Influence of silver and titanium dioxide nanoparticles on in vitro blood-brain barrier permeability

奈米銀及奈米二氧化鈦對體外血腦屏障模型通透性之影響

陳以婕(Chen, I Chieh)

指導教授 ： 黃鈺軫

國立清華大學/原子科學院/生醫工程與環境科學系/碩士(2015年)

https://doi.org/10.6843/NTHU.2015.00275

摘要

本研究主要探討兩種工業常用的銀和二氧化鈦奈米粒子。將奈米粒子分別暴露於單培養系統及共培養系統24小時後，探討其毒性及對血腦屏障通透性之影響。首先，利用單層培養系統探討奈米銀(<10nm)及兩種粒徑之奈米二氧化鈦(3-5nm ST-01,30-50nm ST-21)對小鼠內皮細胞(bEnd.3)及星狀細胞(ALT)的毒理效應。再者，為研究奈米粒子對血腦屏障之影響，我們將內皮細胞及星狀細胞進行共培養模擬血腦屏障之結構，再將奈米粒子暴露於此，進而探討奈米粒子在共培養系統的毒理效應及血腦屏障之通透性影響。毒理效應之研究包含細胞生存率、奈米粒子攝食情形、活性氧化物之產生及細胞激素的釋放(MCP-1)；而通透性之影響則包含跨內皮電阻值的變化(TEER)、緊密連結蛋白之表現(ZO-1、claudin-5)和奈米粒子之通透係數(permeability coefficient)。此外，我們也假設當細胞先被脂聚醣(LPS)刺激引起發炎反應後，再暴露奈米粒子是否受到更嚴重的影響。由實驗結果顯示，不論是奈米銀或奈米二氧化鈦皆傾向於刺激細胞產生活性氧化物質導致細胞調控失衡而死亡，而血腦屏障模型也受到奈米粒子的刺激後，導致跨內皮電阻值下降、緊密連接蛋白受到破壞，並使得奈米粒子通透屏障，其原因與活性氧化物質及細胞激素的產生有關。比較兩種奈米粒子所產生的效應，我們認為奈米銀比起奈米二氧化鈦具有較高的毒性，因奈米銀僅在低濃度(2ppm)就可使細胞有明顯的毒理及通透效應，而奈米二氧化鈦則需要較高濃度(100ppm)才有。另外，脂聚醣的預先刺激，並沒有使奈米粒子對細胞產生更嚴重的反應，但對血腦屏障的通透效應則具有較大的影響，可能與脂聚醣會刺激細胞免疫反應使大量的細胞激素釋放(MCP-1)有關。

關鍵字

奈米銀 ； 奈米二氧化鈦 ； 血腦屏障 ； 通透性 ； 奈米毒性

並列摘要

In this study, we divided as mono-culture and BBB model system to explore the toxicity effect of TiO2 (3-5nm ST-01, 30-50nm ST-21) and Ag NPs (<10nm). In vitro BBB model by co-culture endothelial cells (bEnd.3) and astrocytes (ALT) were established to estimate whether BBB dysfunction. Accordingly, four works will be examined after exposing nanoparticles 24 hours, all of which are cell viability, uptake potential, intracellular reactive oxygen species (ROS), and cytokines (MCP-1). In addition, the integrity of BBB was estimated by measuring the tranendothelial electrical resistance (TEER), calculating the permeability and observing the tight junction protein expression. On the other hand, we also compare the condition with or without lipopolysaccharide (LPS), which is assumed as the inflammatory situation. Consequently, we found that the toxicity mechanism of Ag-NPs and TiO2 NPs in the cells were trend to follow the way by producing ROS to gradually induce cell death. BBB were influenced by this two kind of nanoparticles to decrease TEER value, disrupt tight junction proteins and increase permeability of nanoparticles. The reason of this were associated with ROS generation and cytokines secretion. Furthermore, we found that Ag-NPs were more noxious than TiO2 NPs according to the lower lethal dosage (2ppm) and higher permeability in the BBB model. On the other hand, LPS treatment would stimulate MCP-1 release to make severer effect on BBB model although it did not have significant influence with co-culture nanoparticles.

並列關鍵字

silver nanoparticles ； titanium dioxide nanoparticles ； blood-brain barrier ； permeability ； nanotoxicity

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