear even without bulging, whereas for hyperelastic tubes, a pressure maximum is necessarily accompanied by bulging. Further, the decrease in pressure beyond the maximum occurs gradually over timescales as long as an hour, whereas bulging of hyperelastic tubes induces an instantaneous drop in pressure. We also observe permanent deformation upon deflation, a decrease in the pressure maximum during a subsequent second inflation, and more severe bulge localization at low inflation rates. Existing theory of hyperelastic tube inflation cannot capture the observed behaviors, even qualitatively. Finite element simulations suggest that many of the observations can be explained by viscoelasticity, specifically that a slow material response allows the pressure to remain high for long durations, which in turn allows growth of multiple bulges.

Preparation of Cellulose Pineapple (Ananas comosus) Peel as Adsorbent of Remazol Yellow Dye

The extraction of cellulose from pineapple (Ananas comosus) peel has been carried out through delignification using alkaline and hydrolysis with acid. The extraction of cellulose was carried out by de-waxing, delignification followed by hydrolysis with H2SO4 acid. The cellulose obtain was identified by FTIR and SEM-EDS. The results showed that the FTIR spectra of pineapple peel cellulose contain hydroxyl and carboxyl functional groups which useful in the adsorption process. The morphology of cellulose has a more homogeneous and porous shape. The cellulose obtained was used for adsorption of Remazol yellow dye by studying adsorption parameters, namely the effect of pH, contact time and solution concentration. The adsorption process was obtained at pH 2, the optimum contact time was 30 minutes and concentration at 100 mg/L with an adsorption capacity is 19.888 mg/g.

Lipidure-based micropattern fabrication for stereotyping cell geometry

Cell autonomous behaviors such as migration and orchestration of cell polarity programs are required for physiological tissue formation. Micropatterns are cell-adhesive shapes that confine cell(s) to a user defined geometry. This biophysical confinement allows researchers to standardize the cell shape, and in doing so, stereotype organelle and cytoskeletal systems that can have an arbitrary organization. Thus, micropatterning can be a powerful tool in interrogation of polarity programs by enforcing a homogenous cell shape and cytoskeletal organization. A major drawback of this approach is the equipment and reagent costs associated with fabrication. Here, we provide a characterization of a compound called Lipidure (2-Methacryloyloxy ethyl phosphorylcholine) that is up to 40X less expensive than other cell repulsive coating agents. We found that Lipidure is an effective cell-repulsive agent for photolithography-based micropattern fabrication. Our results demonstrate that Lipidure is sensitive to deep UV irradiation for photolithography masking, stable in both benchtop and aqueous environments, non-toxic in prolonged culture, and effective at constraining cell geometry for quantification of cytoskeletal systems.

Mask and plate: a scalable front metallization with low-cost potential for III–V-based tandem solar cells enabling 31.6 % conversion efficiency

Low-cost approaches for mass production of III–V-based photovoltaics are highly desired today. For the first time, this work presents industrially relevant mask and plate for front metallization of III–V-based solar cells replacing expensive photolithography. Metal contacts are fabricated by nickel (Ni) electroplating directly onto the solar cell’s front using a precisely structured mask. Inkjet printing offers low-cost and high-precision processing for application of an appropriate plating resist. It covers the solar cell’s front side with narrow openings for subsequent electroplating. The width of the resulting Ni contacts is as low as (10.5 ± 0.8) µm with sharp edges and homogenous shape. The 4 cm2-sized champion III–V-on-silicon triple-junction solar cell with mask and plate front metallization reaches a certified conversion efficiency η of (31.6 ± 1.1) % (AM1.5 g spectrum). It performs just as well as the reference sample with photolithography-structured evaporated front contacts, which reaches η = (31.4 ± 1.1) %.

Design of gefitinib-loaded PLGA microspheres via microfluidics for lung cancer

Lung cancer is one of the most prevalent tumors with rapid progression and poor prognosis, which badly affects human physical and mental health. Although traditional anti-cancer therapies, such as chemotherapy and radiation, have demonstrated some degree of effectiveness in treating tumors, they remain encumbered by the frequent, uncontrollable, and large dosage of drug administration. Here, we introduced the Gefitinib-loaded PLGA microspheres generated from microfluidics for lung cancer therapy. The microspheres had a homogeneous shape and a high drug loading rate. Studies have shown that PLGA microspheres not only provided greater loading efficiency and sustained release of gefitinib but also protected the drug from rapid breakdown. The results of animal experiments also showed that the drug-loaded microspheres could achieve or even outperform the efficiency of daily medication with less frequency. Therefore, it is foreseen that PLGA microspheres will have great potential in developing therapies for lung cancer.

