High doses of hydroxyapatite nanoparticle (nHAP) impairs microcirculation in vivo

Nanoparticles has surrounded the population by their use in electronics, medicine and cosmetics. The exposure to nanoparticles coming from different sources is uncountable as the amount of nanoparticles in which a person is exposed daily. In this direction and considering that microcirculation is the main and most affected system by nanoparticles in the first moment, responsible to transport and deal with nanoparticles internally, we evaluated a massive exposure (1 g/Kg) of a well-known nanoparticle (hydroxyapatite) and the impact on the microvessels. The results showed a massive destruction of venules, arterioles, and capillaries when nHAPs were administered topically. However, systemic administration of high doses of nHAP did not affect microcirculation but altered biochemical parameters of blood samples from treated animals. The data demonstrated that even well docu-mented nanoparticles at high doses might affect the whole-body homeostasis. Finally, the results raise the ne-cessity for further investigation of the effect of nanoparticles in microcirculation and the impact in the whole-body homeostasis.

Automated summary

Nanoparticles have become widely used in electronics, medicine, and cosmetics, leading to daily exposure to a significant amount of nanoparticles. This study focused on the impact of a high dosage of hydroxyapatite nanoparticles on microvessels. The results showed that topical administration of these nanoparticles caused significant destruction of venules, arterioles, and capillaries. However, systemic administration did not affect microcirculation but altered biochemical parameters in the blood samples. These findings suggest the need for further investigation into the effects of nanoparticles on microcirculation and overall body homeostasis.