Cancer treatment is one of the most active fields in medical research, and a new breakthrough from Johns Hopkins University could change the way cancer immunotherapy works. Researchers have found that larger nanoparticles—specifically 400 nanometers in size—may be more effective in targeting the immune cells that fight cancer, a surprising discovery that challenges the long-standing belief that smaller is better when it comes to drug delivery systems.

This innovative approach has the potential to revolutionize how mRNA-based therapies are delivered to fight cancer. Let’s dive into this exciting discovery and understand how larger particles might be the key to more effective and precise cancer treatments.

Why Larger Particles Work Better for Cancer Immunotherapy

For years, the biomedical community adhered to the idea that smaller nanoparticles (less than 200 nanometers) were optimal for delivering therapeutic treatments. These tiny particles were believed to be less likely to be captured by phagocytic cells, which engulf and destroy foreign bodies. However, recent research led by Hai-Quan Mao, a professor at the Whiting School of Engineering and director of the Institute for NanoBioTechnology (INBT), turns this conventional wisdom on its head.

According to Mao and his team, larger particles, specifically 400 nanometers in size, are actually more effective in reaching the monocytes, the immune cells responsible for attacking and eliminating abnormal cells, including cancer cells. These larger particles avoid being captured by other cells, which can reduce the effectiveness of the treatment.

The study, published in Proceedings of the National Academy of Sciences, highlights how mRNA particles, when designed to be slightly larger than traditional nanoparticles, can be efficiently picked up by circulating monocytes. This development could open new pathways for using mRNA as a cancer treatment, enabling the body to utilize its immune system to fight cancer more effectively.

The Science Behind the Larger Particles

To create these larger particles, the team at Johns Hopkins, led by Yizong Hu, a former postdoctoral fellow in Mao’s lab, used a method that involved assembling smaller mRNA nanoparticles into larger clusters. By manipulating the electrical charge of the particles’ surface, they were able to control how the nanoparticles bonded together. This innovation ensured the particles remained stable and effective after being delivered inside the body.

This research is a major shift in the field of drug delivery. Previously, smaller particles (100–200 nanometers) were commonly used to avoid capture by phagocytic cells. However, monocytes are naturally inclined to "eat" larger particles, a process known as size-dependent phagocytosis. The research suggests that the 200–1,000 nanometer range might be more ideal for effectively targeting these cells.

Potential Applications Beyond Cancer

While the main focus of the study is on cancer treatment, this discovery could have broader applications. The ability to deliver mRNA-based drugs specifically to monocytes could be beneficial for not only cancer therapy but also for any treatments that involve programming immune responses. By targeting the immune system with these larger particles, the technology could also be useful in vaccine development or in treating autoimmune diseases and infections.

The Path Forward: What’s Next for This Research?

This new approach to cancer treatment is still in its early stages, but the potential is significant. According to Stephany Y. Tzeng, an assistant research professor in biomedical engineering, and Jordan J. Green, a professor of biomedical engineering, the next steps involve refining the method and testing it further for other applications.

By demonstrating that larger particles can target immune cells more effectively, the researchers have set the groundwork for a new generation of cancer therapies that could be less invasive and more tailored to individual patients' needs. As the field of cancer immunotherapy evolves, it’s clear that larger nanoparticles could play a crucial role in transforming how we approach cancer treatment.

Conclusion: A New Era in Cancer Treatment

The discovery that larger nanoparticles could be more effective in targeting the immune cells responsible for fighting cancer is a groundbreaking step in the field of cancer immunotherapy. By leveraging the body’s immune system to fight cancer, researchers at Johns Hopkins University are paving the way for more precise and effective treatments.

While this research is still in its early stages, it offers promising possibilities for improving cancer treatment options in the future. With continued innovation and testing, this discovery could lead to more successful treatments, potentially saving countless lives and changing the landscape of cancer care.

Credit

This article is based on research from Johns Hopkins University and published in Proceedings of the National Academy of Sciences. Insights were provided by Hai-Quan Mao, Yizong Hu, Stephany Y. Tzeng, and Jordan J. Green, with contributions from the Institute for NanoBioTechnology and the Whiting School of Engineering.

For more information on innovative cancer treatments and breakthroughs, visit Johns Hopkins University or consult other trusted scientific sources.