Nano-Sized Ultrasound Contrast Agent: Salting-Out Method
Nano-Sized Ultrasound Contrast Agent: Salting-Out Method
复制标题
纳米超声造影剂：盐析法
DOI：
10.2310/7290.2010.00007
复制
发表时间：
2010
影响因子：
2.8
通讯作者：
J. Lewandowski
中科院分区：
文献类型：
--
作者：
M. Wheatley;J. Lewandowski
使用超声造影剂(UCAS)、稳定的充气体能极大地增强超声对肿瘤的成像效果。它们一般小于7μm才能自由通过毛细管床。开发一种纳米制剂将使它们能够通过血管新生血管的渗漏毛孔渗出。我们描述了一种具有回声功能的纳米级聚乳酸UCA的研制。初始胶体悬浮液的粘度(保护性胶体[聚乙烯醇(PVA)]的浓度和相对分子质量以及聚合物的浓度)是决定颗粒大小和多分散性(增加粘度均增大)的关键。添加造孔剂碳酸铵和樟脑，也增加了中空回声胶囊的大小(如5wt%的PVA，平均固体纳米胶囊尺寸386±25 nm，多分散指数0.367±0.14，平均UCA640±18 nm，多分散指数0.308±0.027)。粘度对所得纳米UCA的回声影响相反，2%PVA为21.69±0.78分贝，10%PVA为12.1±0.8分贝。然而，用10%PVA制备的UCA在超声束中的半衰期更长(15分钟比10分钟)，这意味着外壳更厚。优化将需要在大小、回声和稳定性之间进行折衷。
Tumor imaging by ultrasound is greatly enhanced by the use of ultrasound contrast agents (UCAs), stabilized, gas-filled bodies. They are generally less than 7 μm to pass freely through the capillary bed. Development of a nano-sized agent would enable them to extravasate through the leaky pores of angiogenic vessels. We describe the development of an echogenic, nano-sized polylactic acid UCA by adaptation of a salting-out method. The viscosity of the initial colloidal suspension (concentration and molecular weight of protective colloid [polyvinyl alcohol (PVA)] and concentration of polymer) was key in determining particle size and polydispersity (increasing viscosity increased both). Addition of the porogens ammonium carbonate and camphor, required to produce hollow echogenic capsules, also increased the size (eg, 5 wt% PVA, mean solid nanocapsule size 386 ± 25 nm, polydispersity index 0.367 ± 0.14, and mean UCA size 640 ± 18 nm, polydispersity index 0.308 ± 0.027). Viscosity had the opposite effect on echogenicity of the resultant nano-UCA, which ranged from 21.69 ± 0.78 dB for 2% PVA to 12.1 ± 0.8 dB for 10% PVA. The UCA prepared with 10% PVA, however, had a longer half-life in the ultrasound beam (t½ > 15 minutes vs t½ < 10 minutes), suggesting a thicker shell. Optimization will require compromise among size, echogenicity, and stability.
登录
查看更多内容
影响因子：
4.2
作者：
Wheatley, Margaret A.;Forsberg, Flemming;El-Sherif, Dalia
通讯作者：
El-Sherif, Dalia
DOI：
10.1073/pnas.95.8.4607
发表时间：
1998-04-14
影响因子：
11.1
作者：
Hobbs, SK;Monsky, WL;Jain, RK
通讯作者：
Jain, RK
影响因子：
4.9
作者：
El-Sherif, DM;Wheatley, MA
通讯作者：
Wheatley, MA
影响因子：
2.9
作者：
Dayton, P;Klibanov, A;Ferrara, K
通讯作者：
Ferrara, K