Researchers at Nagoya University in Japan have developed a lipid nanoparticle that delivers mRNA to cells five times more effectively. By attaching a sulfur-containing ring structure—a cyclic disulfide—to lipid molecules, they found that significantly more mRNA can escape from cell components that normally destroy genetic material. When tested as a cancer vaccine in mice, the new delivery system stopped tumor growth. The study, published in the journal RSC Medicinal Chemistry, demonstrates the first successful use of cyclic disulfide-containing lipids to improve mRNA delivery in animals and suppress tumor growth.