Nanoparticle size and surface charge determine effects of PAMAM dendrimers on human platelets in vitro.
Blood platelets are essential in maintaining hemostasis. Various materials can activate platelets and cause them to aggregate. Platelet aggregation in vitro 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 in vitro. 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.
Nanotechnology Characterization Laboratory, Advanced Technology Program, SAIC-Frederick Inc, NCI-Frederick, Frederick, Maryland 21702, United States.
Marina A
MA
Dobrovolskaia
Anil K
AK
Patri
Jan
J
Simak
Jennifer B
JB
Hall
Jana
J
Semberova
Silvia H
SH
De Paoli Lacerda
Scott E
SE
McNeil
D001792:Blood Platelets / Q000187:drug effects* / Q000648:ultrastructure; D050091:Dendrimers / Q000009:adverse effects* / Q000737:chemistry; D005434:Flow Cytometry; D006801:Humans; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000009:adverse effects* / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D010974:Platelet Aggregation / Q000187:drug effects
D050091:Dendrimers; C104700:PAMAM Starburst