Near-infrared absorbing polymer nano-particle as a sensitive contrast agent for photo-acoustic imaging
Near-infrared absorbing polymer nano-particle as a sensitive contrast agent for photo-acoustic imaging
复制标题
DOI：
10.1039/c4nr04724a
复制
发表时间：
2015-01-01
期刊：
影响因子：
6.7
通讯作者：
Ito, Shinzaburo
中科院分区：
文献类型：
--
作者：
Aoki, Hiroyuki;Nojiri, Mayumi;Ito, Shinzaburo
采用纳米乳法制备了具有近红外（NIR）光吸收的聚合物纳米颗粒（PNPs），用于光声成像造影剂的制备。含有萘菁硅的PNP具有较高的吸收系数，可达10(10)M-1 cm（-1）。这与等离子体金纳米颗粒相当，等离子体金纳米颗粒已被研究作为PA造影剂。对于大于100 nm的PNP，与吸收系数和尺寸相似的金纳米粒子相比，PA信号增强。在PNP的情况下，由于聚合物材料的低热扩散率，光吸收的热量被限制在颗粒中。结果表明，PNP的强热约束效应增强了PA信号的产生效率，并且通过增加PNP的基体聚合物的Gruneisen参数可以增强PA信号的强度。在吸收系数相同的情况下，聚甲基丙烯酸甲酯PNP的PA信号比金纳米粒子的PA信号大9倍。我们证明，在体内PA成像中，PNP的检测限约为10(-13)m。吸收近红外的PNP将成为PA成像敏感造影剂的一个有希望的候选。
Polymer nano-particles (PNPs) with a near-infrared (NIR) light absorption were prepared by the nanoemulsion method to develop contrast agents for photo-acoustic (PA) imaging. The PNP containing silicon naphthalocyanine showed a high absorption coefficient up to 10(10) M-1 cm(-1). This is comparable to plasmonic gold nano-particles, which have been studied as PA contrast agents. For the PNP larger than 100 nm, the enhancement of the PA signal was observed compared to the gold nano-particle with a similar absorption coefficient and size. In the case of the PNP, the heat by the light absorption is confined in the particle due to the low thermal diffusivity of polymer materials. We showed that the strong thermal confinement effect of PNP results in the enhancement of the efficiency of the PA signal generation and that the PA intensity can be enhanced by the increase of the Gruneisen parameter of the matrix polymer of PNP. The PA signal from the PNP of poly(methyl methacrylate) was 9-fold larger than that of gold nano-particles with the same absorption coefficient. We demonstrated that in the in vivo PA imaging the detection limit of PNP was of the order of 10(-13) M. The NIR absorbing PNP will be a promising candidate of a sensitive contrast agent for PA imaging.