Date of Award

Summer 8-16-2022

Level of Access Assigned by Author

Open-Access Thesis



Degree Name

Master of Science (MS)


Biological Engineering


Karissa Tilbury

Second Committee Member

Andre Khalil

Third Committee Member

Michael Mason


Although breast cancer is a growing health concern worldwide, the challenge to minimize mortality rate partly comes from the heterogeneity in its pathological characteristics. The tumor microenvironment is a complex hub of signaling cascades that plays a key role for the progression of cancer to develop to metastatic stage. The extracellular matrix (ECM), as a major component of the tumor microenvironment, contains signatures that have cues to understand tumor progression. Here, the unique microstructural collagen alterations specific to reactive stromal/tumor cell interactions and interactions of reactive stromal fibroblasts with different tumor cell types MCF7A and MDA-MB-231 were investigated. Early alterations of collagen were characterized using the label free, collagen specific, multiphoton laser scanning imaging modality known as Second Harmonic Generation microscopy (SHG). The directionality effect of SHG, calculated as the ratio between the forward and backward SHG (FSHG/BSHG), is used to characterize the different collagen signatures locally at 10-pixel (3.52μm) dilation from the cell boundaries. Activated fibroblasts remodel collagen differently resulting significantly higher FSHG/BSHG than deactivated fibroblasts and Wilcoxon rank-sum test gives p0.05) in their FSHG/BSHG ratio.