Researchers at Weill Cornell Medicine and Cornell Engineering made tiny silica particles that can both kill prostate cancer cells and wake up the body’s immune system. In mouse experiments, these particles caused several tumors to disappear completely.
Tiny particles with a double attack
The particles are called ultrasmall fluorescent core‑shell silica nanoparticles, or Cornell "C' dots". They were first built to help doctors see tumors during surgery. Now scientists have found that the particles themselves can hurt cancer cells while leaving normal cells mostly safe.
How the particles destroy cancer
The particles trigger a rare form of cell death called ferroptosis. Ferroptosis happens when too much iron‑driven oxidation damages the fats that make up cell membranes, causing the cell to break apart.
Inside the blood, the silica particles pick up positively charged iron ions. They then carry the iron into tumor cells, where the iron fuels the oxidation that leads to ferroptosis.
Turning a "cold" tumor into a "hot" one
Beyond killing cells, the particles change the environment around the tumor. Immune cells such as T cells and macrophages become active fighters instead of staying quiet.
The particles also make the tumors respond better to approved immunotherapy drugs. They disrupt several metabolic pathways in the tumor, slowing its growth even more.
Targeting prostate cancer cells
To make sure the treatment finds prostate cancer cells, scientists attached a molecule that recognizes PSMA, a protein on the surface of these cells. A small amount of particles ended up in other organs, but no toxicity was seen outside the tumors.
Best results with combination therapy
When mice with aggressive prostate cancer received the silica particles alone, they lived a little longer. Adding an immune‑checkpoint blocker improved survival further.
The strongest outcome happened when the particles were used together with both the checkpoint blocker and a drug that blocks CSF‑1R (which targets tumor‑associated macrophages). In this triple combo, five out of ten mice had complete tumor remission and lived indefinitely.
What comes next?
The research team plans to test the safety and effectiveness of these silica particles in human clinical trials. Their long‑term goal is to create a new class of cancer therapy that can act on inflammation, immunity, and metabolism all at once.
The study was funded by the U.S. Department of Defense, the National Cancer Institute, and several cancer research foundations.