实验利用末端修饰带有羧基的聚乙烯醇（PVA）膜材制备出聚合物微气泡，并通过化学耦联将纳米颗粒装载于气泡表面。膜壳表面修饰磁性纳米颗粒的微气泡与实验室前期研制出的膜壳内嵌入纳米纳米颗粒的微气泡进行比较，发现表面装载纳米颗粒的微气泡具有更高的电荷，这有利于微气泡在溶液中的稳定；通过磁滞回线测量，发现对于同样的纳米颗粒装载量，表面装载纳米颗粒的微气泡具有更强的饱和磁化强度。分别采用频率为3.5MHz的临床用超声诊断仪和7T小动物磁共振成像仪进行显影体外实验，发现表面装载纳米颗粒的微气泡具有更强的超声显影和磁共振显影增强功能。
Wen He, Fang Yang, Yihang Wu, Song Wen, Ping Chen, Yu Zhang, Ning Gu. Microbubbles with surface coated by superparamagnetic iron oxide nanoparticles. Materials Letters, 2012, 68(1): 64-67
Fig. 1. SEM images of (a) blank microbubbles, (b) SPIO-coated microbubbles, (c) SPIO-embedded microbubbles, TEM images of (d) blank microbubble, (e) SPIO-coated microbubble, (f) SPIO-embedded microbubble, (g-i) are partially enlarged images of (d-f).
Fig. 2. B-mode ultrasound images of (a) distilled water, (b) blank microbubbles, (c) SPIO-coated microbubbles and (d) SPIO-embedded microbubbles.
Fig. 3 (a) MR images of SPIO-embedded microbubbles (I), SPIO-coated microbubbles (II); relationship between R2 and volume fraction of two types of microbubbles (b), and (c) hysteresis loops of (I) and (II).
