A mathematical threshold of 1.76 bits determines whether the immune system will attack or ignore a medical nanoparticle.
April 25, 2026
Original Paper
Ligand Conformational Entropy Denes a Critical Threshold Governing Electrostatic Control of NanocarrierImmune Cell Interactions
SSRN · 6419778
The Takeaway
Conventional wisdom says that the surface charge of a nanoparticle is what tells the immune system how to react to it. This research reveals that the flexibility and shape shifting of the molecules on the particle surface are actually more important. If the conformational entropy of these molecules passes a specific bit threshold, it can completely override the effect of the electrical charge. This means that a particle with a dangerous charge can still sneak past immune cells if its surface is sufficiently chaotic. Designers can use this specific number to build drug delivery systems that are invisible to the body natural defenses. Information theory is now being used to predict the biological fate of medicine.
From the abstract
Surface charge is widely considered a primary determinant of nanoparticleimmune cell interactions, yet nominally similar nanocarriers often elicit markedly dierent immune responses. Here, we show that ligand conformational diversityquantied as an informationtheoretic entropyacts as a regime-switching variable that governs when electrostatic charge controls cellular uptake and when it does not. Using an information-theoretic framework to encode congurational diversity at the nanobio interface, we