小鼠脑血管的近红外二区光声成像

Photoacoustic imaging in the second near-infrared window of cerebrovasculature in mice

目的建立小鼠脑血管网络的近红外二区光声成像系统, 并探究光声波开启血脑屏障的可行性。方法使用1064 nm波长激光对不同浓度的纳米材料PATQ-T进行光声成像。暴露3~8周龄KM小鼠颅骨, 通过尾静脉注射将纳米材料打进小鼠体内, 在1064 nm的波长下对进行注射前后的脑血管网络进行成像, 然后用532 nm的激光产生光声波, 观察血脑屏障在光声波作用下的开启情况。结果近红外光声成像系统拥有较好横向分辨率, 约为80 μm。通过光声成像可以看到PATQ-T的光声信号强度随浓度的增加而增强。在1064 nm的波长下, PATQ-T显示了较好的光声增强效果。经光声波激发后, 在血管网络周围出现了明显的光声信号增强。结论通过光声成像技术可以对小鼠脑血管网络进行成像。光声波具有开启血脑屏障的作用。

Objective To establish a near-infrared second-window(NIR-II)photoacoustic imaging system for visualizing the cerebrovasculature in mice,and to investigate whether photoacoustic waves could be used to open the blood-brain barrier.Methods Firstly,photoacoustic imaging of the nano-material PATQ-T at different concentrations was completed by using a 1064 nm laser.A cranial fenestration was then performed in KM mice aged 3-8 weeks.Nanomaterials were injected into the mice via caudal vein.Photoacoustic imaging of the mouse cerebrovasculature with the 1064 nm laser was conducted before and after the injection.A 532 nm laser was used to generate the photoacoustic waves attempted for photoacoustic opening of the blood-brain barrier.Results The NIR-II photoacoustic imaging system showed a high lateral resolution of approximately 80μm.On this system,the photoacoustic signal intensity of PATQ-T increased along its concentration.Favorable enhancement of PATQ-T was achieved by using the 1064 nm laser.Photoacoustic wave excitation led to significant enhancement of photoacoustic signals around the cerebrovasculature.Conclusion Photoacoustic imaging allows visualization of cerebrovasculature in mice.Photoacoustic waves are useful to open the blood-brain barrier.