Tag Archives: Sangeeta N. Bhatia

Detect lung cancer early by inhaling a nanosensor

The technology described in a January 5, 2024 news item on Nanowerk has not been tried in human clinical trials but early pre-clinical trial testing offers promise,

Using a new technology developed at MIT, diagnosing lung cancer could become as easy as inhaling nanoparticle sensors and then taking a urine test that reveals whether a tumor is present.

Key Takeaways

*This non-invasive approach may serve as an alternative or supplement to traditional CT scans, particularly beneficial in areas with limited access to advanced medical equipment.

*The technology focuses on detecting cancer-linked proteins in the lungs, with results obtainable through a simple paper test strip.

*Designed for early-stage lung cancer detection, the method has shown promise in animal models and may soon advance to human clinical trials.

*This innovation holds potential for significantly improving lung cancer screening and early detection, especially in low-resource settings.

A January 5, 2024 Massachusetts Institute of Technology (MIT) news release (also on EurkeAlert), which originated the news item, goes on to provide some technical details,

The new diagnostic is based on nanosensors that can be delivered by an inhaler or a nebulizer. If the sensors encounter cancer-linked proteins in the lungs, they produce a signal that accumulates in the urine, where it can be detected with a simple paper test strip.

This approach could potentially replace or supplement the current gold standard for diagnosing lung cancer, low-dose computed tomography (CT). It could have an especially significant impact in low- and middle-income countries that don’t have widespread availability of CT scanners, the researchers say.

“Around the world, cancer is going to become more and more prevalent in low- and middle-income countries. The epidemiology of lung cancer globally is that it’s driven by pollution and smoking, so we know that those are settings where accessibility to this kind of technology could have a big impact,” says Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and of Electrical Engineering and Computer Science at MIT, and a member of MIT’s Koch Institute for Integrative Cancer Research and the Institute for Medical Engineering and Science.

Bhatia is the senior author of the paper, which appears today [January 5, 2024] in Science Advances. Qian Zhong, an MIT research scientist, and Edward Tan, a former MIT postdoc, are the lead authors of the study.

Inhalable particles

To help diagnose lung cancer as early as possible, the U.S. Preventive Services Task Force recommends that heavy smokers over the age of 50 undergo annual CT scans. However, not everyone in this target group receives these scans, and the high false-positive rate of the scans can lead to unnecessary, invasive tests.

Bhatia has spent the last decade developing nanosensors for use in diagnosing cancer and other diseases, and in this study, she and her colleagues explored the possibility of using them as a more accessible alternative to CT screening for lung cancer.

These sensors consist of polymer nanoparticles coated with a reporter, such as a DNA barcode, that is cleaved from the particle when the sensor encounters enzymes called proteases, which are often overactive in tumors. Those reporters eventually accumulate in the urine and are excreted from the body.

Previous versions of the sensors, which targeted other cancer sites such as the liver and ovaries, were designed to be given intravenously. For lung cancer diagnosis, the researchers wanted to create a version that could be inhaled, which could make it easier to deploy in lower resource settings.

“When we developed this technology, our goal was to provide a method that can detect cancer with high specificity and sensitivity, and also lower the threshold for accessibility, so that hopefully we can improve the resource disparity and inequity in early detection of lung cancer,” Zhong says.

To achieve that, the researchers created two formulations of their particles: a solution that can be aerosolized and delivered with a nebulizer, and a dry powder that can be delivered using an inhaler.

Once the particles reach the lungs, they are absorbed into the tissue, where they encounter any proteases that may be present. Human cells can express hundreds of different proteases, and some of them are overactive in tumors, where they help cancer cells to escape their original locations by cutting through proteins of the extracellular matrix. These cancerous proteases cleave DNA barcodes from the sensors, allowing the barcodes to circulate in the bloodstream until they are excreted in the urine.

In the earlier versions of this technology, the researchers used mass spectrometry to analyze the urine sample and detect DNA barcodes. However, mass spectrometry requires equipment that might not be available in low-resource areas, so for this version, the researchers created a lateral flow assay, which allows the barcodes to be detected using a paper test strip.