Theory of Photoluminescence Spectral Line Shapes of Semiconductor Nanocrystals.

Single-molecule photoluminescence (PL) spectroscopy of semiconductor nanocrystals (NCs) reveals the nature of exciton-phonon interactions in NCs. Understanding the homogeneous spectral line shapes and their temperature dependence remains an open problem. Here, we develop an atomistic model to describe the PL spectrum of NCs, accounting for excitonic effects, phonon dispersion relations, and exciton-phonon couplings. We validate our model using single-NC measurements on CdSe/CdS NCs from T = 4 to 290 K, and we find that the slightly asymmetric main peak at low temperatures is comprised of a narrow zero-phonon line (ZPL) and acoustic phonon sidebands. Furthermore, we identify the specific phonon modes that give rise to the optical phonon sidebands. At temperatures above 200 K, the spectral line width shows a stronger dependence upon the temperature, which we demonstrate to be correlated with higher order exciton-phonon couplings. We also identify the line width dependence upon reorganization energy, NC core sizes, and shell thicknesses.

Controlled fabrication of novel zirconia nanoparticles with tailored size, morphology, crystal phases, surface properties, and acidity via Indonesian Boehmeria virgata-mediated eco-friendly synthesis

Green synthesis of ZrO2 NPs from plant sources has gained significant attention due to its advantages, such as eco-friendly and low-cost production compared to chemical synthesis methods. The objectives of this work were to study the characteristics of green synthesized ZrO2 NPs using three types of Boehmeria virgata leaf extracts in n-hexane (ZrO2–H), methanol (ZrO2-M), and water (ZrO2–W) at various calcination temperatures (500, 700, and 900 °C). ZrO2 NPs with different structures, morphologies, surface properties, and acidity were fabricated through an eco-friendly synthesis method using three types of Indonesian B. virgata leaf extract at various calcination temperatures. The resulting ZrO2 NPs exhibited monoclinic and tetragonal phases, while a tetragonal-dominated structure was detected on ZrO2–H 700, ZrO2-M 700, and ZrO2-M 900 NPs. SEM images showed that ZrO2–H and ZrO2-M NPs possessed homogenous nanospheres shape, whereas the combination of nanoflakes and nanospheres was observed in ZrO2–W NPs. Based on the analysis of TEM micrographs, the average nanoparticle sizes of ZrO2–H, ZrO2-M, and ZrO2–W at calcination temperatures of 900 °C were determined to be 16.02 nm, 34.63 nm, and 17.63 nm respectively. The formed ZrO2 NPs prepared using BVLEs, exhibited a specific surface area ranging from 11.32 to 58.86 m2/g, a pore volume ranging from 0.058 to 0.183 cm³/g, and a pore diameter ranging from 9.85 to 58.65 nm. The acidity of ZrO2 NPs ranged from 0.0397 mmol/g up to 1.6045 mmol/g. The calcination temperature influenced the XRD crystallite size, surface texture (specific area and porosity), and acidity of ZrO2 NPs mediated by BVLEs. This green and simple synthesis method offers an alternative technique for forming highly valuable ZrO2 NPs compared to chemical synthesis methods.

Manufacturing of High Conductivity, High Strength Pure Copper with Ultrafine Grain Structure

Applications of Copper (Cu) range from small scale applications such as microelectronics interconnects to very large high-powered applications such as railguns. In all these applications, Cu conductivity and ampacity play vital roles. In some applications such as railguns, where Cu also plays a structural role, not only is high conductivity needed, but high strength, high ductility, and high wear resistance are also critical. Current technologies have achieved their full potential for producing better materials. New approaches and technologies are needed to develop superior properties. This research examines a new fabrication approach that is expected to produce Cu with superior mechanical strength, enhanced wear resistance, and increased electrical conductivity. Materials with refined grain structures were obtained by breaking down the coarse-grained Cu particles via cryogenic ball milling, followed by the consolidation of powders using cold isostatic pressing (CIP) and subsequent Continuous Equal Channel Angular Pressing (C-ECAP). The mixture of fine and ultrafine grains, with sizes between 200 nm to 2.5 µm and an average of 500 nm, was formed after ball milling at cryogenic temperatures. Further processing via C-ECAP produced nanostructured Cu with average grain sizes below 50 nm and excellent homogenous equiaxed grain shapes and random orientations. The hardness and tensile strength of the final Cu were approximately 158% and 95% higher than the traditional coarse-grained Cu bar, respectively. This material also displayed a good electrical conductivity rate of 74% International Annealed Copper Standard (IACS), which is comparable to the current Cu materials used in railgun applications.

