Calcium carbonate as silver carrier in composite materials obtained in green seaweed extract with topical applications

Two new Ag–AgCl/CaCO 3 composite materials, with different molar ratios Ag:CaCO 3 , were obtained in a green seaweed ( Ulva lactuca ) extract by a two steps synthesis. The first step consists in a green, partial reduction of Ag(I) in order to obtain Ag–AgCl crystals, which are deposited in the second step on CaCO 3 . The composites were characterized by XRD, SEM, EDX, UV–vis, and FTIR spectroscopy. The morphology of composite materials consists in aggregates of calcite nanoparticles, decorated with Ag–AgCl, and the aggregates shape depends on the Ag(I):Ca(II) initial molar ratio. The aggregates are also capped with phytochemicals from green seaweeds, mainly polysaccharides. The composites can be used as a model for the utilization of calcium carbonate as silver carrier in medical applications. The dermatological properties of composites were tested in vivo for healing of burns. An accelerated healing was noticed for the composite with higher silver content. The promising results obtained in vivo recommend the Ag–AgCl/CaCO 3 composites for topical applications. Highlights Ag–AgCl/CaCO 3 composites obtained in seaweed extract were successfully tested for burns healing. Healing effect and oxidative activity increase with silver content. Capping polysaccharides improve the topical activity of composites. Calcite powder obtained in seaweed extract can be used as a silver carrier in topical treatment.