We've published work in Advanced Functional Materials on heparin-folate nanoparticles (HF NPs) as a way to unlock heparin's anticancer potential without the bleeding risk that has always prevented clinical use. Heparin is best known as an anticoagulant, but it also has real immunomodulatory and anti-angiogenic activity through neutrophil activation, complement regulation, and VEGF neutralization. The problem has been that the doses needed to exploit those effects would cause dangerous bleeding, and chemically chopping heparin into low-molecular-weight forms only partly solves it.