MIT Nanobots: Millimeter-Sized Precision Against Cancer

MIT researchers have developed a method for mass-producing specialized nanoparticles—virtual medical "nanobots"—capable of delivering cancer drugs directly to tumors. This technology promises to revolutionize cancer treatment, increasing efficacy and reducing devastating side effects.

Nanotechnology, the science of manipulating matter at incredibly small scales (a nanometer is one billionth of a meter), is opening revolutionary frontiers in medicine. Within this field, nanomedicine refers to the use of nanometer-sized tools and devices to diagnose, prevent, and treat diseases at the molecular level. Medical "nanobots," although the term may conjure up science-fiction images of tiny robots, in current practice often refer to nanoparticles cleverly designed to interact with biological systems in specific ways.

At the Massachusetts Institute of Technology (MIT), Professor Paula Hammond's laboratory has been at the forefront of developing these types of nanoparticles. Her work has focused on multilayered polymer-coated particles loaded with therapeutic drugs. These nanoparticles are designed to function as high-precision delivery vehicles. The idea is that they can navigate the bloodstream and specifically target tumor cells, releasing their drug payload directly at the cancer site. This "smart pump" approach has the potential to maximize the drug's effect on cancer cells while minimizing exposure to the body's healthy cells, thereby reducing many of the debilitating side effects associated with traditional chemotherapy. The ability of these nanoparticles to recognize and target cancerous tissue makes them significant promise for more effective and less invasive cancer treatments.

One of the biggest challenges in bringing promising nanoparticle-based therapies from the lab to the clinic has been the difficulty of producing them on a large scale in a consistent and efficient manner. Original layer-by-layer assembly techniques, while effective in creating particles with precise properties, are laborious and time-consuming, involving multiple steps of polymer application and centrifugation to remove excess. Subsequent attempts to optimize purification, such as tangential flow filtration, improved the process but still presented limitations in terms of manufacturing complexity and maximum production scale.

The recent breakthrough by the MIT team, led by Paula Hammond, Ivan Pires, and Ezra Gordon, lies precisely in overcoming this manufacturing obstacle. They have developed a method that uses a microfluidic mixing device to assemble nanoparticles quickly and in large quantities. This device allows new polymer layers to be added sequentially as the particles flow through a microchannel. Crucially, the researchers can accurately calculate the amount of polymer needed for each layer, eliminating the need for costly and time-consuming purification steps after each addition.

This engineering innovation is just as important as the design of the nanoparticle itself, unlocking the potential for clinical-scale production. The microfluidic device employed is already used in Good Manufacturing Practices (GMP) manufacturing for other types of nanoparticles, such as mRNA vaccines, facilitating their adoption and ensuring safety standards and consistency. Using this new method, researchers can generate 15 milligrams of nanoparticles (enough for approximately 50 doses) in just a few minutes, compared to nearly an hour with the original technique.

“There’s a lot of promise with the nanoparticle systems we’ve been developing… We’re really excited more recently by the successes we’ve been seeing in animal models for our ovarian cancer treatments in particular.” – Paula Hammond, MIT.

The efficacy of nanoparticles manufactured using this new mass-production method has been validated in preclinical studies. MIT researchers created nanoparticles loaded with interleukin-12 (IL-12), a cytokine known for its ability to activate the immune system against cancer cells. In mouse models of ovarian cancer, these nanoparticles demonstrated similar performance to those manufactured using the original technique, delaying tumor growth and even, in some cases, curing the disease.

A particularly interesting and unique aspect of these nanoparticles is their mechanism of action. They not only deliver drugs, but also interact with the immune system in a sophisticated manner. They bind to cancerous tissue but, remarkably, do not enter the cancer cells themselves. Instead, they act as markers on the surface of these cells, allowing the immune system to be locally activated directly within the tumor. This ability to combine targeted drug delivery with localized immunostimulation represents a powerful synergy, offering a multifaceted attack against cancer.

Although initial research has focused on cancers of the abdominal cavity, such as ovarian cancer, the researchers believe this technology could be applied to other types of cancer, including glioblastoma, an aggressive brain cancer. The team has already applied for a patent for this technology and is working with MIT's Deshpande Center for Technology Innovation with an eye toward potential commercialization, which could accelerate the arrival of these medical "nanobots" to patients who need them. This breakthrough underscores how the convergence of materials science, chemical engineering, and immunology is forging the future of precision oncology.