Doxorubicin‐Loaded Microrobots for Targeted Drug Delivery and Anticancer Therapy

Abstract

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.

Magnetic Microrobots for In Vivo Cargo Delivery: A Review

“…Malilick et al activated the carboxyl groups (-COOH) on the surface of MMRs by using ethyl(dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The carboxyl groups formed stable covalent bonds with the amines (-NH 2 ) in DOX, thereby fixing DOX to the MMRs [87]. Similarly, Song et al introduced a magnetic tri-bead microrobot by mixing dicarboxylic azide compounds and biotin with NH 2 -Fe 3 O 4 microbeads to prepare azide/biotin beads.…”

“…However, the slow-release methods lack control over drug release, which may result in premature or insufficient drug delivery [87]. Moreover, slow release is very timeconsuming, and the MMRs may significantly change their position due to continuous propulsion, hindering the precision of targeted delivery [95].…”

Upstream mobility and swarming of light activated micromotors

“…1–3 For example, as a proof on concept, micron-sized particles have been loaded with a cancer killing agent, doxorubicin, and magnetically manipulated to cancer cells in vitro . 4,5 Other microrobots have been used to deliver signaling molecules which were released on demand with light activation. 6 Micromotor swarms, in particular, are promising candidates for biomedical applications due to their enhanced capabilities compared to that of a single particle.…”