Scientists at MIT have announced that they developed novel nanoparticles to detect cancer in urine samples. As well as detecting the presence of tumors, the nanoparticles can also accumulate at tumor sites and function as an imaging agent, helping to identify their location. These multifunctional particles could be very useful for routine cancer screening and helping clinicians to determine whether a tumor has spread or recurred. “This is a really broad sensor intended to respond to both primary tumors and their metastases,” said Sangeeta Bhatia, a researcher involved in the study. “It can trigger a urinary signal and also allow us to visualize where the tumors are.” The nanoparticles are covered with peptides that can be naturally cleaved by proteases present on the surface of cancer cells. These cleaved peptides end up in the urine to form a synthetic biomarker where they can be detected through a simple urine test. The researchers have already tested the nanoparticles in animal models of cancer, and they successfully highlighted the presence of tumors. So far, so good, but clinicians need to know where exactly the tumors are, and if they spread to multiple sites in the body. Happily, the nanoparticles also function as a tumor imaging agent. The researchers included the radioactive agent copper-64 within the particles, which can be detected using PET (positron emission tomography) imaging. The particles’ surface is also studded with peptides that are attracted to the acidic tumor microenvironment, helping to enhance particle accumulation and retention within tumors. The researchers have high hopes that the system could be very useful for long-term monitoring of cancer patients. “Those patients could be monitored with the urinary version of the test every six months, for instance,” said Bhatia. “If the urine test is positive, they could follow up with a radioactive version of the same agent for an imaging study that could indicate where the disease had spread. We also believe the regulatory path may be accelerated with both modes of testing leveraging a single formulation.” Excitingly, the system may even serve as a cancer test . “The vision is that you could use this in a screening paradigm – alone or in conjunction with other tests – and we could collectively reach patients that do not have access to costly screening infrastructure today,” said Bhatia. “Every year you could get a urine test as part of a general check-up. You would do an imaging study only if the urine test turns positive to then find out where the signal is coming from. We have a lot more work to do on the science to get there, but that’s where we would like to go in the long run.” Source
