Shaping nanoparticle diffusion through biological barriers to drug delivery

Nanoparticle drug delivery systems encounter many biological barriers, such as the extracellular matrix and mucus gels, that they must bypass to gain access target cells. A design parameter has recently gained attention is nanoparticle shape, it been shown elongated rod–shaped nanoparticles achieve higher diffusion rates through gels. However, optimal dimensions of rod-shaped enhance this effect yet be established. To systematically approach this, were synthesized by mechanically stretching 100 ​nm, 200 500 ​nm spherical nanoparticles. Transmission electron microscopy confirmed procedure yields a significant fraction rods remaining spheres could removed centrifugation. Fluorescent multiple particle tracking analysis was then used characterize in MaxGel®, model hydrogel. When dispersed MaxGel, we found exhibited greatest enhancement rate when their length far exceeds average hydrogel network size. These results further establish importance shape criterion improve nanoparticle-based systems.