How to Improve Gene Therapy Development

Neil Demarse | Morgan Ulrich
May 09, 2022

Gene therapy is an approach to disease treatment where a patient’s genetic makeup is altered rather than using drugs or surgery. Gene therapy treatment is accomplished through the activation of a particular gene, repairing faulty genes, or introducing new genes to help fight disease. 

Gene therapy enables the creation of personalized medical care as well as the treatment of diseases that are incurable with standard drugs and surgical methods. Developing new gene therapies is therefore a highly active area of research, particularly since the first approval of US federal funding for human embryonic stem cell research in 2001.1  

With potential for curing debilitating disease and support from the FDA, gene therapy development has accelerated greatly, but there are still many hurdles to ensure the efficacy and reproducibility of gene therapy product development and manufacture, which require new analytical methods for monitoring formulation and batch-to-batch variability. Measuring thermal stability of gene therapy treatments, ascertaining whether RNA contamination has occurred, or determining cargo loading and drug product serotypes are important details that need to be accurately characterized and monitored. 

Differential Scanning Calorimetry

Differential scanning calorimetry is a versatile tool that can help address many of the remaining questions in gene therapy treatment. By measuring small changes in the temperature of a therapeutic product sample versus a reference sample, DSC enables researchers to measure, with excellent precision, the changes in heat capacity of the sample that may result from changes to the sample’s structure, solvent environment, and forced degradation. In turn, this data can be used to deduce information on changes in intermolecular interactions, quantification of empty and full capsids and DNA cargo loading, and LNP design and optimization. 

One key advantage of differential scanning calorimetry for gene therapy development is that it can be used to establish structure-property relationships of samples in their native solution environments. Many microscopy techniques require the freezing and immobilization of biomolecules, but a differential scanning calorimeter can measure properties in solution. Therefore, measurements can be made in conditions closer to the real application. 

Differential scanning calorimetry has become a key tool in drug design and protein structure identification. The excellent sensitivity of the method and the reproducibility with which particular phase transitions can be measured have made it a central tool in pharmaceutical development and biomedical research.2  

TA Instruments – Nano DSC

TA Instruments offers an extensive range of suitable differential scanning calorimetry instruments for gene therapy development. The Nano DSC is a simple and robust tool for comparability measurements of drug product candidates, formulations and manufactured batches.3  

The Nano DSC is an incredibly versatile instrument for measuring biomaterials in solution and has been designed to handle even incredibly small protein volumes. This advantage is both due to the incredible sensitivity of the detector that can be used with as little as 2 µg of substrate. The sample capillary cell is also designed to hold total volumes as small as 300 µL. 

The sensitivity of DSC measurements even for very small concentrations is important for carrier loading measurements, where only a small amount of material may be incorporated into a virus or cell. This capability can be used for formulation optimization to create lipid nanoparticles from capsids.  

The Nano DSC can be used to measure full protein folding dynamics and identify the protein stability of various species alongside a full thermodynamic characterization. These types of measurements also extend to binding and interactions of protein species with other molecules.  

Often, RNA and DNA are targets in gene therapy. A therapeutic treatment may target a particular DNA region for disease treatment. The Nano DSC is sensitive enough to detect potential contamination from double-stranded RNAs and other species. Differential scanning calorimetry is a powerful technique for quality control or release testing of therapeutic treatments and tracking any batch to batch variability. 

Serotype characterization is very important in gene therapy since different serotypes of the same species can have very different behavior in terms of clinical safety. The Nano DSC offers strong measurement reliability within the diverse range of serotypes in a species. 

Contact us today to learn more about how the Nano DSC can accelerate your gene therapy development. 

How does an ITC Instrument Work?

An isothermal titration calorimetry instrument works by comparing the output of a reference cell and a measurement cell. Like for other calorimetry measurements, the two cells are enclosed in an adiabatic jacket to minimize interactions with the surrounding environment.

The cells are designed to be as close to identical as is possible. The reference cell contains a buffer solution similar to what will be used in the measurement cell and has a reference heater attached to the cell.

As the titration is performed in the measurement cell on the macromolecule of interest, there is an enthalpy change in the system. Since this reaction results in a temperature change and the two sample and reference cells are joined by highly efficient thermally conductive alloys, the temperature in the reference cell starts to change. The power to the heater required to keep the reference cell constant is measured and used to record the overall thermochemistry of the binding event.

TA Instruments

TA Instruments support even the most challenging of measurements in the life sciences with a range of isothermal titration calorimetry instruments. As many intermolecular interactions and binding energies can be very weak, TA Instruments has designed isothermal titration calorimetry measuring devices to be as sensitive as possible with outstanding baseline stability.2

TA Instruments offers both the Nano Isothermal Titration Calorimetry instrument and the Affinity ITC that are designed to be straightforward, simple-to-use instruments without sacrificing exceptional measurement performance. With low-volume cells ideal for precious vaccine therapy materials, the Affinity can also be integrated with 96-well autosamplers to accelerate your development processes.

Contact TA Instruments today to find out how your life sciences application, from drug to vaccine therapy development, could benefit from the reliability, accuracy and reproducibility of industry-leading ITC measurements.

References:

  1. The White House Archives, President George W. Bush (2008). https://georgewbush-whitehouse.archives.gov/infocus/bushrecord/factsheets/stemcells.html, Accessed April 2022 
  2. Chiu, M. H., & Prenner, E. J. (2011). Differential scanning calorimetry : An characterization of macromolecules and their interactions. J Pharm Bioall Sci, 3(1), 39–59. https://doi.org/10.4103/0975-7406.76463 
  3. TA Instruments (2022) Nano DSC, https://www.tainstruments.com/wp-content/uploads/Nano_DSC.pdf, accessed April 2022