University of Utah researchers report that iron-rich hemozoin crystals inside the malaria parasite Plasmodium falciparum move through the parasite’s digestive compartment because reactions involving hydrogen peroxide at the crystal surface generate chemical propulsion. The work, published in Proceedings of the National Academy of Sciences, links a long-observed phenomenon to peroxide chemistry and could point to new antimalarial drug strategies and ideas for engineered micro- and nanoscale devices.
The malaria parasite Plasmodium falciparum produces iron-containing hemozoin crystals as it detoxifies heme released during hemoglobin digestion. Researchers have long observed that these crystals move within the parasite’s digestive compartment (often called the food vacuole) while the parasite is alive and that the motion stops when the parasite dies.
In a study led by University of Utah biochemist Paul A. Sigala, the team reports evidence that the motion is driven by chemistry involving hydrogen peroxide (H_2O_2). The researchers found that hemozoin can catalyze reactions with hydrogen peroxide and that exposing isolated hemozoin crystals to hydrogen peroxide causes them to move, consistent with a chemical-propulsion mechanism.
The researchers also report that manipulating the parasite’s environment to reduce peroxide-related chemistry can slow the crystals’ movement even when the parasites remain viable. In the University of Utah’s account of the work, postdoctoral researcher Erica Hastings said the underlying peroxide-decomposition reaction is widely used in propulsion technologies, and she argued that identifying parasite-specific chemistry could open directions for drug development.
The team proposes that keeping crystals in motion could help the parasite manage oxidative stress by consuming hydrogen peroxide and could help prevent crystal aggregation, maintaining a reactive surface for processing toxic heme. The researchers describe the phenomenon as a biological example of a self-propelled metallic nanoparticle.
The study, “Chemical propulsion of hemozoin crystal motion in malaria parasites,” was published in Proceedings of the National Academy of Sciences (PNAS) in 2025 (volume 122, issue 44) and is authored by Hastings and colleagues. The findings, the researchers say, could inform efforts to design antimalarial approaches that interfere with crystal-surface chemistry and may also provide concepts relevant to engineered self-propelled particles for applications such as targeted drug delivery.
