Synthesis of a grape-like conductive carbon black/Ag hybrid as the conductive filler for soft silicone rubber

Schematic of the fabrication procedure of SMCB@Ag with the grape-like structure.

Facile Cell-Friendly Hollow-Core Fiber Diffusion-Limited Photofabrication

Bioprinting emerges as a powerful flexible approach for tissue engineering with prospective capability to produce tissue on demand, including biomimetic hollow-core fiber structures. In spite of significance for tissue engineering, hollow-core structures proved difficult to fabricate, with the existing methods limited to multistage, time-consuming, and cumbersome procedures. Here, we report a versatile cell-friendly photopolymerization approach that enables single-step prototyping of hollow-core as well as solid-core hydrogel fibers initially loaded with living cells. This approach was implemented by extruding cell-laden hyaluronic acid glycidyl methacrylate hydrogel directly into aqueous solution containing free radicals generated by continuous blue light photoexcitation of the flavin mononucleotide/triethanolamine photoinitiator. Diffusion of free radicals from the solution to the extruded structure initiated cross-linking of the hydrogel, progressing from the structure surface inwards. Thus, the cross-linked wall is formed and its thickness is limited by penetration of free radicals in the hydrogel volume. After developing in water, the hollow-core fiber is formed with centimeter range of lengths. Amazingly, HaCaT cells embedded in the hydrogel successfully go through the fabrication procedure. The broad size ranges have been demonstrated: from solid core to 6% wall thickness of the outer diameter, which was variable from sub-millimeter to 6 mm, and Young’s modulus ∼1.6 ± 0.4 MPa. This new proof-of-concept fibers photofabrication approach opens lucrative opportunities for facile three-dimensional fabrication of hollow-core biostructures with controllable geometry.

Determination of total protein content in biomedical products by the PDMS-assisted lab-in-a-syringe assay using 3D printed scaffolds removal

The aim of our work was to develop a low-cost, portable device for the fast and easy determination of total protein content by using PDMS-based lab-in-a-syringe technology with removal of 3D-printed channels. We proposed two designs with a one-step PDMS curing and a two-step PDMS-curing fabrication procedure. The one-step PDMS microdevices were found to be the best in the view of preparation, repeatability, and stability of the reagent. This design was then applied for the determination of total protein content in biomedical products using the Bradford assay.

Reduction of reverse leakage current at the TiO2/GaN interface in field plate Ni/Au/n-GaN Schottky diodes

This paper presents the fabrication procedure of TiO2 passivated field plate Schottky diode and gives a comparison of Ni/Au/n-GaN Schottky barrier diodes without field plate and with field plate of varying diameters from 50 to 300 µm. The influence of field oxide (TiO2) on the leakage current of Ni/Au/n-GaN Schottky diode was investigated. This suggests that the TiO2 passivated structure reduces the reverse leakage current of Ni/Au/n-GaN Schottky diode. Also, the reverse leakage current of Ni/Au/n-GaN Schottky diodes decreases as the field plate length increases. The temperature-dependent electrical characteristics of TiO2 passivated field plate Ni/Au/n-GaN Schottky diodes have shown an increase of barrier height within the temperature range 300…475 K.

Bacterial safety study of the production process of hemoglobin-based oxygen carriers

Hemoglobin microparticles (HbMP) produced with a three-step procedure including co-precipitation of hemoglobin with manganese carbonate, protein crosslinking and dissolution of the carbonate template were shown to be suitable for application as artificial oxygen carriers. First preclinical safety investigations delivered promising results. Bacterial safety plays a decisive role during the production of the HbMP. Therefore, bioburden and endotoxin content of the starting materials (especially hemoglobin) and the final particle suspension are intensively tested. However, some bacteria may not have been detected by the standard tests due to low concentration. The aim of this study was to investigate how these bacteria would behave in the fabrication process. Biocidal effects are known for glutaraldehyde and for ethylenediaminetetraacetic acid, chemicals that are used in the fabrication process of HbMP. It could be shown that both chemicals prevent bacterial growth at the concentrations used during the HbMP fabrication. In addition, the particle production was carried out with hemoglobin solutions spiked with Escherichia coli or Staphylococcus epidermidis. No living bacteria could be detected in the final particle suspensions. Therefore, we conclude that the HbMP fabrication procedure is safe in respect of a bacterial contamination.

