Caffeine-loaded gold nanoparticles conjugated with PLA-PEG-PLA copolymer for in vitro cytotoxicity and anti-inflammatory activity

The purpose of the study was to develop caffeine-loaded gold nanoparticles (AuNPs) using a poly(lactic acid)-polyethylene glycol-poly(lactic acid) (PLA-PEG-PLA) polymer to enhance the anti-inflammatory activity of caffeine. Caffeine-loaded AuNPs were conjugated to PLA-PEG-PLA copolymer matrix via π-back bond between AuNPs and the ester carbonyl group of the polyester. The π-back bonded ester carbonyl oxygen strongly interacted with the caffeine molecule and exhibited enhanced anti-inflammatory activity. The physico-chemical characteristics of the resulting nanoconjugates were evaluated by a series of microscopic, diffraction, and spectroscopic methods. In vitro assays indicated increasing membrane stabilization of red blood cells and enhanced inhibition of protein denaturation.