Magnetically powered cancer cell microrobots for surgery-free generation of targeted tumor mouse models

In precision therapy, patient-derived cancer cells are inoculated into the same organ from which they are derived to simulate the micro- environment of the original tumor. However, due to the high technical difficulty and low success rate of the required surgical operation, appropriate animal models are lacking, which restricts its application. Here, we report a surgery-free method for creating a desired tumor mouse model using cancer cell microrobots guided by rotating gradient magnetic fields. The uptake of magnetic particles produces cancer cell microrobots. The external magnetic field enables the microrobots to hover around the target localization, enhancing their ability to penetrate the vascular endothelium. In vivo tests in mice demonstrate the capability of creating a desired tumor mass in a particular body location. This work provides a promising method to generate a targeted tumor mouse model without using conventional surgery operations for further precision medicine treatment study of cancer.