New molecular camera could revolutionize bladder cancer screening

Bladder cancer remains one of the most persistent and costly cancers to manage. Every year, roughly 85,000 Americans receive the diagnosis. For many patients, treatment succeeds at first. The challenge comes later.

About half of bladder cancer patients develop new tumors within five years of treatment. That constant threat of recurrence forces patients into years of monitoring, repeated procedures, and ongoing anxiety. The disease carries one of the highest lifetime treatment costs of any cancer because doctors must keep searching for signs that it has returned.

Now, researchers at the Massachusetts Institute of Technology have developed a technology that could dramatically improve how doctors monitor those patients. Their new system uses a catheter coated with nanosensors that can detect cancer-related proteins directly inside the bladder, allowing physicians to find tiny tumors long before they become visible through conventional methods.

The study shows that the approach can identify extremely small amounts of a bladder cancer biomarker and create a chemical map showing exactly where the signal originates.

“It’s like a camera for molecules instead of light,” said Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and senior author of the study. “If you have a billion nanosensors in an array, you can use them to make a chemical image that helps you locate their source.”

Bladder cancer is the tenth most common cancer worldwide. In 2020 alone, about 573,000 people were diagnosed, and approximately 213,000 died from the disease.

Roughly 75% of cases are classified as non-muscle invasive bladder cancer. These tumors remain confined to the bladder lining and can often be treated successfully. However, they frequently return.

To watch for recurrence, doctors rely heavily on cystoscopy, a procedure that inserts a camera into the bladder to look for suspicious growths. While effective, cystoscopy is invasive, uncomfortable, and expensive. Patients often undergo the procedure every year, and sometimes more frequently.

Urine-based tests provide another option. These tests search for cancer-related biomarkers, including nuclear matrix protein 22, or NMP-22. However, urine testing faces a major limitation.

The bladder continuously fills and empties. Biomarkers released by tumors become diluted in hundreds of milliliters of urine. They can also break down before testing occurs. As a result, small or early-stage tumors often escape detection.

Researchers wanted to solve this problem by moving the sensor directly to the source.

Instead of analyzing diluted urine after it leaves the body, the MIT team developed a catheter that detects biomarkers inside the bladder itself.

The technology relies on single-walled carbon nanotubes, tiny hollow cylinders made of carbon that naturally fluoresce when exposed to laser light. Over the past decade, Strano’s laboratory has developed ways to coat these nanotubes with specially designed polymers that function like synthetic antibodies.

These coatings recognize specific target molecules. When a target binds to the nanotube surface, the fluorescent signal changes in a measurable way.

For this project, researchers engineered a sensor specifically designed to detect NMP-22, an FDA-approved biomarker associated with bladder cancer.

The sensor uses a phospholipid-based polymer coating called DSPE5k. During testing, it showed strong selectivity for NMP-22 while largely ignoring other proteins commonly found in urine.

When exposed to NMP-22, the nanosensor’s fluorescence decreased by more than 35%, creating a clear signal that cancer-related proteins were present.

The device does more than simply detect cancer markers. It can also show where they originate.

Researchers coated a standard urinary catheter with billions of nanosensors arranged in a ring-shaped pattern. Inside the catheter sits a miniature rotating ball lens.

The lens emits laser light and records fluorescent signals from the nanotubes. As it rotates 360 degrees and moves through the bladder, it scans the surrounding tissue and builds a three-dimensional chemical map.

These maps reveal areas where biomarkers are concentrated.

“If you are scanning over a region of tissue, you would like to know not just that there is a signal indicating that a tumor is there, but also its location so that you can treat it or perform a biopsy,” Strano said.

“Before an early-stage tumor breaks through the urothelium so that it’s visible, it’s under the surface but still emitting chemical signals that can be imaged. When a chemical hits the catheter, we don’t just detect its presence, but we collect a map that pinpoints its location.”

In effect, the system functions like a camera that sees chemistry instead of light.

To evaluate the sensor, researchers first tested it using six bladder cancer cell lines and healthy bladder cells.

The cancer cells were treated with the chemotherapy drug gemcitabine, causing many of them to die. As cancer cells broke apart, they released NMP-22 and other cellular contents.

The nanosensors responded strongly to material released from cancer cells. Healthy cells generated only minimal responses.

