摘要
Accurately distinguishing between the endogenous formation and exogenous exposure of Fe-bearing particles(e.g.,magnetic Fe particles)within biological organisms is the prerequisite for scientifically evaluating their health risks.However,this remains a challenging task due to lacking the comprehensive understanding of the endogenous formation process of Fe-bearing particles.Here,we report the formation dynamics of Fe-bearing particles under conditions closely resembling actual physiological conditions,and compare the morphological and structural differences between endogenous and exogenous Fe-bearing particles.We find that Fe-bearing particles can indeed form under physiological conditions at 37℃.In this process,phosphate plays a crucial role in the oxidation and mineralization of iron ions.Moreover,endogenously formed Fe-bearing particles typically have a diameter of less than8 nm,and iron is the only metal element present.Therefore,we propose that Fe-bearing particles found in the body with a diameter larger than 8 nm are mainly derived from exogenous exposure.For Fe-bearing particles smaller than 8 nm,it is necessary to combine associated elements and crystal structure characteristics to distinguish between endogenous and exogenous sources.This study provides direct evidence from endogenous metabolism for tracing Fe-bearing particles,especially magnetic iron particles,within the human body.
基金
supported by the National Natural Science Foundation of China(Nos.22222610,22376202,and 22193051)
the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750100)
Chinese Academy of Sciences Project for Young in Basic Research(No.YSBR-086)
the National Key R&D Program of China(Nos.2023YFF0614200 and 2023YFC3708301)。
