ABSTRACT
Over the past few years, nanoparticles have gained tremendous recognition in several diagnostic and therapeutic applications (Jamieson et al. 2007; Boisselier and Astruc 2009; —anh and Green 2010). For instance, in 2006 alone, there were more than 250 nanoparticle-based products in pharmaceutical pipeline (Dobrovolskaia et al. 2008). A nanoparticle used for either therapeutics or for diagnostics is designed to deliver the drug at the site of action or perform its function at a desired site without being toxic to the body. For a nanoparticle to be biocompatible, understanding its probable interactions with the biological system is extremely important. Many factors including size, shape, nature, and composition of a nanoparticle, and route of administration decide the fate of the nanoparticle. In addition, the interference of the nanoparticle and its adverse eŸects on the host system also determine its use as a biocompatible material. Hence a bottom-up approach of nanobiomaterial design by evaluating the in¯uence of the physical and chemical properties of the material on biological system is necessary. Humans have a very well-developed policing system called the immune system to protect us from invading organisms like bacteria, virus, and other parasites. Immune system is distributed throughout the body via the circulatory and lymphatic systems. Many nanoparticle products are designed for intravenous administration such as targeted and controlled drug delivery, as contrast agents for imaging or as vaccine carriers. However, the mechanism of interaction of nanoparticles with blood is not well understood. —ere is a possibility of a nanoparticle being recognized as foreign and its getting cleared from the blood by the immune system before it reaches the target. Once the nanoparticle is recognized by the immune system and sent for clearance or detoxi™cation to either liver or kidney, it can create damage to the organs if it is toxic/nondegradable/incompatible. A pictorial representation of possible interactions and outcomes of nanoparticles with various cellular and molecular components of blood is shown in the Figure 31.1.
