DESIGN AND EXPERIMENT OF A NEW ROTARY COATING MACHINE BASED ON LabVIEW

In view of the problems of long coating time, complicated manual operation, high multi-seed rate of coated seeds, low qualified rate, and low degree of automation of control equipment in traditional rotary coating machine, a new type of rotary coating machine was designed while using LabVIEW with a complete electric control system, which can effectively improve the speed and quality of coating. The system uses single-chip microcomputer as the lower computer, LabVIEW as the upper computer, and uses programming electronic control technology to set seed coating parameters in advance, precisely control each part and achieve precise supply. Batch supply of powder and liquid greatly improves the automation and intelligence of the operating system, improves the coating efficiency, reduces the multi-seed rate and the seedless rate, and increases the coating pass rate. In order to improve the coating quality and the supply accuracy of the coating machine, the error analysis and calibration test of the seed supply system, powder supply system and liquid supply system were carried out. After the test verification, the supply error was controlled within 2% to meet the demand for precise supply. The test results show that the pass rate of the seeds coated by the new rotary coating machine is increased by 15% to 20% compared with the seeds coated by the traditional manual coating.

Facilitating GL13K Peptide Grafting on Polyetheretherketone via 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide: Surface Properties and Antibacterial Activity

In the present work, the antimicrobial peptide (AMP) of GL13K was successfully coated onto a polyetheretherketone (PEEK) substrate to investigate its antibacterial activities against Staphylococcus aureus (S. aureus) bacteria. To improve the coating efficiency, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was mixed with a GL13K solution and coated on the PEEK surface for comparison. Both energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) data confirmed 30% greater peptide coating on PEEK/GL13K-EDC than PEEK without EDC treatment. The GL13K graft levels are depicted in the micrograms per square centimeter range. The PEEK/GL13K-EDC sample showed a smoother and lower roughness (Rq of 0.530 µm) than the PEEK/GL13K (0.634 µm) and PEEK (0.697 µm) samples. The surface of the PEEK/GL13K-EDC was more hydrophilic (with a water contact angle of 24°) than the PEEK/GL13K (40°) and pure PEEK (89°) samples. The pure PEEK disc did not exhibit any inhibition zone against S. aureus. After peptide coating, the samples demonstrated significant zones of inhibition: 28 mm and 25 mm for the PEEK/GL13K-EDC and PEEK/GL13K samples, respectively. The bacteria-challenged PEEK sample showed numerous bacteria clusters, whereas PEEK/GL13K contained a little bacteria and PEEK/GL13K-EDC had no bacterial attachment. The results confirm that the GL13K peptide coating was able to induce antibacterial and biofilm-inhibitory effects. To the best of our knowledge, this is the first report of successful GL13K peptide grafting on a PEEK substrate via EDC coupling. The present work illustrates a facile and promising coating technique for a polymeric surface to provide bactericidal activity and biofilm resistance to medical implantable devices.

Optimization of critical parameters for coating of polymeric nanoparticles with plasma membrane vesicles by sonication

Top-down functionalization of nanoparticles with cellular membranes imparts nanoparticles with enhanced bio-interfacing capabilities. Initial methods for membrane coating involved physical co-extrusion of nanoparticles and membrane vesicles through a porous membrane; however, recent works employ sonication as the disruptive force to reform membranes around the surface of nanoparticles. Although sonication is widely used, there remains a paucity of information on the effects of sonication variables on coating efficiency, leading to inconsistent membrane coating across studies. In this work, we present a systematic analysis of the sonication parameters that influence the membrane coating. The results showed that sonication amplitude, time, temperature, membrane ratio, sample volume, and density need to be considered in order to optimize membrane coating of polymeric nanoparticles.

Influence of mechanical deflector assisted electroless nickel deposits for wear resistance

This investigation reports the effect of mechanical deflector during coating on the mechanical properties of the Electroless Ni-P deposits. Micro hardness of the electroless Ni-P deposits was measured using shimadzu micro hardness measuring unit employing a diamond indenter and pin-on-disc wear tester was used to measure the wear resistance of the deposits. The characteristics of deposits produced in presence of mechanical deflector are found to be superior from those produced using conventional deposition techniques. Enhancement in properties are correlated with modified crystallinity and the conversion of Ni-P in to possible phosphides in the presence of mechanical deflector. It has been noticed that the coating efficiency has 30% hike with mechanical deflector. Annealing at 350ºC has reached the maximum hardness of 950 Hv and subsequent increase in wear resistance.

