Dendritic Nanotechnologies Focuses Dendrimer Development On Industry Rather Than Pharma

Xconomy Detroit/Ann Arbor — 

Over the last decade, Mt. Pleasant, MI-based Dendritic Nanotechnologies (DNT) has helped make Michigan into a world center of research on the versatile, tendriled molecules known as dendrimers. But while the molecules have a range of important applications, from killing microbes to reducing the unwanted side effects of drugs and pesticides, the company has ceded most R&D on the life-sciences side of dendrimers to its Australian parent company, Starpharma. DNT is now focused on dendrimers’ potential in more prosaic areas such as agriculture and cosmetics.

“Where DNT primarily plays around in is what we like to call the more industrial settings,” says Joe Heinzelmann, DNT’s product manager. Applications such as coatings and water purification have the advantage of requiring higher volume than the pharmaceutical industry, he says. Recently, for example, DNT signed a research and collaboration agreement with a U.S. agricultural company to enhance the performance of pesticides.

While Heinzelmann couldn’t disclose the company’s name due to confidentiality restrictions, he said the general principle in agriculture is similar to drug-delivery applications, where dendrimers are able to extend the persistence of an active molecule, potentially reducing the amount that needs to be used. The result in pharma could be fewer unintended side-effects; in pesticides, less chance of causing unintended damage to crops.

To back up, a little dendrimer history. It was here in Michigan about 30 years ago that Dow chemist Donald Tomalia first synthesized the molecules in his Midland lab. Dendrimers’ tendrils, or branches, make it possible to custom-engineer one molecule to perform as many tasks as the laws of chemistry and physics allow. Each appendage can have a separate task-one to sense disease-causing agent and another destroy it, for example.

Tomalia founded DNT in 2001 in a joint venture with Starpharma, based in Melbourne, Australia. Starpharma immediately began to investigate dendrimer technology as a potential anti-HIV microbicide. The product it eventually came up with, VivaGel, is currently undergoing clinical trials and has been granted Fast Track drug review status in the United States by the FDA.

Tomalia left DNT in late 2007, but remains affiliated with the National Dendrimer and Nanotechnology Center at Central Michigan University in Mt. Pleasant. His work there, along with others in the state, has helped establish Michigan as a center for dendrimer research.

Starpharma is using a variety of the molecules called polylysine dendrimers, which are about to go off patent. Other dendrimer companies, like rival Dendritech of Midland, MI, also use polylysine dendrimers. So, to keep a proprietary edge, and to address questions of cost and toxicity that have plagued dendrimers since their invention, DNT introduced its so-called Priostar line of dendrimers about three years ago.

The company says that Priostar dendrimers are not only less expensive than rivals’ products, but are less time-consuming to produce. Priostar dendrimers are made using “click chemistry,” what Tomalia has called “a versatile new strategy” for producing dendrimers in which different components or attributes can be added, assembly-line style.

But exactly how Priostar dendrimers are being used, beyond the collaboration with the unnamed agricultural firm, Heinzelmann won’t say. He would only exlain that the partnership is “one of our big forays into industrial settings … to provide near-term revenues.” How long will it take to develop a commercial product? “That’s confidential,” he says.

Priostar dendrimers are also seeing some success in cosmetics; active ingredients can be attached to the molecules and delivered under the skin. But which cosmetic companies is DNT partnering with? Heinzelmann pauses and says, again, “That’s not publicly available.”

Pretty much all he can say is that he’s confident that 30 years of research and development on the life sciences applications of dendrimers will pay off in the form of industrial applications as well.

“We are working as hard as we can to get something out in the near term,” Heinzelmann says.