Tissue-specific uptake and distribution of liquid crystal monomers (LCMs) in mice

Increasing evidence indicated that liquid crystal monomers (LCMs) in liquid crystal displays can be released into the environment, and ubiquitously detected in environmental matrices and even human bodies. Yet databases regarding its uptake and distribution in mammals are lacking. In this study, four LCMs (namely 3dFB, 2OdF3B, 2teFT, and 6OCB) with various physiochemical properties and structures were selected as the target compounds. The LCMs were in vivo and in vitro exposed to mice and rat liver microsomes (RLM). LCMs were found in all mouse tissues, including brain. Pharmacokinetics parameters, C_max-tissue/C_max-blood, ranged from 27.5 to 214, indicating the preferential deposition of LCMs to tissues rather than blood. The LCMs distributed preferentially to lipophilic tissues, and relative mass contribution of LCMs from liver and adipose was 43-98 %. The physicochemical properties (i.e., Kow, molecular weight, and functional groups) had pronounced effect on distribution and accumulation of LCMs. The 2teFT with the highest Kow and molecular weight showed the relatively higher accumulation potential and half elimination time in all the tissues. The 6OCB containing cyano-group was more accumulative than the fluorinated 3dFB with the comparable Kow. In RLM assays, 2teFT and 6OCB were resistant to metabolic degradation. While 3dFB and 2OdF3B underwent rapid degradation with 93.7 % and 72.4 % being metabolized at 360 min. Findings in this study bear significant implications for the biomonitoring and overall risk evaluation of LCMs.