Engineering 3D adipose cell models by support bath bioprinting of mature adipocytes in gellan gum hydrogels

Mature adipocytes (ACs) are essential for modeling human adipose tissue physiology in vitro, yet their large size, buoyancy, and shear sensitivity make them challenging to incorporate into engineered three-dimensional (3D) constructs. This study introduces an agarose support-bath (SB) extrusion workflow for bioprinting geometrically defined adipose constructs using a gellan gum (GG) bioink. We examined the viscosity of GG solutions and SBs to identify a low-shear printability window suitable for lipid-laden cells. SB printing significantly enhanced filament stability, pore uniformity, and construct accuracy compared to free extrusion. Viability assays showed that ACs remained intact and metabolically active after 3 d post-printing, with minimal membrane damage and maintained unilocular morphology. Immunofluorescence staining revealed uniform lipid-filled cells and expression of perilipin A, while basal and stimulated glycerol release indicated retained metabolic activity. These findings demonstrate that the established SB extrusion protocol enables gentle, precise deposition of ACs using a GG-based bioink. This workflow offers a reproducible and accessible platform for generating physiologically relevant adipose cell models, supporting early-stage biological assessment, preliminary drug testing, and soft tissue engineering.