Event Abstract Back to Event Modelling mammary tumour invasiveness using engineered anisotropic collagen scaffolds Robert D. Hume1, Sara Pensa2, Anke Husmann3, Jonathan J. Campbell3, Peter A. Kreuzaler4, Ruth E. Cameron3 and Christine J. Watson1 1 University of Cambridge, Department of Pathology, United Kingdom 2 University of Cambridge, Department of Pharmacology, United Kingdom 3 University of Cambridge, Department of Materials Science and Metallurgy, United Kingdom 4 University of Cambridge, Department of Biochemistry, United Kingdom The field of tissue engineering has shown that 3D culture can have implications on cellular phenotype. Advances in culture techniques include the use collagen gels and the mixture of extracellular matrix (ECM) proteins known as Matrigel®. These gels mimic the ECM in which the cells normally reside. However, in the mammary gland it is known that cells exist within a dense network of collagen fibres, other ECM proteins and stromal cells such as adipocytes. Other evidence has shown that organization of collagen fibres is required for branching morphogenesis of mammary epithelium as well as highly orientated fibres around mammary tumours (Provenzano, Eliceiri et al. 2006; Schedin and Keely 2011). We sought to synthesize a biologically relevant collagen scaffold with organized fibres seeded with adipocytes to mimic the ECM of the mammary gland. Following this we intended to culture mammary tumours in such scaffolds to provide an organotypic model of mammary tumour invasion. Collagen scaffolds with orientated fibres (anisotropic) radiating out from a central seeding cone were engineered using a modified freeze drying method (Davidenko, Campbell et al. 2010). A stromal preadipocyte cell line was seeded throughout the scaffold, cultured and differentiated to provide a ‘synthetic fat pad’ using a previously established method developed in our laboratory (Campbell, Davidenko et al. 2011). Tumours were generated either via injection of a syngeneic cancer cell line into recipient mice or overexpression of the Wnt1 oncogene in transgenic mice. Following tumour excision the ‘synthetic fat pad’ was then seeded with murine tumour fragments into the seeding cone. Fixed scaffolds were examined by immunohistochemistry identifying that cancer cells migrated from the tumour edge into the scaffolds in both tumour types. Migratory cancer cells within the scaffold from Wnt1 tumours show a distinct morphology to ‘normal’ cancer cells in the body of the tumour fragment. Unlike commonly used ECM gels this model enables sequential seeding of stroma and tumour fragments within an orientated fibrous scaffold thus providing a novel 3D organotypic tumour migration assay. Future refinement of the model could humanise the system whereby human stroma and human cancer biopsies would be used in conjunction with cancer therapeutics. This could provide a potential screening method to provide personalized medicine strategies for breast cancer patients.