PNNL

Abstract

The growing commerce in micro- and nanotechnology is expected to increase our exposure to submicron and nanoscale particles. One of the main targets of this exposure are the cells that line the respiratory tract, among them are the alveolar type II epithelial cells that have microvilli at their exposed apical surface. Here we show a pathway by which positively charged inorganic submicron and nanoscale particles take advantage of the actin turnover machinery within filopodia and microvilli-like structures to guide and advance their way into these cells. Our observations bring a new view of how submicron and nanoscale inorganic matter can be assimilated into the cellular environment and take advantage of its machinery. While the pathway that we describe can be exploited for a targeted drug delivery, it also points to properties of submicron or nanoscale particles that should be avoided in order to reduce particle internalization and possible toxicity.