外场诱导的诊断和治疗用微气泡

实验主要研究了交变磁场诱导作为微囊内包裹成分进行控制释放的可能性。实验首先制备了膜壳装载超顺磁性Fe3O4纳米颗粒，内部包裹L-精氨酸的聚合物微囊，然后利用膜壳中Fe3O4纳米颗粒对外界交变磁场的响应从而能够引起微囊膜壳渗透性等性质的改变而进行微囊内外物质的交换，使膜壳内的精氨酸和膜壳外的H2O2接触，产生NO气体，产生的NO气体一方面可用于超声显影增强用造影剂，另一方面也可用于心血管疾病治疗用的治疗药物。

Fang Yang, Ping Chen, Wen He, Ning Gu, Xizhi Zhang, Kun Fang, Yu Zhang, JianFei Sun, Jiayi Tong.Bubble Microreactors Triggered by an Alternating Magnetic Field as Diagnostic and Therapeutic Delivery Devices. Small, 2010, 6(12): 1300-1305

Figure 1.Magnetization curves of the naked Fe3O4 nanoparticles and Fe3O4-inclusion microcapsules at room temperature.

Figure 2.Morphology of Fe3O4-inclusion microcapsules: (a, c) Optical microscopy and SEM images before alternating magnetic field treatment; (b, d) Optical microscopy and SEM images immediately after alternating magnetic field treatment; (e) SEM image of the damaged microreactors after further ultrasonic exposure.

Figure 3.The in vitro ultrasound images of the different samples: (a) de-gassed and de-ionized water; (b) the microcontainer solution before alternating magnetic field treatment; (c, d) the microcontainer solution after alternating magnetic field treatment when US imaging lasted for 2min and 10min respectively; (e) After magnetic field treatment, the US images of mean grey scale change curve were captured. The enhancement of the ultrasound imaging was changed over the time.