Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyojadong, Pohang 790-784, South Korea.
Biosens Bioelectron. 2010 Mar 15;25(7):1571-8. doi: 10.1016/j.bios.2009.11.010. Epub 2009 Nov 17.
In applying the X-ray particle image velocimetry (PIV) technique to biofluid flows, the most pivotal prerequisite is suitable flow tracing sensors which should be detected effectively by the X-ray imaging system. In this study, to design those flow tracing sensors, X-ray contrast agent Iopamidol was encapsulated into the poly(vinyl alcohol) (PVA) microparticles crosslinked by glutaraldehyde (GA). The characteristics of the fabricated particle sensors were determined by optical microscopy, scanning electron microscopy, dynamic light scattering, laser Doppler electrophoresis and nuclear magnetic resonance spectroscopy ((1)H NMR). The amount of Iopamidol in the microparticles was measured using the energy dispersive X-ray spectroscopy (EDS) and (1)H NMR. The physical properties of the PVA microparticles are effectively controlled in terms of the average particle size, degree of crosslinking, degree of swelling and encapsulation efficiency of Iopamidol. By changing the amount of crosslinker, the degree of crosslinking and the efficiency of the Iopamidol encapsulation reached to the optimal. To some extent, the zeta-potential of the PVA microparticles is increased in less ionic media where the particles can effectively repel each other prohibiting aggregation. The X-ray absorption ability of the designed tracing sensors was examined by a synchrotron X-ray imaging technique. The X-ray absorption coefficients of the particle sensors were expressed by an exponential law assuming the spherical shape of the microparticles. The X-ray contrast agent, Iopamidol, was successfully encapsulated into the bio-compatible and bio-degradable PVA. With the controlled physical properties of the flow tracing sensors designed in this study, the particle sensors exhibit excellent X-ray absorption contrast fairly applicable in biological systems.
在将 X 射线粒子图像测速（PIV）技术应用于生物流体流动时，最关键的前提是需要能够被 X 射线成像系统有效检测的合适的流动示踪传感器。在这项研究中，为了设计这些流动示踪传感器，将造影剂碘帕醇包封到戊二醛（GA）交联的聚乙烯醇（PVA）微球中。通过光学显微镜、扫描电子显微镜、动态光散射、激光多普勒电泳和核磁共振波谱（1H NMR）来确定所制备的颗粒传感器的特性。通过能量色散 X 射线光谱（EDS）和 1H NMR 来测量微球中碘帕醇的含量。通过改变交联剂的用量，可以有效地控制 PVA 微球的平均粒径、交联度、溶胀度和碘帕醇的包封效率等物理性质。通过改变交联剂的用量，达到了最佳的交联度和碘帕醇包封效率。在离子强度较低的介质中，微球的zeta 电位会在一定程度上增加，此时颗粒可以有效地相互排斥，防止聚集。通过同步加速器 X 射线成像技术来检测设计的示踪传感器的 X 射线吸收能力。假设微球为球形，用指数定律来表示示踪传感器的 X 射线吸收系数。造影剂碘帕醇已成功地包封到生物相容性和可生物降解的 PVA 中。通过控制本研究中设计的流动示踪传感器的物理性质，所制备的颗粒传感器表现出优异的 X 射线吸收对比，非常适用于生物系统。
