Dynamic stimulation promotes functional tissue-like organization of a 3D human lymphoid microenvironment model in vitro

This work focused on generating a three-dimensional (3D) in vitro dynamic model to study chronic lymphocytic leukemia (CLL) cell dissemination, homing, and mechanisms of therapy resistance. We used a gelatin-based, hard porous biomaterial as a support matrix to develop 3D tissue-like models of the human lymph node and bone marrow, which were matured inside bioreactors under dynamic perfusion of medium. Comparing static and dynamic cultures of these 3D constructs revealed that perfusion promoted a tissue-like internal organization of cells, characterized by the expression of specific functional markers and deposition of an intricate extracellular matrix protein network. Recirculation of CLL cells within the dynamic system led to changes in leukemic cell behavior and in the expression of key markers involved in tumor progression. These findings suggest that the model is well suited for investigating the pathophysiological mechanisms of CLL and potentially other hematological malignancies.