Department of Chemical and Geological Sciences, The University of Modena and Reggio Emilia, Via Campi 103, I-41125 Modena, Italy.
Department of Chemical and Geological Sciences, The University of Modena and Reggio Emilia, Via Campi 103, I-41125 Modena, Italy.
Environ Res. 2019 Apr;171:550-557. doi: 10.1016/j.envres.2019.01.011. Epub 2019 Jan 8.
The mechanisms by which mineral fibers induce adverse effects in vivo are still not well understood. The mechanisms of fiber dissolution in the lungs and subsequent release of metals in the extracellular/intracellular environment must be taken into account.
For the first time, the kinetics of release of metals during the acellular in vitro dissolution of chrysotile, crocidolite and fibrous erionite were determined.
In vitro acellular dissolution of chrysotile, crocidolite, and fibrous erionite-Na was conducted using a solution mimicking the phagolysosome environment active during the phagocytosis process (pH=4.5, at 37 °C). The kinetics of release of a representative selection of metals were determined over a period of three months.
Despite the fact that the difference in Fe content between chrysotile and crocidolite is one order of magnitude, the much faster dissolution rate of chrysotile compared to crocidolite prompts greater release of available active surface Fe in the first weeks of the dissolution experiment and comparable amounts after 90 d. Such active iron may promote the formation of toxic hydroxyl radicals. The fast release of metals like Cr, Ni and Mn from chrysotile is also a source of concern whereas the release of V in solution is negligible.
Because chrysotile undergoes fast dissolution with respect to crocidolite and fibrous erionite, it behaves like a carrier that releases its metals' cargo in the lung environment, mimicking the phenomenon that explains the toxicity of nanoparticles. Hence, the toxicity paradigm of a non biodurable fiber like chrysotile should also take into account the release of toxic metals in the intracellular/extracellular medium during the rapid dissolution process.
目前，人们对于矿质纤维在体内诱发不良反应的机制还没有完全理解。在研究中，必须考虑纤维在肺部的溶解机制，以及随后金属在细胞外/细胞内环境中的释放机制。
本研究首次测定了温石棉、青石棉和纤维状透闪石在体外无细胞溶解过程中金属释放的动力学。
采用模拟吞噬过程中溶酶体环境的溶液（pH=4.5，37°C）对温石棉、青石棉和纤维状透闪石-Na 进行体外无细胞溶解。在三个月的时间内，测定了代表性金属的释放动力学。
尽管温石棉和青石棉之间的铁含量差异为一个数量级，但温石棉的溶解速度比青石棉快得多，这促使在溶解实验的最初几周内释放出更多的可用活性表面铁，90 天后的释放量相当。这种活性铁可能会促进有毒羟自由基的形成。温石棉中铬、镍和锰等金属的快速释放也令人担忧，而钒在溶液中的释放则可以忽略不计。
与青石棉和纤维状透闪石相比，温石棉的溶解速度较快，因此它可以像载体一样在肺部环境中释放其金属货物，这模拟了解释纳米颗粒毒性的现象。因此，对于像温石棉这样非生物可降解纤维的毒性范式，也应该考虑在快速溶解过程中细胞内/细胞外介质中释放有毒金属的问题。
