Hildebrandthickman0721

Scalable fabrication concepts of 3D kidney tissue models are required to enable their application in pharmaceutical high-throughput screenings. Yet the reconstruction of complex tissue structures remains technologically challenging. We present a novel concept reducing the fabrication demands, by using controlled cellular self-assembly to achieve higher tissue complexities from significantly simplified construct designs. We used drop-on-demand bioprinting to fabricate locally confined patterns of renal epithelial cells embedded in a hydrogel matrix. These patterns provide defined local cell densities (cell count variance less then 11 %) with high viability (92 ± 2 %). Based on these patterns, controlled self-assembly leads to the formation of renal spheroids and nephron-like tubules with a predefined size and spatial localization. With this, we fabricated scalable arrays of hollow epithelial spheroids. Atezolizumab manufacturer The spheroid sizes correlated with the initial cell count per unit and could be stepwise adjusted, ranging from Ø = 84, 104, 120 to 131 µm in diameter (size variance less then 9 %). Furthermore, we fabricated scalable line-shaped patterns, which self-assembled to hollow cellular tubules (Ø = 105 ± 22 µm). These showed a continuous lumen with prescribed orientation, lined by an epithelial monolayer with tight junctions. Additionally, upregulated expression of kidney-specific functional genes compared to 2D cell monolayers indicated increased tissue functionality, as revealed by mRNA sequencing. Furthermore, our concept enabled the fabrication of hybrid tubules, which consisted of arranged subsections of different cell types, combining murine and human epithelial cells. Finally, we integrated the self-assembled fabrication into a microfluidic chip and achieved fluidic access to the lumen at the terminal sites of the tubules. With this, we realized flow conditions with a wall shear stress of 0.05 ± 0.02 dyne/cm² driven by hydrostatic pressure for scalable dynamic culture towards a nephron-on-chip model.The thermal properties of individual single-walled carbon nanotubes (SWCNTs) have been well documented in the literature following decades of intensive study. However, when SWCNTs form a macroscale assembly, the thermal transport in these complex structures usually not only depends on the properties of the individual tubes, but also is affected and sometimes dominated by inner structural details, e.g. bundles and junctions. In this work, we first performed an experimental measurement of the thermal conductivities of individual SWCNT bundles of different sizes using a suspended micro-thermometer. The results, together with the data that we obtained from a previous work, give a complete experimental understanding of the effect of bundling on the thermal conductivity of SWCNTs. With these quantitative understandings, we propose a phenomenological model to describe the thermal transport in two-dimensional (2D) SWCNT films. The term 'line density' is defined to describe the effective thermal transport channels in this complex 2D network. Along with experimentally obtained geometric statistics and film transparency, the thermal conductance of SWCNTs is estimated, and the effects of bundle length, diameter, and contact conductance are systematically discussed. Finally, we extend this model to explain thermal transport in 2D networks of one-dimensional van der Waals heterostructures, which are coaxial hetero-nanotubes we recently synthesized using SWCNTs as the template. This extended model suggests that the contribution of boron nitride nanotubes (BNNTs) to the overall performance of a SWCNT-BNNT heterostructured film depends on the transparency of the original SWCNT film. The increase in the thermal conductance of a highly transparent film is estimated to be larger than that of a less transparent film, which shows a good agreement with our experimental observations and proves the validity of the proposed phenomenological model.Boron nitride quantum dots (BNQDs) have been proposed as probes for bioimaging owing their to outstanding photoluminescent properties, although their hydrophobic nature and strong aggregation tendency in aqueous media limit their application in the biomedical field. In this work, we synthesize BNQDs by a liquid exfoliation-solvothermal process under pressure from boron nitride nanoparticles in N,N-dimethylformamide. The BNQDs display an average size of 3.3 ± 0.6 nm, as measured by transmission electron microscopy, and a (100) crystalline structure. In addition, a quantum yield of 21.75 ± 0.20% was achieved. To ensure complete dispersibility in water and prevent possible elimination by renal filtration upon injection, the BNQDs (20% w/w) are encapsulated within poly(ethylene glycol)-b-poly(epsilon-caprolactone) nanoparticles by a simple and scalable nanoprecipitation method, and hybrid nanocomposite particles with significantly stronger photoluminescence than their free counterparts are produced. Finally, their optimal cell compatibility and bioimaging features are demonstrated in vitro in murine macrophage and human rhabdomyosarcoma cell lines.Fish benefit energetically when swimming in groups, which is reflected in lower tail-beat frequencies for maintaining a given speed. Recent studies further show that fish save the most energy when swimming behind their neighbor such that both the leader and the follower benefit. However, the mechanisms underlying such hydrodynamic advantages have thus far not been established conclusively. The long-standing drafting hypothesis-reduction of drag forces by judicious positioning in regions of reduced oncoming flow-fails to explain advantages of in-line schooling described in this work. We present an alternate hypothesis for the hydrodynamic benefits of in-line swimming based on enhancement of propulsive thrust. Specifically, we show that an idealized school consisting of in-line pitching foils gains hydrodynamic benefits via two mechanisms that are rooted in the undulatory jet leaving the leading foil and impinging on the trailing foil (i) leading-edge suction on the trailer foil, and (ii) added-mass push on the leader foil.