Online Archive

August 30, 2010 11:00 - 12:00

Empa, St. Gallen, C3.11


David Grainger, Ph.D. Professor of Bioengineering, University of Utah, USA

Leadership of diskussion

Prof. Dr Harald Krug, Empa


Possible human toxicity to nanotechnology is an increasing concern for both inadvertent and deliberate human exposures. Current understanding of the fate of nanomaterials in most any size and shape in the human body is poor. Published data for decades demonstrates that microscopic colloids in blood circulation are rapidly filtered by the reticuloendothelial system (RES, also called the mononuclear phagocyte system, MPS), comprising liver, spleen, lung, kidney, and marrow, involved in blood scavenging. This particle filtration is substantially independent of size or chemistry. Wide variations in circulating properties produce quite similar results in mammalian RES clearance (i.e., >90% filtration, some >95%). Efforts historically to ‘target’ particles actively to non-RES disease or tissue sites (i.e., antibody-conjugated vehicles) result in only marginal changes in blood-based biodistribution patterns. That reducing particle size to sub-micron (i.e., nanometer) ranges alters the resulting nanoparticle biodistribution has not been unequivocally shown. A wide body of literature indicates that when ultra-sensitive analytical methods necessary to detect nanoparticles in vivo are used to monitor nanoparticle distribution in animal models (i.e., using radiolabels), the RES/MPS system actively filters a wide variety of nanomaterials, regardless of size, shape or chemistry. Few studies show sensitive data for nanomaterials distributions to tissue from blood distinct from traditional colloid in vivo biodistributions as a function of dosing or materials properties. Most data suggest that nanometer dimension size reductions have not significantly changed their interactions in vivo, despite in vitro distinctions observed with proteins and cell cultures.

The language of the presentation is English
Free entrance, guests are welcome