Imagine a future where cancer treatment affects only the tumor, where eye injections are no longer required and brain surgeries don’t result in large incisions or long recovery times. That’s the future researchers at Michigan State University are working toward.

Their goal is to make medical care easier on patients by using tiny biodegradable tools that can travel through the body and deliver treatment exactly where it’s needed. These tools, called microrobots, are designed to reduce pain, limit side effects and help people heal faster.

In a study with collaborators from Henry Ford Health and Arizona State University, MSU researchers unveiled a breakthrough microrobot design called TriMag. What makes TriMag innovative is that it combines three powerful abilities in one microscopic device so it can be guided precisely through the body using magnetic fields, tracked in real time with advanced imaging, and gently heated to destroy tumor cells — all without surgery.

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While TriMag microrobots are still being tested in early preclinical studies, the advancement represents an important step toward more patient-friendly treatments. By bringing multiple capabilities together into a single device that is smaller than a human hair, this research opens the door to more precise drug delivery, clearer imaging and better-targeted cancer therapies for improved patient comfort and healing.

The research findings appear in Advanced Materials.

According to lead researcher Jinxing Li, a Red Cedar Distinguished Assistant Professor in the MSU College of Engineering and principal investigator in the MSU Institute for Quantitative Health Science and Engineering, current microrobots do not work well inside the human body because they cannot deliver accurate real-time localized images through tissue or organs. And it is challenging to interpret the information that does come from today’s microrobots.

“Now, with advanced microrobotic design and imaging tools, we can reliably build, track and activate microrobots deep inside the human body,” said Li. “Because the TriMag design is so versatile, it opens the door to treatments that were not possible before.”

When used for medical purposes, microrobots could be injected or swallowed. They also could be applied to a patient’s skin, depending on the procedure. Magnets positioned outside of the patient’s body would enable the microrobots to “swim” and be “steered” to exact targets.

Magnetic particle imaging clearly tracks the microrobots in deep tissues and produces real-time three-dimensional images with no radiation or interference from organs or bones. And magnetic heating for cancer treatments can be used to kill tumor cells using a highly targeted process that protects the surrounding tissue. Because the microrobots heat only cancer tumors, not healthy organs, cancer treatments could become more targeted and less damaging.

“The structure of the microrobots is inspired by nature and mimics sperm cells in both their shape and movement,” Li added. “Natural cells that are capable of self-directed movement perform well in a viscous environment like the human body. Our results show the microrobots can also move easily through biological fluids while performing different tasks.”

In addition to treating cancer tumors, microrobots could make eye treatments less invasive and more precise because clinicians could guide microrobots to the exact spot needing treatment rather than injecting medicine into the eyeball. Presurgery imaging could be safer using microrobots to carry contrast agents. And complex brain surgeries could be less invasive.

“Microrobots also hold promise for complex brain surgeries,” said Ian Lee, neurosurgeon at Henry Ford Health and one of the study’s co-authors. “They offer a less invasive way to navigate delicate brain structures in humans. Less invasiveness means faster recovery for patients. Additionally, microrobots could make many current procedures less painful.”

Devices this small require extreme accuracy to benefit patient care and biological research. MSU researchers fabricated the TriMag microrobots using a high-precision three-dimensional printer in the IQ 3D Printing Core.

“When the microrobot’s job is done, it safely biodegrades,” Li explained. “They’re made with edible polymers — similar to materials in dissolvable drug capsules — and tiny iron oxide particles. The body breaks them down, and their components are either used naturally, like iron for hemoglobin, or removed through normal processes.”

The microrobots have been tested in biological fluids and animal models. While human trials are still years away, researchers say this breakthrough provides one of the strongest platforms yet for developing microrobots that could reach clinical use.

This research is supported by the National Science Foundation, the National Institutes of Health and the Henry Ford Health + Michigan State University Health Sciences Cancer Seed Funding Program.

Postdoctoral scholar Liuxi Xing and doctoral student Yulu Cai from MSU are the lead contributing authors. Additional collaborators include Yapei Zhang, Kevin Mozel, Zhengxu Tang, Vittorio Mottini, Saumya Nigam, Bryan R. Smith and Ping Wang from MSU; Tavarekere N. Nagaraja from Henry Ford Health; and Tengteng Tang and Xiangjia Li from Arizona State University.