Ogawa Yuuki, Mizutani Manabu, Okamoto Ryuta, Kitajima Hideki, Ezoe Sachiko, Kino-Oka Masahiro
Department of Medical Innovation, Osaka University Hospital, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Regen Ther. 2019 Apr 25;12:36-42. doi: 10.1016/j.reth.2019.04.002. eCollection 2019 Dec 15.
Preventing the contamination of processed cells is required for achieving reproducible manufacturing. A droplet is one of the potential causes contamination in cell manufacturing. The present study elucidates the formation mechanism and characteristics of droplets based on the observation and detection of droplets on the base surface of the biological safety cabinet (BSC) where cell processing is conducted under unidirectional airflow. Pouring fluorescent solution into the vessel using a measuring pipette was conducted to visualize the formation of droplets by videos as well as visual detection by blacklight irradiation on the base surface of the BSC. The experiments revealed that airborne and non-airborne droplets emerged from bursting bubbles, which formed when the entire solution was pushed out of the measuring pipette. Therefore, the improving procedure of pouring technique when entire solution was not pushed out of the pipette realized no formation of the droplets due to the prevention of emergence of bubble. In addition, an alternative procedure in which the entire solution was poured into the deep point of the test tube prevented the flying of non-airborne droplets outside the tube, while airborne droplets that escaped the tube rode the airflow of BSC. These results suggested a method for the prevention of the droplet formation, as well as the deposit control of droplets onto the surface in BSC, leading to cleanup area in the BSC for changeover with environment continuity.
为实现可重复的生产制造，防止加工细胞受到污染至关重要。液滴是细胞制造过程中潜在的污染原因之一。本研究基于在单向气流下进行细胞处理的生物安全柜（BSC）底面观察和检测液滴，阐明了液滴的形成机制和特性。使用移液器将荧光溶液倒入容器中，通过视频观察液滴的形成，并通过在BSC底面进行黑光照射进行视觉检测。实验表明，当整个溶液从移液器中推出时形成的破裂气泡会产生空气传播和非空气传播的液滴。因此，当整个溶液未从移液器中推出时改进倾倒技术的程序，通过防止气泡出现实现了不形成液滴。此外，将整个溶液倒入试管深处的替代程序可防止非空气传播的液滴飞出试管，而逸出试管的空气传播液滴则随着BSC的气流移动。这些结果提出了一种防止液滴形成以及控制液滴在BSC表面沉积的方法，从而实现BSC内的清洁区域，以便在环境连续的情况下进行转换。
