Faculty of Electrical Engineering and Information Technology, Ruhr-Universitaet Bochum, Germany.
Ultrasound Med Biol. 2011 Dec;37(12):2105-15. doi: 10.1016/j.ultrasmedbio.2011.09.007.
Ultrasound is an established therapy method for bone fracture healing, hyperthermia and the ablation of solid tumors. In this new emerging field, ultrasound is further used for microbubble-enhanced drug delivery, gene therapy, sonoporation and thrombolysis. To study selected therapeutic effects in defined experimental conditions, in vitro setups are designed for cell and tissue therapy. However, in vitro studies often lack reproducibility and the successful transfer to other experimental conditions. This is partly because of the uncertainty of the experimental conditions in vitro. In this paper, the ultrasound wave propagation in the most common in vitro ultrasound therapy setups for cell culture wells is analyzed in simulations and verified by hydrophone measurements. The acoustic parameters of the materials used for culture plates and growth media are determined. The appearance and origin of standing waves and ring interference patterns caused by reflections at interfaces is revealed in simulations and measurements. This causes a local maximal pressure amplitude increase by up to the factor of 5. Minor variations of quantities (e.g., growth medium volume variation of 2.56%) increase or decrease the peak rarefaction pressure at a cell layer by the factor of 2. These pressure variations can affect cell therapy results to a large extent. A sealed cell culture well submersed in a water bath provides the best reproducibility and therefore promises transferable therapy results.
超声在骨折愈合、高热和实体肿瘤消融方面已经是一种成熟的治疗方法。在这个新出现的领域，超声还被进一步用于微泡增强药物输送、基因治疗、声孔和溶栓。为了在特定的实验条件下研究选定的治疗效果，设计了用于细胞和组织治疗的体外装置。然而，体外研究往往缺乏可重复性，并且难以成功地转移到其他实验条件。这部分是因为体外实验条件的不确定性。在本文中，通过模拟分析并通过水听器测量验证了最常见的细胞培养皿体外超声治疗装置中的超声波传播。确定了用于培养板和生长培养基的材料的声学参数。在模拟和测量中揭示了界面反射引起的驻波和环形干扰图案的出现和起源，这导致局部最大压力幅度增加了 5 倍。数量的微小变化（例如，生长培养基体积变化 2.56%）会使细胞层的峰值稀疏压力增加或减少 2 倍。这些压力变化会在很大程度上影响细胞治疗的效果。密封的细胞培养皿浸入水浴中可提供最佳的重现性，因此有望获得可转移的治疗效果。
