Nanoparticles and the blood coagulation system. Part II: safety concerns.

Nanoparticle interactions with the blood coagulation system can be beneficial or adverse depending on the intended use of a nanomaterial. Nanoparticles can be engineered to be procoagulant or to carry coagulation-initiating factors to treat certain disorders. Likewise, they can be designed to be anticoagulant or to carry anticoagulant drugs to intervene in other pathological conditions in which coagulation is a concern. An overview of the coagulation system was given and a discussion of a desirable interface between this system and engineered nanomaterials was assessed in part I, which was published in the May 2013 issue of Nanomedicine. Unwanted pro- and anti-coagulant properties of nanoparticles represent significant concerns in the field of nanomedicine, and often hamper the development and transition into the clinic of many promising engineered nanocarriers. This part will focus on the undesirable effects of engineered nanomaterials on the blood coagulation system. We will discuss the relationship between the physicochemical properties of nanoparticles (e.g., size, charge and hydrophobicity) that determine their negative effects on the blood coagulation system in order to understand how manipulation of these properties can help to overcome unwanted side effects.