Further experiments confirmed that NMP-22 was responsible for much of the signal. When researchers reduced NMP-22 production using gene-silencing techniques, sensor responses dropped significantly.

The team then attached the sensors to catheters using a durable coating made from tannic acid. Testing showed that the sensors remained stable under different pH levels, urine conditions, sterilization procedures, and fluid flow rates.

The catheter also demonstrated excellent safety characteristics. Even when small amounts of sensor material detached, cell viability remained high.

One of the most important findings involved sensitivity.

Computer modeling suggested that placing sensors directly inside the bladder could improve detection capability by more than 50,000-fold compared with traditional urine sampling.

In practical experiments, the catheter produced signals roughly 182 times stronger than measurements taken from diluted fluids.

Animal bladder tests demonstrated that the technology could identify biomarker release from simulated tumors as small as 16 square millimeters.

The system successfully detected signals up to two centimeters away from their source. Researchers also showed that it could accurately pinpoint cancer cells placed at different locations within a test chamber.

Using porcine bladders, which closely resemble human bladders, the device generated clear three-dimensional maps of NMP-22 release under different fluid volumes.

Even when the bladder contained up to 400 milliliters of fluid, the sensor maintained strong performance.

The technology’s flexibility may prove just as important as its sensitivity.

Researchers have already developed dozens of nanotube-based sensors that detect different biological targets, including hydrogen peroxide, viral proteins, riboflavin, and other molecules.

In one demonstration, the team replaced the NMP-22 sensor with a different nanotube coating and successfully detected hydrogen peroxide instead.

That suggests the platform could eventually be adapted for many diseases beyond bladder cancer.

“The beauty of polymer chemistry is that if we understand the molecular structures of target biomarkers and the design principles of binding sites, we can develop new sensors tailored to different diseases,” said Wonjun Yim, a Schmidt Science postdoctoral fellow and co-lead author of the study.

“You can imagine if these sensors were integrated onto the catheter, they could reveal invisible biomarkers that current endoscopic procedures miss, opening the door to detecting many other diseases in the future.”

This technology could significantly change how bladder cancer is monitored after treatment. By detecting biomarkers directly at their source, doctors may be able to identify recurring tumors months or even years earlier than current methods allow. Earlier detection often means simpler treatments, fewer complications, and better outcomes for patients.

The approach could also reduce the need for repeated invasive procedures. If future clinical studies confirm its effectiveness, the system may allow physicians to perform faster and less costly screenings in a doctor’s office while improving diagnostic accuracy.

Beyond bladder cancer, the platform offers a new way to visualize disease-related chemistry inside the body. Researchers could potentially adapt the sensors to detect biomarkers linked to gastrointestinal disorders, cardiovascular disease, infections, or other cancers. As more disease-specific sensors are developed, the technology may become a versatile tool for diagnosing conditions that currently remain hidden until symptoms appear.

These resources explore surveillance, the evidence behind urinary biomarkers and the molecular recognition chemistry used in nanosensors.

Clinical Implementation of Urinary Biomarkers for Surveillance of Non-muscle-invasive Bladder Cancer (NMIBC): Considerations from the European Association of Urology NMIBC Guideline Panel: Explains the clinical evidence, regulatory requirements and cost-effectiveness questions involved in biomarker-guided follow-up. (European Urology Oncology, 2025)

Urine biomarkers in bladder cancer — current status and future perspectives: Reviews available biomarkers, benign sources of interference and the validation needed for broader clinical use. (Nature Reviews Urology, 2023)

Urinary biomarkers for bladder cancer diagnosis and NMIBC follow-up: a systematic review: Evaluates clinical validity and utility across eleven urinary biomarker tests, including NMP-22 assays. (World Journal of Urology, 2023)

Bladder Cancer Treatment (PDQ®)–Health Professional Version: Provides clinical context on disease stages, recurrence and treatment options against which new monitoring tools must be assessed. (National Cancer Institute, 2025)

Protein-targeted corona phase molecular recognition: Describes foundational work using polymer-coated nanotubes to recognize proteins through changes in fluorescence. (Nature Communications, 2016)

Research findings are available online in the journal Nature Nanotechnology.

The original story "New molecular camera could revolutionize bladder cancer screening" is published in The Brighter Side of News.

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