Non inflammatory properties of ex situ thiol-based copper chelates

Abstract Copper complexes were synthesized via thiol complexation with either d or l -penicillamine (DP and LP), l -cysteine (LC) and reduced glutathione (GR) by solution-precipitation method. Complex formation was demonstrated by thiol disappearance by FTIR and Raman. DP, LC and GR complexes were crystalline as shown by XRD, but LC and GR complexes exhibited higher decomposition temperatures as shown by TGA. DP and LP copper complexes were cytotoxic to macrophages in the 800 to 1600 µM range but not for LC and only at 1600 µM for GR complexes. The later complexes slightly suppressed IL-1β, IL-6 and TNF-α production while enhancing IL-4 and IL-10 expression. These results suggest that LC and GR based copper complexes can be promising fillers or coatings for biomedical applications.