The Enteric Nervous System (ENS) is a complex network of neurons and glia, which regulates sensorimotor function throughout the gastroinestinal tract (GI). Here we investigated the role of the ENS and intestinal myofibroblasts in the maintenance of a primary intestinal epithelial barrier through regulation of monolayer permeability, cytokine production, and differentiation of intestinal stem cells. Utilizing a novel, in vitro, transwell-based coculture system, murine small intestinal stem cells were isolated and cultured with ENS neurons and glia or subepithelial myofibroblasts. Results show that the ENS contributes to regulation of intestinal stem cell fate, promoting differentiation into chemosensory enteroendocrine cells, with 0.9% of cells expressing chromogranin A when cultured with ENS versus 0.6% in cocultures with myofibroblasts and 0.3% in epithelial cultures alone. Additionally, enteric neurons and myofibroblasts differentially release cytokines Macrophage Inflammatory Protein 2 (MIP-2), Transforming Growth Factor beta 1 (TGF-β1), and Interleukin 10 (IL-10) when cultured with intestinal epithelial cells, with a 1.5 fold increase of IL-10 and a 3 fold increase in MIP-2 in ENS cocultures compared to coculture with myofibroblasts. These results indicate the importance of enteric populations in the regulation of intestinal barrier function.

Here we report benchtop fabrication of multilayer thermoplastic organs-on-chips via laser cut and assembly of double sided adhesives. Biocompatibility was evaluated with Caco-2 cells and primary human intestinal organoids. Chips with Luer fluidic interfaces were economical ($2 per chip) and were fabricated in just hours without use of specialized bonding techniques. Compared with control static Transwell™ cultures, Caco-2 and organoids cultured on chips formed confluent monolayers expressing tight junctions with low permeability. Caco-2 cells on chip differentiated ~4 times faster compared to controls and produced mucus. To demonstrate the robustness of laser cut and assembly, we fabricated a dual membrane, tri-layer gut chip integrating 2D monolayers, 3D cell culture, and a basal flow chamber. As proof of concept, we co-cultured a human, differentiated monolayer and intact organoids in a chip with multi-layered contacting compartments. The epithelium exhibited 3D tissue structure and organoids formed in close proximity to the adjacent monolayer. The favorable features of thermoplastics, such as low gas and water vapor permeability, in addition to rapid, facile, and economical fabrication of multilayered devices, make laser cut and assembly an ideal fabrication technique for developing organs-on-chips and studying multicellular tissues.

These results demonstrate that US stimulation of DRG neurons in vitro impacts neurite morphology and enhances total extension, indicating the potential for advancing and understanding driving mechanisms of ultrasonic therapies for peripheral nerve regeneration.

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Here we report benchtop fabrication of multilayer thermoplastic organs-on-chips via laser cut and assembly of double sided adhesives. Biocompatibility was evaluated with Caco-2 cells and primary human intestinal organoids. Chips with Luer fluidic interfaces were economical ($2 per chip) and were fabricated in just hours without use of specialized bonding techniques. Compared with control static Transwell™ cultures, Caco-2 and organoids cultured on chips formed confluent monolayers expressing tight junctions with low permeability. Caco-2 cells on chip differentiated ~4 times faster compared to controls and produced mucus. To demonstrate the robustness of laser cut and assembly, we fabricated a dual membrane, tri-layer gut chip integrating 2D monolayers, 3D cell culture, and a basal flow chamber. As proof of concept, we co-cultured a human, differentiated monolayer and intact organoids in a chip with multi-layered contacting compartments. The epithelium exhibited 3D tissue structure and organoids formed in close proximity to the adjacent monolayer. The favorable features of thermoplastics, such as low gas and water vapor permeability, in addition to rapid, facile, and economical fabrication of multilayered devices, make laser cut and assembly an ideal fabrication technique for developing organs-on-chips and studying multicellular tissues.

Regardless of the intervention for peripheral nerve repair, slow rates of axonal regeneration often result in poor clinical outcomes. Thus, using new materials such as biologically inspired, biocompatible, organic rosette nanotubes (RNTs) could provide a tailorable scaffold to modulate neurite extension and attachment for improved nerve repair. RNTs are obtained through the spontaneous self-assembly of a synthetic DNA base analogue featuring the hydrogen bond triads of both guanine and cytosine, the G∧C base. Here, we investigated the potential of RNTs functionalized with lysine and Arg-Gly-Asp-Ser-Lys (RGDSK) peptide to support neural growth. We hypothesized that (a) due to their dimensions, the RNTs would support neuron attachment, and (b) their conjugation to the integrin-binding peptide RGDSK would further enhance neurite outgrowth compared to unfunctionalized RNT. Neurite extension was examined on a variety of RNT structures, including RNT with a lysine side chain (K1), a mixture of the K1 and a free RGDS peptide, RNT alone, an RGDSK-functionalized RNT, in addition to poly-d-lysine and laminin controls. Both whole dorsal root ganglion (DRG) and single dissociated DRG neurons were seeded onto RNT-coated substrates containing various ratios of peptides. Analysis of neuron morphometrics showed that RNT blends support DRG neuron attachment and neurite extension, with RGDS presentation increasing neurite outgrowth from whole DRG by up to 47% over a 7-day period compared to K1 alone (p < 0.013). In addition, while RNTs increased the sprouting of primary neurites extending from dissociated DRG neurons, the total neurite outgrowth per neuron remained the same. These results show that functionalized biomimetic RNTs provide a support for neurite growth and extension and have the ability to modulate neuronal morphology. These results also pave the way for the design of injectable RNT-based nanomaterials that support guided neural regeneration following traumatic injury.

Ceftibuten, C15H14N4O6S2, with the systematic name (6R,7R)-7-{[(Z)-2-(2-amino-1,3-thiazol-4-yl)-4-carboxybut-2-enoyl]amino}-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, is a third generation, orally administered cephalosporin antibiotic with broad antimicrobial activity and stability against extended spectrum β-lactamases. Ceftibuten can exist in various hydration states and to better understand the location of the water molecules of crystallization and their effect on the structure, the crystal structures of anhydrous (I) and hydrated (II) ceftibuten were determined and both occur as zwitterions with proton transfer from the carboxylate group adjacent to the β-lactam ring to the N atom of the thiazole ring. The β-lactam ring in (I) is almost planar but the equivalent grouping in (II) is slightly buckled. In the extended structure of (I), O—H...O and N—H...O hydrogen bonds link the molecules into a three-dimensional network. In (II), O—H...Oc, N—H...Oc, O—H...Ow, N—H...Ow and Ow—H...Ow (c = ceftibuten, w = water) hydrogen bonds link the components into a three-dimensional network. A large void space is present within the anhydrous crystal structure that can accommodate between two and three molecules of water.