Morphological aspects of interactions between microparticles and mammalian cells: intestinal uptake and onward movement.

Uptake of ingested microparticles into small intestinal tissues and on to secondary organs has moved from being an anecdotal phenomenon to a recognised and quantifiable process, which is relevant to risk assessment of accidental exposure, treatment of multi-organ dysfunction syndrome and therapeutic uses of encapsulated drug or vaccine delivery. This review puts in context with the literature the findings of a morphological study of microparticle uptake, using two approaches. The first is a rat in vivo in situ model, appropriate to a study rooted in the exposure of human populations to microparticles.