Bioprinting of Hydrogel Tumor Slices as a 3D Model for Mantle Cell Lymphoma.

Mantle cell lymphoma (MCL) is a rare, aggressive B-cell neoplasm that frequently relapses and only shows a limited response to conventional chemotherapy. A major challenge in MCL research is culturing primary MCL cells ex vivo, as cells tend to undergo spontaneous apoptosis when cultured in 2D suspension culture. Although 3D models are known to better recapitulate the in vivo situation of solid tumors, their application is still poorly explored in lymphomas. Developing 3D models that replicate the in vivo conditions of MCL within the lymph node could enhance their survival, facilitate the study of the MCL-tumor microenvironment crosstalk, and mimic the in vivo drug response. Here, a 3D printed model of MCL in the form of hydrogel tumor slices was established, along with an optimized culture method. A standardized process was developed using MCL cell lines or primary MCL cells, in which the cells are immersed in a hydrogel containing alginate, type I collagen, and basement membrane matrix by bioprinting into a gelatin support bath. The resulting MCL hydrogel tumor slices are cultured on a filter support to maintain their stability throughout the culture period. Drug treatments can be applied to the system. The response of single cells inside the hydrogel tumor slice can be tracked by four-color live 3D fluorescence imaging. Primary MCL cells demonstrated a stable viability when cultured in the hydrogel tumor slices. This protocol provides a detailed description of the generation, culture, and analysis of MCL cells in hydrogel tumor slices. By closely mimicking the tumor microenvironment and utilizing an air-liquid interface culture, the presented model enhances physiological relevance compared to the traditional 2D culture. It offers significant potential for advancing both biological and therapeutic studies of MCL.