Doxorubicin‐Loaded Microrobots for Targeted Drug Delivery and Anticancer Therapy

Micro‐sized magnetic particles (also known as microrobots [MRs]) have recently been shown to have potential applications for numerous biomedical applications like drug delivery, microengineering, and single cell manipulation. Interdisciplinary studies have demonstrated the ability of these tiny particles to actuate under the action of a controlled magnetic field that not only drive MRs in a desired trajectory but also precisely deliver therapeutic payload to the target site. Additionally, optimal concentrations of therapeutic molecules can also be delivered to the desired site which is cost‐effective and safe especially in scenarios where drug dose‐related side effects are a concern. In this study, MRs are used to deliver anticancer drugs (doxorubicin) to cancer cells and subsequent cell death is evaluated in different cell lines (liver, prostate, and ovarian cancer cells). Cytocompatibility studies show that MRs are well‐tolerated and internalized by cancer cells. Doxorubicin (DOX) is chemically conjugated with MRs (DOX‐MRs) and magnetically steered toward cancer cells using the magnetic controller. Time‐lapsed video shows that cells shrink and eventually die when MRs are internalized by cells. Taken together, this study confirms that microrobots are promising couriers for targeted delivery of therapeutic biomolecules for cancer therapy and other non‐invasive procedures that require precise control. A simple strategy to prepare doxurubicin‐loaded microrobots (DOX‐MRs) that are self‐propelled in presence of an external magnetic field. These microrobots are carboxylic group‐functionalized paramagnetic beads that allow covalent conjugation of DOX on its outer surface. Microrobots are ingested by cancer cells after DOX‐MRs treatment, where DOX is cleaved, and released by proteolytic enzyme activity.