Laser direct-write based fabrication of a spatially-defined, biomimetic construct as a potential model for breast cancer cell invasion into adipose tissue.

Epithelial-adipose interaction is an integral step in breast cancer cell invasion and progression towards lethal metastatic disease. Understanding the physiological contribution of obesity, a major contributor to breast cancer risk and negative prognosis in post-menopausal patients, on cancer cell invasion requires detailed co-culture constructs that reflect mammary microarchitecture. Using laser direct-write, a laser-based CAD/CAM bioprinting technique, we have demonstrated the ability to construct breast cancer cell-laden hydrogel microbeads into spatially defined patterns in hydrogel matrices containing differentiated adipocytes. Z-stack imaging confirmed the three-dimensional nature of the constructs, as well as incorporation of cancer cell-laden microbeads into the adipose matrix. Preliminary data was gathered to support the construct as a potential model for breast cancer cell invasion into adipose tissue. MCF-7 and MDA-MB-231 breast cancer cell invasion was tracked over 2 weeks in an optically transparent hydrogel scaffold in the presence of differentiated adipocytes obtained from normal weight or obese patient tissue. Our model successfully integrates adipocytes and gives us the potential to study cellular and tissue-level interactions towards the early detection of cancer cell invasion into adipose tissue.