The Pattern of Granuloma Formation in the Liver of Rats as a Reflection of the Mechanism of Internalization of Submicron Silicon Particles.

A morphological analysis of the liver of Wistar rats was performed 2 months after a single intravenous injection of porous silicon particles of different sizes (60-80, 250-300, and 500-600 nm; 2 mg/ml, 1 ml). Histological, immunohistochemical, and electron microscopic methods showed the development of CD68 granulomas in all experimental groups. Injection of 60-80-nm porous silicon particles led to the formation of single large granulomas (>2000 μm), while 500-600-nm nanoparticles caused the formation of numerous smaller granulomas.