Gold Particle Analyser: Detection and quantitative assessment of electron microscopy gold probes.

Gold particle probes are an essential electron microscopy tool to examine protein localisation, as well as protein trafficking. They can be introduced into living cells when conjugated to a protein that is endocytosed or to an antibody against a cell surface protein. Alternatively, gold particles can be introduced into fixed cells or tissue when conjugated to antibodies, immunoglobulin binding molecules or chemical probes applied to permeabilised samples or electron microscopy sections. Colloidal gold particles that have not been enlarged through chemical (gold or silver) enhancement are typically spherical and can be prepared in a range of specific sizes, allowing multiple proteins to be localised within a single sample. The typically homogeneous shape and size of the colloidal gold makes them ideal for computer assisted detection and analysis. Here we demonstrate a program developed to automatically identify two sizes of gold particle and perform a range of analyses that includes (i) distribution and cluster analysis; (ii) selection and analysis of gold particles allocated close to or either side of a membrane; (iii) measurement of organelle size; (iv) estimation of the number of gold particles within an aggregate and (v) the detection of chemically enhanced irregular sized and shaped gold particles. We show this easy-to-use program can greatly assist electron microscopists, to reliably and efficiently analyse gold particles within their images.

Dependence of deposition bath temperature for p-electrodeposited-Cu2O onto n-TiO2/ZnO bilayer thin films

The synthesis of semiconductor materials is crucial to produce the best properties of heterojunction thin films solar cell. Titanium dioxide (TiO2) is coupled with zinc oxide (ZnO) to promote high transmittance due to low utilization of the solar spectrum. In this project, p-Cu2O as absorbing layer was deposited onto n-TiO2/ZnO bilayer thin film which acts as window layer in order to complete the device. Several bath temperatures of 30, 40, 50 and 60 °C were manipulated during Linear Sweep Voltammetry (LSV) measurement and electrodeposition process for p-Cu2O thin film. The LSV measurement was employed to determine the potential value and electrochemical properties of p-Cu2O thin film. Based on findings, the suitable deposition potential chosen is − 0.4 V vs Ag/AgCl. The p-Cu2O thin film deposited at bath temperature of 40 °C exhibited the highest diffraction peak intensity in the (111)-preferred plane orientation showing high crystallinity. The surface morphology of homogeneous and well-defined triangular shape with thickness of 4.93μm was observed. The estimated bandgap energy of 1.92 eV acquired indicated to p-Cu2O thin film. The n-TiO2/ZnO bilayer/p-Cu2O heterojunction thin film was successfully fabricated and showed significant electrical rectification properties. Here in, bath temperature influenced to the enhancement of heterointerface growth development in several properties.

Thermodynamically and Kinetically Controlled Nucleation and Growth of Halide Perovskite Single Crystals.

Halide perovskites are ideal for next-generation optical devices and photovoltaics. Although perovskite single-crystals show reproducible optoelectronic properties, significant variations in the crystal size, anisotropy, density, defects, photoluminescence (PL), and carrier lifetime affect the sample properties and device performances. Homogenous size and shape FA/MAPbBr3 single microcrystals (MCs) with controlled edge lengths, crystal densities, PL lifetimes, and PL intensities are prepared by thermodynamically controlling and kinetically separating the crystal nucleation-growth processes using optimum N-cyclohexyl-2-pyrrolidone (CHP) concentration. The crystal growth kinetics at different CHP concentrations and temperatures are estimated spectroscopically by measuring the concentration of Pb (II). High-density cubic MCs with a homogenous size distribution, high PL intensities, and long PL lifetimes are obtained within minutes at high temperatures by the controlled addition of the pyrrolidone derivative. Conversely, the crystal size nonlinearly increases with time at low temperatures. The isotropically grown high-density single crystals at controlled nucleation-growth rates at 190°C with 20% CHP show the highest PL intensity and the longest PL lifetimes. This method offers thermodynamic and kinetic control of perovskite single-crystal growth with shape control.

