7 research outputs found
Nanoparticle Size and Surface Charge Determine Effects of PAMAM Dendrimers on Human Platelets <i>in Vitro</i>
Blood platelets are essential in maintaining hemostasis.
Various materials can activate platelets and cause them to aggregate.
Platelet aggregation <i>in vitro</i> is often used as a
marker for materials’ thrombogenic properties, and studying
nanomaterial interaction with platelets is an important step toward
understanding their hematocompatibility. Here we report evaluation
of 12 formulations of PAMAM dendrimers varying in size and surface
charge. Using a cell counter based method, light transmission aggregometry
and scanning electron microscopy, we show that only large cationic
dendrimers, but not anionic, neutral or small cationic dendrimers,
induce aggregation of human platelets in plasma <i>in vitro</i>. The aggregation caused by large cationic dendrimers was proportional
to the number of surface amines. The observed aggregation was not
associated with membrane microparticle release, and was insensitive
to a variety of chemical and biological inhibitors known to interfere
with various pathways of platelet activation. Taken in context with
previously reported studies, our data suggest that large cationic
PAMAM dendrimers induce platelet aggregation through disruption of
membrane integrity