Development of Antimicrobial CuO/(3-aminopropyl)Triethoxysilane Activated Carbon Fiber

CuO nanoparticles (NPs) have been used for the antimicrobial agent against different pathogenic microorganisms. In this study, CuO NPs are immobilized on the surface of activated carbon fiber (ACF) with the enhancement of (3-aminopropyl)triethoxysilane (APTES) as an organic binder. The obtained fibers are evaluated by coating efficiency, structural deformation, and antimicrobial activities. In the results, APTES can improve the immobilization of CuO on the surface of ACF. Also, the curing of silane layers at high temperature leads to the high coating efficiencies as well as structural reinforcement. The samples with drying step after APTES coating step (denoted as DA-CuO) have the highest antimicrobial activity against both Escherichia coli and Staphylococcus aureus after 24 hours treatment, respectively.

Affinity Tag Coating Enables Reliable Detection of Antigen-Specific B Cells in Immunospot Assays

Assessment of humoral immunity to SARS-CoV-2 and other infectious agents is typically restricted to detecting antigen-specific antibodies in the serum. Rarely does immune monitoring entail assessment of the memory B-cell compartment itself, although it is these cells that engage in secondary antibody responses capable of mediating immune protection when pre-existing antibodies fail to prevent re-infection. There are few techniques that are capable of detecting rare antigen-specific B cells while also providing information regarding their relative abundance, class/subclass usage and functional affinity. In theory, the ELISPOT/FluoroSpot (collectively ImmunoSpot) assay platform is ideally suited for antigen-specific B-cell assessments since it provides this information at single-cell resolution for individual antibody-secreting cells (ASC). Here, we tested the hypothesis that antigen-coating efficiency could be universally improved across a diverse set of viral antigens if the standard direct (non-specific, low affinity) antigen absorption to the membrane was substituted by high-affinity capture. Specifically, we report an enhancement in assay sensitivity and a reduction in required protein concentrations through the capture of recombinant proteins via their encoded hexahistidine (6XHis) affinity tag. Affinity tag antigen coating enabled detection of SARS-CoV-2 Spike receptor binding domain (RBD)-reactive ASC, and also significantly improved assay performance using additional control antigens. Collectively, establishment of a universal antigen-coating approach streamlines characterization of the memory B-cell compartment after SARS-CoV-2 infection or COVID-19 vaccinations, and facilitates high-throughput immune-monitoring efforts of large donor cohorts in general.

Development of Antimicrobial MgO–CuO/Activated Carbon Fiber

Activated carbon fiber (ACF) is widely used as an adsorption fiber in air purification systems. In this study, MgO and CuO nanoparticles were immobilized on ACF with enhancement of (3-aminopropyl)triethoxysilane (APTES). The obtained fibers’ coating efficiency, structural deformation, and antimicrobial activities were investigated. The MgO–CuO/APTES/ACF fiber (DA-MC) sample showed high antimicrobial activity (<90%) against both Escherichia coli and Staphylococcus aureus after 24-hour treatment. DA-MC also showed the highest coating efficiency, with no observed structural deformation. The presence of APTES and curing step at high temperature is believed to increase the coating efficiency and thus result in the high antimicrobial activity and also protect the ACF from deformation.