The researchers designed the strip to detect up to four different DNA barcodes, each of which indicates the presence of a different protease. No pre-treatment or processing of the urine sample is required, and the results can be read about 20 minutes after the sample is obtained.

“We were really pushing this assay to be point-of-care available in a low-resource setting, so the idea was to not do any sample processing, not do any amplification, just to be able to put the sample right on the paper and read it out in 20 minutes,” Bhatia says.

Accurate diagnosis

The researchers tested their diagnostic system in mice that are genetically engineered to develop lung tumors similar to those seen in humans. The sensors were administered 7.5 weeks after the tumors started to form, a time point that would likely correlate with stage 1 or 2 cancer in humans.

In their first set of experiments in the mice, the researchers measured the levels of 20 different sensors designed to detect different proteases. Using a machine learning algorithm to analyze those results, the researchers identified a combination of just four sensors that was predicted to give accurate diagnostic results. They then tested that combination in the mouse model and found that it could accurately detect early-stage lung tumors.

For use in humans, it’s possible that more sensors might be needed to make an accurate diagnosis, but that could be achieved by using multiple paper strips, each of which detects four different DNA barcodes, the researchers say.

The researchers now plan to analyze human biopsy samples to see if the sensor panels they are using would also work to detect human cancers. In the longer term, they hope to perform clinical trials in human patients. A company called Sunbird Bio has already run phase 1 trials on a similar sensor developed by Bhatia’s lab, for use in diagnosing liver cancer and a form of hepatitis known as nonalcoholic steatohepatitis (NASH).

In parts of the world where there is limited access to CT scanning, this technology could offer a dramatic improvement in lung cancer screening, especially since the results can be obtained during a single visit.

“The idea would be you come in and then you get an answer about whether you need a follow-up test or not, and we could get patients who have early lesions into the system so that they could get curative surgery or lifesaving medicines,” Bhatia says.

Here’s a link to and a citation for the paper,

Inhalable point-of-care urinary diagnostic platform by Qian Zhong, Edward K. W. Tan, Carmen Martin-Alonso, Tiziana Parisi, Liangliang Hao, Jesse D. Kirkpatrick, Tarek Fadel, Heather E. Fleming, Tyler Jacks, and Sangeeta N. Bhatia. Science Advances 5 Jan 2024 Vol 10, Issue 1 DOI: 10.1126/sciadv.adj9591

This paper is open access.

Sunbird Bio (the company mentioned in the news release) can be found here.

A millionth of a trillionth of a gram: attoscale weight

Researchers at the Massachusetts Institute of Technology (MIT) have found a means of measuring particle weight, with increased accuracy, at the attoscale according to a Jan. 13, 2014 news item on ScienceDaily,

MIT engineers have devised a way to measure the mass of particles with a resolution better than an attogram — one millionth of a trillionth of a gram. Weighing these tiny particles, including both synthetic nanoparticles and biological components of cells, could help researchers better understand their composition and function.

The Jan. 13, 2014 MIT news release by Anne Trafton (also on EurekAlert), which originated the news item, describes the origins of the technology that the researchers adapted to achieve increased resolution,

The system builds on a technology previously developed by Scott Manalis, an MIT professor of biological and mechanical engineering, to weigh larger particles, such as cells. This system, known as a suspended microchannel resonator (SMR), measures the particles’ mass as they flow through a narrow channel.

By shrinking the size of the entire system, the researchers were able to boost its resolution to 0.85 attograms —more than a 30-fold improvement over the previous generation of the device.

“Now we can weigh small viruses, extracellular vesicles, and most of the engineered nanoparticles that are being used for nanomedicine,” says Selim Olcum, a postdoc in Manalis’ lab  …

Manalis first developed the SMR system in 2007 to measure the mass of living cells, as well as particles as small as a femtogram (one quadrillionth of a gram, or 1,000 attograms). Since then, his lab has used the device to track cell growth over time, measure cell density, and measure other physical properties, such as stiffness.

