A novel approach for heavy metal poisoning treatment, a model. Mercury poisoning by means of chelating microspheres: hemoperfusion and oral administration.

The chelating drugs BAL (2,3-dimercaptopropanol), EDTA (ethylenediaminetetraacetic acid), and penicillamine (2-amino-3-mercapto-3-methylbutanoic acid), which are used for metal poisoning, are toxic and there is a real need for alternatives, especially for severe cases. A novel approach for treatment of heavy-metal poisoning is under investigation in our group. The approach utilizes the synthesis of chelating microspheres specific for the desired metallic compound. The microspheres are suggested for use in severe cases by means of hemoperfusion, as a first aid, and then by oral administration. As a model this approach was tried for mercury poisoning. Polymercaptal microspheres of 0.8 micrometer average size were synthesized. The microspheres have a high surface area, have a high affinity toward organic and inorganic mercury compounds, and can compete easily with albumin and cysteine in the ability to bind mercury compounds. These microspheres also were encapsulated with agarose--a blood compatible polymer--and were tried successfully for plasma perfusion (in 10 min, 40% of CH3HgCl and of HgCl2 were removed from 20 ppm of poisoned plasma).