We quantified the influence of the elements of the extracorporeal oxygenation (ECMO) circuit on drug sequestration by focusing on the interactions between materials and drugs. Tubing of three different brands (Tygon/Maquet/Terumo) and oxygenators of two different brands (Maquet/Terumo) were used. Drugs included dexmedetomidine, meropenem, and heparin, which were dissolved in deionized water. Tubing was cut into approximately 7 cm sections and allowed drug solutions enclosed inside by clamping both ends. The oxygenator housing, gas membrane, and heat exchanger were dissected into approximately 1 g pieces and submerged into drug solutions. The experimental samples were then immersed in a water bath at 37°C for 1, 6, 12, and 24 h. After 24 h, the dexmedetomidine concentration was significantly reduced in all three types of tubing (<30.1%), the oxygenator heat exchanger from Maquet Inc. (41.8%), and the gas exchanger from Terumo Inc. (8.6%), while no significant losses were found for meropenem and heparin compared with the control group. The heparin concentration within the Maquet gas exchanger, on the contrary, increased significantly compared with the control group at 1 and 12 h (p < 0.05). Our in vitro study reveals that material selection is a vital part of ECMO development.

In living tissue, cells exist in three-dimensional (3D) microenvironments with intricate cell-cell interactions. To model these cellular environments, numerous techniques for generating cell spheroids have been proposed and improved. However, previously reported methods still have limitations in uniformity, reproducibility, scalability, throughput, etc. Here, we present a centrifugal microfluidic-based spheroid (CMS) formation method for generating both co-culture and mono-culture 3D spheroids in a highly controlled manner. We designed circularly arrayed microwells to allow the even distribution of cells introduced at the center of a rotating platform and to provide identical hypergravity conditions at each well by the centrifugal forces generated. Compared with conventional well plate-based spheroid formation, the CMS formation method significantly promotes sphericity and consistency in both size and shape with high production yields. In addition to mono-culture spheroids, we successfully generated co-culture spheroids in concentric, Janus, and sandwich shapes using human adipose-derived stem cells and human lung fibroblasts, demonstrating the versatility of our CMS formation method. We believe that our new method for generating 3D spheroids will become one of the essential technologies in the field of 3D cell culture. We also expect that we are providing an innovative means to assess cellular responses, including cell motility under different hypergravity conditions.

No abstract

The process of cardiopulmonary resuscitation (CPR) involves various components that must be followed to deliver high quality of CPR. While the components commonly apply to CPR for all ages from infant to adult, there are several different suggestions for infant CPR such as two-thumb CPR and two-finger CPR. However, the comprehensive evaluation based on all these components has been difficult in the absence of proper evaluation tool. Here, we developed a new manikin-integrated, digital measuring system that objectively estimates overall performance of infant CPR by evaluating individual CPR components one by one including different hand placements. The system collects and analyzes data to present estimations in digital scores according to a new evaluation index constructed based on the previously verified one. The feasibility of the system was validated through simulations with beginners and experts in first aid, resulting in statistically significant differences between the two groups with the indication of specific weaknesses for each group which may provide a basis for creating customized CPR training strategy in compliance with the personal level. We believe that the system would become a valuable assessment tool not only for infant CPR but also for the CPR technique, in general, by reflecting every component in the evaluation.

The large operating range of FREE-D system extends the use of VAD for nearly all patients without being affected by the depth of the implanted pump. Our in-vivo results with the FREE-D system may offer a new perspective on quality of life for patients supported by implanted device.