The original mass sensor consists of a fluid-filled microchannel etched in a tiny silicon cantilever that vibrates inside a vacuum cavity. As cells or particles flow through the channel, one at a time, their mass slightly alters the cantilever’s vibration frequency. The mass of the particle can be calculated from that change in frequency.

To make the device sensitive to smaller masses, the researchers had to shrink the size of the cantilever, which behaves much like a diving board, Olcum says. When a diver bounces at the end of a diving board, it vibrates with a very large amplitude and low frequency. When the diver plunges into the water, the board begins to vibrate much faster because the total mass of the board has dropped considerably.

To measure smaller masses, a smaller “diving board” is required. “If you’re measuring nanoparticles with a large cantilever, it’s like having a huge diving board with a tiny fly on it. When the fly jumps off, you don’t notice any difference. That’s why we had to make very tiny diving boards,” Olcum says.

In a previous study, researchers in Manalis’ lab built a 50-micron cantilever — about one-tenth the size of the cantilever used for measuring cells. That system, known as a suspended nanochannel resonator (SNR), was able to weigh particles as light as 77 attograms at a rate of a particle or two per second.

Here’s how the scientists accomplished their latest goal of getting more precise measurements of weight (from the news release),

The cantilever in the new version of the SNR device is 22.5 microns long, and the channel that runs across it is 1 micron wide and 400 nanometers deep. This miniaturization makes the system more sensitive because it increases the cantilever’s vibration frequency. At higher frequencies, the cantilever is more responsive to smaller changes in mass.

The researchers got another boost in resolution by switching the source for the cantilever’s vibration from an electrostatic to a piezoelectric excitation, which produces a larger amplitude and, in turn, decreases the impact of spurious vibrations that interfere with the signal they are trying to measure.

With this system, the researchers can measure nearly 30,000 particles in a little more than 90 minutes. “In the span of a second, we’ve got four or five particles going through, and we could potentially increase the concentration and have particles going through faster,” Cermak says.

To demonstrate the device’s usefulness in analyzing engineered nanoparticles, the MIT team weighed nanoparticles made of DNA bound to tiny gold spheres, which allowed them to determine how many gold spheres were bound to each DNA-origami scaffold. That information can be used to assess yield, which is important for developing precise nanostructures, such as scaffolds for nanodevices.

The researchers also tested the SNR system on biological nanoparticles called exosomes — vesicles that carry proteins, RNA, or other molecules secreted by cells — which are believed to play a role in signaling between distant locations in the body.

They found that exosomes secreted by liver cells and fibroblasts (cells that make up connective tissue) had different profiles of mass distribution, suggesting that it may be possible to distinguish vesicles that originate from different cells and may have different biological functions.

The researchers are now investigating using the SNR device to detect exosomes in the blood of patients with glioblastoma (GBM), a type of brain cancer. This type of tumor secretes large quantities of exosomes, and tracking changes in their concentration could help doctors monitor patients as they are treated.

Glioblastoma exosomes can now be detected by mixing blood samples with magnetic nanoparticles coated with antibodies that bind to markers found on vesicle surfaces, but the SNR could provide a simpler test.

Here’s a link to and a citation for the researchers’ abstract,

Weighing nanoparticles in solution at the attogram scale by Selim Olcuma, Nathan Cermak, Steven C. Wasserman, Kathleen S. Christine, Hiroshi Atsumi, Kris R. Payer, Wenjiang Shen, Jungchul Lee, Angela M. Belcher, Sangeeta N. Bhatia, and Scott R. Manalis. Proceedings of the National Academy of Sciences of the United States of America (PNAS), doi: 10.1073/pnas.1318602111 Published online Jan. 13, 2014

This article is behind a paywall.