Preparation of In0.5Sc1.5Mo3O12 nanofibers and its negative thermal expansion property

Orthorhombic In0.5Sc1.5Mo3O12 nanofibers were prepared by electrospinning followed by a heat treatment. The effects of post-annealing temperatures on the phase composition, microstructure and morphology were investigated by XRD, SEM, HRTEM and XPS. Negative thermal expansion (NTE) behaviors of the In0.5Sc1.5Mo3O12 nanofibers were analyzed by high-temperature XRD. Results indicate that the as-prepared In0.5Sc1.5Mo3O12 nanofibers show an amorphous structure with smooth and homogeneous shape. The average diameter of the as-prepared In0.5Sc1.5Mo3O12 nanofibers is around 515 nm. Well crystallized orthorhombic In0.5Sc1.5Mo3O12 nanofibers could be prepared after post-annealing at 550 °C for 2 h with an average diameter of about 192 nm. The crystallinity of In0.5Sc1.5Mo3O12 nanofibers gradually improved with the increase of annealing temperature. However, too high post-annealing temperature leads to a damage of sample's fiber structure. The high-temperature XRD results reveal that In0.5Sc1.5Mo3O12 nanofibers show an anisotropic NTE, and the coefficients of thermal expansion (CTEs) along a-axis and c-axis were −5.95 × 10−6 °C−1 and -3.54 × 10−6 °C−1, while the one along b-axis is 5.61 × 10−6 °C−1. The volumetric CTE of In0.5Sc1.5Mo3O12 nanofibers is −3.90 × 10−6 °C−1 and the linear one is 1.3 × 10−6 °C−1 in 25–700 °C.

Mechanism of nanoparticle aggregation in gas-liquid microfluidic mixing

Using gas-liquid segmented micromixers to prepare nanoparticles that have a homogeneous particle size, controllable shape, and monodispersity advantages. Although nanoparticle aggregation within a microfluid has been shown to be affected by the shear effect, the shear effect triggering conditions in gas-liquid two-phase flow is unclear and the aggregation behavior of nanoparticles under the shear effect is difficult to predict, resulting in uncontrollable physical and chemical properties of nanoparticle aggregates. In this study, a numerical simulation of nanoparticle aggregation in gas-liquid two-phase flow under the shear effect is performed using the CFD-DEM method. Then, the effects of total flow rate, gas-liquid two-phase flow ratio, and particle volume fraction on particle aggregation were analyzed to achieve control of particle aggregation shape and size. Meanwhile, the triggering mechanism of the shear effect and the mechanism of the shear effect on the aggregation of nanoparticles were clarified. The results show that increasing the total flow rate or decreasing the gas-liquid two-phase flow rate ratio can induce the shear effect, which reduces the particle aggregation size and makes the morphology tend to be spherical. Moreover, increasing the particle volume fraction, and total flow rate or decreasing the gas-liquid two-phase flow rate ratio also increases the number of particle collisions and induce interparticle adhesion. Hence, particle adhesion and the shear effect compete with each other and together affect particle aggregation.

Ultra-fast photocatalytic degradation and seed germination of band gap tunable nickel doping ceria nanoparticles

Doping transition metal ions into cerium oxide (CeO2) results in interesting modifications to the material, including an increase in surface area, a high isoelectric point, biocompatibility, greater ionic conductivity, and catalytic activity. Herein, various concentrations (1–5%, 10% and 20%) of nickel (Ni) doped CeO2 nanoparticle have been made by a facile chemical process. Using a variety of cutting-edge analytical techniques, the structural, optical, and photocatalytic properties of undoped and varied concentrations (1–5%, 10%, and 20%) of Ni doped CeO2 nanoparticles have been investigated. Pure cubic fluorite structure with average crystallite sizes in the region of 12–15 nm was determined by X-ray diffraction (XRD) investigation. Transmission electron microscopy (TEM), which revealed highly homogeneous hexagonal shape of the particles with average size of 15 nm, was also used to determine microstructural information. According to the optical absorption, the band gaps of Ni doped and undoped CeO2 nanoparticles were found to be 2.96 eV and 1.95 eV, respectively. When exposed to sunlight, the narrow band gap Ni doped CeO2 nanoparticles worked as an active visible light catalyst to remove the dyes Rose Bengal (RB) and Direct Yellow (DY). The best photodegradation efficiencies for RB and DY dyes were found about 93% and 97%, respectively, using the 5% Ni-doped CeO2 catalyst. The apparent rate constant values of 0.039 for RB and 0.040 min−1 were attained for DY. As well, the treated, untreated dye solution and control solutions were utilized to assess the toxicity of commercially accessible Vigna Radiata seeds. In this study exhibits percentages of length and germination increased by 30–35% when compared to dye pollutant solution. The Ni doped CeO2 can provide a substantial alternative for current industrial waste management because of its quick photocatalytic activity and remarkable seed germination results.

