Effects of SiO2 nanoparticles on phospholipid membrane integrity and fluidity.
Effects of SiO2 nanoparticles on phospholipid membrane integrity and fluidity.
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DOI：
10.1016/j.jhazmat.2015.01.063
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发表时间：
2015-04
影响因子：
13.6
通讯作者：
Xiaoran Wei;Wei Jiang;Junchao Yu;Lei Ding;Jingtian Hu;G. Jiang
中科院分区：
文献类型：
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作者：
Xiaoran Wei;Wei Jiang;Junchao Yu;Lei Ding;Jingtian Hu;G. Jiang
硅纳米粒子是一种广泛应用的纳米材料，具有致病性。使用巨单层囊泡（GUV）作为模型细胞膜，研究了五种不同的SiO2纳米粒子对膜完整性和流动性的影响。GUV由1，2-二油酰基-sn-甘油基-3-磷酸胆碱（DOPC）通过温和水合方法制备，并通过向囊泡中加入带电荷的脂质调节为带正电荷或负电荷。SiO2纳米粒子对带相反电荷的膜造成更严重的损伤，因为静电引力有利于与磷脂形成氢键。NP暴露剂量/时间的增加和NP沉降过程加重了膜损伤。应用荧光探针Laurdan和计算的广义偏振（GP）值评价膜相。阴离子SiO2 NPs增加GP值并诱导膜凝胶化。阳离子SiO2纳米粒子不改变正电荷GUV和纯DOPC囊泡的相态，但诱导负电荷GUV的凝胶化。细胞膜完整性的破坏和膜相的改变是细胞毒性的可能机制，因为细胞生理活动需要分离的细胞内环境和流体膜相来支持蛋白质和调节分子转运。
Silicon nanoparticles (NPs) are widely used nanomaterials and reported to have pathogenicity. Effects of five different SiO2NPs on the membrane integrity and fluidity were studied using giant unilamellar vesicles (GUVs) as model cell membranes. GUVs were made from 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) by gentle hydration method, and adjusted to be positively- or negatively-charged by adding charged lipids into vesicles. SiO2NPs caused more serious damage to oppositely-charged membrane because electrostatic attraction favored the hydrogen bonding to the phospholipids. Increase in NP exposure dose/time and NP sedimentation process aggravated the membrane damage. The membrane phases were evaluated applying the fluorescent probe Laurdan and the calculated generalized polarization (GP) values. Anionic SiO2NPs increased the GP value and induced membrane gelation. Cationic SiO2NPs did not change the phase of positively-charged GUV and pure DOPC vesicles, but induced the gelation of negatively-charged GUV. Break of membrane integrity and change in membrane phase are possible mechanisms of cytotoxicity because cellular physiological activities require a separated intracellular environment and a fluid membrane phase to support proteins and regulate molecular transport.