A novel wide-range microfluidic dilution device for drug screening.

Area of Science:

• Biotechnology and Biomedical Engineering
• Microfluidics and Lab-on-a-Chip Technology
• Enzymology and Cellular Kinetics

Background:

• Gradient dilution is essential for biological sample analysis.
• Existing methods may lack precision or efficiency for certain applications.
• Microfluidic systems offer potential for advanced biological assays.

Purpose of the Study:

• To develop and validate novel microfluidic dilution chips.
• To demonstrate the application of these chips in enzymatic kinetics and oxidative stress studies.
• To explore the utility of the chips for drug screening and toxicology assessments.

Main Methods:

• Designed and fabricated two serial wide-range dilution chips (1:1 and 1:4 dilution rates) based on a microfluidic oscillator.
• Utilized oscillatory methods by adjusting chamber sizes and incorporating air chambers for dilution.
• Applied the chips to estimate kinetic parameters of β-galactosidase and conduct oxidative stress tests on Caenorhabditis elegans.

Main Results:

• Successfully created microfluidic dilution chips with controllable dilution rates.
• Estimated kinetic parameters for β-galactosidase: K_m = 602 ± 73 μM and k_cat = 72 ± 12/s.
• Achieved results for Caenorhabditis elegans oxidative stress tests consistent with traditional 96-well plate methods.

Conclusions:

• The novel microfluidic dilution chip effectively generates wide-range sample concentration gradients.
• The chip is suitable for accurate enzymatic reaction kinetics studies and drug screening in nematode models.
• This technology holds promise for applications in drug screening, drug toxicology, and environmental toxicology.