Modeling the Effect of Disorder in the Two-Dimensional Electronic Spectroscopy of Poly-3-hexyltiophene in an Organic Photovoltaic Blend: A Combined Quantum/Classical Approach.

We introduce a first-principles model of the 12-mer poly-3-hexyltiophene (P3HT) polymer system in the realistic description of an organic photovoltaic blend environment. We combine Molecular Dynamics (MD) simulations of a thin-film blend of P3HT and phenyl-C61-butyric acid methyl ester (PCBM) to model the interactions with a fluctuating environment with Time-Dependent Density Functional Theory (TDDFT) calculations to parametrize the effect of the torsional flexibility in the polymer and construct an exciton-type Hamiltonian that describes the photoexcitation of the polymer. This allows us to reveal the presence of different flexibility patterns governed by the torsional angles along the polymer chain which, in the interacting fluctuating environment, control the broadening of the spectral observables. We identify the origin of the homogeneous and inhomogeneous line shape of the simulated optical signals. This is paramount to decipher the spectroscopic nature of the ultrafast electron-transfer process occurring in organic photovoltaic (OPV) materials.

Vancomycin Loaded Amino-Functionalized MCM-48 Mesoporous Silica Nanoparticles as a Promising Drug Carrier in Bone Substitutes for Bacterial Infection Management.

Orthopedic infections due to biofilm formation in biomaterial-based implants have become challenging in bone tissue engineering. In the present study, in vitro antibacterial analysis of amino-functionalized MCM-48 mesoporous silica nanoparticles (AF-MSNs) loaded with vancomycin is analyzed for its potential as a drug carrier for the sustained/controlled release of vancomycin against Staphylococcus aureus. The effective incorporation of vancomycin into the inner core of AF-MSNs was observed by alternation in the absorption frequencies obtained by Fourier transform infrared spectroscopy (FTIR). Dynamic light scattering (DLS) and high resolution-transmission electron microscopy (HR-TEM) results show that all the AF-MSNs had homogeneous spherical shapes with a mean diameter of 165.2 ± 1.25nm, and there is a slight change in the hydrodynamic diameter after vancomycin loading. Furthermore, the zeta potential of all the AF-MSNs (+ 30.5 ± 0.54mV) and AF-MSN/VA (+ 33.3 ± 0.56mV) were positively charged due to effective functionalization with 3-aminopropyl triethoxysilane (APTES). Furthermore, cytotoxicity results show that the AF-MSNs have better biocompatibility than non-functionalized MSNs (p < 0.05), and results prove AF-MSNs loaded with vancomycin show better antibacterial effect against S. aureus than non-functionalized MSNs. Results confirm that bacterial membrane integrity was affected by treatment with AF-MSNs and AF-MSN/VA by staining the treated cells with FDA/PI. Field emission scanning electron microscopy (FESEM) analysis confirmed the shrinkage of bacterial cells and membrane disintegration. Furthermore, these results demonstrate that amino-functionalized MSNs loaded with vancomycin significantly increased the anti-biofilm and biofilm inhibitory effect and can be incorporated with biomaterial-based bone substitutes and bone cement to prevent orthopedic infections post-implantation.

Photocatalytic degradation of PET coupled to green hydrogen generation using flexible Ni2P/TiO2/C nanofiber film catalysts

The increasing accumulation of waste plastics has a range of negative impacts on the land and marine environments. Solar-driven methods of converting waste into useful chemicals and green energy H2 are gaining attention due to their efficiency, stability and low cost. Here, flexible nickel phosphide/titanium dioxide/carbon nanofiber (Ni2P/TiO2/C NFs) film photocatalyst was prepared by electrospinning, heat treatment, hydrothermal method, and phosphate treatment. The obtained Ni2P/TiO2/C NFs presented a continuous homogeneous fibrous shape with TiO2 NPs incorporation into the carbon NFs and Ni2P NPs coating on the surface of the NFs. The film exhibited promising flexibility and excellent light absorption performance. As a result, the Ni2P/TiO2/C NFs film was utilized to reform polyethylene terephthalate (PET) into a variety of organic products and clean energy H2 under alkaline aqueous conditions. In addition, the flexible Ni2P/TiO2/C NFs film could be easily separated from the solution for recycling, and the stable hydrogen production performance was maintained after multiple cycles. This work applies an inexpensive and recyclable composite photocatalyst to the recycling of waste polyester, which is a crucial step towards the practical application of recyclable photocatalysts in resource recovery.

