Jonathan L. Sessler

The R. P. Doherty, Jr.-Welch Regents Chair in Chemistry
The University of Texas at Austin 

A two-time cancer survivor, Jonathan Sessler has spent much of his research career looking for a cure. He works primarily in supramolecular and medicinal chemistry, focusing on porphyrins, a biological pigment molecule that makes blood red and grass green. His goal is to make the compounds bigger while retaining their biological features.

“Our group’s main focus is the design and construction of molecules tailored to accomplish specific objectives,” he explains, “either to understand better complex biochemical processes or perhaps to eventually find application as therapeutic or diagnostic agents.”

In the late 1980s, he created a new class of molecules he called texaphyrins – named for the fact they resemble the Texas star – which are a larger version of normal blood pigments. Texaphyrins accumulate in cancer cells, making them the perfect vehicle to deliver cancer-specific drugs. The electronics of the systems allows them to inhibit the self-repair process of cancer cells, while their larger size allows them to capture heavy metals, such as gadolinium within their core. This, in turn, allows for MRI. Sessler says that this potential ability to both treat and diagnose cancerous disease is one of the main motivating forces behind his research.

In other work, the Sessler lab is using molecular assembly to construct potential drug delivery system, as well as to create self-healing materials for chemical signaling and waste remediation.