Our New Tracer

We place great emphasis on maximum transparency from the very beginning. Since our tracer is injected into patients' bodies, it is only natural for us to fully disclose its structure and properties. This way, everyone can understand how our metabolic tracer works and why it is safe.

We use a signal enhancement method called PHIP+, an advanced version of Parahydrogen-Induced Polarization (PHIP). A prerequisite for a molecule to be hyperpolarized using this method is the presence of an unsaturated bond. Such bonds occur naturally and play important roles in the human body, for example in the form of unsaturated fatty acids.

From the start, we focused on pyruvate as a metabolic tracer. Pyruvate is the ideal metabolite for imaging metabolism: it is a central product of glucose breakdown. When the human body absorbs glucose, it is split into two pyruvate molecules, which then enter the citric acid cycle, the central pathway for energy production.

The challenge: pyruvate does not contain an unsaturated bond and therefore cannot be directly hyperpolarized using the PHIP method.

To overcome this challenge, we attached a so-called unsaturated side arm to the pyruvate molecule. This side arm can absorb parahydrogen, allowing us to use the resulting spin order to generate hyperpolarization in the pyruvate part of the molecule.

The key advantage of this side arm is that it can be readily removed after hyperpolarization, leaving the desired metabolite, pyruvate, in its hyperpolarized state.