基于细菌的递送策略最近成为药物递送领域独特的研究方向。然而，细菌载体进入血液后很快就会被免疫细胞吞噬。利用这一现象，我们试图利用免疫细胞传递微米级细菌载体的潜力，发现灭活细菌在静脉注射后可以通过CD11b细胞搭便车在肿瘤部位积聚。为此，我们设计了金铂双金属纳米酶包被的细菌载体（Au-Pt@VNP20009，APV）。利用低剂量X射线诱导的强烈肿瘤炎症反应，进一步增强CD11b免疫细胞协助APV搭车进行肿瘤靶向递送的能力，可显着缓解肿瘤缺氧和免疫抑制，抑制肿瘤生长和转移。我们的工作阐明了细菌载体靶向递送的潜在机制，为细菌载体递送策略和临床肿瘤放射免疫治疗开辟了新视野。本文受版权保护。保留所有权利。本文受版权保护。版权所有。

Bacterial-based delivery strategies have recently emerged as a unique research direction in the field of drug delivery. However, bacterial vectors are quickly phagocytosed by immune cells after entering the bloodstream. Taking advantage of this phenomenon, herein, we seek to harness the potential of immune cells to delivery micron-sized bacterial vectors, and find that inactivated bacterial could accumulate at tumor-site after intravenous injection through CD11b+ cells hitchhiking. To this end, we then design a gold-platinum bimetallic nanozyme coated bacterial vector (Au-Pt@VNP20009, APV). Utilizing strong tumor inflammatory response induced by low dose X-rays, we further heighten the ability of CD11b+ immune cells to assist APV hitchhiking for tumor-targeted delivery, which could significantly relieve tumor hypoxia and immunosuppression, and inhibit tumor growth and metastasis. Our work elucidates the potential mechanisms of bacterial vector targeted delivery, opening up new horizons for bacterial vector delivery strategies and clinical tumor radio-immunotherapy. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.