Hepatocyte cultures: From collagen gel sandwiches to microfluidic devices with integrated biosensors

Jose M. de Hoyos-Vega; Hye Jin Hong; Gulnaz Stybayeva; Alexander Revzin

doi:10.1063/5.0058798

Rat Hepatocyte Cultures: Collagen Gel Sandwich and Immobilization Cultures

Cytochrome P450 Protocols ◽

10.1385/1-59259-998-2:247 ◽

2006 ◽

pp. 247-254 ◽

Cited By ~ 2

Author(s):

Mathieu Vinken ◽

Greetje Elaut ◽

Tom Henkens ◽

Peggy Papeleu ◽

Sarah Snykers ◽

...

Keyword(s):

Collagen Gel ◽

Rat Hepatocyte ◽

Hepatocyte Cultures ◽

Collagen Gel Sandwich

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Ion Conductance-Based Perfusability Assay of Vascular Vessel Models in Microfluidic Devices

Micromachines ◽

10.3390/mi12121491 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1491

Author(s):

Rise Akasaka ◽

Masashi Ozawa ◽

Yuji Nashimoto ◽

Kosuke Ino ◽

Hitoshi Shiku

Keyword(s):

Network Formation ◽

Umbilical Vein ◽

Collagen Gel ◽

Microfluidic Devices ◽

Ion Current ◽

Ion Currents ◽

Ion Conductance ◽

Microscopic Imaging ◽

Vessel Formation ◽

Center Channel

We present a novel methodology based on ion conductance to evaluate the perfusability of vascular vessels in microfluidic devices without microscopic imaging. The devices consisted of five channels, with the center channel filled with fibrin/collagen gel containing human umbilical vein endothelial cells (HUVECs). Fibroblasts were cultured in the other channels to improve the vascular network formation. To form vessel structures bridging the center channel, HUVEC monolayers were prepared on both side walls of the gel. During the culture, the HUVECs migrated from the monolayer and connected to the HUVECs in the gel, and vascular vessels formed, resulting in successful perfusion between the channels after culturing for 3–5 d. To evaluate perfusion without microscopic imaging, Ag/AgCl wires were inserted into the channels, and ion currents were obtained to measure the ion conductance between the channels separated by the HUVEC monolayers. As the HUVEC monolayers blocked the ion current flow, the ion currents were low before vessel formation. In contrast, ion currents increased after vessel formation because of creation of ion current paths. Thus, the observed ion currents were correlated with the perfusability of the vessels, indicating that they can be used as indicators of perfusion during vessel formation in microfluidic devices. The developed methodology will be used for drug screening using organs-on-a-chip containing vascular vessels.

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Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156420 ◽

1989 ◽

Vol 47 ◽

pp. 888-889

Author(s):

Arthur J. Wasserman ◽

Azam Rizvi ◽

George Zazanis ◽

Frederick H. Silver

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Collagen Gel ◽

Collagen Fibers ◽

Control Group ◽

Guide Tube ◽

Sprague Dawley ◽

Silicone Tube ◽

Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

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