BME Master's Defense Announcement for Heather George (L. Solorio, advisor) Everyone is invited to attend the public presentation beginning at 11:30 am. Title: Microtissues Demonstrate Properties of Wound Healing in 3D Date: July 18th, 2022 Time: 11:30 am Location: Zoom Link: https://purdue-edu.zoom.us/j/95847791786 Meeting ID: 958 4779 1786 One tap mobile +16465588656,,95847791786# US (New York) +16469313860,,95847791786# US Dial by your location +1 646 558 8656 US (New York) +1 646 931 3860 US +1 301 715 8592 US (Washington DC) +1 312 626 6799 US (Chicago) +1 669 444 9171 US +1 669 900 6833 US (San Jose) +1 253 215 8782 US (Tacoma) +1 346 248 7799 US (Houston) Meeting ID: 958 4779 1786 Find your local number: https://purdue-edu.zoom.us/u/ayhuE6JAP Advisory Committee: Luis Solorio, chair; Adrian Buganza; Jason Hanna Abstract: An essential stage of repair for a healing wound is the proliferation of cells in the damaged space. Epithelial cells, such as fibroblasts, grow and migrate to aid in construction of new tissue and to close the wound. Current methods of studying fibroblast epithelialization in wound healing include a 2D wound healing assay in which a cell monolayer is scratched, and the cells migrate into the pseudo-wound. However, this lacks the 3D architecture of a physiological wound. Current 3D models of wound healing often rely on the use of a preexisting matrix for structural assistance, however an isolated system of cell growth without requirement of structural aid may gather new insights on intercellular behavior and mechanical properties. We hypothesize that proliferating fibroblasts in 3D on a tessellated SU-8 scaffold creates a more physiologically relevant model for wound healing. This project looks at optimizing fibroblast adhesion and proliferation for 3D microtissue fabrication by altering surface and extracellular matrix (ECM) properties to a SU-8 scaffold. Additionally, we consider the effect of different geometries on cell proliferation and cellular stresses/strains, fibronectin production as pseudo-wounds close, and make comparisons to intercellular cancer behavior. Our results show around a 77% decrease in overall culture time required for the microtissues to reach full confluency. Varying geometries in the tessellated design have revealed structural changes in the actin cytoskeleton formation of fibroblasts, and increased fibronectin production along edges of tensioned cells preparing to "close" the wound. When compared to human breast cancer cells, the cancer cells lack the ability to make critical cell to cell junctions that we observe in fibroblasts, noting the characteristic that cancer is similar to a wound that never heals.