Effect of a hydrogel-based scaffold material on the establishment of a patient-derived bladder cancer xenograft model

Bladder cancer is treated by surgical removal of the tumor followed by injection of anticancer drugs or the Bacillus Calmette-Guerin vaccine. However, there are insufficient effective drug options depending on the risk category of bladder cancer. One of the reasons for this is the limited number of suitable experimental models that reproduce the pathology of bladder cancer for each risk category. There has been increasing interest in the patient-derived xenograft model as an experimental model to reproduce the original nature of the tumor in a patient. However, there are unresolved problems regarding its practical use, such as the low success rate of engraftment, variation in the growth rate between experiments, and the lack of a reliable method to prepare a patient-derived xenograft model from cryopreserved tumor tissue. In this study, the effect of scaffold material on the preparation of a bladder cancer patient-derived xenograft model was investigated and it was found that gelatin/polyethylene glycol-based hydrogel offers advantages for engraftment of cryopreserved bladder cancer tissue. It was shown that the proliferation of cryopreserved bladder cancer cells was promoted with less necrosis and thrombi around the tissue when transplanted into immunodeficient animals with glycol-based hydrogel compared to transplantation with Matrigel or without any scaffold. This study proposes a new method to generate patient-derived xenograft models from cryopreserved bladder cancer tissue, which is expected to have improved proliferation activity after transplantation.