Mesenchymal stem cells (MSCs) play a critical role in stem cell therapy due to their tissue-mimicking abilities. However, conventional 2D culture conditions often lead to the loss of their native hypoxic niche, potentially limiting their therapeutic efficacy. 3D bioprinting offers a method to recreate intricate biological environments by integrating cells with extracellular matrices. Therefore, it is essential to adapt 3D printing techniques to accurately replicate the MSCs' ecological niche, facilitating the integration of 3D printing technology into clinical applications. In this study, we optimized MSCs' therapeutic capabilities using the performed cellular aggregates (PCA) bioprinting method. We observed that the printed matrix creates a hypoxic microenvironment, resulting in a significant increase in the level of production of several paracrine signaling molecules and immunomodulatory factors by MSCs. Furthermore, MSCs exhibited enhanced stemness and proliferative capacity in the early stages of the culture. RNA-seq analysis revealed that these changes in cellular behavior were associated with the hypoxic environment created during the bioprinting procedure of MSCs. By optimizing the bioink composition and printing parameters, we successfully simulated the in vivo hypoxic microenvironment, leading to notable improvements in MSC characteristics and immunomodulatory capacity. RNA sequencing analysis further confirmed the activation of hypoxia signaling pathways, which are crucial for stem cell properties. These findings offer valuable insights into leveraging 3D bioprinting for MSC-based therapies in regenerative medicine.
Keywords: 3D bioprinting; RNA sequencing; cellular aggregates; hypoxic niche; mesenchymal stem cells (MSCs); regenerative medicine.