How Charge Density Dictates the Fate and Diffusion of Nanoparticles in Fibrous Networks

We examine how charged nanoparticles (NPs) diffuse and interact within negatively charged polymer networks, essential for biological and biomedical applications. Using molecular dynamics simulations and experimental studies, we explore the effects of NP size, surface charge density (𝜁), and concentration on NP permeation. We propose a scaling law for NP diffusion, showing that both concentration and 𝜁 significantly influence NP movement. Our findings, supported by controlled release experiments, categorize NP behavior into sticking, sliding, and bouncing regimes based on variations in 𝜁, concentration, and NP size. These insights are crucial for optimizing NP design in drug delivery and material applications.