Using Origami Method in the Development and Testing of Liver Microstructure Devices

Undergraduate #333
Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering

Gabriel Fernandez - Middlesex Community College
Co-Author(s): Carol Livermore and Tian Liu, Northeastern University, MA Joshua Miranda, MA

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The availability of human tissue and organs is critical for transplants. It is the intent of our group to develop engineered liver tissue using methods similar to origami folding patterns. My research focused on a packaged device that would replicate liver lobule structure and hold cells while they carry out their proper functions. This work has culminated in development of the manufacturing technology and demonstration of the intended flow functionality. The device is composed of two biocompatible materials, polydimethylsiloxane (PDMS) and a polycarbonate nanoporous membrane. First the nanoporous membrane is folded with a mold to form a flat-topped, accordion-folded structure. Alternate folded channels will be lined with hepatic cells to filter the blood and endothelial cells to flow cell culture medium. Perfusion through the membrane is to supply the hepatic cells with nutrients. The accordion folds separate the channels that house the endothelial and hepatic cells, but the structure needs an outer package to hold the contents inside. To accomplish this, the folded nanoporous membrane is encased in a nanoporous membrane coated with PDMS. The PDMS seals to the folded membrane when it is cured and prevents leaks. The package successfully holds fluid inside the device, but fluid connections are a challenge. Fluid connections control the distribution of cells into the proper channel locations and enable cell culture medium to flow through the endothelial channels. We accomplished this by designing a manifold that joins one external connection to all of the folded endothelial channels and a second external connection to all of the folded hepatic channels. The device was tested by flowing water dyed two different colors into the two manifolds. In a successful device, the hepatic channels can be filled without leaking to the endothelial channels and vice versa. The channels do not remain isolated long term because the membrane allows perfusion. For short term operation, isolation between channels indicates success and immediate leakage indicates device failure. The detailed fabrication process was optimized until successful devices were created, as shown by their flow performance. The next stage in the research will be to test the devices for biological functionality as an origami-folded scaffold for liver tissue engineering. With this successful innovation we could help save many lives by increasing the availability of liver tissue for transplants.

Funder Acknowledgement(s): Funding for this research was provided by the NSF through the EFRI-REM program under award #1332249.

Faculty Advisor: Carol Livermore and Tian Liu, livermore@neu.edu