A novel wide-range microfluidic dilution device for drug screening

Abstract

Microfluidic dilution chip is a crucial approach to perform gradient dilution of experimental samples in many biological investigations. In this study, we developed two serial wide-range dilution chips with dilution rates of 1:1 and 1:4 on the basis of the microfluidic oscillator by designing a series chamber, which was similar to a series circuit. The size of this chamber was adjusted and mixed with the neighboring air chamber to form dilution rates by oscillatory methods. We applied this microfluidic oscillator to estimate cellular kinetics and perform an acute oxidative stress test on Caenorhabditis elegans (C. elegans) in order to further validate their effectiveness. We estimated the kinetic parameters of β-galactosidase, the biocatalyst responsible for the hydrolysis of lactose, and found out that K m was 602 ± 73 μM and k cat was 72 ± 12/s. In addition, our result of the study on acute oxidative stress of C. elegans using this novel chip was consistent with the result using 96-well plates. Overall, we believe that this novel chip can be applied to enzymatic reaction kinetics to evaluate accurately drug screening in bio-nematode models such as C. elegans. In summary, we have provided a novel microfluidic dilution chip that can form a wide range of sample concentration gradients. Our chip may facilitate drug screening, drug toxicology, and environmental toxicology.

Microfluidics in High-Throughput Drug Screening: Organ-on-a-Chip and C. elegans-Based Innovations

“…For example, pretreating the channel surface with 75% alcohol and a substance such as Triton X100 can effectively reduce the absorbency [54]. Importantly, this treatment also prevents protein coating on the PDMS surface, which can help to further improve the accuracy of the experiment [55]. In some cases, in addition to these surface modifications, low-temperature curing of PDMS replicas can reduce the number of uncrosslinked free oligomers, which can reduce water absorption [56].…”

“…In addition to these representative examples of C. elegans chip, a more comprehensive set of previous studies can be found in Table 3. Hydrogen peroxide Using the priming valve, the flows were controlled [55] Cu 2+…”

Revolutionizing sample preparation: a novel autonomous microfluidic platform for serial dilution

“…13 In an alternative mechanism, oscillatory microfluidics was used to execute stepwise serial dilution via coordinated operation of pneumatic valves to first meter both the sample and diluent in separate microfluidic chambers and afterwards mix them through oscillatory liquid manipulation. 14 This process was then repeated to prepare a 6-fold dilution series of a hydrogen peroxide solution and study the oxidative stress in C. elegans nematodes. The main drawback of this approach is the need to control each valve individually with an external control unit which makes the device bulky and not compatible with POC applications.…”