Magnetically guided biohybrid microrobots with multimodal locomotion for barrier penetration and multifunctional tumor treatment.

Penetrating biological and physical barriers within the body is essential for microrobots to access target sites and achieve effective therapeutic outcomes. However, synthetic microrobots exhibit limited deformability and dynamicity, which are required to navigate tight and complex microenvironments. Here, by leveraging the soft, deformable body of Euglena gracilis, we develop a novel biohybrid microrobot platform that integrates magnetic architectures for controlled propulsion, deformation, and multi-modal locomotion. This design not only preserves the natural motility of microalgae but also leverages their intrinsic therapeutic properties, including chlorophyll-dependent photodynamic therapy (PDT) and immune modulation through E. gracilis natural products. Our biohybrid microrobots navigate through dense three-dimensional biological matrices and around tumor spheroids, exhibiting targeted delivery to tumor regions under both magnetic control and autonomous tumor tropic behavior. This multi-functional platform combines adaptive locomotion, controllable and chemotactic guidance, offering a new paradigm for precision medicine without the need for exogenous drug loading, and has the potential to become a versatile future solution for tumor targeting and dynamic, adaptive treatment in complex medical environments.