Patient-Derived Bladder Tumor Organoids Isolation and Culture: Conventional and Cost-Reduction Strategy.

Organoids are three-dimensional structures generated in vitro from tissue samples, induced pluripotent stem cells (iPSCs), and/or adult stem cells. Patient-derived organoids (PDOs) represent one of the most physiologically relevant culture systems, closely recapitulating the histological and functional features of the original tissue. They can be established in the laboratory for various applications, including regenerative medicine, drug screening, personalized medicine, and targeted therapy. Since 2009, organoid isolation and culture protocols have been reported for multiple organs, such as the colon, stomach, liver, lung, brain, breast, and bladder. Here, we describe a protocol for the isolation and culture of bladder tumor organoids derived from patients undergoing cystectomy or transurethral resection of bladder tumor (TUR). In addition to the conventional methodology, we introduce a cost-effective alternative approach utilizing sodium alginate hydrogel and fibroblast-conditioned medium (FCM). This strategy offers a reproducible, xeno-free, and low-cost platform that is well suited for both clinical research and resource-limited laboratory settings.