Multi-adjacent Microwell Stickers for the Study of Paracrine Signaling in Cancer

Graduate #8
Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology

Reinaldo Agostini - University of Puerto Rico, Mayaguez Campus
Co-Author(s): Karla P. Ramos, Jorge Almodóvar, and Maribella Domenech, University of Puerto Rico, Mayaguez Campus

Triple Negative Breast Cancer (TNBC) is distinguished by various characteristics which are associated to its poor prognosis. This type of cancer is aggressive in nature and has no targeted therapies. The tumor microenvironment has shown to modulate tumor cell behavior and response to clinical therapies. Current in vitro technologies allow us to observe multicellular interactions for extended periods; however, these present a variety of limitations including the need for cell sorting, requirement of large amounts of cells and lack tunable discrete adjacent compartments. Other technologies such as microfluidic platforms lack of a user-friendly interface, and require specialized instrumentation and training which make it difficult to be routinely used in a cell biology laboratory. To overcome these problems, an open multi-microwell made of polystyrene (PS) film bound to medical grade double-sided adhesive tape was manufactured to probe tumor-stromal interactions. The devices were printed out using a razor-blade plotter and layered into a 3-dimensional structure. Cell viability and proliferation was evaluated for three days in tumor cells, fibroblasts and macrophage clusters. Devices made of polydimethylsiloxane (PDMS) or electrospun collagen type 1 fibers instead of PS were also evaluated. Results show similar cell viability and growth when comparing PS and PDMS devices with NIH-3T3 fibroblasts and MDA-MB-231 human breast adenocarcinoma cells. On the other hand, macrophage-differentiated THP-1 cells presented higher viability and proliferation for PS than for PDMS devices. Collagen devices presented additional challenges for device preparation, cell seeding, viability and proliferation measurements. Initial findings suggest that cell viability and proliferation are lower than PS devices, but collagen thickness may be interfering with assays and slightly interferes with visual confirmation of cell seeding. In conclusion, PS microwell stickers provide greater functionality and compatibility with cells than PDMS devices prepared through soft lithography. The stickers’ user-friendliness provide flexibility for testing diverse biomaterials with varying conditions for each cell type in multiculture cell signaling studies. Future studies varying material thickness, size, design and using other materials such as cellulose fibers and gelatin will be evaluated and employed for additional tools in probing.
References: Domenech, M., et. al. (2009). Cellular observations enabled by microculture: paracrine signaling and population demographics. Integrative biology, 1(3), 267-274.
Goers, L., et. al. (2014). Co-culture systems and technologies: taking synthetic biology to the next level. Journal of The Royal Society Interface, 11(96), 20140065.
Quail, D. F., et. al. (2013). Microenvironmental regulation of tumor progression and metastasis. Nature medicine, 19(11), 1423-1437.

Funder Acknowledgement(s): NSF CREST HRD-134156 grant to Maribella Domenech.

Faculty Advisor: Maribella Domenech, maribella.domenech@upr.edu

Role: I worked on the design, manufacturing and implementation of the polystyrene and collagen materials. I also worked on the tri-culture aspects for cell viability, proliferation and data analysis.