Polysialic acid-functionalized liposomes for efficient honokiol delivery to inhibit breast cancer growth and metastasis

To improve the anti-metastasis effects of honokiol (HNK) on breast cancer, we designed cationic liposomes (Lip) in which HNK was encapsulated into Lip, and its surface was modified with negatively charged polysialic acid (PSA-Lip-HNK) for efficient treatment of breast cancer. PSA-Lip-HNK possessed a homogeneous spherical shape and high encapsulation efficiency. In vitro 4T1 cell experiments indicated that PSA-Lip-HNK increased cellular uptake and cytotoxicity via the endocytosis pathway mediated by PSA and selectin receptors. Furthermore, the significant antitumor metastasis impact of PSA-Lip-HNK was confirmed by wound healing and cell migration and invasion. Enhanced in vivo tumor accumulation of the PSA-Lip-HNK was observed in 4T1 tumor-bearing mice by living fluorescence imaging. For in vivo antitumor experiments using 4T1 tumor-bearing mice, PSA-Lip-HNK exhibited a higher tumor growth and metastasis inhibition compared with unmodified liposomes. Therefore, we believe that PSA-Lip-HNK well combined biocompatible PSA nano-delivery and chemotherapy, providing a promising drug delivery approach for metastatic breast cancer therapy.

Catalytic performance of CoMoW Sulfide catalysts supported on hierarchically structured porous silicas for HDS reactions

In this work, monolithic silica materials with hierarchical porosity were synthesized by the sol-gel method combined with a dual hard-soft templating route. Silica materials were used for the synthesis of hydrodesulfurization CoMoW-S catalysts by the immersion technique using transition metal salts as precursors, followed by oxidation and sulfidation in H2S/H2 mixture. Styrene-HEMA copolymer hard template presented homogeneous well-defined spherical shape with an average diameter of about 800 nm. Samples prepared over the hard template presented similar morphology. The surface areas of all supports prepared resulted in around 800 m2.g−1 and decreased to 220 m2.g−1 on average after the sulfidation process. Small-angle X-ray diffraction confirmed the presence of the 2D hexagonal or Im3m array of mesopores in all samples. The CoMoW oxide state catalysts presented low intensity peaks assigned to the b-CoMo(W)O4 phase and minor peaks related to MoO3 and polyoxides with the general formula MoxW1-xO3. The high conversion was obtained for catalysts supported on hierarchically structured porous silicas, even greater than that of the commercial catalyst used as reference (>30–50%). XPS results revealed that the degree of sulfidation and CoMoWS active species resulted higher in the CoMoW-HOPSCM catalyst compared to the CoMoW-MoNoSBA-15 sample, which in turn coincides with the catalytic activity results.

High order assembly of multiple protein cages with homogeneous sizes and shapes via limited cage surface engineering.

Protein cages are attractive building blocks to build high order materials such as 3D cage lattices, which offer accurately ordered bio-templates. However, controlling the size or valency of these cage-to-cage assemblies is extremely difficult due to highly multivalent and symmetric cage structures. Here, various high order cage assemblies with homogeneous sizes and geometries are constructed by developing an anisotropic ferritin cage with limitedly exposed binding modules, leucine zipper. The anisotropic ferritin is produced as expressed in cells without the need of complex in vitro cage fabrication by careful subunit manipulation. Ferritin cages with limitedly exposed zippers are assembled around a core ferritin with fully exposed opposing zippers, generating homogeneous high order structures, whereas two fully exposed ferritins are assembled into heterogeneous cage aggregates. Diverse fully exposed core cages are prepared by varying the zipper-ferritin fusion geometries and even by using larger cage structures. With these core cages and the anisotropic ferritin, a range of high order cage assemblies with diverse ferritin valencies (3 to over 12) and sizes (over 40 nm) are created. Cell surface binding and internalization of cage structures are greatly varied by assembly sizes, where high order ferritins are clearly more effective than monomeric ferritin.