A multiple-funnels cell culture insert for the scale-up production of uniform cell spheroids

Introduction: Formation of cell spheres is an important procedure in biomedical research. A large number of high-quality cell spheres of uniform size and shape are required for basic studies and therapeutic applications. Conventional approaches, including the hanging drop method and suspension culture, are used for cell sphere production. However, these methods are time consuming, cell spheres cannot be harvested easily, and it is difficult to control the size and geometry of cell spheres. To resolve these problems, a novel multiple-funnel cell culture insert was designed for size controlling, easy harvesting, and scale-up production of cell spheres. Methods: The culture substrate has 680 micro-funnels with a 1-mm width top, 0.89 mm depth, and 0.5 mm square bottom. Mouse embryonic stem cells were used to test the newly developed device. The seeded embryonic stem cells settled at the downward medium surface toward the bottom opening and aggregated as embryoid bodies (EBs). For cell sphere harvest, the bottom of the culture insert was put in contact with the medium surface in another culture dish, and the medium in the device flowed down with cell spheres by hydrostatic pressure. Results: Compact cell spheres with uniform size and shape were collected easily. The diameter of the spheres could be controlled by adjusting the seeding cell density. Spontaneous neural differentiation (nestin and Tju1) and retinoic acid-induced endodermal differentiation (Pdx-1 and insulin I) were improved in the EBs produced using the new insert compared to those in EBs produced by suspension culture. Conclusions: This novel cell culture insert shall improve future studies of cell spheres and benefit clinical applications of cell therapy

On the evaporation rate of ultra-thin liquid film at the nanostructured surface: A molecular dynamics study

Molecular dynamic (MD) simulations have been carried out to study the effect of the nanostructures on the evaporation rate of the ultra-thin liquid film at the solid surface. Simple Lennard-Jones (LJ) fluids are simulated as the ultra-thin liquid film in the non-equilibrium simulation system. The liquid film is confined in a nanochannel composed of two solid surfaces designed with nanostructures in a shape of molecular-scale unevenness. The potential function between solid and liquid molecules is represented by a modified LJ function to conduct the solid–liquid interfaces of different surface wettability. For the steady non-equilibrium MD simulation, the liquid film is subjected to the steady heat flux passing through the nanostructured surfaces. It is found that the interface thermal resistance decreases at the nanostructured surface and apparent heat transfer enhancement is achieved due to the surface area increment. For the unsteady non-equilibrium MD simulation, the vapor has been sandwiched between the liquid films in contact with the nanostructured surfaces of high and low temperature respectively. It is found that the evaporation rate of the ultra-thin liquid film has a larger value than that of the flat surface when the film thickness is larger than that of the adsorbed layer

Therapeutic Potential of Orally Administered Rubiscolin-6

Rubiscolins are naturally occurring opioid peptides derived from the enzymatic digestion of the ribulose bisphosphate carboxylase/oxygenase protein in spinach leaves. They are classified into two subtypes based on amino acid sequence, namely rubiscolin-5 and rubiscolin-6. In vitro studies have determined rubiscolins as G protein-biased delta-opioid receptor agonists, and in vivo studies have demonstrated that they exert several beneficial effects via the central nervous system. The most unique and attractive advantage of rubiscolin-6 over other oligopeptides is its oral availability. Therefore, it can be considered a promising candidate for the development of a novel and safe drug. In this review, we show the therapeutic potential of rubiscolin-6, mainly focusing on its effects when orally administered based on available evidence. Additionally, we present a hypothesis for the pharmacokinetics of rubiscolin-6, focusing on its absorption in the intestinal tract and ability to cross the blood–brain barrier

On the evaporation rate of ultra-thin liquid film at the nanostructured surface: A molecular dynamics study

Molecular dynamic (MD) simulations have been carried out to study the effect of the nanostructures on the evaporation rate of the ultra-thin liquid film at the solid surface. Simple Lennard-Jones (LJ) fluids are simulated as the ultra-thin liquid film in the non-equilibrium simulation system. The liquid film is confined in a nanochannel composed of two solid surfaces designed with nanostructures in a shape of molecular-scale unevenness. The potential function between solid and liquid molecules is represented by a modified LJ function to conduct the solid–liquid interfaces of different surface wettability. For the steady non-equilibrium MD simulation, the liquid film is subjected to the steady heat flux passing through the nanostructured surfaces. It is found that the interface thermal resistance decreases at the nanostructured surface and apparent heat transfer enhancement is achieved due to the surface area increment. For the unsteady non-equilibrium MD simulation, the vapor has been sandwiched between the liquid films in contact with the nanostructured surfaces of high and low temperature respectively. It is found that the evaporation rate of the ultra-thin liquid film has a larger value than that of the flat surface when the film thickness is larger than that of the adsorbed layer

The Small GTPase Rab5a Is Essential for Intracellular Transport of Proglutelin from the Golgi Apparatus to the Protein Storage Vacuole and Endosomal Membrane Organization in Developing Rice Endosperm1[C][W][OA]

Rice (Oryza sativa) glutelins are synthesized on the endoplasmic reticulum as larger precursors, which are then transported via the Golgi to the protein storage vacuole (PSV), where they are processed into acidic and basic subunits. Three independent glutelin precursor mutant4 (glup4) rice lines, which accumulated elevated levels of proglutelin over the wild type, were identified as loss-of-function mutants of Rab5a, the small GTPase involved in vesicular membrane transport. In addition to the plasma membrane, Rab5a colocalizes with glutelins on the Golgi apparatus, Golgi-derived dense vesicles, and the PSV, suggesting that Rab5a participates in the transport of the proglutelin from the Golgi to the PSV. This spatial distribution pattern was dramatically altered in the glup4 mutants. Numerous smaller protein bodies containing glutelin and α-globulin were evident, and the proteins were secreted extracellularly. Moreover, all three independent glup4 allelic lines displayed the novel appearance of a large dilated, structurally complex paramural body containing proglutelins, α-globulins, membrane biomarkers for the Golgi apparatus, prevacuolar compartment, PSV, and the endoplasmic reticulum luminal chaperones BiP and protein disulfide isomerase as well as β-glucan. These results indicate that the formation of the paramural bodies in glup4 endosperm was due to a significant disruption of endocytosis and membrane vesicular transport by Rab5a loss of function. Overall, Rab5a is required not only for the intracellular transport of proglutelins from the Golgi to the PSV in rice endosperm but also in the maintenance of the general structural organization of the endomembrane system in developing rice seeds