Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
Lab Chip. 2017 Oct 11;17(20):3504-3513. doi: 10.1039/c7lc00056a.
Liquid perfluorocarbon (PFC) nanodroplets may have a better chance to extravasate through inter-endothelial gaps (400-800 nm) into tumor interstitium for extravascular imaging, which holds promise as an innovative strategy for imaging-guided drug delivery, early diagnosis of cancer and minimally invasive treatment of cancer. Currently available emulsion technologies still face challenges in reducing droplet sizes from the microscale to the nanoscale. To control size and ensure monodispersity of PFC nanodroplets, we developed a flame-shaped glass capillary and polydimethylsiloxane (PDMS) hybrid device that creates a concentric flow of the dispersed phase enclosed by the focusing continuous phase at the cross-junction. Through adjustment of the pressure applied, a stable tip-streaming mode can be obtained for PFC nanodroplet generation. Using this device, we synthesized various kinds of PFC nanodroplets as small as 200 nm in diameter with polydispersity index (PDI) <0.04. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were carried out for the characterization of the PFC nanodroplets. Finally, ultrasound imaging was conducted to demonstrate that the liquid PFC nanodroplets can be used for enhancing the ultrasound contrast upon vaporization.
液体全氟碳（PFC）纳米液滴可能更容易通过内皮细胞间隙（400-800nm）渗出到肿瘤间质中进行血管外成像，这有望成为一种创新的成像引导药物输送、癌症早期诊断和微创治疗癌症的策略。目前可用的乳液技术在将液滴尺寸从微米级减小到纳米级方面仍面临挑战。为了控制尺寸并确保 PFC 纳米液滴的单分散性，我们开发了一种火焰形玻璃毛细管和聚二甲基硅氧烷（PDMS）混合装置，该装置在十字接头处创建了被聚焦连续相包围的分散相的同心流。通过调整施加的压力，可以获得用于 PFC 纳米液滴生成的稳定尖端流模式。使用该装置，我们合成了各种直径小至 200nm 的 PFC 纳米液滴，多分散指数（PDI）<0.04。通过动态光散射（DLS）和透射电子显微镜（TEM）对 PFC 纳米液滴进行了表征。最后，进行了超声成像以证明液体 PFC 纳米液滴可用于在蒸发时增强超声对比。
