Metal-free contrast agents: novel approaches
The joint expertise of CIBER-BBN Nanomol Group – NANBIOSIS U6 from at ICMAB-CSIC (José Vidal and Vega Lloveras) and NANBIOSIS U25 at UAB (Ana Paula Candiota), led to a recently published article in the prestigious journal Biomacromolecules
Brain tumours such as Glioblastomas are a challenge in the clinics and proper diagnosis and follow-up are crucial for patient outcome. Contrast agents are usually administered to patients for assessing blood brain barrier integrity and quantitation of enhancing areas are part of the clinical criteria for estimating response/relapse. However, most contrast agents currently used in clinics are based in metal elements such as Gadolinium and are not exempt of risks. In addition, due to the renal excretion route, administering such agents to some patients is contraindicated. Our work explored the potential of organic radicals anchored to dendrimers to act as contrast agents for glioblastoma studies, proposing a metal-free alternative for contrast enhanced glioblastoma studies. The article describes details of synthesis and characterization of these agents, as well as in vivo, ex vivo and in vivo magnetic resonance studies. The orthotopic immunocompetent GL261 glioblastoma murine model was used for in vivo and ex vivo studies. The novel contrast agent proved to be non-harmful for wild type mice and produced sustained and long lasting contrast in tumour-bearing mice, even in much lower doses in comparison with gadolinium administration.
The diagnosis and follow-up of high-grade brain tumours such as glioblastomas relies mostly in MRI, and contrast agents currently used are based on Gadolinium, which is not exempt of risks. The resarchers’ approach explores organic radicals anchored to dendrimers as a metal-free alternative to produce contrast enhancement in MRI, safer than Gadolinium-based compounds, and with translational potential.
Article of reference:
Zhang S, Lloveras V, Lope-Piedrafita S, Calero-Pérez P, Wu S, Candiota AP, Vidal-Gancedo J. Metal-Free Radical Dendrimers as MRI Contrast Agents fof Glioblastoma Diagnosis: Ex Vivo and In Vivo Approaches. Biomacromolecules. 2022 Jun 24. doi: 10.1021/acs.biomac.2c00088.
