DAB-32

DAB-32 is a positively charged dendrimer-linked nitroxide, specifically a polypropyleneimine (DAB) dendrimer with 32 nitroxide groups attached to its terminal amino groups. It functions as an MRI contrast agent designed for cartilage imaging. With a molecular weight of 8,890 daltons and 30 positive charges, DAB-32 utilizes the paramagnetic attributes of nitroxides to increase signal intensity and shorten the T1 and T2 relaxation rates of water protons in tissues. Its positive charge facilitates preferential diffusion into cartilage by attracting to the negatively charged glycosaminoglycans (GAGs) within the cartilage matrix. Preliminary in vitro studies evaluated its affinity for cartilage and diffusivity, while preliminary in vivo studies in rabbits investigated its pharmacokinetics after intraarticular injection, demonstrating a longer half-life in joint fluid compared to Gd-DTPA. The research was conducted by institutions including Brigham and Women's Hospital, Harvard Medical School, University of Maryland School of Pharmacy, and SciTrials, LLC, with one of the authors being a founder of NitroSci.