超音波是一種非侵入性的診斷與治療工具，具有方便使用、低成本、與即時性觀測等優點，近年來許多科學家積極發展多功能超音波顯影劑，提升超音波於生物醫學的應用價值。本研究提出一種同時具有超音波顯影與治療功能的材料，此材料是以雙重乳化的方式合成，外殼為聚乳酸-羥基乙酸共聚物 (poly(lactic-co-glycolic acid), PLGA) 鑲嵌四氧化三鐵奈米粒子，中心包覆雙氧水 (H2O2)，作為氣體的來源，增強超音波影像的對比。材料在超音波環境下會破裂，釋放包覆於中心的雙氧水，雙氧水與鑲嵌於聚乳酸-羥基乙酸共聚物殼層中的四氧化三鐵奈米粒子接觸，發生芬頓反應 (Fenton reaction) 產生活性氧化物質 (Reactive oxygen species, ROS) ，利用活性氧化物質對細胞的毒殺效果達到癌症治療的目的。因為鑲嵌在聚乳酸-羥基乙酸共聚物殼層中的四氧化三鐵奈米粒子具有磁響應之特性與磁振造影的功能，因此可藉由磁導引的方式將材料導引至腫瘤部位產生磁振影像，再給予超音波刺激誘導材料破裂進行活性氧化物質介導的癌症治療，由實驗結果證實本材料於生物影像之觀測與惡性腫瘤的治療都有很好的應用價值。

We demonstrate a successful synthesis of a theranostic polymersomes and provide a series of imaging and therapy platform in this article. We synthesis the theranostic polymersomes by double emulsion (water/oil/water) method. The core area of the polymersomes is hydrophilic, and the space between the core and outer shell is hydrophobic. The hydrophobic ligand iron oxide nanoparticles can be embedded in the hydrophobic space. Due to the component of Fe3O4 nanoparticles which provides ferromagnetic property, it can be applied as T2-negative contrast agents of magnetic resonance imaging (MRI). We can use magnet targeting the tumor site to guide the polymersomes to tumor. Combining with ultrasound irradiate, this material can get ultrasound imaging and induced ROS mediated therapy. The in vivo test provide a strong evidence for cancer treatment.

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