Affinity tag coating enables reliable detection of antigen-specific B cells in ImmunoSpot assays

Assessment of humoral immunity to SARS-CoV-2 and other infectious agents is typically restricted to detecting antigen-specific antibody in the serum. Rarely does immune monitoring entail assessment of the memory B cell compartment itself, although it is these cells that engage in secondary antibody responses capable of mediating immune protection when pre-existing antibodies fail to prevent re-infection. There are few techniques that are capable of detecting rare antigen-specific B cells while also providing information regarding their precursory frequency, class/subclass usage and functional affinity. In theory, the ELISPOT/FluoroSpot (collectively ImmunoSpot) assay platform is ideally-suited for antigen-specific B cell assessments since it provides this information at single-cell resolution for individual antibody-secreting cells (ASC). Here, we tested the hypothesis that antigen coating efficiency could be universally improved across a diverse set of viral antigens if the standard direct (non-specific, low affinity) antigen absorption to the membrane was substituted by high affinity capture. Specifically, we report an enhancement in assay sensitivity and a reduction in required protein concentrations through the capture of recombinant proteins via their encoded hexahistidine (6XHis) affinity tag. Affinity tag antigen coating enabled detection of SARS-CoV-2 Spike receptor binding domain (RBD)-reactive ASC, and also significantly improved assay performance using additional control antigens. Collectively, establishment of a universal antigen coating approach streamlines characterization of the memory B cell compartment after SARS-CoV-2 infection or COVID-19 vaccinations, and facilitates high-throughput immune monitoring efforts of large donor cohorts in general.

Efficient Surface Immobilization of Chemically Modified Hyaluronans for Enhanced Bioactivity and Survival of In Vitro-Cultured Embryonic Salivary Gland Mesenchymal Cells

Embryonic salivary gland mesenchyme (eSGM) secretes various growth factors (bioactives) that support the proper growth and differentiation of salivary gland epithelium. Therefore, eSGM cells can be used as feeder cells for in vitro-cultured artificial salivary gland if their survival and bioactivity are properly maintained. As eSGM is encapsulated in a hyaluronan (HA)-rich developmental milieu, we hypothesized that mimicking this environment in vitro via surface immobilization of HA might enhance survival and bioactivity of eSGM. In this study, various HA derivatives, conjugated with catechol (HA–CA), thiol (HA–SH), or amine (HA–EDA) moieties, respectively, were screened for their efficacy of culturing eSGM-derived feeder cells in vitro. Among these HA derivatives, HA–CA showed the highest surface coating efficiency and growth enhancement effect on the embryonic submandibular gland. In addition, the HA–CA coating enhanced the production of growth factors EGF and FGF7, but not FGF10. These effects were maintained when eSGM cells isolated from the embryonic salivary gland were re-seeded to develop the feeder layer cells. CD44s (a major HA receptor) in eSGM cells were clustered at the cell membrane, and enhanced EGF expression was detected only in CD44 cluster-positive cells, suggesting that membrane clustering of CD44 is the key mechanism for the increased expression of EGF.

CFD-DEM simulation of particle coating process coupled with chemical reaction flow model

Particle coating process, one of the main methods to improve the particle properties, is widely used in industrial production and pharmaceutical industry. For the scale up and optimization of this process, a mechanistic and detailed study is needed or numerical simulation as an alternative way. Decomposition of substances usually involves multiple chemical reactions and produces multiple substances in the actual chemical reaction. In the study, a chemical reaction flow (CRF) model has been established based on kinetic mechanism of elementary reaction, the theory of molecular thermodynamics and the sweep theory. It was established with the comprehensive consideration of the decomposition of substances, deposition process, adhesion process, desorption process, hydrogen inhibition, and clearance effect. Then the CFD-DEM model was coupled with CRF model to simulate particle coating process by FB-CVD method, and the CFD-DEM-CRF coupling model was implemented in the software Fluent-EDEM with their user definition function (UDF) and application programming interface (API). The coating process in the spouted bed was analyzed in detail and the coating behavior under different conditions were compared at the aspects of CVD rate, coating efficiency, particle concentration distribution, particle mixing index and gas concentration distribution. It is found that the average CVD rate is 6.06 × 10−4 mg/s when the inlet gas velocity is 11 m/s and bed temperature is 1273 K, and simulation result agrees with the experimental result well. Average CVD rate and coating efficiency increase with temperature increasing, but decrease acutely with mass fraction of injected hydrogen increasing. The CFD-DEM-CRF coupling model can be developed as a basic model for investigating particle coating process in detail and depth and can provide some guidance for the operating conditions and parameters design of the spouted bed in the real coating process.