Effects of mechanical index on contrast-enhanced imaging of ultrasound-responsive polymeric nanodroplets
10.3760/cma.j.cn131148-20200306-00150
- VernacularTitle:机械指数对超声响应型聚合物纳米液滴造影成像的影响
- Author:
Yaqiong LI
1
;
Ruiqing LIU
;
Luwen LIU
;
Ye ZHANG
;
Yuejin WU
;
Shaobo DUAN
;
Zhiyang CHANG
;
Lianzhong ZHANG
Author Information
1. 河南省人民医院 郑州大学人民医院药学部 450003；河南省超声分子影像与纳米技术工程研究中心，郑州 450003
- From:
Chinese Journal of Ultrasonography
2020;29(9):807-811
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To prepare ultrasound-responsive nanodroplets with block polymer PEG-PCL as shell and perfluoropentane (PFP) as core, and study the effects of mechanical index (MI) on contrast-enhanced imaging properties of nanodroplet.Methods:PEG-PCL micelles were first prepared by dialysis, and then the micelles were mixed with PFP for emulsification to obtain nanodroplets. The particle size and zeta potential of nanodroplets were measured, and the morphology of nanodroplets were observed using transmission electron microscope (TEM). The stability of nanodroplets after storage at 25 ℃ and 37 ℃ was investigated. The phase transition and contrast-enhanced imaging of nanodroplets in vitro under a series of mechanical index (MI) were studied using an ultrasound diagnostic instrument.Results:The particle size of the nanodroplets was (356.6±5.6)nm, and the zeta potential was -(7.30±0.14)mV. The nanodroplets were close to spherical under TEM and had a clear core-shell structure. The particle size and dispersion of the nanodroplets increased after storage at 37 ℃ and 25 ℃. For imaging in vitro, no acoustic signal were observed at 25 ℃ when the MI varied from 0.08 to 1.0. At 37 ℃, acoustic signals were observed when MI≥0.4, and the intensity was stronger for higher MIs.Conclusions:The contrast-enhanced imaging of nanodroplets are closely related to the MI, and a higher MI could induce the phase transition of more nanodroplets and produce stronger contrast enhancement. This study could provide basis for the application of polymeric nanodroplets in ultrasound diagnosis and targeted therapy.
