Inhibition of phosphoinositol 3 kinase contributes to nanoparticle-mediated exaggeration of endotoxin-induced leukocyte procoagulant activity

Abstract

Aim: Disseminated intravascular coagulation is an increasing concern for certain types of engineered nanomaterials. Recent studies have shed some light on the nanoparticle physicochemical properties contributing to this toxicity; however, the mechanisms are poorly understood. Leukocyte procoagulant activity (PCA) is a key factor contributing to the initiation of this toxicity. We have previously reported on the exaggeration of endotoxin-induced PCA by cationic dendrimers. Herein, we report an effort to discern the mechanism. Materials & methods: Poly(amidoamine) dendrimers with various sizes and surface functionalities were studied in vitro by the recalcification test, flow cytometry and other relevant assays. Results & conclusion: Cationic dendrimers exaggerated endotoxin-induced PCA, but their anionic or neutral counterparts did not; the cationic charge prompts this phenomenon, but different cationic surface chemistries do not influence it. Cationic dendrimers and endotoxin differentially affect the PCA complex. The inhibition of phosphoinositol 3 kinase by dendrimers contributes to the exaggeration of the endotoxin-induced PCA. Original submitted: 4 February 2013; Revised submitted: 2 June 2013