Green preparation of gold nanoparticles and their activity in photothermal cancer therapy

In this work, a simple strategy to valorise agricultural waste was developed and applied in the green synthesis of gold nanoparticles. Grape marc waste, obtained from Lambrusco winery production, contain high amounts of polar substances (tannins, polyphenolic compounds, and reducing agents) that can act as starting materials for nanoparticle formation. In this way, hazardous substances generally used in conventional methodology can be avoided, enhancing their biocompatibility and favouring their possible use in medical applications. After a hydrothermal extraction at 65°C, grape marc extract (GM) was successfully employed in gold nanoparticles preparation (GM-AuNPs)1. After purification and characterisation their biocompatibility was demonstrated on human fibroblast (FibH) and MCF-7 breast cancer cells incubated with different concentrations of GM-AuNPs. Moreover, the in vitro photothermal capacity of GM-AuNPs was evaluated using a NIR (808nm) laser2. Different GM-AuNPs’ concentrations were irradiated and the temperature variation was evaluated every minute until 10 minutes of irradiation. Starting from these interesting results, the applicability of GM-AuNPs in photothermal killing of MCF-7 and bacterial cells was finally evaluated.