DARPA (US Defense Advanced Research Projects Agency), nanoparticles, and your traumatized brain

According to the May 10, 2013 news item on Nanowerk,

DARPA, the U.S. Defense Advanced Research Projects Agency, has awarded $6 million to a team of researchers to develop nanotechnology therapies for the treatment of traumatic brain injury and associated infections.

Led by Professor Michael J. Sailor, Ph.D., from the University of California San Diego [UC San Diego], the award brings together a multi-disciplinary team of renowned experts in laboratory research, translational investigation and clinical medicine, including Erkki Ruoslahti, M.D., Ph.D. of Sanford-Burnham Medical Research Institute, Sangeeta N. Bhatia, M.D., Ph.D. of Massachusetts Institute of Technology and Clark C. Chen, M.D., Ph.D. of UC San Diego School of Medicine.

Ballistics injuries that penetrate the skull have amounted to 18 percent of battlefield wounds sustained by men and women who served in the campaigns in Iraq and Afghanistan, according to the most recent estimate from the Joint Theater Trauma Registry, a compilation of data collected during Operation Iraqi Freedom and Operation Enduring Freedom.

“A major contributor to the mortality associated with a penetrating brain injury is the elevated risk of intracranial infection,” said Chen, a neurosurgeon with UC San Diego Health System, noting that projectiles drive contaminated foreign materials into neural tissue.

The May 9, 2013 UC San Diego news release by Susan Brown, which originated the news item, describes the reasons why DARPA wants to use nanoparticles in therapies for people suffering from traumatic brain injury,

Under normal conditions, the brain is protected from infection by a physiological system called the blood-brain barrier. “Unfortunately, those same natural defense mechanisms make it difficult to get antibiotics to the brain once an infection has taken hold,” said Chen, associate professor and vice-chair of research in the Division of Neurosurgery at UC San Diego School of Medicine.

DARPA hopes to meet these challenges with nanotechnology. The agency awarded this grant under its In Vivo Nanoplatforms for Therapeutics program to construct nanoparticles that can find and treat infections and other damage associated with traumatic brain injuries.

“Our approach is focused on porous nanoparticles that contain highly effective therapeutics on the inside and targeting molecules on the outside,” said Sailor, the UC San Diego materials chemist who leads the team. “When injected into the blood stream, we have found that these silicon-based particles can target certain tissues very effectively.”

Several types of nanoparticles have already been approved for clinical use in patients, but none for treatment of trauma or diseases in the brain. This is due in part to the inability of nanoparticle formulations to cross the blood-brain barrier and reach their intended targets.

“Poor penetration into tissues limits the application of nanoparticles to the treatment of many types of diseases,” said Ruoslahti, distinguished professor at Sanford-Burnham and partner in the research. “We are trying to overcome this limitation using targeting molecules that activate tissue-specific transport pathways to deliver nanoparticles.”

There is another major hurdle for treating brain injuries (from the news release),

Treating brain infections is becoming more difficult as drug-resistant strains of viruses and bacteria have emerged. Because drug-resistant strains mutate and evolve rapidly, researchers must constantly adjust their approach to treatment.

In an attempt to hit this moving target, the team is making their systems modular, so they can be reconfigured “on-the-fly” with the latest therapeutic advances.

Nanocomplexes that contain genetic material known as short interfering RNA, or siRNA, developed by Bhatia’s research group at MIT, will be key to this aspect of the team’s approach.

“The function of this type of RNA is that it specifically intereferes with processes in a diseased cell. The advantage of RNA therapies are that they can be quickly and easily modified when a new disease target emerges,” said Bhatia, a bioengineering professor at MIT and partner in the research.

But effective delivery of siRNA-based therapeutics in the body has proven to be a challenge because the negative charge and chemical structure of naked siRNA makes it very unstable in the body and it has difficulty crossing into diseased cells. To solve these problems, Bhatia has developed nanoparticles that form a protective coating around siRNA.

“The nanocomplexes we are developing shield the negative charge of RNA and protect it from nucleases that would normally destroy it. Adding Erkki’s tissue homing and cell-penetrating peptides allows the nanocomplex to transport deep into tissue and enter the diseased cells,” she said.

