In Vivo Biodistribution of Nanoparticles

Abstract

Nanoparticles have potential applications in diagnostics, imaging, gene and drug delivery and other types of therapy. Iron oxide nanoparticles, gold nanoparticles and quantum dots have all generated substantial interest and their properties and applications have been thoroughly studied. Yet, metal-containing particles raise biodistribution and toxicity concerns because they can be quickly cleared from the blood by the reticuloendothelial system and can remain in organs, such as the liver and spleen, for prolonged periods of time. Design considerations, such as size, shape, surface coating and dosing, can be manipulated to prolong blood circulation and enhance treatment efficacy, but nonspecific distribution has thus far been unavoidable. Renal excretion of nanoparticles is possible and is size dependent, but the need to incorporate coatings to particles for increased circulation can hinder such excretion. Further long-term studies are needed because recent work has shown varying degrees of in vivo toxicity as well as varying levels of nanoparticle excretion over time. The interaction of these particles with immune cells and their effect on the innate and adaptive immune response also needs further characterization. Finally, more systematic in vitro approaches are needed to both guide in vivo work and better correlate nanoparticle properties to their biological effects.

Synthetic Lipid Nanoparticles Targeting Steroid Organs

“…Uptake of lipidots in the liver but not in the spleen is reminiscent of the uptake of lipoprotein complexes rather than that of most artificial nanoparticles. Small nanoparticles (e.g., quantum dots , 5.5 nm (24) or "soft" dendrimer nanoparticles , 15 nm (25)) avoid phagocytosis and are cleared from the blood by the kidneys, but larger organic or inorganic nanoparticles accumulate in the spleen and liver through phagocytosis by the mononuclear phagocyte system (21,22). In contrast, chylomicrons and very low density lipoproteins (VLDL) are avidly and rapidly taken up in the liver; for example, 50 %ID of VLDL labeled with small particles of iron oxide are present in liver 20 min after intravenous injection (26).…”

Interaction of curcumin nanoformulations with human plasma proteins and erythrocytes

“…[56][57][58] Some nanoparticles can escape the phagocytosis process but may have a tendency to bind to serum proteins which disturb native immunity. To avoid this problem, selection of nanoformulations must be based on minimal interaction with serum proteins.…”

The nanotoxicology revolution

“…Meanwhile, some general principles have been convincingly demonstrated. After intravenous application, gold nanoparticles are mostly found in the reticuloendothelial system in the liver, spleen, lymph nodes and bone marrow (Almeida et al 2011). Larger gold nanoparticles are efficiently taken up by the liver, whereas smaller nanoparticles may target other organs (Almeida et al 2011).…”