Project Summary
This proposal aims to revolutionize the micro-calorimetry field by miniaturizing an adiabatic
scanning calorimeter (ASC) to improve the accuracy of thermodynamic data of protein unfolding.
Unlike the thousands of existing microscopic-DSCs (differential scanning calorimeters), a micro-
ASC does not have to sacrifice accuracy for sensitivity during phase transitions, and actually
improves in accuracy as the scan approaches a phase transition. This is particularly important as
micro-calorimetry is the gold standard to provide experimental measurements of enthalpy, binding
affinity, and heat capacity to calculate the entropy and Gibbs energy of protein structural changes.
The significance of the proposed work is it will produce a suite of tools that can increase the pace
of pharmacological and biological chemistry discoveries, by understanding the fundamental role
thermodynamics has in disease occurrence, diagnosis, and treatment.
Recent advancements in 3D printing of microfluidic devices can remove the roadblocks that have
prevented taking advantage of ASC’s benefits when studying protein folding/unfolding and
stability. Aim 1 will build on our previous experience with both 3D printing and injecting liquid
materials to improve the capabilities of microfluidic devices by making micro-ASC devices. We
will design a series of printed calorimeter sections using our custom digital light project
stereolithography (DLP-SL) 3D printer. Each printed section can then be modified after printing
to achieve a different function, including but not being limited to: (1) casting molds to make metallic
enclosures, a thermoelectric generator composed of injectable materials, and (3) low thermal
conductivity aerogel impregnated resins. Then, because the printer can print internal features as
small as 7, we can make sure each section has a barb and a mating receptor to allow the
different printed sections to be assembled together into a calorimeter. Aim 2 will use these
functionalized sections to create the adiabatic conditions, low thermal conductance, low thermal
noise, and high sensitivities needed for both a micro-ASC and a micro-ITC (isothermal titration
calorimeter) on the same microfluidic platform. Aim 3 will use the micro-ASC/ITC devices to
measure the unfolding dynamics of two amyloid proteins, amyloid- (A) and lysozyme. This will
show that the technology is suitable for improved thermodynamic measurements and can be
applied to other protein systems. The overall objective of this study is develop a series of devices
that can be widely accessible, and then use those tools to measure the fundamental
thermodynamic behavior that dictates the stability of key amyloid proteins that can cause disease.