The Binding Affinities of Serum Proteins to Nanoparticles.

Nanoparticles can be coated with targeting ligands to deliver medical agents to specific cells. Serum protein adsorption affects the binding of nanoparticles to target cells. We hypothesized that serum proteins and target receptors compete for binding to nanoparticles. We tested the serum protein binding affinity of 251 nanoparticle designs. Here, we discovered that the binding affinities of serum proteins and receptors to a nanoparticle determine whether it can bind to target cells. We developed and validated a quantitative metric, the binding ratio, to identify nanoparticle designs that can bind to targets in serum with 90% sensitivity and 88% specificity. Using the binding ratio as a numerical guideline for nanoparticle design enabled us to improve the efficiency of nanoparticle binding to target cellular receptors.