Efficient methods to expand stem cells ex vivo hold significant promise in many clinical applications. For example, hematological malignancies account for nearly 10% of cancer related deaths in the United States of America and frequently require a transplant to successfully treat the disease. Ex vivo expanded hematopoietic stem cells (HSCs) could help narrow treatment gaps; however, generating viable dosages of HSCs currently fall short of expectations with difficulties in expanding HSCs and the loss of cellular multipotency. Coculture with mesenchymal stem cells (MSCs) aims to provide the necessary intercellular signaling to counteract monoculture deficiencies. Typically, achieving these and other clinical goals have relied on 2D polystyrene (PS) as the

fundamental substrate for cell culture. With the emergence of 3D printing, improved biomimicry with 3D culture models are becoming widely available. In this dissertation, we develop a 3D PS culture substrate for adherent and non-adherent cells, working towards a model for the bone marrow niche. To achieve this goal, the objectives of the work were to: (1) develop a 3D printing method for PS and surface functionalization strategy to facilitate extracellular matrix protein and MSC adhesion, (2) assess the effects of the underlying surface functionality on osteogenic differentiation under static and dynamic conditions, and (3) validate the culture model successfully cultures multiple cell types with a model non-adherent cell line, demonstrating validity and translatability as a bone marrow niche model. In converting PS from a 2D culture platform to a 3D printed one, we take steps to increase the biomimicry of in vitro cell culture without sacrificing fundamental PS properties (e.g. optical clarity, cost-effectiveness, disposability). Continued development and of the model would see an efficient method for studying the complex bone marrow niche with applications in pharmacology and cancer diagnostics.