Evidence of size-dependent effect of silica micro- and nano-particles on basal and specialized monocyte functions.

AIM: To analyze the effect of silica particles on monocyte/macrophage functions.

MATERIALS & METHODS: Silica micro- and nanoparticles were obtained by the Stöber method. Their effect on monocyte/macrophage proliferation, activation, membrane integrity and metabolic activity were determined.

RESULTS: Silica particles inhibit cell proliferation while 10 nm nanoparticles (NPs) did not affect it. Similarly, silica particles induced strong cell activation. However, 10 nm NPs do not alter IL-12 or nitrite levels. Furthermore, bigger NPs and microparticles increase cell membrane damage and reduce the number of living cells but smallest NPs (10 and 240 nm) did not.

CONCLUSION: Cell activation properties of silica particles could be useful tools for immune stimulation therapy, while 10 nm NPs would be suitable for molecule transportation.