Isothermal titration calorimetry in a 3D-printed microdevice

Area of Science:

• Biophysical Chemistry
• Microfluidics
• Sensor Technology

Background:

• Miniaturized Isothermal Titration Calorimetry (ITC) offers advantages in cost, speed, and reagent use for biomolecular interaction analysis.
• Existing micro-devices often lack precise condition control, suffer from evaporation or adsorption, leading to inaccurate results.
• Accurate concentration information and preserved biomolecular properties are crucial for reliable ITC measurements.

Purpose of the Study:

• To develop a novel microdevice for quantitative Isothermal Titration Calorimetry (ITC) measurements of biomolecular interactions.
• To overcome limitations of existing micro-devices, including poor condition control and sample adsorption.
• To enable low-cost, high-precision analysis of biomolecular binding events.

Main Methods:

• Integration of 3D-printed microfluidic structures with a polymer-based MEMS thermoelectric sensor.
• Utilizing a differential cantilever configuration for calorimetric chambers to enhance thermal insulation and reduce thermal mass.
• Employing non-permeable 3D-printed materials to prevent sample adsorption and ensuring reversible, leak-free assembly for device reusability.

Main Results:

• The microdevice successfully performed quantitative ITC characterization of the ribonuclease A (RNase A) and cytidine 2'-monophosphate (2'CMP) binding system.
• Accurate thermodynamic parameters, including stoichiometry, binding constant, and enthalpy change, were obtained down to a sample concentration of 0.2 mM.
• The obtained results align with previously reported literature values, validating the device's performance.

Conclusions:

• The presented microdevice enables accurate and quantitative ITC measurements of biomolecular interactions.
• The combination of 3D-printing and MEMS technology provides a robust, reusable platform for microfluidic calorimetry.
• This technology holds significant potential for advancing low-volume, cost-effective analysis of biomolecular binding in research and diagnostics.