心血管疾病（CVD）是造成死亡最常見(jiàn)的原因之一，因此血管重塑，如動(dòng)脈硬化中的冠狀動(dòng)脈重塑顯得非常有必要。血管細(xì)胞以及血流力學(xué)信號(hào)傳導(dǎo)在組織重塑和平衡中起到至關(guān)重要的作用。動(dòng)脈血管壁呈多細(xì)胞結(jié)構(gòu)，由內(nèi)皮細(xì)胞（EC）層及其周?chē)难芷交〖?xì)胞（VSMC）組成。目前的3D血管壁構(gòu)建體不能模擬天然組織的機(jī)械條件，也不能在相關(guān)的血液動(dòng)力學(xué)條件下監(jiān)測(cè)細(xì)胞間相互作用。

基于此，荷蘭埃因霍芬理工大學(xué)的Cecilia M. Sahlgren、Nicole C. A. van Engeland團(tuán)隊(duì)建立了動(dòng)脈內(nèi)皮細(xì)胞和平滑肌細(xì)胞的3D微流控芯片模型，其模擬了細(xì)胞組成、細(xì)胞間相互作用以及動(dòng)脈壁的機(jī)械環(huán)境。血液動(dòng)力學(xué)EC-VSMC-芯片上信號(hào)傳導(dǎo)由兩個(gè)平行的聚二甲基硅氧烷（PDMS）細(xì)胞培養(yǎng)通道組成，由柔性多孔PDMS膜隔開(kāi)，模仿內(nèi)部彈性薄層的孔隙率（圖 1A-E）。

血流動(dòng)力學(xué)EC-VSMC-芯片上信號(hào)傳導(dǎo)允許人主動(dòng)脈內(nèi)皮細(xì)胞（EC）和人主動(dòng)脈血管平滑肌細(xì)胞（VSMC）的共培養(yǎng)，由多孔膜分離，這使得EC-VSMC相互作用和信號(hào)傳導(dǎo)成為可能，這對(duì)血管壁的發(fā)育和穩(wěn)態(tài)至關(guān)重要。該裝置可以實(shí)現(xiàn)對(duì)細(xì)胞實(shí)時(shí)成像和對(duì)血液動(dòng)力學(xué)條件的控制。培養(yǎng)通道兩側(cè)均被真空通道包圍（圖 1F），以通過(guò)施加循環(huán)抽吸誘導(dǎo)循環(huán)應(yīng)變，導(dǎo)致細(xì)胞培養(yǎng)通道中膜的機(jī)械拉伸和松弛。另外，通過(guò)在EC側(cè)產(chǎn)生介質(zhì)流來(lái)模擬血流。

Fig. 1 Schematic overview of the vessel wall on a chip device layer, consisting of two vacuum chambers and a cell culture chamber (A). The microfabricated vessel wall device uses compartmentalized PDMS microchannels to form an organized co-culture of ECs and VSMCs whereby physiological arterial strain and shear stress from the blood flow can be recreated (B). Schematic top view of the final microfluidic device with culture channels (red) and vacuum channels (blue) (C and D). Three PDMS layers are aligned and irreversibly bonded to form two sets of three parallel microchannels, separated by a thin PDMS membrane with pores (E). Selective etching of the membrane layers in the vacuum channels produces two large side chambers to which vacuum is applied, causing mechanical stretching of the membrane in the culture channel (F).

為了確定細(xì)胞確實(shí)通過(guò)基質(zhì)涂覆的多孔膜接觸，研究人員將EC和VSMC接種在常規(guī)裝置和具有完整膜的對(duì)照裝置中，并用對(duì)其進(jìn)行免疫熒光染色。通過(guò)共聚焦顯微鏡成像顯示EC和VSMC可以通過(guò)常規(guī)裝置中的膜孔連接，而在對(duì)照裝置中細(xì)胞不發(fā)生相互作用（圖 2）。

Fig. 2 Cross section of artery-on-a-chip. Immunohistochemistry staining of the device without pores (control, A) and with porous membrane (B). In green the VSMCs and in red the ECs. Number 1 depicts the VSMC side of the device, number 2 the membrane, and number 3 the ECs side. Scalebar represents 50 μm, n = 3–4.

為了研究血液動(dòng)力學(xué)下EC和VSMC的行為，EC和VSMC分別用CellTracker Green和Orange標(biāo)記，然后種到裝置中。兩種細(xì)胞類(lèi)型在貼附到膜上后表現(xiàn)出隨機(jī)排列和類(lèi)似鵝卵石的形態(tài)（圖3 A-D）。當(dāng)細(xì)胞粘附到膜上后，裝置的細(xì)胞培養(yǎng)通道連接到壓力驅(qū)動(dòng)的IBIDI系統(tǒng)以在膜的兩側(cè)分別保持細(xì)胞相應(yīng)培養(yǎng)基流動(dòng)。此外，真空通道連接到壓力驅(qū)動(dòng)的IBIDI系統(tǒng)以誘導(dǎo)應(yīng)變，在脈動(dòng)血流期間模擬循環(huán)周向應(yīng)變。在動(dòng)態(tài)培養(yǎng)后EC層沒(méi)有看到明顯的細(xì)胞排列，而VSMC的排列方向與給力方向垂直，且比靜態(tài)條件下的細(xì)胞更趨于細(xì)長(zhǎng)的紡錘形（圖3E-H）。

Fig. 3 Live staining of vessel wall on a chip device. A–D. Images were taken directly after adhesion of VSMCs (B) and ECs (C) whereby A and D are merged images. E–H. Live cell stainings after 4 days of dynamic culturing, VSMCs (F), ECs (G) and merged images (E and H). ECs are stained in green and VSMCs in red. Scalebar represents 100 μm, n = 3.

本研究由荷蘭埃因霍芬理工大學(xué)的Cecilia M. Sahlgren、Nicole C. A. van Engeland團(tuán)隊(duì)完成，于2018年5月發(fā)表于Lab on a Chip。論文鏈接：

http://pubs.rsc.org/-/content/articlelanding/2018/lc/c8lc00286j#!divAbstract（轉(zhuǎn)載僅供參考學(xué)習(xí)及傳遞有用信息，版權(quán)歸原作者所有，如侵犯權(quán)益，請(qǐng)聯(lián)系刪除）