Dendritic NanoTechnologies, Inc.

Abstract

At recent FDA conferences focused on the potential of nanotechnology, Tomalia gave a presentation on the significance of dendrimers as fundamental nanoscale building blocks and their unique applications as a function of generation. For example, generation-7, -8, or -9 dendrimers may have applications as nano-scaffolding for gene vectors; generation-4, -5, or -6 dendrimers may be useful as nanocontainers in small-molecule drug delivery. The FDA’s Center for Drug Evaluation and Research (CDER), in particular, takes an active position in educating scientists about the unique regulatory issues nanomedicine presents.DNT is also pursuing the scaffolding idea to improve diagnostic imaging. In 1994, Tomalia, in collaboration with 2003 Nobel laureate and magnetic resonance imaging (MRI) researcher Paul C. Lauterbur, PhD at the University of Illinois and others co-published the first paper showing the importance of dendrimer scaffolding by demonstrating that conjugating high multiples of a gadolinium chelate contrast agent on the surface of a dendrimer produced the highest relaxivity measurements known. Relaxivity is a technical process used to improve the contrast of MRI images. The higher the relaxivity, the better the contrast. The dendrimer-based imaging product achieved relaxivity ratings between 40 and 50. By comparison, Magnevist, a commercial chelated gadolinium contrast agent, has a relaxivity rating of approximately 4.0–5.0. “With these enhanced contrast properties, we have the potential to detect disease at a much earlier stage,” says Tomalia. The past 11 years have seen the publication of dozens of papers that used dendrimers as scaffolding to present MRI contrast agents. “They have allowed entirely new in vivo diagnostics of vascular systems, ischemia, tumor diagnostics (primary and metastatic) at incredibly high resolutions,” explains Tomalia. “You can image things never possible before.” In September 2004, an NCI/NIH examination of the 10-year preclinical research history of dendrimer-based contrast agents suggested that these materials are ready for IND approval consideration.DNT, in collaboration with the MIT Institute for Soldier Nanotechnologies and a consortium of other nanotechnology-inclusive companies such as Carbon Nanotechnologies, Inc., Triton Biosystems, Nomadics, Inc., and Dow Corning are also investigating the use of dendrimer nanotechnology innovations to protect U.S. soldiers in the field. Tomalia’s former colleague James Baker also started NanoProtect, a commercial venture with similar goals. Baker also founded two other nanotechnology-based entities, NanoBio Corporation and NanoCure Corporation. NanoCure, in particular, pursues product pipeline similar to that of DNT and also applies dendrimer technology.Though dendrimers represent only one approach to nanotechnology, they appear to hold significant potential as fundamental building blocks for nanoscale synthesis for biological and industrial applications. And DNT, although still a small, 20-person, privately held venture, is well positioned to offer new contributions to the field.