Nicolai Lehnert: “I am attracted to the project because of the intriguing combination of basic and applied science, and the prospect of improving the lives and safety of patients.”

A team of U-M researchers has been awarded $2.1 million dollars by the National Institutes of Health to develop safer intravascular (IV) catheters. U-M chemists Nicolai Lehnert and Mark Meyerhoff, working with Michigan Medicine research scientist Alvaro Rojas-Pena, are developing the technology that will incorporate a nitric oxide (NO) generating system in the catheters.

Nitric oxide is naturally produced in our arteries and used by our bodies to suppress blood clotting and fight infections. The team aims to greatly reduce the number of fatalities related to blood clots and infection that occur with regular catheters. IV catheter infections alone take the lives of nearly 20,000 patients each year in the U.S.

The new catheter system is based on a low-cost method of producing very pure nitric oxide gas via an electrochemical reaction. The method was pioneered by Meyerhoff and Lehnert in previous work (called “E_NOgen”). This approach uses a copper-containing compound as the catalyst to make NO gas from nitrite. Lehnert is an inorganic chemist whose lab group has done research on the copper complexes and is working to synthesize new, improved catalysts for greater NO generation.

“Electrochemical nitric oxide generation --E-NOgen—is simple, controllable, and inexpensive, and, importantly, can be miniaturized and incorporated in dual lumen catheters to provide them with nitric oxide-releasing properties,” explains Lehnert, a professor of chemistry and principal investigator on this grant.

Multiple Uses in Medicine

The E-NOgen approach could also be applied to other medical uses including inhaled nitric oxide therapy and coronary bypass operations. The ability to miniaturize the NO-generating system would also allow it to be incorporated into medical devices used in ambulances and in the field, as well as intensive care units.

Inhaled nitric oxide (INO) therapy has become a mainstay of intensive care for lung failure patients. It is an essential treatment in neonatology, lung transplantation, pulmonary hypertension and most recently as an antiviral agent to fight COVID-19 infections. However, current INO technology requires the use of nitric oxide gas cylinders, which are very expensive to operate ($3,000 per day), heavy, hazardous, and can therefore not be used by mobile units. The E-NOgen system allows for the design of small, portable INO devices that could be used by medical personnel in the field, and that can be operated at much lower cost.

Another clinical use of nitric oxide is to prevent blood activation and organ failure caused by cardiopulmonary bypass (CPB). There are 500,000 surgeries per year in US alone. A heart-lung machine makes heart surgery possible, but it can lead to inflammation and organ failure. Research has shown that adding nitric oxide in the use of the heart-lung machine could reduce these problems, but clinical use is prevented by the high cost of gas phase nitric oxide. However, using the E-NOgen approach, nitric oxide could be produced much cheaper, on demand, in a small portable device, therefore enabling standard application of nitric oxide in CPB, the researchers explain.

Lehnert is excited by the research and gratified by its potential usefulness. “I am attracted to the project because of the intriguing combination of basic and applied science, and the prospect of improving the lives and safety of patients.”


Optimization of Cu(II)-ligand catalysts, membrane materials, and coatings for O2-tolerant, portable, and low-cost electrochemical nitric oxide generation devices/catheters

The team

  • Nicolai Lehnert (PI), Professor of chemistry
  • Mark Meyerhoff. Professor emeritus of Chemistry
  • Alvaro Rojas-Pena, Assistant Research Scientist, Transplant Surgery