Effective delivery of therapeutic modality throughout the tumorous nidus plays a crucial role in successful solid tumor treatment. However, conventional nanomedicines based on enhanced permeability and retention (EPR) effect have yielded limited delivery/therapeutic efficiency, due mainly to the heterogeneity of the solid tumor. Leukocytes, which could intrinsically migrate across the vessel wall and crawl through tissue interstitium in a self-deformable manner, have currently emerged as an alternative drug delivery vehicle. In this review, we start with the intrinsic properties of leukocytes (e.g., extravasation and crawling inside tumor), focusing on unveiling the conceptual rationality of leveraging leukocytes as EPR-independent delivery vehicles. Then we discussed various cargoes-loading/unloading strategies for leukocyte-based vehicles as well as their promising applications. This review aims to serve as an up-to-date compilation, which might provide inspiration for scientists in the field of drug delivery.

在整个肿瘤病灶中有效传递治疗方式在成功治疗实体瘤中起着至关重要的作用。然而，主要由于实体瘤的异质性，基于增强通透性和保留（EPR）效应的传统纳米药物产生的递送/治疗效率有限。白细胞本质上可以通过血管壁迁移并以自变形方式爬过组织间质，目前已成为替代药物输送载体。在这篇综述中，我们从白细胞的内在特性（例如，肿瘤内的外渗和爬行）开始，重点揭示了利用白细胞作为 EPR 独立递送载体的概念合理性。然后我们讨论了基于白细胞的车辆的各种货物装卸策略及其有前途的应用。本综述旨在作为最新的汇编，可能为药物输送领域的科学家提供灵感。