载印度墨水相变型光声/超声双模态造影剂的制备及体外显影

Preparation of India ink encapsulated phase-transition contrast agent for photoacoustic/ultrasound dual-mode imaging in vitro

目的制备一种新型的光声/超声双模态造影剂,观察其体外光致相变作用以及光声/超声显影效果。方法采用多步乳化法合成载印度墨水及全氟己烷(PFH)的高分子微球(i-PFH-PLGA),检测其基本理化性质、光致相变作用及体外增强光声及超声成像的显像效果。结果制备的i-PFH-PLGA呈球型,平均粒径为(542.1±68.91)nm。经激光辐照后,显微镜下可观察到较多的i-PFH-PLGA纳米粒发生液气相转变产生微泡;体外光声成像实验显示,i-PFH-PLGA纳米粒可检测到明显的光声信号,且光声信号的强度随纳米粒浓度的增加而增强;体外超声成像实验显示,经激光照射后,i-PFH-PLGA纳米粒组回声强度较辐照前明显增强(P<0.05),而单纯的液态氟碳和印度墨水辐照前后回声强度未见明显改变。结论成功制备出的载印度墨水和液态氟碳的双模态造影剂可用于体外光声/超声成像研究。

Objective To prepare a new photoacoustic/ultrasound dual-mode contrast agent,and to investigate its optical droplet vaporization effect and multifunctional imaging in vitro.Methods The polymeric nanoparticles loaded with India ink and perfluorohexane（i-PFH-PLGA）were synthesized by multi-emulsion technology,and its physicochemical properties,optical droplet vaporization effect and photoacoustic/ultrasound imaging were assessed.Results The nanoparticles were spherical,with average particle size of（542.1±68.91）nm.After the pulsed laser irradiation,the phase-transition could be observed by the optical microscope.Photoacoustic imaging in vitro,i-PFH-PLGA showed a strong photoacoustic signal,and the signal intensity increased with the rising of i-PFH-PLGA concentration.The ultrasonic signal intensity enhanced after triggered by pulsed laser system,while no specific changes were found in the PFH-PLGA group and ink group.Conclusion The dual-modality nanoparticles loaded with India ink and perfluorohexane is successfully prepared,which can be used as contrast agents for photoacoustic/ultrasound imaging in vitro.