Singapore Scientists Develop Grain-Sized Robots That Can Move Through Human Body To Deliver Drugs

A new medical breakthrough could pave the way for improved therapies in the future.

Scientists at Singapore’s Nanyang Technological University (NTU) have developed grain-sized robots that can move through the body using magnetic fields to precisely deliver drugs where needed.

The new innovation, which was published in the scientific journal Advanced Materials, is believed to be the first reported instance of miniature robots that can transport up to four different drugs and release them in reprogrammable orders and doses.

Previously, robots of this scale were only able to carry up to three types of drugs and cannot be programmed for release in order.

In addition, they are said to be more dexterous than existing miniature robots, capable of quickly rolling and crawling to get over obstacles. That extra dexterity brings great potential for navigating complex, unstructured environments inside the human body.

In lab experiments, the robots were able to accomplish tasks in water that mimicked conditions in the human body.

The scientists first placed them on a surface divided into four sections, and they were able to successfully move to each section at speeds between 0.30 mm and 16.5 mm per second while releasing a different drug in each section. This experiment proves the robots’ ability to carry multiple drugs and release them in a controlled manner.

Meanwhile, in another experiment, the scientists replaced water with a thicker liquid to simulate the challenging environment inside the human body. The results showed that the robots could still navigate the thick liquid and release sufficient drugs over eight hours. Even after that, the robots exhibited minimal drug leakage, making them good candidates for treatments requiring the precise delivery of multiple drugs at different times and locations.

Such breakthroughs, according to the scientists, bring greater precision functions in drug delivery, which have the potential to significantly improve therapeutic outcomes while minimising side effects.

Assistant Professor Lum Guo Zhan from the School of Mechanical and Aerospace Engineering (MAE) said the scientists were inspired by the 1960s film ‘Fantastic Voyage’, in which a submarine crew was shrunk to the size of a cell to repair damage in an injured scientist’s brain.

“What was a scenario in a sci-fi movie is now becoming closer to reality with our lab’s

Innovation,” said Assistant Professor Lum.

The miniature robots were created using smart magnetic composite materials (magnetic microparticles and polymers), which are non-toxic and safe to administer to a human body.

Co-author of the study Yang Zilin said that the breakthroughs could have a key role in the future of drug delivery, especially in the field of cancer treatment.

Providing an independent view, Dr Yeo Leong Litt Leonard, Senior Consultant and surgeon at the Division of Neurology, Department of Medicine, National University Hospital and Ng Teng Fong General Hospital, said, “As a doctor who performs minimally invasive procedures, we currently use a catheter and a wire to move through blood vessels to treat problems. But I can foresee it will not be long before this is superseded by tiny robots that can autonomously swim through the body to reach places we can't get to with our tools.”

However, before the robots are deployed for use in medical treatments, the scientists first aim to evaluate their performance with organ-on-chip devices and animal models.

They also look to make the robots even smaller so that they could eventually be used to provide revolutionary treatments for conditions such as brain tumours, bladder cancer, and colorectal cancer.

Scientists at NTU have developed grain-sized robots that can move through the body using magnetic fields to precisely deliver drugs where needed.
This is the first reported instance of miniature robots that can transport up to four different drugs and release them in reprogrammable orders and doses.
The miniature robots were created using smart magnetic composite materials, which are non-toxic and safe to administer to a human body.