Antimonene-gold Based Twin-Core SPR Sensor with Side Polished Semi-Arc Groove Dual Sensing Channel: An Investigation with 2D Material

We propose surface plasmon resonance (SPR) based single-side polished photonic crystal fiber (SSP-PCF) sensor for low as well as high refractive index (RI) sensing. To achieve this, an active metal gold (Au) is deposited on the PCF's flat narrow channels to form a dual-sensing channel. Following that, a thin nanolayer antimonene is deposited on Au, as its buckled honeycomb lattice structure aids in the trapping of numerous biomolecules. For the sensing range of 1.27 to 1.39, numerical results show that the wavelength sensitivity (WS) and amplitude sensitivity (AS) mounted on 77000 nmRIU-1 and 1320.41 RIU-1, respectively, with wavelength resolution (RW), and amplitude resolution (RA), as high as 1.298\(\times\)10-6 RIU, and 8.6\(\times\)10-7 RIU. The promising results obtained from the proposed SSP-PCF sensor offers improved refractive index sensing with a fine figure of merit (FOM), i.e., 311.74 RIU-1 for the sensing range of 1.27 to 1.39, which covers most known analytes such as proteins, cancer cells, glucose, viruses, DNA/RNA, medicinal drugs, halogenated organic acids. Further, the proposed sensor's design requires a simple fabrication procedure.

High-throughput acoustofluidic microchannels for single cell rotation

There is a growing desire for cell rotation in the field of biophysics, bioengineering and biomedicine. We herein present novel microfluidic channels for simultaneous high-throughput cell self-rotation using local circular streaming generated by ultrasonic wave excited bubble arrays. The bubble traps achieve high homogeneity of liquid-gas interface by setting capillary valves at the entrances of dead-end bubble trappers orthogonal to the main microchannel. In such a highly uniform bubble array, rotation at different fields of bubble-relevant vortices is considered equal and interconvertible. The device is compatible with cells of various size and retains manageable rotation velocity when actuated by signals of varying frequency and voltage. Experimental observations were confirmed consistent with theoretical estimation and numerical simulation. Comparing with the conventional approaches of cell rotation, our device has multiple merits such as high throughput, low cost and simple fabrication procedure, and high compatibility for lab-on-chip integration. Therefore, the platform holds a promise in cell observation, medicine development and biological detection.

An Assessment of the Influence of Dental Porcelain Slurry Preparation on Flexural Strength of Different Feldspathic Porcelains

Chipping remains a big challenge during the clinical application of glass ceramics in dentistry. The fabrication procedure used affects the mechanical properties of dental feldspathic porcelain and is associated with technical failures. This study aimed to compare the effect of the use of manufacturers’ liquids versus H2O on the flexural strength of glass ceramics. Specimens (n = 120, n = 15 per group) (25 × 4 × 1.2 mm) were obtained using four porcelain powders (Creation CC, IPS InLine, Noritake EX-3, and Vita VM 13). Four groups were produced using porcelain powder and modeling liquid, and four groups using distilled water. The specimens were fired, sintered, and polished. Flexural strength was measured using a universal testing machine. Statistical analyses were conducted using post hoc Tukey’s, two-way ANOVA, and Weibull analysis. Flexural strength values (mean ± SD) of the ceramic-manufacturer’s liquid mixture ranged between 67.2 ± 10.2 and 85.8 ± 12.8 MPA (NR < VT < IV < CR), while flexural strength values of the ceramic–water mixture were between 72.2 ± 6.9 and 95.2 ± 12 MPA (CR < NR < VT < IV). While the choice of the ceramic type significantly affected flexural strength, the use of water vs. manufacturers’ liquid showed in almost all cases no significance. To achieve better flexural strength results, InLine should be used with distilled water mixtures, while all ceramic powders except for Noritake can be used with the manufacturer’s liquid mixtures.

Digital Denture Fabrication: A Technical Note

Fabricating a complete denture in a conventional manner may be complicated and difficult. The purpose of this article was to describe the benefits of a fully digital workflow and fabrication procedure of complete dentures based on digital impressions of edentulous jaws. The digital data for the workflow were acquired using an intraoral scanner and were then used to design the denture base and teeth. The resulting data were exported to a 3D printer or a milling machine for denture fabrication.

Mechanical and Optical Properties of the Experimental and Commercial Dental Composites: A Systematic Review

Highly demand of aesthetic needed made dental composites become a major role as dental restorations. Minimal invasive of sound tissue and the ability to mimic the original teeth also have the recommendation to choose dental composites. The developments of dental composites mostly focus on filler systems to improve mainly in the mechanical and optical properties due to the esthetic aspect of dental care recently has become increasing importance. According to the component of dental composites, the fillers had a big role to determine the properties of dental composite. Many kinds of fillers have been utilized to improve the properties. Two kinds of dental composites had been known based on their fabrication procedure; i.e. experimental and commercial. The experimental dental composites had been produced by the researcher on their formula to obtain good properties while commercial dental composites were made by many manufacturers which have each brand that has each product of excellence, especially in mechanical and optical properties. The aim of this review focused on the mechanical and optical properties of experimental dental composites and commercial dental composites including describes many factors that affect those properties.