# Magnetic Microrobots for Drug Delivery: A Review of Fabrication Materials, Structure Designs and Drug Delivery Strategies

## TL;DR

Magnetic microrobots offer a new way to deliver drugs precisely in the body, with benefits over traditional methods and challenges in moving them to clinical use.

## Contribution

A comprehensive review of fabrication materials, structural designs, and drug delivery strategies for magnetic microrobots.

## Key findings

- Magnetic microrobots enable remote control and precise navigation for improved drug delivery.
- Structural designs and drug release mechanisms enhance therapeutic efficacy and targeting precision.
- Key challenges include biological safety, large-scale production, and navigation in complex environments.

## Abstract

Magnetic microrobots have emerged as a promising platform for drug delivery in recent years. By enabling remotely controlled motion and precise navigation under external magnetic fields, these systems offer new solutions to overcome the limitations of traditional drug delivery nanocarriers, such as inadequate tissue penetration and heterogeneous biodistribution. Over the past few years, significant advancements have been made in the structural design of magnetic microrobots, as well as in drug loading techniques and stimuli-responsive drug release mechanisms, thereby demonstrating distinct advantages in enhancing therapeutic efficacy and targeting precision. This review provides a comprehensive overview of magnetic drug delivery microrobots, which are categorised into biomimetic structural, bio-templated and advanced material-based types, and introduces their differences in propulsion efficiency and biocompatibility. Additionally, drug loading and release strategies are summarised, including physical adsorption, covalent coupling, encapsulation, and multistimuli-responsive mechanisms such as pH, enzyme activity and thermal triggers. Overall, these advancements highlight the significant potential of magnetic microrobots in targeted drug delivery and emphasise the key challenges in their clinical translation, such as biological safety, large-scale production and precise targeted navigation within complex biological environments.