Self-Propelled Microrobots Effectively Delivered Drugs in the Bladder of Lab Mice, Could One Day Transport Medicine Inside the Human Body

One of the patients' struggles during medical treatment is experiencing pain as the drug is injected into their bodies. For instance, treating painful bladder syndrome involves weeks of returning to the clinic as the doctor injects dexamethasone solution into the bladder through a catheter. To overcome this challenge, scientists tried to find a better approach to drug delivery.

Transporting Drugs Using Microrobots

At the University of Colorado Boulder, engineers developed a new type of tiny, self-propelled robot that can move through liquid at incredible speeds. Lead author Jin Lee from the Department of Chemical and Biological Engineering worked with other researchers in designing microrobots that measure only 20 micrometers wide, smaller than the width of a human hair. With a speed of 3 millimeters per second, they can travel even faster than a cheetah in relative terms.

The microrobots were made from biocompatible polymers using a technology resembling 3D printing. The tiny machines appear like small rockets with three additional tiny fins. Aside from it, each of the robots also carries bubbles of confined air which will cause the machines to vibrate upon exposure to an acoustic field. This will push the water away and cause the microrobots to move forward.

The microrobots can perform other important functions, too. When thousands of these machines were deployed to the bladders of lab mice, these tiny machines could deliver high concentrations of dexamethasone, a steroid drug used to treat various inflammatory conditions. The microrobots spread through the organs before clinging onto the bladder walls, making them hard to be released in the urine.

Once the microrobots were inside the bladder, they slowly released the dexamethasone for two days. The steady flow of medicine gave more time for the patients to receive more medication.

This indicates that the microrobots can be useful in curing bladder diseases and other health problems.

According to Lee, much work will be needed before it can travel inside the human body. For now, they ensure that the microrobots are biodegradable to dissolve inside a person's body. In the future, it allows transporting prescription drugs to the areas of the human body that are hard to reach.

"Imagine if microrobots could perform certain tasks in the body, such as non-invasive surgeries," said Lee. "Instead of cutting into the patient, we can simply introduce the robots to the body through a pill or an injection, and they would perform the procedure themselves," she added.

What is Painful Bladder Syndrome?

Painful bladder syndrome (PBS), or interstitial cystitis, is a chronic health problem that causes pressure and pain in the bladder and may sometimes cause pelvic pain. Although this disease's exact cause is unknown, it is usually linked to other chronic conditions such as fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome.

People of all ages can experience BPS, but it is more common in women over 30. Some of its symptoms include intense pelvic pain, strong urges to pee, and needing to pee more than usual.

Several treatment options are offered to patients with BPS. They may be asked to take over-the-counter painkillers, drugs for nerve pain, or medicine that can block histamine in the bladder. Some drugs called intravesical medication can be delivered directly into the bladder using a catheter in a process called bladder instillations.