Developing three-dimensional (3D) in vitro tumor model with vasculature systems suitable for testing endovascular interventional therapies remains a challenge. Here we develop an orthotopic liver tumor spheroid model that captures...

Transarterial chemoembolization (TACE) has emerged as the mainstay treatment for patients suffering from unresectable intermediate hepatocellular carcinoma and also holds the potential to treat other types of hypervascular cancers such as renal cell carcinoma. However, an in vitro model for evaluating both embolic performance and drug-release kinetics of the TACE embolic agents is still lacking since the current models greatly simplified the in vivo vascular systems as well as the extracellular matrices (ECM) in the organs. Here, we developed a decellularized organ model with preserved ECM and vasculatures as well as a translucent appearance to investigate chemoembolization performances of a clinically widely used embolic agent, i.e., a doxorubicin-loaded ethiodised oil (EO)-based emulsion. We, for the first time, utilized an ex vivo model to evaluate the liquid-based embolic agent in two organs, i.e., liver and kidneys. We found that the EO-based emulsion with enhanced stability by incorporating an emulsifier, i.e., hydrogenated castor oil-40 (HCO), showed an enhanced occlusion level and presented sustained drug release in the ex vivo liver model, suggesting an advantageous therapeutic effect for TACE treatment of hepatocellular carcinoma. In contrast, we observed that drug-release burst happened when applying the same therapy in the kidney model even with the HCO emulsifier, which may be explained by the presence of the specific renal vasculature and calyceal systems, indicating an unfavorable effect in the renal tumor treatment. Such an ex vivo model presents a promising template for chemoembolization evaluation before in vivo experiments for the development of novel embolic agents.

Neoantigens derived from somatic mutations in cancer cells can induce antigen‐specific T‐cell immune response for cancer immunotherapy. However, the 3D models for assessing neoepitope immunogenicity and efficacy of anti‐tumor T‐cell immune response to neoantigens are less than perfect. Here, a 3D tumor model based on recellularized liver matrix is leveraged with HepG2 cells to investigate T cell cytotoxic reactivity toward hepatocellular carcinoma (HCC) neoantigens. The whole exome sequencing (WES) data of 364 HCC patients in The Cancer Genome Atlas database are collected and 25 highly potential immunogenic neoantigens to human leukocyte antigen (HLA)‐A*02:01 molecule in silico are predicted. Six of the HCC neoantigen candidates are functionally validated with high immunogenicity by measuring cellular interferon‐γ secretion and cytotoxicity during neoantigen‐specific T‐cell immune responses in vitro. Then, the minigene of six functionally identified neoantigen peptides is constructed and the minigene‐modified GFP‐HepG2 cells are generated. Neoantigen‐specific immune response is observed with highly secreted Granzyme B, IFN‐γ, and PD‐1 when targeting the minigene‐modified GFP‐HepG2 cells in the 3D RLM HCC tumor model. Overall, the 3D RLM tumor model provides a novel strategy for preclinical assessment of the efficacy of neoantigen‐specific T cell immune response, which helps develop personalized cancer vaccines and immunotherapy treatments for HCC patients.

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Photothermal therapy has attracted enormous attention as an efficient treatment modality in cancer ablation but still encounters a major bottleneck due to the limited penetration depth of light inside tissues. To overcome the challenge of deep tissue penetration, we present a strategy of endovascular photothermal precision embolization (EPPE), which employs an endovascular optical fiber to induce local embolization only in the entrance of feeding vessels through photothermal heating for the purpose of fully blocking the blood supply of the whole tumor. In EPPE, we apply a highly efficient and biocompatible photothermal agent, i.e., near-infrared (NIR)-light-absorbing diketopyrrolopyrrole-dithiophene-based nanoparticle, which exhibits a high cell-killing efficacy at a concentration of 200 μg/mL using 808 nm laser irradiation of 0.5 W/cm 2 within 5 min in both 2D cell culture and a 3D tumor spheroid model. We verify the feasibility of EPPE in an ex vivo organ-structured recellularized liver model and further confirm the in vivo efficacy of the photothermal treatment in a rat liver model. The photothermal treatment combined with the embolization effect holds promise to serve as an effective starvation therapy to treat tumors of varying sizes and locations.