Nanoparticle distribution during systemic inflammation is size-dependent and organ-specific

Area of Science:

• Nanomedicine
• Immunology
• Pharmacology

Background:

• Inflammation alters physiological conditions, impacting drug delivery systems.
• Nanocarrier-based therapies for inflammatory diseases require understanding biodistribution changes.
• Polystyrene nanoparticles are widely used in biomedical research.

Purpose of the Study:

• To investigate how systemic inflammation affects nanoparticle biodistribution.
• To determine the influence of nanoparticle size on distribution during inflammation.
• To explore the mechanisms underlying inflammation-induced biodistribution changes.

Main Methods:

• Induction of systemic inflammation using low-dose lipopolysaccharide (LPS) in mice.
• Administration of 20 nm, 100 nm, and 500 nm fluorescent polystyrene nanoparticles.
• Quantification of nanoparticle organ retention using High-Performance Liquid Chromatography (HPLC).
• Histological analysis to determine nanoparticle deposition sites.

Main Results:

• Nanoparticles of all sizes redistributed during inflammation, with increased accumulation in the spleen's marginal zones.
• Lipopolysaccharide-induced inflammation caused splenic macrophage polarization and altered leukocyte nanoparticle uptake in a size-dependent manner.
• Spleen vasculature permeability significantly increased following LPS treatment.

Conclusions:

• Systemic inflammation significantly alters nanoparticle biodistribution through multiple, size-dependent mechanisms.
• Understanding these changes is crucial for developing effective nanocarrier therapies for inflammatory conditions.
• Inflammation-induced alterations in immune cell function and vascular permeability are key factors influencing nanoparticle distribution.