(147c) Interfacial Transport of Polymeric Nanomedicine in the Proximity of Cellulose Surfaces

The increased production and commercial use of nanoparticulate drug delivery systems combined with a lack of regulation to govern their disposal may result in their introduction to soils and ultimately into groundwater systems. To better understand how such particles interact with environmentally significant interfaces, we study the adsorption, desorption, and removal behavior of polyethylene glycol-based nanoparticulate drug delivery systems on and from cellulose, which is the most common organic compound on Earth. In this presentation, I am going to talk about the dynamics of adsorption for such nanoparticles. Our studies indicated that such an adsorption process is only partially reversible, and most of the adsorbate particles do not desorb from the cellulose surface even upon rinsing with a large amount of water. The rate constant of adsorption decreases with increasing particle size. Furthermore, hydrodynamic forces acting parallel to the surfaces are found to be of great importance in the context of particle dynamics near the cellulose surface, and ultimately responsible for the removal of some fraction of particles via rolling or sliding. As the particle size increases, the removal rates of the particles increases for a given hydrodynamical condition.