Bhatia has previously used the cell-penetrating nanocomplex to deliver siRNA to a tumor cell and shut down its protein production machinery. Although her group’s effort has focused on cancer, the team is now going after two other hard-to-treat cell types: drug-resistant bacteria and inflammatory cells in the brain.

“The work proposed by this multi-disciplinary team should provide new tools to mitigate the debilitating effects of penetrating brain injuries and offer our warfighters the best chance of meaningful recovery,” Chen said. [emphasis mine]

BTW, the term ‘warfighters’ is new to me; are we replacing the word ‘soldier’?

Returning to the matter at hand, I found DARPA’s In Vivo Nanoplatforms for Therapeutics program which is described this way on its home page,

Disease limits soldier readiness and creates healthcare costs and logistics burdens. Diagnosing and treating disease faster can help limit its impact. [emphasis mine] Current technologies and products for diagnosing disease are principally relegated to in vitro (in the lab) medical devices, which are often expensive, bulky and fragile.

DARPA’s In Vivo Nanoplatforms (IVN) program seeks to develop new classes of adaptable nanoparticles for persistent, distributed, unobtrusive physiologic and environmental sensing as well as the treatment of physiologic abnormalities, illness and infectious disease.

The IVN Diagnostics (IVN:Dx) program effort aims to develop a generalized in vivo platform that provides continuous physiological monitoring for the warfighter. [emphasis mine] Specifically, IVN:Dx will investigate technologies that may provide:

  • Implantable nanoplatforms using bio-compatible and nontoxic materials
  • In vivo sensing of small and large molecules of biological interest
  • Multiplexed detection of analytes at clinically relevant concentrations
  • External interrogation of the nanoplatform free from any implanted communications electronics
  • Complete system demonstration in a large animal

The IVN Therapeutics (IVN:Tx) program effort will seek unobtrusive nanoplatforms for rapidly treating disease in warfighters.

(I see DARPA is using both soldier and warfighter’.)

This team is not the only one wishing to deliver drug therapies in a targeted fashion to the brain. My Feb. 19, 2013 posting mentioned Chad Mirkin (Northwestern University) and his team’s efforts with spherical nucleic acids (SNAs), from the posting,

Potential applications include using SNAs to carry nucleic acid-based therapeutics to the brain for the treatment of glioblastoma, the most aggressive form of brain cancer, as well as other neurological disorders such as Alzheimer’s and Parkinson’s diseases. Mirkin is aggressively pursuing treatments for such diseases with Alexander H. Stegh, an assistant professor of neurology at Northwestern’s Feinberg School of Medicine. (originally excerpted from this the Feb. 15, 2013 news release on EurekAlert)

Coincidentally, Mirkin has just been named ‘Chemistry World Entrepreneur of the Year’ by the UK’s Royal Society of Chemistry, from the May 10, 2013 news item on Nanowerk,

Northwestern University scientist Chad A. Mirkin, a world-renowned leader in nanotechnology research and its application, has been named 2013 Chemistry World Entrepreneur of the Year by the Royal Society of Chemistry (RSC). The award recognizes an individual’s contribution to the commercialization of research.

The RSC is honoring Mirkin for his invention of spherical nucleic acids (SNAs), new globular forms of DNA and RNA. These structures form the basis for more than 300 products commercialized by licensees of the technology.

I’m never quite sure what to make of researchers who receive public funding then patent and license the results of that research.

Getting back to soldiers/warfighters, I’m glad to see this research being pursued. Years ago, a physician mentioned to me that soldiers in Iraq were surviving injuries that would have killed them in previous conflicts. The problem is that the same protective gear which insulates soldiers against many injuries makes them vulnerable to abusive head trauma (same principle as ‘shaken baby syndrome’). For example, imagine having a high velocity bullet hit your helmet. You’re protected from the bullet but the impact shakes your head so violently, your brain is injured.