结直肠癌（CRC）是全球主要的健康问题，制定有效的治疗策略至关重要。酶前药疗法（EPT）在对抗肿瘤方面显示出前景，但在实现治疗酶的持续表达和最佳生物分布方面面临挑战。为了解决这些问题，通过口服前药（5-氟胞嘧啶，5-FC）构建了真菌触发的原位化疗药物发生器（命名为 SC@CS@5-FC），用于治疗原位结直肠肿瘤。当SC@CS@5-FC通过酿酒酵母（SC）的趋向性靶向肿瘤时，化疗发生器可以在肿瘤微环境中丰富的透明质酸酶（HAase）的作用下通过酶响应门降解，释放前药（5-FC） 。无毒的5-FC被SC的胞嘧啶脱氨酶(CD)催化生成有毒的化疗药物5-氟尿嘧啶(5-FU)。同时，SC和锌配位壳聚糖纳米粒子可以作为免疫佐剂，激活抗原呈递细胞，进一步增强治疗效果。我们的结果表明，SC@CS@5-FC 可以有效抑制原位结直肠癌模型中的肿瘤生长并延长小鼠的生存期。这项工作利用活体 SC 作为化疗发生器 SC@CS@5-FC 的发电机和定位系统，为治疗原位结直肠癌提供了口服酶前药疗法的策略。

Colorectal cancer (CRC) is a major global health concern, and the development of effective treatment strategies is crucial. Enzyme prodrug therapy (EPT) shows promise in combating tumors but faces challenges in achieving sustained expression of therapeutic enzymes and optimal biological distribution. To address these issues, a fungi-triggered in situ chemotherapeutics generator (named as SC@CS@5-FC) was constructed via oral delivery of a prodrug (5-fluorocytosine, 5-FC) for the treatment of orthotopic colorectal tumor. When SC@CS@5-FC targets the tumor through tropism by Saccharomyces cerevisiae (SC), the chemotherapeutic generator could be degraded under abundant hyaluronidase (HAase) in the tumor microenvironment by an enzyme-responsive gate to release prodrug (5-FC). And nontoxic 5-FC was catalyzed to toxic chemotherapy drug 5-fluorouracil (5-FU) by cytosine deaminase (CD) of SC. Meanwhile, SC and zinc-coordinated chitosan nanoparticles could be used as immune adjuvants to activate antigen-presenting cells and further enhance the therapeutic effect. Our results demonstrated that SC@CS@5-FC could effectively inhibit tumor growth and prolong mouse survival in an orthotopic colorectal cancer model. This work utilizes living SC as a dynamotor and positioning system for the chemotherapeutic generator SC@CS@5-FC, providing a strategy for oral enzyme prodrug therapy for the treatment of orthotopic colorectal.