The word chelation is derived from Greek χηλή, chēlē, meaning "claw";
HOPO is a chelator with high stability for Gd and other toxic heavy metals. As I have stressed with DTPA, DTPA has higher stability with most heavy metals (starting with Gd and Lead) than any other chelators currently available. Hence DTPA should always be used to chelate Gd (probably lead as well) up to the present time, Feb 2022. That is until a more stable chelator comes available. That more stable chelator includes HOPO. HOPO apparently also has low stability constant with native metals, which is also of considerable value, as it should then remove less native metals and cations than Ca-DTPA... not sure how it compares to Zn-DTPA.
HOPO is also manufactured as an oral agent, which would make it a game changer, in the treatment of GDD and deposition diseases of other heavy metals. It vastly increases its ease of use and centers therefore that can use it.
I wish the best of luck to the HOPO team to get the agent FDA approved swiftly. Determining safety ofcourse is the major reason that FDA approval is necessary.
There should be an oral version of DTPA and variants also available in the future.
The future for treatment of heavy metals is bright. We all wish that the future was now, but it isn't. Hence for now we have to do the best we can with what we have available to us.
Richard Semelka, MD