Spheroid Assembly

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Background: Tissue analogs hold great promise as drug and environmental screening tools. However, technical challenges remain to the process of building these tissue analogs, including minimal control over soluble factors presented to the cell and inability to direct cell-cell aggregation from suspension culture. Technology: Johnna Temenoff, Jennifer Lei, and William Murphy from the School of Chemistry and Biochemistry at Georgia Tech have developed an interaction between glucosamine and a binding partner (HEPpep) to promote assembly of cell spheroids into small microtissue constructs in a dynamic culture environment. The microtissues are composed of smaller cell and tissue building blocks formed together to build larger microtissue. This technology demonstrates a novel method to self-assemble a population of microtissues out of smaller building blocks in suspension culture. These microtissues can be composed of different cell types to recapitulate in vivo tissues and control cell-cell interactions. The microtissues can further be used for modelling and drug screening as well as for tissue repair and regeneration. Current tissue assembly techniques (encapsulation in hydrogels, scaffold-free aggregation and microfluidics) are all static culture techniques, whereas this technique allows for the formation of microtissues in a dynamic culture environment.  Moreover, strong binding can be obtained between cells/cell types that may not otherwise strongly interact, since the interaction is driven by the coating. Potential Commercial Applications: This invention would be useful to co-deliver growth factors in close proximity to cells while retaining cell injectability.  Such cell therapies may be useful in a wide range of degenerative diseases.  Moreover, the directed aggregation approach makes this technology useful for building in vitro assays for drug screening, and generating complex tissues involving multiple cells types such as skin, pancreas, and liver. Benefits / Advantages: Results in assembly of cells containing multiple cell populations. The “bottom-up” assembly approach forms small microtissues with multiple cell populations Cell spheroids can be coated with heparin without compromising viability or function Modification of glucosamine effects protection and release of growth factors and may influences cell proliferation/differentiation