Authors:Maryam Parsian, Pelin Mutlu, Ender Yildirim, Can Ildiz, Can Ozen, Ufuk Gunduz Abstract: Biomicrofluidics, Volume 16, Issue 3, May 2022. One of the issues limiting the development of personalized medicine is the absence of realistic models that reflect the nature and complexity of tumor tissues. We described a new tissue culture approach that combines a microfluidic chip with the microdissected breast cancer tumor. “Tumor-on-a-chip” devices are suitable for precision medicine since the viability of tissue samples is maintained during the culture period by continuously feeding fresh media and eliminating metabolic wastes from the tissue. However, the mass transport of oxygen, which arguably is the most critical nutrient, is rarely assessed. According to our results, transportation of oxygen provides satisfactory in vivo oxygenation within the system. A high level of dissolved oxygen, around 98%–100% for every 24 h, was measurable in the outlet medium. The microfluidic chip system developed within the scope of this study allows living and testing tumor tissues under laboratory conditions. In this study, tumors were generated in CD-1 mice using MDA-MB-231 and SKBR-3 cell lines. Microdissected tumor tissues were cultured both in the newly developed microfluidic chip system and in conventional 24-well culture plates. Two systems were compared for two different types of tumors. The confocal microscopy analyses, lactate dehydrogenase release, and glucose consumption values showed that the tissues in the microfluidic system remained more viable with respect to the conventional well plate culturing method, up to 96 h. The new culturing technique described here may be superior to conventional culturing techniques for developing new treatment strategies, such as testing chemotherapeutics on tumor samples from individual patients. Citation: Biomicrofluidics PubDate: 2022-05-05T05:17:36Z DOI: 10.1063/5.0087532
Authors:Run Ze Gao, Vivian Ngoc Tram Mai, Nicholas Levinski, Jacqueline Mary Kormylo, Robin Ward Murdock, Clark R. Dickerson, Carolyn L. Ren Abstract: Biomicrofluidics, Volume 16, Issue 3, May 2022. A proof of concept of a novel air microfluidics-enabled soft robotic sleeve to enable lymphedema treatment is presented. Compression sleeves represent the current, suboptimal standard of care, and stationary pumps assist with lymph drainage; however, effective systems that are truly wearable while performing daily activities are very scarce. This problematic trade-off between performance and wearability requires a new solution, which is addressed by an innovative microfluidic device. Its novelty lies in the use of light, small, and inexpensive air microfluidic chips (35 × 20 × 5 mm3 in size) that bring three major advantages compared to their traditional counterparts. First, each chip is designed with 16 fluidic channels with a cross-sectional area varying from 0.04 to 1 mm2, providing sequential inflation and uniform deflation capability to eight air bladders, thereby producing intentional gradient compression to the arm to facilitate lymph fluid circulation. The design is derived from the fundamentals of microfluidics, in particular, hydraulic resistance and paths of least resistance. Second, the air microfluidic chip enables miniaturization of at least eight bulky energy-consuming valves to two miniature solenoid valves for control increasing wearability. Third, the air microfluidic chip has no moving parts, which reduces the noise and energy needed. The cost, simplicity, and scale-up potential of developing methods for making the system are also detailed. The sequential inflation, uniform deflation, and pressure gradient are demonstrated, and the resulted compression and internal air bladder pressure were evaluated. This air microfluidics-enabled sleeve presents tremendous potential toward future improvements in self-care lymphedema management. Citation: Biomicrofluidics PubDate: 2022-05-03T02:45:00Z DOI: 10.1063/5.0079898
Authors:Xiao Li, Yiteng Jin, Jialin Shi, Xiaoqiang Sun, Qi Ouyang, Chunxiong Luo Abstract: Biomicrofluidics, Volume 16, Issue 3, May 2022. The mechanical properties of cells are of great significance to their normal physiological activities. The current methods used for the measurement of a cell’s mechanical properties have the problems of complicated operation, low throughput, and limited measuring range. Based on micropipette technology, we designed a double-layer micro-valve-controlled microfluidic chip with a series of micropipette arrays. The chip has adjustment pressure ranges of 0.03–1 and 0.3–10 kPa and has a pressure stabilization design, which can achieve a robust measurement of a single cell's mechanical properties under a wide pressure range and is simple to operate. Using this chip, we measured the mechanical properties of the cells treated with different concentrations of paraformaldehyde (PFA) and observed that the viscoelasticity of the cells gradually increased as the PFA concentration increased. Then, this method was also used to characterize the changes in the mechanical properties of the differentiation pathways of stem cells from the apical papilla to osteogenesis. Citation: Biomicrofluidics PubDate: 2022-05-03T02:35:12Z DOI: 10.1063/5.0085876