Clinorotation-mediated stiffening of Jurkat T-cell-laden lymph node- inspired nanocellulose-alginate 3D-bioprinted droplets

Abstract Three-dimensional bioprinted droplets intended to support immune-cell expansion should reproduce not only the biochemical environment of lymphoid tissues, but also their mechanical and transport-related cues. Here, we developed a simplified lymph node-inspired platform based on droplets bioprinted with a nanocellulose-reinforced alginate bioink which resemble size, shape and stiffness of native lymphoid tissue, and laden with Jurkat cells, used here as a tractable human T-cell line model, and investigated whether clinorotation could promote their flow-mediated mechanical maturation. Droplet motion and surrounding hydrodynamic environment were characterized by video tracking and computational fluid dynamics, whereas local and bulk mechanics were assessed by nanoindentation and rheology after static or dynamic culture. Under the selected rotational regime, the droplets followed stable orbital trajectories within a suspension-based, low-shear environment. Prolonged dynamic conditioning induced marked stiffening of nanocellulose-alginate droplets, as demonstrated by an increase in apparent Young’s modulus and higher storage moduli. This response was formulation-dependent and was not reproduced to same extent in alginate hydrogels, indicating that nanocellulose network plays a key role in enabling flow-responsive mechanical maturation. Compared with static controls, dynamically cultured droplets showed higher cell viability, enhanced proliferation, and increased intracellular ATP over 10 days. As proof of concept, dynamically conditioned Jurkat-laden droplets were interfaced with U87 glioblastoma cells in a transwell assay and induced a greater reduction in U87 viability than static droplets or free-cell controls. These findings identify clinorotation as a flow-mediated conditioning strategy capable of promoting mechanical maturation of nanocellulose-reinforced 3D-bioprinted droplets toward the stiffness range of native lymph node while supporting Jurkat T-cell expansion and subsequent immune-tumor interaction studies. The observed biological response likely reflects the integrated contribution of matrix remodeling, hydrodynamic loading, enhanced mass transport, and waste removal.