“Designing for ex vivo integrity and in vivo durability at the same time is not an added complexity; it’s the more honest version of the problem.”
Over the past several years, the mRNA–lipid nanoparticle (LNP) field has moved at a pace that few of us anticipated. But as the science has matured, so has the complexity of a question that sounds deceptively simple: what do we actually mean by stability? Depending on who you ask, the answer is different - physicochemical integrity during storage, potency retention after thawing, moisture sensitivity, or how long the biology lasts once the particle is in the body. In my view, it means all of these things, and conflating them is one of the more common and costly mistakes the field makes.
I think about mRNA–LNP stability across four levers: intelligent sequence engineering, liquid-state formulation integrity before the dose enters the body, water removal to enable warmer storage, and co-design of RNA and LNP for durability after administration. The first two are easy to confuse with the last two because they share vocabulary, such as stability, integrity, and potency, but they belong to different realities. One lives in the vial. The other lives in the bloodstream. Keeping that distinction clear is where good development decisions start.
