Pulmonary surfactant suppressed phenanthrene adsorption on carbon nanotubes through solubilization and competition as examined by passive dosing technique.
Pulmonary surfactant suppressed phenanthrene adsorption on carbon nanotubes through solubilization and competition as examined by passive dosing technique.
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DOI：
10.1021/es2044773
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发表时间：
2012-05
影响因子：
11.4
通讯作者：
Jian Zhao;Zhenyu Wang;H. Mashayekhi;P. Mayer;B. Chefetz;B. Xing
中科院分区：
文献类型：
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作者：
Jian Zhao;Zhenyu Wang;H. Mashayekhi;P. Mayer;B. Chefetz;B. Xing
在肺表面活性剂（Curosurf）及其主要成分二棕榈酰磷脂酰胆碱（DPPC）和牛血清白蛋白（BSA）存在的情况下检查了菲在碳纳米管（CNT）上的吸附。基于预加载聚合物的平衡分配的被动计量方法已成功用于测量受控自由溶解浓度下的菲结合和形态形成，同时避免了相分离步骤。 Curosurf、DPPC和BSA都可以线性增溶菲，并且Curosurf对菲的增溶作用比单独组分（DPPC或BSA）高4倍。在 Curosurf、DPPC 或 BSA 存在下，多壁碳纳米管 (MWCNT) 对菲的吸附受到抑制，显示出肺表面活性剂（或 DPPC、BSA）和菲之间的竞争吸附。 Curosurf和菲之间的竞争吸附最强。因此，当吸附菲的碳纳米管进入呼吸道时，菲可以由于增溶作用和竞争作用而被解吸。呼吸道中吸附在三个多壁碳纳米管上的菲的生物可及性与其外径的大小呈正相关。此外，首次成功分离了增溶和竞争对菲从多壁碳纳米管中解吸的贡献。这些发现证明了肺表面活性剂如何增强解吸，从而可能增强碳纳米管上吸附的菲的生物吸收的两种机制。
Adsorption of phenanthrene on carbon nanotubes (CNTs) was examined in the presence of pulmonary surfactant (Curosurf) and its main components, dipalmitoyl phosphatidylcholine (DPPC) and bovine serum albumin (BSA). A passive-dosing method based on equilibrium partitioning from a preloaded polymer was successfully employed to measure phenanthrene binding and speciation at controlled freely dissolved concentrations while avoiding phase separation steps. Curosurf, DPPC, and BSA could all linearly solubilize phenanthrene, and phenanthrene solubilization by Curosurf was 4 times higher than individual components (DPPC or BSA). In the presence of Curosurf, DPPC or BSA, adsorption of phenanthrene by multiwalled CNTs (MWCNTs) was suppressed, showing competitive adsorption between pulmonary surfactant (or DPPC, BSA) and phenanthrene. Competitive adsorption between Curosurf and phenanthrene was the strongest. Therefore, when phenanthrene-adsorbed CNTs enter the respiratory tract, phenanthrene can be desorbed due to both solubilization and competition. The bioaccessibility of phenanthrene adsorbed on three MWCNTs in the respiratory tract would be positively related to the size of their outer diameters. Moreover, the contribution of solubilization and competition to desorption of phenanthrene from MWCNTs was successfully separated for the first time. These findings demonstrate the two mechanisms on how pulmonary surfactants can enhance desorption and thus possibly biological absorption of phenanthrene adsorbed on CNTs.