南京医科大学 生物医学工程与信息学院 生物医学工程系
Department of Biomedical Engineering,Nanjing Medical University
目的：制备温度/超声双重响应型脂质相变液滴(lipid phase-change droplets,LPCDs),并将其与水凝胶进行复合,通过温度或低强度聚焦超声(low intensity focused ultrasound,LIFU)调控LPCDs的内核发生液-气相转变,继而调控水凝胶的结构和力学性能。方法：首先通过薄膜水化法制备出脂质膜壳的全氟己烷(perfluorohexane,PFH)相变液滴,对其在温度和LIFU调控下的形貌变化、相转变能力进行表征,同时评估了液-气相变前后LPCDs的超声造影能力。在此基础上将其与水凝胶进行复合,通过各项表征评估温度/超声引起的液滴相变对水凝胶内部结构、浮力和机械性能的影响。结果：LPCDs在温度或超声调控下有良好的相转变能力和超声造影能力。脂质液滴相变可使水凝胶内部生成直径在微米量级的诸多气孔,浮力得到显著提高,压缩应力和溶胀性能也有所变化。结论：脂质相变液滴-水凝胶复合材料(LPCDs@Hy)是一种有潜力的智能响应型诊疗用微纳材料。
Objective:Prepare temperature/ultrasound dual-responsive lipid phase-change droplets (LPCDs) and combine them with hydrogels to regulate liquid-gas transitions in the core of lipid droplets by temperature or low intensity focused ultrasound (LIFU), and then regulate the structure and mechanical properties of the hydrogels. Methods: Firstly, perfluorohexane (PFH) phase-change droplets of lipid membrane shell were prepared by thin-film hydration method. The morphological changes and phase transition ability under the control of temperature and LIFU were characterized. At the same time, the contrast-enhanced ability of LPCDs before and after liquid-gas phase transition was evaluated. On this basis, it was combined with hydrogels, and the effects of temperature / ultrasound induced droplet transition on the internal structure, buoyancy and mechanical properties of hydrogels were evaluated by characterization.Results: LPCDs had good phase transition ability and contrast-enhanced ultrasound ability under the control of temperature or ultrasound. Lipid droplet phase transitions can cause many micro-pores inside the hydrogel, which significantly improving buoyancy, varying compressive stress and swelling properties. Conclusion: lipid phase change droplet-hydrogel Composite material( LPCDs@Hy ) is a kind of potential intelligent response micro/nano material for diagnosis and treatment.