• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Photons Plus Ultrasound: Imaging and Sensing 2006; Progress in Biomedical Optics and Imaging; vol.7, no.9 >Metallic nanoparticles as optoacoustic contrast agents for medical imaging
【24h】

Metallic nanoparticles as optoacoustic contrast agents for medical imaging

机译：金属纳米粒子作为医学成像的光声造影剂

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A contrast agent for optoacoustic imaging and laser therapy of early tumors is being developed based on gold nanocolloids strongly absorbing visible and near-infrared light. The optoacoustic signals obtained from gold nanospheres and gold nanorods solutions are studied. In the case of 100 nm nanospheres as an example, a sharp increase in the total area under the curve of the optoacoustic signal is observed when the laser fluence is increased beyond a threshold value of about 0.1 J/cm~2. The change in the optoacoustic signal profile is attributed to the formation of water vapor bubbles around heated nanoparticles, as evidenced via thermoacoustic microscopy experiments. It has been determined that, surprisingly, gold nanoparticles fail to generate detectable nanobubbles upon irradiation at the laser fluence of ～2 mJ/cm~2, which heats the nanoparticles up to 374℃, the critical temperature of water. Only when the estimated temperature of the particle reaches about 10,000℃, a marked increase of the optoacoustic pressure amplitude and a changed profile of the optoacoustic signals indicate nanobubble formation. A nanoparticle based contrast agent is the most effective if it can be activate by laser pulses with low fluence attainable in the depth of tissue. With this goal in mind, we develop targeting protocols that form clusters of gold nanocolloid in the target cells in order to lower the bubble formation threshold below the level of optical fluence allowed for safe laser illumination of skin. Experiments and modeling suggest that formation of clusters of nanocolloids may improve the sensitivity of optoacoustic imaging in the detection of early stage tumors.
机译：基于强烈吸收可见光和近红外光的金纳米胶体，正在开发一种用于早期肿瘤的光声成像和激光治疗的造影剂。研究了从金纳米球和金纳米棒溶液获得的光声信号。例如，在100 nm纳米球的情况下，当激光通量增加到超过约0.1 J / cm〜2的阈值时，在光声信号曲线下的总面积会急剧增加。如通过热声显微镜实验所证明的，光声信号分布的变化归因于加热的纳米颗粒周围水蒸气气泡的形成。令人惊讶的是，已经确定，金纳米颗粒在〜2 mJ / cm〜2的激光能量密度下照射后无法产生可检测到的纳米气泡，从而将纳米颗粒加热到水的临界温度374℃。仅当估计的粒子温度达到约10,000℃时，光声压力幅度才会显着增加，并且光声信号的轮廓发生变化才表明会形成纳米气泡。如果可以通过在组织深度达到低通量的激光脉冲激活，则基于纳米颗粒的造影剂是最有效的。出于这一目标，我们开发了靶向协议，该协议可在靶细胞中形成金纳米胶体簇，以将气泡形成阈值降低到安全激光照射皮肤所允许的光学通量水平以下。实验和建模表明，纳米胶体簇的形成可以提高光声成像在早期肿瘤检测中的敏感性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号